Aerial antenna characterization for hardware timing

文档序号：621169 发布日期：2021-05-07 浏览：16次中文

阅读说明：本技术 硬件定时的空中天线表征 (Aerial antenna characterization for hardware timing ) 是由 G·奥罗斯科瓦尔德斯 T·德克特 J·D·H·兰格 C·N·怀特 K·F·格罗希于 2019-09-19 设计创作，主要内容包括：描述了用于对具有集成天线的集成电路(IC)进行硬件定时测试的天线表征系统和方法,所述集成天线被配置成用于空中发射和/或接收。可以将要测试的IC(例如,被测装置(DUT))安装到消声室中的可调节定位器上。可以在通过多个朝向来不断转变所述可调节定位器的同时使用所述消声室内的天线或探头阵列对所述IC的射频(RF)特性(例如,包含发射特性、接收特性和/或波束成形特性)进行空中测试。可以采用计数器和参考触发智能来将测量结果与所述DUT的朝向相关联。(Antenna characterization systems and methods for hardware timing testing of Integrated Circuits (ICs) with integrated antennas configured for over-the-air transmission and/or reception are described. An IC to be tested (e.g., a Device Under Test (DUT)) may be mounted on an adjustable positioner in the anechoic chamber. An antenna or probe array within the anechoic chamber may be used to over-the-air test Radio Frequency (RF) characteristics (e.g., including transmit, receive, and/or beamforming characteristics) of the IC while continuously transitioning the adjustable positioner through multiple orientations. Counters and reference triggering intelligence may be employed to associate measurements with the orientation of the DUT.)

1. An Antenna Characterization System (ACS), comprising:

a computer comprising a processor coupled to a non-transitory memory medium;

a chamber;

a Radio Frequency (RF) measurement system coupled to the computer, wherein the RF measurement system is configured to perform RF measurements on a Device Under Test (DUT); and

an adjustable locator positioned within the chamber and coupled to the computer, wherein the adjustable locator is configured to:

positioning the DUT within the chamber according to a plurality of orientations;

automatically transmitting one or more signals to the computer in response to the adjustable positioner positioning the DUT in accordance with each of the plurality of orientations,

wherein the computer is configured to:

in response to receiving the signal from the adjustable positioner, transmitting a plurality of acquisition triggers to the RF measurement system to acquire a plurality of RF measurements of the DUT;

receiving results of the plurality of RF measurements from the RF measurement system;

generating antenna characterization information based at least in part on the signal received from the adjustable locator and the results of the plurality of RF measurements.

2. An ACS according to claim 1,

wherein the adjustable locator comprises a hardware sensor configured to detect an orientation of the adjustable locator,

wherein the one or more signals are transmitted in response to detection by the hardware sensor of the adjustable positioner oriented according to each orientation of the plurality of orientations.

3. An ACS according to claim 1,

wherein the antenna characterization information is usable to design antenna characteristics of the DUT.

4. The ACS according to claim 1, wherein in generating the antenna characterization information, the computer is configured to:

correlating the results of the plurality of RF measurements with the signals received from the adjustable positioner to determine a respective one of the plurality of orientations of the DUT that corresponds to each of the results of the RF measurements; and is

Storing results of the plurality of RF measurements and an associated list of respective orientations of the DUTs thereof in the memory medium.

5. An ACS according to claim 1,

wherein the computer is further configured to:

adjusting one or more counter values based on the signal received from the adjustable positioner, wherein the correlating the results of the plurality of RF measurements with the signal received from the adjustable positioner comprises determining an orientation of the DUT based on the adjusted one or more counter values.

6. An ACS according to claim 1,

wherein said positioning said DUT within said chamber according to said plurality of orientations comprises continually transitioning said DUT through said plurality of orientations without stopping movement of said adjustable positioner between orientations.

7. An ACS according to claim 6,

wherein said constantly transitioning the AUT through the plurality of orientations is performed at a speed such that a time between successive transmissions of the one or more signals is greater than an acquisition time of each of the RF measurements.

8. An ACS according to claim 1,

wherein the computer is further configured to:

transmitting a stop trigger to the adjustable positioner to stop movement of the adjustable positioner while said transmitting each of the acquisition triggers to the RF measurement system, and

wherein the RF measurement system is configured to:

upon completion of each of the RF measurement acquisitions, transmitting an activation trigger to the adjustable positioner to resume motion of the adjustable positioner.

9. An ACS according to claim 1,

wherein transmitting the one or more signals to the computer through the adjustable positioner and transmitting the plurality of acquisition triggers to the RF measurement system through the computer are performed by direct hardware signaling.

10. An ACS according to claim 1,

wherein the chamber is an anechoic chamber.

11. A method for performing an antenna characterization procedure, the method comprising:

with an adjustable positioner positioned indoors and coupled to a computer:

positioning a Device Under Test (DUT) within the chamber according to a plurality of orientations; and

automatically transmitting one or more signals to the computer in response to the adjustable positioner positioning the DUT in accordance with each of the plurality of orientations; and

by the computer:

in response to receiving the signal from the adjustable positioner, transmitting a plurality of acquisition triggers to an RF measurement system to acquire a plurality of RF measurements of the DUT;

receiving results of the plurality of RF measurements from the RF measurement system;

generating antenna characterization information based at least in part on the signal received from the adjustable locator and the results of the plurality of RF measurements; and

storing the antenna characteristic information in a memory.

12. The method of claim 11, wherein the first and second light sources are selected from the group consisting of,

wherein the adjustable locator comprises a hardware sensor configured to detect the orientation of the adjustable locator,

wherein the one or more signals are transmitted in response to detection by the hardware sensor of the adjustable positioner oriented according to each orientation of the plurality of orientations.

13. The method of claim 11, wherein the first and second light sources are selected from the group consisting of,

wherein the antenna characterization information is usable to design antenna characteristics of the DUT.

14. The method of claim 11, wherein in generating the antenna characterization information comprises:

storing results of the plurality of RF measurements and an associated list of respective orientations of the DUT of the results in the memory medium.

15. The method of claim 11, the method further comprising:

by the computer:

16. The method of claim 11, wherein the first and second light sources are selected from the group consisting of,

17. The method of claim 16, wherein the first and second light sources are selected from the group consisting of,

18. The method of claim 11, the method further comprising:

by the computer:

transmitting a stop trigger to the adjustable positioner to stop movement of the adjustable positioner while said transmitting each of the acquisition triggers to the RF measurement system, an

By the RF measurement system:

upon completion of each of the RF measurement acquisitions, transmitting an activation trigger to the adjustable positioner to resume motion of the adjustable positioner.

19. The method of claim 11, wherein the first and second light sources are selected from the group consisting of,

20. The method of claim 11, wherein the first and second light sources are selected from the group consisting of,

wherein the chamber is an anechoic chamber.

Technical Field

The present invention relates to the field of semiconductor and/or mobile device testing, and more particularly to hardware timing over-the-air antenna characterization.

Background

The importance of antenna transmission and reception technology is growing rapidly, for example, as generation 5 (5G) wireless technology is becoming more and more common. Current methods for testing integrated circuits having integrated antennas for transmitting and/or receiving over-the-air signals may be slow and/or expensive, for example, in part because the integrated circuits being tested may need to be positioned according to many different orientations, and the integrated antennas may need to be tested according to multiple transmit powers and/or frequencies. Accordingly, improvements in the art are desired.

Disclosure of Invention

Various embodiments of antenna characterization systems and methods for hardware timing testing of Integrated Circuits (ICs) with integrated antennas configured for over-the-air transmission and/or reception are presented below. An IC to be tested (e.g., a Device Under Test (DUT)) may be mounted on an adjustable positioner in the anechoic chamber. The power and data connections of the IC may be tested through the fixed conductive interface. An aerial test of Radio Frequency (RF) characteristics (e.g., including transmission characteristics, reception characteristics, beamforming characteristics, etc.) of the IC may be performed using an antenna or probe array within the anechoic chamber while continuously transitioning the adjustable positioner through multiple orientations. Counters and reference triggering intelligence may be employed to associate measurements with the orientation of the DUT.

This summary is intended to provide a brief overview of some subject matter described in this document. Thus, it will be understood that the features described above are merely examples and should not be construed to narrow the scope or spirit of the subject matter described herein in any way. Other features, aspects, and advantages of the subject matter described herein will become apparent from the following detailed description, the drawings, and the claims.

Drawings

The invention may be better understood when the following detailed description of the preferred embodiments is considered in conjunction with the following drawings, in which:

FIG. 1 illustrates a computer system configured to perform testing of an integrated circuit, in accordance with some embodiments;

FIG. 2 is an exemplary block diagram of the computer system of FIG. 1 in accordance with some embodiments;

fig. 3 illustrates multi-antenna beamforming using coarse and fine phase shifters according to some embodiments;

FIGS. 4-9 illustrate an exemplary integrated circuit Device Under Test (DUT) in accordance with some embodiments;

FIG. 10 illustrates a measurement setup for full array testing and single element testing according to some embodiments;

fig. 11 is a display of a 3D beamforming mode according to some embodiments;

fig. 12 is a schematic diagram showing a typical setup for over-the-air (OTA) antenna testing, according to some embodiments;

FIG. 13 is a detailed illustration of an example adjustable positioner according to some embodiments;

fig. 14 is a schematic diagram showing an OTA antenna test setup using a combination of positioning arms and rotational positioners, in accordance with some embodiments;

fig. 15 is an isometric illustration of an OTA antenna test setup using a 3D positioning arm according to some embodiments;

fig. 16 is a flow diagram showing a method for a software driver to characterize over-the-air (OTA) transmission properties of an AUT, in accordance with some embodiments;

FIG. 17 illustrates a two-pass code track of a quadrature encoder according to some embodiments;

FIG. 18 illustrates how the dual pass of a quadrature encoder according to some embodiments results in incrementing and decrementing counter values;

FIG. 19 is a system diagram showing components and connections of a hardware-timed over-the-air (OTA) test system according to some embodiments;

fig. 20 illustrates a timing diagram of signal sequence and counter transitions in an OTA antenna characterization process according to some embodiments;

FIG. 21 is a system diagram showing components and connections of a hardware-timed over-the-air (OTA) test system including a computer, according to some embodiments;

FIG. 22 is a system diagram showing components and connections of a hardware-timed over-the-air (OTA) test system incorporating start/stop triggers according to some embodiments;

fig. 23 is a communication flow diagram showing a simplified method for making coordinated OTA antenna measurements in accordance with some embodiments;

fig. 24 is a communication flow diagram showing a method for making coordinated OTA antenna measurements that include reference triggers used by a radio frequency signal analyzer, in accordance with some embodiments;

fig. 25 is a communication flow diagram showing a method for making coordinated OTA antenna measurements in which some acquisition triggers overlap with ongoing measurement acquisition and do not trigger subsequent acquisition, in accordance with some embodiments;

fig. 26 is a simulated illustration of an antenna transmission power curve simulated as a sinc function, in accordance with some embodiments;

fig. 27 is a representation of distortion measurements when angular velocity is much greater than the inverse of acquisition time, in accordance with some embodiments; and is

Fig. 28 is an illustration of high fidelity measurements when angular velocity is comparable to the inverse of acquisition time, in accordance with some embodiments.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the present invention as defined by the appended claims.

Detailed Description

Term(s) for

The following is a glossary used in this application:

memory medium — any of various types of non-transitory computer accessible memory devices or storage devices. The term "memory medium" is intended to encompass: mounting media such as CD-ROM, floppy disk 104, or tape devices; computer system memory or random access memory such as DRAM, DDR RAM, SRAM, EDO RAM, Rambus RAM, etc.; non-volatile memory such as flash memory, magnetic media such as a hard disk drive or optical storage device; registers or other similar types of memory elements, and the like. The memory medium may also include other types of non-transitory memory or combinations thereof. In addition, the memory medium may be located in a first computer executing the program or may be located in a second, different computer connected to the first computer through a network such as the internet. In the latter case, the second computer may provide the program instructions to the first computer for execution. The term "memory medium" may encompass two or more memory media, which may reside in different locations, e.g., in different computers connected by a network.

Carrier media-memory media as described above, and physical transmission media such as buses, networks, and/or other physical transmission media that convey signals such as electrical, electromagnetic, or digital signals.

Programmable hardware element — including various hardware devices that include a plurality of programmable functional blocks connected by programmable interconnects. Examples include FPGAs (field programmable gate arrays), PLDs (programmable logic devices), FPOAs (field programmable object arrays), and CPLDs (complex PLDs). Programmable function blocks can range from fine grained (combinational logic or look-up tables) to coarse grained (arithmetic logic units or processor cores). The programmable hardware elements may also be referred to as "reconfigurable logic".

Processing element-refers to various elements or combinations of elements capable of performing functions in a device (e.g., user equipment or cellular network device). The processing elements may include, for example: a processor and associated memory, portions or circuitry of a single processor core, an entire processor core, a processor array, circuitry such as an ASIC (application specific integrated circuit), programmable hardware elements such as Field Programmable Gate Arrays (FPGAs), and any of the various combinations of the above.

Software program-the term "software program" is intended to have its full breadth of ordinary meaning and includes any type of program instructions, code, script, and/or data, or combination thereof, that can be stored in a memory medium and executed by a processor. Exemplary software programs include programs written in text-based programming languages, such as C, C + +, PASCAL, FORTRAN, COBOL, JAVA, assembly language, and the like; graphics programs (programs written in a graphics programming language); an assembly language program; a program compiled into machine language; a script; and other types of executable software. The software program may comprise two or more software programs that interoperate in some manner. Note that the various embodiments described herein may be implemented by a computer or software program. The software program may be stored as program instructions on a memory medium.

Hardware configuration programs — programs, such as netlists or bit files, may be used to program or configure programmable hardware elements.

Procedure-the term "procedure" is intended to have its full breadth of ordinary meaning. The term "program" encompasses 1) a software program that can be stored in a memory and executed by a processor, or 2) a hardware configuration program that can be used to configure programmable hardware elements.

Computer system-any of various types of computing or processing systems, including a personal computer system (PC), mainframe computer system, workstation, network appliance, internet appliance, Personal Digital Assistant (PDA), television system, grid computing system, or other device or combination of devices. In general, the term "computer system" may be broadly defined to encompass any device (or combination of devices) having at least one processor that executes instructions from a memory medium.

Measurement devices-including instruments, data acquisition devices, smart sensors, and any of a variety of types of devices configured to acquire and/or store data. The measurement device may optionally be further configured to analyze or process the collected or stored data. Examples of measurement devices include instruments such as conventional stand-alone "box" instruments, computer-based instruments (instruments on a card) or external instruments, data acquisition cards, devices external to a computer that operate similar to data acquisition cards, smart sensors, one or more DAQs or measurement cards or modules in a rack, image acquisition devices such as image acquisition (or machine vision) cards (also known as video capture boards) or smart cameras, motion control devices, robots with machine vision, and other similar types of devices. Exemplary "stand-alone" instruments include oscilloscopes, multimeters, signal analyzers, arbitrary waveform generators, spectrometers, and similar measurement, test, or automation instruments.

The measurement device may be further configured to perform a control function, for example, in response to analysis of the collected or stored data. For example, the measurement device may send control signals to an external system or sensor, such as a motion control system, in response to certain data. The measurement device may also be configured to perform automated functions, i.e., may receive and analyze data and issue automated control signals in response.

Functional unit (or processing element) — refers to various elements or combinations of elements. Processing elements include, for example, circuitry such as an ASIC (application specific integrated circuit), portions or circuits of individual processor cores, an entire processor core, individual processors, programmable hardware devices such as Field Programmable Gate Arrays (FPGAs), and/or larger portions of a system including multiple processors, and any combination thereof.

Auto-refers to an action or operation performed by a computer system (e.g., software executed by a computer system) or a device (e.g., circuitry, programmable hardware elements, ASIC, etc.) without user input directly specifying or performing the action or operation. Thus, the term "automatically" is in contrast to an operation that is manually performed or specified by a user, wherein the user provides input to directly perform the operation. An automated program may be initiated by input provided by a user, but subsequent actions performed "automatically" are not specified by the user, i.e., are not performed "manually," where the user specifies each action to be performed. For example, a user filling out an electronic form by selecting each field and providing input specifying the information (e.g., by typing in the information, selecting a check box, a single check, etc.) is manually filling out the form, but the computer system must update the form in response to the user action. The form may be automatically filled in by a computer system, wherein the computer system (e.g., software executing on the computer system) analyzes the fields of the form and fills in the form without any user input specifying answers to the fields. As indicated above, the user may invoke automatic filling of the form, but not participate in the actual filling of the form (e.g., the user does not manually specify answers for the fields, but rather the answers are automatically completed). This specification provides various examples of automatically performing operations in response to actions that a user has taken.

Also-refers to parallel execution or progression in which tasks, processes, or programs are executed in an at least partially overlapping manner. For example, concurrency may be implemented using "strong" or strict parallelism, where tasks are executed in parallel (at least in part) on respective computing elements, or "weak parallelism," where "tasks" are executed in an interleaved manner, such as by time-multiplexing of execution threads.

Wireless-refers to a communication, monitoring, or control system in which electromagnetic or acoustic waves transmit signals through space rather than along wires.

About-refers to a value within a specified tolerance or acceptable error range or uncertainty of a target value, where the particular tolerance or range is typically dependent on the application. Thus, for example, in various applications or embodiments, the term about may mean: within.1% of the target value, within.2% of the target value, within.5% of the target value, within 1%, 2%, 5%, or 10% of the target value, etc., as required by a particular application of the inventive technique.

FIG. 1-computer System

Fig. 1 illustrates a computer system 82 configured to implement embodiments of the techniques disclosed herein. Embodiments of methods for (e.g., for production testing of integrated circuits) are described below. Note that various embodiments of the technology disclosed herein may be implemented in a variety of different ways. For example, in some embodiments, some or all of the techniques may be implemented with a textual or graphical program that may be deployed to or used to configure any of a variety of hardware devices.

However, while some embodiments are described in terms of one or more programs (e.g., graphical programs) executing on a computer (e.g., computer system 82), these embodiments are merely exemplary and are not intended to limit the technology to any particular implementation or platform. Thus, for example, in some embodiments, the techniques may be implemented on or by a functional unit (also referred to herein as a processing element) that may include, for example, circuitry such as an ASIC (application specific integrated circuit), portions or circuits of individual processor cores, an entire processor core, individual processors, a programmable hardware device such as a Field Programmable Gate Array (FPGA), and/or a larger portion of a system that includes multiple processors, and any combination thereof.

As shown in FIG. 1, the computer system 82 may include a display device configured to display a graphical program when the graphical program is created and/or executed. The display device may also be configured to display a graphical user interface or a front panel of the graphical program during execution of the graphical program. The graphical user interface may comprise any type of graphical user interface, e.g., depending on the computing platform.

Computer system 82 may include at least one memory medium on which one or more computer programs or software components according to one embodiment of the present invention may be stored. For example, the memory medium may store one or more programs, such as graphical programs, that are executable to perform the methods described herein. The memory medium may also store operating system software and other software for the operation of the computer system. Various embodiments further comprise receiving or storing instructions and/or data implemented in accordance with the foregoing description on a carrier medium.

Exemplary System

Embodiments of the invention may relate to performing test and/or measurement functions; controlling and/or modeling an instrument or industrial automation hardware; modeling and simulation functions, such as modeling or simulating a device or product being developed or tested, etc. Exemplary test applications include hardware-in-the-loop testing and rapid control prototyping, among others.

It should be noted, however, that embodiments of the present invention may be used in a variety of applications and are not limited to the above-described applications. In other words, the applications discussed in this specification are merely exemplary, and embodiments of the present invention may be used in any of various types of systems. Thus, embodiments of the system and method of the present invention are configured for use in any of a variety of types of applications, including control of other types of devices, such as multimedia devices, video devices, audio devices, telephony devices, internet devices, etc., as well as general purpose software applications, such as word processing, spreadsheets, network control, network monitoring, financial applications, games, etc.

FIG. 2-computer System Block diagram

FIG. 2 is a block diagram 12 representing one embodiment of the computer system 82 shown in FIG. 1. Note that any type of computer system configuration or architecture can be used as desired, and fig. 2 illustrates a representative PC embodiment. It should also be noted that the computer system may be a general purpose computer system, a computer implemented on a card mounted in a rack, or other type of embodiment. For simplicity, computer elements not necessary to understand the present description are omitted.

The computer may include at least one central processing unit or CPU (processor) 160 coupled to a processor or host bus 162. The CPU 160 may be any of various types, including any type of processor (or multiple processors), as well as other features. A memory medium, typically comprising RAM and referred to as main memory 166, is coupled to host bus 162 through memory controller 164. The main memory 166 may store programs (e.g., graphics programs) configured to implement embodiments of the present technology. The main memory may also store operating system software and other software for the operation of the computer system.

The host bus 162 may be coupled to an expansion or input/output bus 170 through a bus controller 168 or bus bridge logic. The expansion bus 170 may be a PCI (peripheral component interconnect) expansion bus, but other bus types may be used. The expansion bus 170 includes slots for various devices, such as the devices described above. Computer 82 further includes a video display subsystem 180 and a hard disk drive 182 coupled to expansion bus 170. The computer 82 may also include a GPIB card 122 coupled to the GPIB bus 112 and/or an MXI device 186 coupled to the VXI chassis 116.

As shown, the device 190 may also be connected to a computer. The device 190 may contain a processor and memory that may execute a real-time operating system. The apparatus 190 may also or instead include programmable hardware elements. The computer system may be configured to deploy the program to the device 190 for execution of the program on the device 190. The deployed program may take the form of graphical program instructions or data structures that directly represent a graphical program. Alternatively, the deployed program may take the form of text code (e.g., C code) generated from the program. As another example, the deployed program may take the form of compiled code generated from the program or from textual code generated from the program in turn.

FIGS. 3-8-Integrated Circuit with antenna (IC)

Integrated Circuits (ICs) with integrated antennas are becoming more and more popular. Such ICs are included in many devices and may be configured to perform various functions, including wireless communication (e.g., including transmission and/or reception) and radar. In particular, the 5G wireless communication standard (or other standards) may provide for the use of millimeter wave (mmW) band wireless signals and beamforming (e.g., directional transmission/reception). It is contemplated that upcoming cellular communication technologies (e.g., 5G or other technologies) may use multiple antennas in a coordinated manner to focus the transmitted energy at a point in space. The pattern formed by the antenna elements is referred to as a beam and the process of focusing the energy is referred to as beamforming. ICs or application specific ICs (asics) may be important elements of many wireless devices configured to communicate using such standards. For example, an IC with an integrated antenna array (e.g., a phased array) may be a common way to incorporate such 5G wireless functionality.

Fig. 3 illustrates an example phased array architecture that can be used for beamforming. Fig. 3 illustrates a hybrid phased array antenna analog and digital architecture that can be used to focus the energy of the Tx signal at a particular spatial location. As illustrated, the process phase shifter processes digital signals that are sent through a digital-to-analog converter (DAC) and a Power Amplifier (PA), then processed by fine phase shifters and transmitted by four antennas to form a directional beam.

Fig. 4 shows a phased array of antennas that may be incorporated into an IC such as a Complementary Metal Oxide Semiconductor (CMOS) Monolithic Microwave Integrated Circuit (MMIC). In various possibilities, the IC may be approximately 1cm by 1 cm.

Fig. 5 illustrates an exemplary IC that includes an integrated antenna array.

Fig. 6 shows an exemplary array of 256 antennas on a chip. It should be noted that other numbers or configurations of antennas and other sizes of chips, modules, and/or entire mobile devices or user equipment devices (UEs) are possible.

Fig. 7 illustrates an exemplary IC. As shown, the IC includes a plurality (e.g., any desired number) of antenna patches mounted to a chip (e.g., a Printed Circuit Board (PCB), a glass wafer, a silicon wafer, etc.). The antenna patch may transmit signals to or from the integrated RF chip(s). Note that the RF chip may be contained within the chip, but may not reach the entire thickness of the chip. In the example shown, the RF chip reaches a height h1, which is h1 less than the entire height h2 of the chip. The RF chip may be connected to other elements of the IC, for example, by a wired connection.

Fig. 8 illustrates different types of antenna connections for an exemplary IC. In a first configuration, the antenna may be embedded in a Printed Circuit Board (PCB) on which the RF chip and heat sink are mounted. According to some embodiments, this configuration may be useful for relatively low frequencies (e.g., about 75 GHz). In a second configuration, the antenna patch may be embedded in a package block, which in turn is mounted to the RF chip and (e.g., layer 2) PCB. The RF chip may be connected (via the PCB) to the heat sink. Such configurations may be useful for intermediate frequencies, such as 94GHz, among various possibilities. A third configuration may include antenna patches embedded in a glass substrate and stacked on an RF chip, for example, over a package, a layer 2 PCB, and a heat sink. In a variant, a glass wafer may be mounted on a silicon wafer instead of a package. Such configurations may be useful for higher frequencies (e.g., 110GHz and above), among various possibilities.

Fig. 9 illustrates an exemplary mmW IC with an integrated antenna array. As shown, each antenna element (e.g., patch) may have dedicated (e.g., per element) circuitry. Note that the particular antenna element circuitry shown is merely exemplary, and other antenna element circuitry configurations may be used as desired.

FIG. 10 mmW IC RF Performance test

As the demand for ICs with integrated antenna arrays increases, it is desirable to improve the cost of producing and testing such ICs. Testing of mmW ICs, for example, according to conventional techniques, may be challenging for various reasons. The Radio Frequency (RF) performance (e.g., mmW transmission and reception) of an Antenna Under Test (AUT) or Device Under Test (DUT) may typically be tested over the air. Anechoic chambers are commonly used for these tests to avoid interference (e.g., due to reflected signals and multipath effects) that may complicate the test measurements. The beamforming requirements may result in many antennas on the package or chip, and it may be desirable to test the beamforming directional function of the antenna array/IC. Testing of the beamforming function may be expensive, time consuming, and/or difficult because measurements may need to be taken from a potentially large number of locations, for example, because RF performance may vary spatially. In other words, in order to test spatial RF performance, measurements must be taken at many locations (e.g., in 3 dimensions, e.g., as a function of x, y, and z position). Such detailed spatial testing may require complex calibration.

FIG. 10 illustrates certain aspects of over-the-air test RF performance, in accordance with some embodiments. The entire array may be tested, for example, using an antenna (e.g., the horn antenna shown) or other type of antenna (e.g., patch, dipole, loop, directional array, etc.). To test the beamforming function of the array, the antenna (or antennas) may be positioned at a measurement distance large enough for the beam to be fully formed. Further, measurements may be taken from various different locations to test the performance of the beam in different directions. Among the various possibilities, the entire array test may involve a relatively high power signal, e.g., +40dBm, as shown. Alternatively, a single component test may be performed. Single element testing may require that the feedhorn be sufficiently far from the antenna element to be tested to avoid RF coupling. This distance may be less than the distance used for beamforming, e.g., for full array testing. Single element testing may not be able to test the beamforming performance of the array. Among the various possibilities, single element testing may involve relatively low power signals, e.g., -10dBm, as shown.

Since the electromagnetic mode of a beamforming antenna array is characterized Over The Air (OTA), there are standardized methods of measuring the actual signal strength of the antenna in a controlled OTA environment. The Antenna Under Test (AUT) or Device Under Test (DUT) may be placed within a chamber (possibly an anechoic chamber to minimize reflections and interference from external sources, although other types of chambers may be used as desired). The antennas may transmit signals and one or more receive antennas (also located indoors) may capture the received power. The AUT may then be moved across the discretized spatial curve. When these points are measured, a 3D pattern is created, as illustrated in fig. 11. According to various embodiments, the measurement method may vary in the type of chamber used, the geometry and order of the measurement grid (e.g., equal angles, downward spiraling into a sphere, single cross-sectional point, etc.), and the calibration method used for the measurement process.

Additionally, while some embodiments describe a DUT or AUT that transmits beamformed signals that are measured by one or more receivers within the chamber, the reverse setup may be done where over-the-air (OTA) reception characteristics of the DUT are tested and/or characterized. For example, one or more transmitters may be positioned within the chamber, and the DUT may receive transmissions of the one or more transmitters, wherein reception characteristics of the DUT receiver may be characterized from multiple directions. As can be appreciated by those skilled in the art, the methods and systems described herein may be applicable to embodiments that characterize one or more OTA receivers of a DUT. Thus, according to some embodiments, the descriptive instances of the one or more receive antennas of the AUT and anechoic chamber, respectively, may be replaced with one or more transmit antennas of the receiver and anechoic chamber, respectively, of the DUT.

FIG. 12-anechoic chamber antenna measurement setup

Fig. 12 is a schematic diagram showing a typical setup for OTA antenna testing according to some embodiments. As illustrated, adjustable positioner 3002 may be rotated along two orthogonal axes (or in some embodiments, only one axis) to capture the output pattern of AUT 2608 according to multiple spatial orientations. The damper 2602 of the anechoic chamber may prevent reflection and interference of the output mode, and the receiving antenna 2604 may measure the output of the AUT. In the previous embodiment, the movement may be controlled by test sequencing software that ensures that the turntable is at a right angle, and then the RF measurement may take a power measurement. A more detailed illustration of an exemplary adjustable positioner 3002 is shown in fig. 13, where the arrows indicate two orthogonal axes of rotation of the positioner. As will be appreciated by those skilled in the art, any of a variety of types of adjustable positioners may be used to hold and orient the AUT or DUT in a variety of orientations, and the examples illustrated in fig. 12 and 13 for the adjustable positioners are merely exemplary and not intended to limit the scope of the present disclosure.

Fig. 14 is an isometric illustration of an OTA test setup with an adjustable positioning arm in combination with DUT rotation. For example, each of the one or more receive antennas and the DUT may be rotated to a plurality of orientations, respectively.

In other embodiments, as illustrated in fig. 15, a 3-D positioning arm may be used to test a mmW antenna array, where the AUT is fixed but one or more receive antennas are rotated through a series of positions. Figure 15 is a schematic illustration of an anechoic chamber configured with a 3-D positioning arm. Among various possibilities, such 3-D positioning arms may operate in an anechoic chamber (e.g., 18GHz-87GHz in size). The 3-D positioning arm may perform a helical scan, for example using a horn antenna to make measurements at any number of positions. As illustrated in fig. 15, the AUT may be installed indoors and may be configured to transmit signals in a beamforming mode (e.g., in the form of a test beam). The 3-D positioning arm can move the feedhorn to various locations within the room to make measurements.

Low reflection antennas (e.g., smaller radar cross sections) may be used for testing, for example, to minimize the impact on the field. The measurements can be made in the near field, for example, in the Fresnel zone (Fresnel zone) of the near field. Tests can be performed to measure the amplitude and phase of the signal/field at any number of locations. The far-field pattern may be calculated based on near-field measurements. The near-field to far-field conversion may be accomplished using any suitable computational method. Such calculations may be relatively simple if the antenna pattern/configuration is known, or more complex for arbitrary patterns. A map of the far-field pattern may be generated. Such 3-D positioning systems may be useful for design and characterization testing, however the equipment may be relatively expensive and testing may be time consuming. First, the testing process itself can take a significant amount of time, for example, because the 3-D positioning arm needs to be moved through a large number of positions to test each DUT. Second, the anechoic chamber may need to be large enough to allow measurements to be taken at sufficient locations (e.g., in 3-D space) to calculate the far-field pattern. In some embodiments, the anechoic chamber may be large enough so that measurements can be made in the far field of radiation. In some embodiments, a Compact Antenna Test Range (CATR) may employ a reflector to reduce far-field distances, thereby enabling far-field measurements in a smaller anechoic chamber.

FIG. 16-conventional approach for software driven AUT characterization

Fig. 16 is a flow diagram showing a conventional method for a software driver to characterize the over-the-air (OTA) transmission properties of an AUT. As illustrated, the positioning mechanism is rotated according to a pre-calculated angle in the sphere (typically by ethernet control), and then the RF characteristics (typically power, Error Vector Magnitude (EVM), or Adjacent Channel Power (ACP), among other possibilities) are measured. The process may be repeated until all predetermined angles are reached and measured. The loop process may have other scan terms such as "input RF power" or "frequency" and these terms may further increase the duration of the process. The AUT characterization typically performs a measurement of the total radiated power. Performing a total radiated power measurement typically involves physically rotating the AUT to many orientations, as the accuracy of this measurement increases with the number of sample points taken around the sphere.

These conventional procedures are typically indeterminate and are performed by software timing routines. In addition, the method relies on start/stop motion in order to allow sufficient setup and pause times at a given location for the measurement system to perform acquisition with sufficient time accuracy. These methods are very slow and the feature test time is critical to the designer. Software interaction is a major component of latency, and embodiments herein improve these traditional approaches by implementing a hardware timed closed loop system. The total test time of the conventional software timing method can be estimated as:

wherein t is_{Positioning device}Is a single time converted to and established at each measurement location and t_RFIs the time at which a single RF measurement is calculated and acquired. In some embodiments described herein, t may be reduced by continually transitioning the DUT through multiple orientations without stopping the movement of the DUT between the orientations_{Positioning device}Thereby reducing the delay of the measurement acquisition process. For example, the ongoing transition process may delete the setup time of the DUT.

In addition, in the software timing measurement acquisition method, the software timing measurement acquisition method is usedOutage, operating system latency, computational latency, and other factors, possibly through t_RFA significant delay is introduced. Embodiments herein describe systems and methods for performing hardware-timed OTA antenna characterization, where direct hardware signaling between structural elements of the antenna characterization system can automatically trigger method steps of the measurement acquisition process without introducing software or processing delays. For example, hardware-triggered digital feedback from an adjustable positioner may be used to maintain a correlation between tracking the orientation of the DUT and corresponding measurement acquisition without using intermittent software instructions to halt the acquisition process. Thus, the time and computational resources for the measurement acquisition process can be greatly reduced.

Coded orientation of adjustable positioner

A variety of encoding schemes may be used to track the orientation of the adjustable positioner. Quadrature encoders are a common type of incremental encoder that use two output channels (a and B) to sense position. Using two code tracks with sectors positioned 90 degrees out of phase, the two output channels of the quadrature encoder indicate both the position and direction of rotation. As illustrated in fig. 17, for example, if a leads B, the disk rotates in a clockwise direction. If B leads A, the disk rotates in a counter-clockwise direction. By monitoring the number of pulses and the relative phase of signals a and B, both the position and direction of rotation can be tracked.

In some embodiments, the quadrature encoder may also contain a third output channel, referred to as a zero or index or reference signal, which provides a single pulse per revolution. This single pulse can be used to accurately determine the reference position.

In some embodiments, the positioner may be configured to derive a digitline, the length of which is proportional to the speed of the positioner, to indicate when and how the positioner is moving.

Hardware timed OTA antenna characterization

According to an exemplary embodiment, the OTA antenna characterization process may be significantly accelerated with a hardware timing measurement system that incorporates a deterministic closed control loop between the measurement system and the motion of the AUT. Most rotary mechanisms (e.g., adjustable positioners) use servomotors or some sort of encoder to determine the exact position. These devices may use position tracking as a method of determining their location within the circle of motion. These signals are typically internal to the rotating mechanism. Embodiments described herein redesign the rotation mechanism to derive the encoder signals to be used in the synchronization of the OTA antenna characterization process.

The rotational mechanism of the adjustable positioner may be comprised of two degrees of freedom (e.g., relative to orthogonal rotational axes), with each degree of freedom having a feedback mechanism. Alternatively, the rotation mechanism may utilize only a single rotational axis. As illustrated in fig. 18, a quadrature encoder providing a digital signal may be used by a digital counter to keep track of the position (count) of the motor. As illustrated, the counter value may increment at the beginning of each pulse on lane a when lane a leads lane B by 90 degrees. Conversely, when lane B leads lane a, the counter value may be decremented at the end of each lane a pulse (e.g., because the rotary mechanism is moving in the opposite direction when lane B leads lane a).

The counter value may always keep track of the angular position of the rotating mechanism. In some embodiments, these counted changes may be combined to create a single signal called a "master trigger". This can be achieved by programming the counter to output a digital signal each time the count changes. Alternatively, digital edge detection circuitry may be used, which is used in many commercially available data acquisition cards. The "master trigger" may be further divided to simply have a way to reduce the number of triggers acquired by the RF subsystem. In other words, a frequency divisor may be employed within the counter device such that only every nth trigger results in a measurement being acquired.

FIG. 19 is a schematic diagram of a semiconductor test system

FIG. 19 is a system diagram showing components and connections of a semiconductor test system, which may alternatively be referred to as an Antenna Characterization System (ACS), according to an example embodiment. As illustrated, a Radio Frequency (RF) measurement system including an RF signal analyzer coupled to a reference trigger input and output may be coupled to a motor control device that controls movement of an adjustable positioner motor through an ethernet (ENET) connection. The motor control device may include a motion control processor configured to direct motion of the adjustable positioner. For example, according to various embodiments, the motor control device may be a National Instruments IC-3120 device or another type of motor control device. As illustrated, the motor control may communicate with both motor drives over Ethernet for Control Automation Technology (ECAT) connection to direct the movement of the motor drives. The two motor drives may be configured to rotate the adjustable positioner according to two orthogonal axes of rotation, as illustrated by the two circular arrows on the adjustable positioner 3002. Each of the motor drivers may in turn be coupled to a counter device, each through two encoder channels a and a'. As described in more detail above with reference to the quadrature encoder scheme, two signal channels between the motor drive of the adjustable positioner and the counter device may determine the direction of movement of the adjustable positioner.

The counter device may contain two separate counters (e.g. corresponding to two axes of rotation of the adjustable positioner) and may additionally contain one or more edge detection devices to detect edges of modified instances of one or the other of the counters. As described in more detail below, the edge detection device may transmit a master trigger to one or more frequency divisors to potentially cause measurement acquisition. The frequency divisor may be configured to only allow measurement acquisitions to be caused every nth main trigger. For example, the frequency divisor may keep a running count of received master triggers and may transmit every nth master trigger to the RF measurement system to trigger the RF signal analyzer to perform measurement acquisition.

As illustrated, the RF signal analyzer may employ a dual "triggered reference input" and "triggered reference output" system to ensure that samples are not collected from locations that are not collected. For example, when the counter device sends an acquisition trigger to a "trigger reference input" (TRI) port of the RF signal analyzer, the TRI may forward the acquisition trigger to a Trigger Reference Output (TRO) only when the RF signal analyzer starts measurement acquisition of the DUT, and may transmit the reference trigger output back to the counter device to inform the counter device that measurement acquisition has been started. On the other hand, if the RF signal analyzer has not completed a previously initiated measurement acquisition when the TRO forwards the acquisition trigger to the RF signal analyzer (e.g., if the RF is still making ongoing, previously initiated measurements at the time the acquisition trigger is received), the TRO may refrain from forwarding the reference trigger output to the counter device. In this case, no measurement is initiated during the current value of the counter (or counters), and the counter device may likewise not forward the current value of the counter (or counters) to the computer for association with the measurement result, thereby avoiding errors in the associated calculations.

Fig. 20 shows a timing diagram of a series of signaling and counter modifications in an exemplary acquisition process. As illustrated, a first motor (e.g., a motor that guides movement of the adjustable positioner about a first axis of rotation) passes through two channels A₁And A₁"transmit periodic signals. The signal is transmitted to a first counter ("counter 1") of a counter device, which is fed from the encoder a of the motor 1₁The leading edge of each instance of the channel's signal increments a counter. Note that the counter is incremented in this case because encoder A is not present₁Channel-leading encoder A₁The "channel 90 degrees. On the contrary, if encoder A₁' channel leading encoder A₁Channel 90 degrees, the counter will be from encoder A₁The trailing edge of each signal of the channel is decremented.

Similarly, the motor 2 (guiding the rotation of the adjustable positioner about a second, orthogonal axis of rotation) passes through two channels A₂And A₂Second counter for transmitting signals to counter device, which is also based on channel A₂The leading edge of the signal modifies the second counter. As used herein, the term "channel" may refer to multiple orthogonal encoder channels corresponding to a particular motor or respective channels in two motors. According to an exemplary embodiment, mayThere are four channels for transmitting signals through the adjustable positioner: a. the₁、A₁`、A₂And A₂And (5) allowing the strain to stand. More generally, any number of motors with corresponding channels, and any number of channels per motor, may be used as desired. Each of the counters outputs its respective first and second counters, which are combined into a master trigger. In fig. 20, the frequency divisor is a common N-1 frequency divisor, such that each input main trigger results in the output of an acquisition trigger. Alternatively, if a frequency divisor of N-2 is employed (not shown in fig. 20), then only every other signal in the main trigger will result in the output of the acquisition trigger.

Fig. 20 additionally illustrates the duration of a series of measurement acquisitions. In addition, it is demonstrated how when an acquisition trigger is sent to the RF signal analyzer while a previous measurement acquisition is still in progress (e.g., a second acquisition trigger is sent while a p1 acquisition is still in progress), no reference trigger output is sent to the counter device. In this way, the recorded counts 1 and 2 will each correspond to a unique measurement acquisition, and when no measurement acquisition is made, the counts 1 and 2 will not be recorded. In a later process, the computer may then correlate the results of each measurement acquisition with the recorded counts of each of counters 1 and 2 to determine the position of the adjustable positioner corresponding to each measurement. In other words, for each RF measurement acquisition, a corresponding measurement (depicted as p in fig. 20) may be calculated_i) The counter values may be stored simultaneously and the table may be populated. Examples are shown in table 1 below.

Table 1: example results of OTA antenna characterization

Azimuthal count	Elevation angle counting	Count/degree	Azimuth angle	Elevation angle	RF power
						1	0	10	0.1	0	p1
2	1	10	0.2	0.1	p2
						3	1	10	0.3	0.1	p3
4	1	10	0.4	0.1	p4
						5	2	10	0.5	0.2	p5
6	2	10	0.6	0.2	p6
						23	5	10	2.3	0.5	p7
34	5	10	3.4	0.5	p8
						45	15	10	4.5	1.5	p9
56	15	10	5.6	1.5	p10
						67	20	10	6.7	2	p11
78	24	10	7.8	2.4	p12
						89	28	10	8.9	2.8	p13
100	32	10	10	3.2	p14
						111	36	10	11.1	3.6	p15
122	40	10	12.2	4	p16
						133	44	10	13.3	4.4	p17
144	48	10	14.4	4.8	p18
						155	52	10	15.5	5.2	p19
166	56	10	16.6	5.6	p20
						177	60	10	17.7	6	p21
188	64	10	18.8	6.4	p22
						199	68	10	19.9	6.8	p23
210	72	10	21	7.2	p24
						221	76	10	22.1	7.6	p25
232	80	10	23.2	8	p26
						243	84	10	24.3	8.4	p27
254	88	10	25.4	8.8	p28
						265	92	10	26.5	9.2	p29

In some embodiments, the translation from the counter value to the [ azimuth, elevation ] pair may be calculated. This may depend on the mechanical design of the positioner and feedback mechanism.

Advantageously, embodiments described herein avoid utilizing software interactions to perform the orientation sequence of the AUT and associated measurement acquisition. An important difference of the embodiments described herein is that the feedback mechanism (counter) is being sampled at the time of the RF measurement, which may achieve better accuracy than other types of synchronization.

A further improvement of the embodiments described with respect to the speed of the AUT characterization process is that the adjustable positioner may be constantly transitioned between multiple orientations of the AUT (i.e., without stopping movement between the orientations). In software triggered embodiments, the error between hardware and software triggers is typically too large to achieve repeatable results with continuous, non-stop motion of the adjustable positioner. Because the system is connected in hardware, the delay and error are so low that repeatable results can be obtained without stopping the positioner motion during the AUT characterization process.

FIG. 21 is a system diagram similar to FIG. 19, including an instrument control computer. In particular, fig. 21 illustrates how a computer may be used to direct the measurement acquisition process described in fig. 19 in some embodiments. In addition, fig. 21 illustrates a motion detection device that can receive signals from the motors 1 and 2 and from the counter device to determine (e.g., by motion detection logic) when to transmit a master trigger (i.e., an acquisition trigger) to the RF measurement system. In some embodiments, the execution of the measurement acquisition process may be controlled by programmable hardware elements of the computer. In other words, in some embodiments, at least some of the methods disclosed herein may be implemented and/or controlled in programmable hardware such as a Field Programmable Gate Array (FPGA). Other configurations of the system diagram are also possible. For example, one or more of the counter devices, motor controls, motion detection devices, and RF signal analyzer/RF measurement systems may be contained within the computer as software, or they may be separate hardware elements (e.g., PXI cards in a modular chassis, for example). The RF measurement system, counter devices and motor controlled structural elements may generally take various forms of software or hardware. The terms "RF measurement system", "counter device", "motor control" and "motion detection device" are intended to be functional descriptors of the roles played by the respective entities in the measurement acquisition process and are not intended to limit their implementation in various embodiments to a particular type of hardware or software.

FIG. 22 is a system diagram similar to FIG. 21, additionally illustrating the functionality of the system to sequentially start and stop the movement of the adjustable positioner during a measurement acquisition process according to some embodiments. In some embodiments, the duration of each measurement acquisition may be long enough that it may be desirable for the adjustable positioner to temporarily stop the motion of the DUT while acquiring each measurement and transition to a subsequent orientation after the measurement acquisition is completed. Alternatively or additionally, it may be desirable to perform multiple measurements in each orientation of the DUT (e.g., it may be desirable to measure the transmission characteristics of the DUT at multiple transmission power levels or multiple different frequencies for each orientation, among other possibilities), and it may be desirable for the adjustable positioner to remain in a particular orientation until multiple measurement acquisitions are completed.

As illustrated in fig. 22, the counter device may transmit a digital stop trigger to the motion control processor at the same time each time an acquisition trigger is transmitted to the RF measurement system, so that the motion control processor stops the motion of the adjustable positioner at the start of each measurement. In some embodiments, the counter device may wait a predetermined period of time after transmitting the digital stop trigger to cause the adjustable positioner to establish a stable position and then transmit an acquisition trigger to the RF measurement system. Alternatively, the counter device may transmit a digital stop trigger to the motion control processor upon receiving a reference trigger output signal from the RF measurement system, such that the counter device will only instruct the motion control processor to stop the motion of the adjustable positioner when the acquisition trigger actually results in the acquisition of a measurement by the RF measurement system.

As further illustrated in fig. 22, when the RF measurement system finishes (i.e., completes) its measurement acquisition, the RF measurement system may transmit a digital activation trigger to the motion control processor to resume motion. In response, the motion control processor may direct the adjustable positioner to transition to a subsequent orientation in the sequence. Advantageously, the implementation of start/stop triggers may improve flexibility with respect to the number and duration of measurements acquired at a single location. Additionally, utilizing hardware timing signaling between structural elements of the measurement acquisition system may reduce delays that would otherwise be introduced through software interaction.

FIGS. 23-25-communication flow diagrams for measurement acquisition

Fig. 23 is a communication flow diagram showing a simplified method for making coordinated OTA antenna measurements in accordance with some embodiments. As illustrated, a computer may configure and equip a Radio Frequency (RF) signal analyzer for an upcoming measurement acquisition process of a Device Under Test (DUT) or Antenna Under Test (AUT). The RF signal analyzer may configure its measurement acquisition and triggering mechanism and wait for "Ref Trig In" for measurement acquisition. The RF signal analyzer may notify the computer when it is ready and configured. The computer may also be equipped with a counter device that can be initialized and that can notify the computer after the counter device has been initialized. The computer may also configure the motion control device with a position scanning scheme, and the motion control device may notify the computer when it and the adjustable positioner are ready to initiate a position scan. For example, the computer may inform the motion control device of a starting position of one or more angles of the adjustable positioner and a series of motion scans of one or more motors through a series of different orientations of the DUT.

The computer may then initiate a position scan and the motion control device may direct the adjustable positioner to begin orienting the DUT through a plurality of different orientations. The adjustable positioner may be continuously transitioned between orientations without stopping movement of the positioner between orientations. In response to the adjustable positioner reaching each of the plurality of orientations, a signal may be automatically sent from the adjustable positioner to the counter device over one or more channels. The counter device may use these signals to modify one or more counters corresponding to one or more respective axes of rotation of the adjustable positioner. For example, the counter device may increment or decrement its counter(s) based on the received signal (e.g., according to the orthogonal coding scheme described above). The counter device may transmit the modified counter to a computer, which may read the counter value and translate the value into the angle and orientation of the adjustable positioner. The counter device may employ an edge detector to detect the leading or trailing edge of the counter (e.g., depending on whether the counter is incremented or decremented) to determine the precise moment in time at which the counter is modified.

In response to the edge detection, the counter device may transmit an acquisition trigger to the RF signal analyzer, which may cause the RF signal analyzer to perform measurement acquisition of the DUT (referred to as "RF signal acquisition" in fig. 23). The RF signal analyzer may transmit the results of the measurement acquisition to a computer, which may read the results and correlate the results with the received counter values to determine the orientation of the adjustable positioner at the time of the measurement. After a series of many such associated measurement acquisitions, the computer may populate a table of measurement results and their associated DUT orientations, and may store the table in memory.

Fig. 24 is a communication flow diagram showing a method for making coordinated OTA antenna measurements that include reference triggers used by a radio frequency signal analyzer, in accordance with some embodiments. Fig. 24 is similar to fig. 23, but fig. 24 explicitly describes the frequency divisor of the counter device and the role played by the reference trigger inputs and outputs of the RF signal analyzer. As illustrated, the frequency divisor filters out every nth acquisition trigger received from the counter device (every 4 th acquisition trigger in the example illustrated in fig. 24, although other values of N are possible). As illustrated, every 4 th acquisition trigger is forwarded to a reference trigger input In a ("Ref Trig In") port of the RF signal analyzer. The Ref Trig In forwards the acquisition trigger to the Ref Trig Out port, which In turn triggers the measurement acquisition. Importantly, if measurement acquisition is initiated, the Ref Trig Out will also forward a trigger back to the counter device instructing the counter device to transmit the current value of the counter to the computer for association with the measurement result. In this way, the counter value is transmitted to the computer for association with the measurement result only when measurement acquisition has been initiated.

Fig. 25 is a communication flow diagram showing a method for making coordinated OTA antenna measurements in which some acquisition triggers overlap with ongoing measurement acquisition and do not trigger subsequent acquisition, in accordance with some embodiments. Fig. 25 is similar to fig. 23 and 24, but fig. 25 clearly shows how the method can be used to accommodate two counters corresponding to two different axes of rotation of the adjustable positioner. Additionally, fig. 25 illustrates how the described method accommodates the case where an acquisition trigger is received by the RF signal analyzer before the previously initiated and ongoing measurement acquisition is complete.

As illustrated, fig. 25 shows that counter 1 and counter 2 (corresponding to two different rotational axes of the adjustable positioner, respectively) can be incremented at two different (and possibly non-symmetrical) rates, respectively. As illustrated, modifications to counter 1 or counter 2 may cause the edge detector to transmit acquisition triggers to the frequency divisor, and the frequency divisor may forward every N acquisition triggers received to the Ref Trig In of the RF signal analyzer to perform measurement acquisition. In the illustrated example of fig. 25, the first such acquisition trigger received by the Ref Trig Out results in a measurement acquisition whose measurement results are transmitted to the computer, and additionally instructs the counter device to transmit the current values of counter 1 and counter 2 to the computer to be associated with the respective measurement results.

However, the second acquisition trigger transmitted to the Ref Trig In is received by the Ref Trig Out before the first RF signal acquisition is completed (i.e., it was received during the previously initiated and ongoing RF measurement acquisition). Therefore, the Ref Trig Out does not initiate subsequent measurement acquisitions and does not instruct the counter device to transmit the current values of counter 1 and counter 2 to the computer to be associated with the measurement results. In this way, even though the series of acquisition trigger transmissions transmitted by the counter device to the RF signal analyzer may be non-periodic (e.g., because the transmission rate depends on the convolution of two different and potentially disproportionate periods, i.e., the two counter modification periods of counters 1 and 2), each set of counter values received by the computer will be associated with a single corresponding measurement.

The following numbered paragraphs describe additional embodiments of the present invention.

In some embodiments, a Semiconductor Test System (STS) includes an anechoic chamber, a counter device, a Radio Frequency (RF) signal analyzer coupled to one or more receive antennas and the counter device, an adjustable positioner coupled to the counter device, and a computer including a processor and coupled to each of the adjustable positioner, the counter device, and the RF signal analyzer. One or more receive antennas may be positioned within the anechoic chamber, and the RF signal analyzer may be configured to collect RF measurements by the one or more receive antennas of the Antenna Under Test (AUT) or Device Under Test (DUT) transmission. The computer may initiate the measurement process on the DUT or AUT according to the following sequence of steps.

In some embodiments, an apparatus configured to be included within a computer included within a Semiconductor Test System (STS) includes memory and a processing element in communication with the memory. The memory may store program instructions executable by the processing element to cause the computer and the STS to initialize a measurement process on the DUT or AUT according to the following sequence of steps.

The STS can initiate a measurement process on the AUT by continuously transitioning the AUT within the anechoic chamber through multiple orientations without stopping the movement of the adjustable positioner between the orientations. The continuously transitioning the AUT through the plurality of orientations occurs at a speed such that a time between successive signal transmissions through each of the one or more channels is greater than an acquisition time of each of the RF measurements.

The adjustable positioner may be configured to automatically transmit a signal to the counter device through the one or more channels in response to the adjustable positioner positioning the AUT according to each of the plurality of orientations. The adjustable locator may provide the signal to the counter device through direct hardware signaling. In other words, the adjustable positioner may pass the signal directly to the counter device without introducing software delays. Instead, the signal may be communicated directly through a wired or wireless connection, and may automatically cause the counter device to perform the following steps.

One or more channels may comprise a first channel and a second channel of a quadrature encoder scheme, wherein said modifying said first counter comprises incrementing or decrementing said first counter, and wherein a relative phase between respective signals of said first and second channels determines whether a counter device increments or decrements said first counter.

For an embodiment, where modifying the first counter comprises incrementing or decrementing the first counter, the counter apparatus may comprise an edge detector configured to detect a leading edge at the time of the incremented first counter and a trailing edge at the time of the decremented first counter. In these embodiments, the transmitting the modified first counter to the computer and the transmitting the first acquisition trigger to the RF signal analyzer may be performed by the edge detector in response to detecting a leading edge of the incremented first counter or a trailing edge of the decremented first counter.

In response to receiving a signal from the adjustable positioner over the one or more channels, the counter apparatus may be configured to modify the first counter, transmit the modified first counter to the computer, and transmit a first acquisition trigger to the RF signal analyzer, wherein the modifying the first counter, transmitting the modified first counter, and transmitting the first acquisition trigger occur multiple times in different respective orientations of the AUT. Similar to the connection between the adjustable positioner and the counter device, the counter device may transmit the first acquisition trigger to the RF signal analyzer through direct hardware signaling such that only a very small (e.g., microseconds or less) amount of delay is introduced in passing the acquisition trigger to the RF signal analyzer.

In some embodiments, in response to receiving the signal from the adjustable positioner, the counter device may modify the second counter, transmit the modified second counter to the computer, and transmit the second acquisition trigger to the RF signal analyzer. The modifying the second counter, transmitting the modified second counter, and transmitting the second acquisition trigger may occur multiple times in different respective orientations of the AUT. The second counter may be associated with a different axis of rotation of the adjustable positioner than the first counter.

The counter device may comprise a frequency divisor and the transmitting the modified first counter to the computer and the transmitting the first acquisition trigger to the RF signal analyzer may be performed by the frequency divisor for every nth modified first counter and nth first acquisition trigger, where N is a positive integer.

In some embodiments, the transmitting of the modified first counter and the second counter to the computer and the transmitting of the first acquisition trigger and the second acquisition trigger to the RF signal analyzer for every nth modified first counter or second counter and nth first acquisition trigger or second acquisition trigger is performed by a frequency divisor, where N is a positive integer. In other words, the frequency divisor may count the receptions of both the first acquisition trigger and the second acquisition trigger, and may transmit every nth acquisition trigger regardless of whether the nth acquisition trigger is the first acquisition trigger or the second acquisition trigger.

The RF signal analyzer may be configured to acquire RF measurements of transmissions to the AUT and relay results of the RF measurements to the computer in response to receiving each of the plurality of first acquisition triggers.

In some embodiments, the acquiring of RF measurements by the RF signal analyzer is not initiated when one of a plurality of first acquisition triggers is received during a previously initiated and ongoing RF measurement acquisition. In these embodiments, the RF signal analyzer may be further configured to transmit a reference trigger to the counter device in response to initiating each RF measurement acquisition, and the transmitting the modified first counter to the computer may be further performed by the counter device in response to the counter device receiving the reference trigger from the RF signal analyzer. In these embodiments, the RF signal analyzer may avoid transmitting the reference trigger to the counter device when receiving the respective first acquisition trigger does not result in initiating acquisition of the RF measurement (i.e., when the RF signal analyzer receives the acquisition trigger before the previously ongoing acquisition is completed).

The computer may be further configured to associate the modified first counter received from the counter device with the RF measurements to determine an orientation of the plurality of orientations of the AUT corresponding to each of the RF measurements, and to output an associated list of the RF measurements and their respective AUT orientations. The result list may be stored in a memory.

Accuracy of RF measurements

The accuracy of the recorded position of the adjustable positioner may be adversely affected by several factors. Depending on the encoder resolution and the N-sampling factor, the exact angle may not fall in the exact point. This may lead to some minor correlation problems with other (second) rotating mechanisms, as the data comparison may have a small angular misalignment error. Additionally, there may be a delay between counting and RF acquisition. However, even if this is a significant error, it has been repaired and can be corrected during calibration of the system delay.

In some embodiments, the maximum error may be the duration of the RF acquisition compared to the angular velocity of the adjustable positioner. Consider a perfect simulation of the antenna power as simulated as a sinc function, as shown in fig. 26. The relative magnitude of the angular velocity and the inverse of the acquisition time may affect the power measurement. If the angular velocity ω_rMuch larger than the inverse of the acquisition time, the ideal power curve shown in fig. 26 may be distorted, as shown in fig. 27. Fig. 27 shows the measurement of distortion when the angular velocity is 50 times greater than the inverse of the acquisition time.

The simulation results show that when the angular velocity is close to the inverse of the RF acquisition time, then the results have a good correlation, as illustrated in fig. 28. The mean square error of figure 28 is less than 5 e-6.

Power is a common measure in OTA antenna characterization. The power can typically be calculated for mm-wave measurements using raw data of about 100 microseconds. This means that angular velocities can be as high as about 10,000 degrees per second without introducing significant distortion. Further, this means that a very detailed 1296 point grid (hemisphere, azimuth and elevation every 5 degrees) can be calculated in about 1.3 seconds using the appropriate trajectory. The number of collection points can be much larger, but to better manage the data, it is usually sufficient to keep the results every 5 degrees and discard all other results.

Some advantages of the embodiments described herein may be summarized as follows. The test time effect through the setup time of the start/stop motion profile is eliminated. Deterministic, repeatable and quantifiable delays can be introduced between the motion and the measurement of beam power. Repeatability of measurements across the AUT sample set is improved due to the deterministic relationship between AUT location and measurements. The variance of the resulting distribution is reduced as the uncertainty of the position/measurement relationship is reduced. Additionally, measurement uncertainty of beam power measurements is eliminated due to adjustable deterministic delays between movement through the set spatial location and measurement of beam power at that location.

Calibration using motion/data time alignment servomechanism

When motion is added to the measurement set of the AUT/DUT, a potential new source of measurement uncertainty can be introduced regarding the position and motion of the AUT that did not previously exist in the non-motivational test scenario. The contribution of this measurement uncertainty to the overall uncertainty of the reported results can be characterized separately by testing the sensitivity of the measurement results (e.g., RF power) to the absolute positioning of the RF beam center relative to the center of the measurement antenna. Methods in the art for characterizing this contribution are known in the measurement uncertainty model for OTA testing. However, when measurements at a given location are not repeatable over time or on a single motion curve, it may not be of value to identify these sources of error because the timing alignment between the acquisition of the RF data and the location of the AUT is non-deterministic.

When the measurement method is triggered with the deterministic pulses described above, the measured data can be reliably repeated over multiple AUTs and at different positions along a single AUT curve, as long as the test settings that affect the motion of the system and the timing delays between the measurement components are not altered.

Some embodiments may implement closed loop processing on sample data flowing through an embedded RT processing node (e.g., a Field Programmable Gate Array (FPGA) or other type of processing node), which allows for in-loop adjustment of the data. After setting up the motion/measurement system, which relies on a trigger pulse sequence, there is a timing delay in the system, which may have an unknown effect on the measurement results and a calculated resulting uncertainty. To avoid this, the servomechanism can be implemented as part of a "fast calibration routine", which can be operated according to the following method steps:

1. a fixed beam state/position is set.

2. The positioner is moved back and forth in azimuth and elevation, passing the beam center to the location where it is expected to be delivered to the center of the test antenna.

3. Each time the positioner is positioned across the settings, a pulse may be generated that is sent to the measurement system to trigger an acquisition.

The FPGA-implemented computational loop can actively find a perfect alignment between the trigger position and the calculated maximum measured power level after the trigger. This alignment time may be used to determine how many pre-trigger samples should be used to trigger acquisition and how many total samples may be used to calculate a measurement for each AUT location.

The following numbered paragraphs describe additional embodiments:

in some embodiments, an Antenna Characterization System (ACS) includes a chamber, which may be an anechoic chamber; a counter device; a Radio Frequency (RF) signal analyzer coupled to one or more receive antennas and the counter device, wherein the one or more receive antennas are positioned within the chamber, wherein the RF signal analyzer is configured to acquire RF measurements by the one or more receive antennas of a transmission of an Antenna Under Test (AUT); an adjustable locator coupled to the counter device; and a computer including a processor and coupled to each of the adjustable positioner, the counter device, and the RF signal analyzer.

The computer may be configured to initiate a measurement process on the AUT by causing the adjustable positioner to continuously transition the AUT within the anechoic chamber through a plurality of orientations without stopping movement of the adjustable positioner between the orientations, wherein the adjustable positioner is configured to automatically transmit a signal to the counter device through one or more channels in response to the adjustable positioner positioning the AUT according to each of the plurality of orientations.

In response to receiving a signal from the adjustable positioner over the one or more channels, the counter device may be configured to modify the first counter value, transmit the modified first counter value to the computer, and transmit a first acquisition trigger to the RF signal analyzer, wherein the modifying the first counter value, transmitting the modified first counter value, and transmitting the first acquisition trigger occur multiple times in different respective orientations of the AUT.

The computer may be further configured to associate the modified first counter value received from the counter device with the RF measurements to determine an orientation of the plurality of orientations of the AUT corresponding to each of the RF measurements, output an associated list of the RF measurements and their respective AUT orientations.

The adjustable locator may provide direct hardware signaling to the counter device, and wherein the counter device provides the first acquisition trigger to the RF signal analyzer through the direct hardware signaling.

The continuously transitioning the AUT through the plurality of orientations occurs at a speed such that a time between successive signal transmissions through each of the one or more channels is greater than an acquisition time of each of the RF measurements.

The modifying the first counter value may comprise incrementing or decrementing the first counter value, and the counter device may comprise an edge detector configured to detect a leading edge at the time of the incremented first counter value and a trailing edge at the time of the decremented first counter value. In these embodiments, the transmitting the modified first counter value to the computer and the transmitting the first acquisition trigger to the RF signal analyzer may be performed by the edge detector in response to detecting a leading edge of the incremented first counter value or a trailing edge of the decremented first counter value.

In some embodiments, the counter device comprises a frequency divisor and the transmitting the modified first counter value to the computer and the transmitting the first acquisition trigger to the RF signal analyzer is performed by the frequency divisor for every nth modified first counter value and nth first acquisition trigger, where N is a positive integer.

In response to receiving a signal from the adjustable positioner through the one or more channels, the counter device may be further configured to modify the second counter value, transmit the modified second counter value to the computer, and transmit a second acquisition trigger to the RF signal analyzer, wherein the modifying the second counter value, transmitting the modified second counter value, and transmitting the second acquisition trigger occur multiple times in different respective orientations of the AUT, and wherein the second counter value may be associated with a rotational axis of the adjustable positioner that is different from the first counter value. In these embodiments, the counter device may comprise a frequency divisor, wherein the transmitting the modified first counter value and the second counter value to the computer and the transmitting the first acquisition trigger and the second acquisition trigger to the RF signal analyzer for every nth modified first counter value or second counter value and nth first acquisition trigger or second acquisition trigger is performed by the frequency divisor, wherein N is a positive integer.

In some embodiments, the acquiring of RF measurements by the RF signal analyzer is not initiated when one of a plurality of first acquisition triggers is received during a previously initiated and ongoing RF measurement acquisition. The RF signal analyzer may be further configured to transmit a reference trigger to a counter device in response to initiating each RF measurement acquisition, and the transmitting the modified first counter value to a computer may be further performed by the counter device in response to the counter device receiving the reference trigger from the RF signal analyzer. The RF signal analyzer may be configured to avoid transmitting the reference trigger to the counter device when receiving the respective first acquisition trigger does not result in initiating acquisition of the RF measurement.

Some embodiments describe a method for measuring transmissions of a Device Under Test (DUT), the method comprising: initiating, by the computer, a measurement process on the DUT by continuously transitioning the DUT within the chamber through the plurality of orientations by the adjustable positioner without stopping movement of the adjustable positioner between the orientations; automatically transmitting a signal through the adjustable positioner through one or more channels to a computer in response to the adjustable positioner positioning the DUT in accordance with each of the plurality of orientations; automatically transmitting, by the computer, a series of acquisition triggers to a Radio Frequency (RF) signal analyzer in response to receiving the signal from the adjustable positioner through the one or more channels.

The method may further comprise, by the RF signal analyzer: automatically acquiring RF measurements of transmissions of a DUT from one or more receive antennas positioned within the chamber in response to receiving each of the series of acquisition triggers; and transmitting the results of the RF measurements to the computer.

The method may further include, by the computer: correlating the signal received from the adjustable positioner with the results of the RF measurements received from an RF signal analyzer to determine an orientation of the DUT that corresponds to each of the results of the RF measurements; and outputting the results of the RF measurements and an associated list of respective orientations of the DUTs.

In some embodiments, the one or more channels comprise a first channel and a second channel of a quadrature encoder scheme, and the method further comprises: determining, by the computer, a direction of motion of the DUT based on a relative phase between respective signals of the first channel and the second channel, wherein the correlating of the signal received from the adjustable positioner with the result of the RF measurement received from the RF signal analyzer is performed based on the determined direction of motion.

In some embodiments, said continually transitioning said DUT through said plurality of orientations is performed at a speed such that a time between successive signal transmissions through each of one or more channels is greater than an acquisition time of each of said RF measurements.

In some embodiments, the signals received from the adjustable positioner include a first set of signals corresponding to movement of the adjustable positioner about a first axis of rotation, and a second set of signals corresponding to movement of the adjustable positioner about a second axis of rotation orthogonal to the first axis of rotation.

In some embodiments, said automatically acquiring the RF measurements by the RF signal analyzer is not performed when an acquisition trigger of the series of acquisition triggers is received during a previously initiated and ongoing RF measurement acquisition, and the RF signal analyzer is further configured to transmit a reference trigger to the computer in response to performing each RF measurement acquisition. The RF signal analyzer may be configured to avoid transmitting the reference trigger to the computer when receiving a respective first acquisition trigger does not result in the RF measurement acquisition.

Said correlating said signal received from said adjustable positioner with said results of said RF measurements received from an RF signal analyzer may be performed to determine an orientation of said DUT corresponding to each of said results of said RF measurements based, at least in part, on said reference trigger received from said RF signal analyzer.

Although the embodiments above have been described in considerable detail, numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. It is intended that the following claims be interpreted to embrace all such variations and modifications.

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Aerial antenna characterization for hardware timing

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