阅读说明：本技术 超宽带(uwb)雷达中的降噪 (Noise reduction in Ultra Wideband (UWB) radar ) 是由 杰弗里·麦克法登 斯坦·伊万诺夫 于 2020-04-03 设计创作，主要内容包括：一种超宽带(UWB)系统,包括外壳和外壳内的超宽带(UWB)发射器阵列,该UWB发射器阵列具有向感兴趣区域(ROI)发射电磁波的发射器部件,UWB阵列具有从ROI中的对象接收反射电磁波并生成对象数据的接收器部件。该系统还包括雷达吸收材料和模式识别设备,该雷达吸收材料被定位成接收从发射器部件发射的不指向ROI的电磁波,该模式识别设备具有处理器,该处理器被配置成处理从ROI反射的电磁波并确定感兴趣对象(OOI)模式是否在对象数据内被识别。(An ultra-wideband (UWB) system includes a housing and an ultra-wideband (UWB) transmitter array within the housing having transmitter means to transmit electromagnetic waves to a region of interest (ROI), the UWB array having receiver means to receive reflected electromagnetic waves from an object in the ROI and generate object data. The system also includes a radar-absorbing material positioned to receive electromagnetic waves emitted from the transmitter component that are not directed toward the ROI, and a pattern recognition device having a processor configured to process the electromagnetic waves reflected from the ROI and determine whether an object of interest (OOI) pattern is identified within the object data.)

1. An ultra-wideband (UWB) system comprising:

a housing;

an ultra-wideband (UWB) transmitter array within the housing, the UWB transmitter array having a transmitter component that transmits electromagnetic waves to a region of interest (ROI), the UWB array having a receiver component that receives reflected electromagnetic waves from an object in the ROI and generates object data;

a radar absorbing material positioned to receive electromagnetic waves emitted from the transmitter component that are not directed at the ROI; and

a pattern recognition device having a processor configured to process electromagnetic waves reflected from the ROI and determine whether an object of interest (OOI) pattern is identified within the object data.

2. The system of claim 1, wherein the transmitter component and the receiver component are located on a front side of a base support facing the ROI.

3. The system of claim 2, wherein the base support includes a back side opposite the front side, wherein the radar-absorbing material is located on the back side of the base support.

4. The system of claim 2, wherein the transmitter component is laterally offset from the receiver component.

5. The system of claim 1, wherein the radar-absorbing material includes a first absorber positioned near the transmitter component and the radar-absorbing material includes a second absorber positioned near the receiver component.

6. The system of claim 5, further comprising a ground plane on the radar absorbing material.

7. The system of claim 6, wherein the first absorber includes a first face facing the transmitter element and a second face facing away from the transmitter element, and the ground plane is disposed on the second face.

8. The system of claim 6, wherein the second absorber includes a third face facing the receiver component and a fourth face facing away from the receiver component, and the ground plane is disposed on the third face and between the second absorber and the base support.

9. The system of claim 1, wherein the housing comprises one or more walls, wherein at least one of the one or more walls comprises a surface that is at an oblique angle relative to the emission of one of the main and back lobes of the energy emitted from the emitter member.

10. The system of claim 1, wherein at least one wall of the enclosure is the radar absorbing material.

11. A method of assembling an ultra-wideband (UWB) system, comprising:

positioning an ultra-wideband (UWB) transmitter array within a housing, the UWB transmitter array having a transmitter component that transmits electromagnetic waves toward a region of interest (ROI), the UWB array having a receiver component that receives reflected electromagnetic waves from an object in the ROI and generates object data;

positioning a radar absorbing material to receive electromagnetic waves emitted from the transmitter component that are not directed at the ROI; and

a pattern recognition device is configured to process electromagnetic waves reflected from the ROI and determine whether an object of interest (OOI) pattern is identified within the object data.

12. The method of claim 11, further comprising positioning the transmitter component and the receiver component on a front side of a base support facing the ROI.

13. The method of claim 12, wherein the base support includes a rear side opposite the front side;

the method also includes positioning the radar-absorbing material on the back side of the base support.

14. The method of claim 12, further comprising laterally offsetting the transmitter component from the receiver component.

15. The method of claim 11, wherein the radar-absorbing material includes a first absorber positioned near the transmitter component and the radar-absorbing material includes a second absorber positioned near the receiver component.

16. The method of claim 15, further comprising positioning a ground plane on the radar-absorbing material.

17. The method of claim 16, wherein the first absorber includes a first face facing the emitter element and a second face facing away from the emitter element;

the method also includes positioning the ground plane on the second face.

18. The method of claim 16, wherein the second absorber includes a third face facing the receiver component and a fourth face facing away from the receiver component;

the method also includes placing the ground plane on the third face and between the second absorber and the base support.

19. The method of claim 11, further comprising forming the housing to include one or more walls having a surface at an oblique angle relative to an emission of one of a main lobe and a back lobe of energy emitted from the emitter member.

20. The method of claim 11, further comprising forming the housing from an absorbent material.

Technical Field

Exemplary technical fields of the present disclosure may relate to security screening and object detection, for example, using Ultra Wideband (UWB) radar.

Background

With gun violence becoming an increasingly social threat, mechanisms to detect weapons hidden on individuals, in bags, or backpacks are becoming increasingly important. Recent events have shown that many public congregation areas may be the subject of unexpected tragedies, and it is becoming increasingly important to be able to scan and detect hidden weapons and contraband in public places.

Traditionally, scanning devices and metal detectors have been used in areas where security is critical, and the public increasingly expects occasional inconveniences to support overall security at a given site. The sites may include airports, voting lines, entrances to courts and other government buildings, stadiums, and the like. Scanning may include screening an individual using a metal detector, a Radio Frequency (RF) detection system, x-rays, or other conventional and known methods and systems. However, while many of these systems have been effective, these systems may include drawbacks that need to be addressed.

For example, metal detection equipment is typically located at a security checkpoint where individuals remove metal-based materials and then pass through an x-ray screening system. The operating costs of these checkpoints can be high and can lead to bottlenecks in the number of people passing through a given area. One known example is at airports. A security officer controls the passage through the pass-through metal detector-having to deal with many positive indicators of the presence of metal, such as when a traveler inadvertently leaves a metal belt buckle on himself. The screening person picks up the individual and detects and identifies the item that caused the positive occurrence by means of a magnetic bar. At the same time, the flight envelope passes through the x-ray scanning device, which can also be expensive, time consuming, and can result in additional searching and delays.

Other commercially available known systems utilize techniques such as magnetometers (i.e., metal detectors) or submillimeter wave imaging. These systems are large in size, may not positively identify a threat, and may indicate the presence of a threat when no threat is present in reality, and may include an individual walking through a cordline area and stopping to receive imaging. Other known systems use sensors (typically vision-based systems) that detect and track individuals in a defined space. However, typically, these systems cannot track individuals when they are behind or blocked by opaque objects (such as walls or partitions), and vision-based systems may present privacy concerns (such as concerns that images may be disclosed and used for nefarious purposes).

Furthermore, such a level of security is not always feasible for many events and locations. For example, sporting events, shopping centers, voting (often as a temporary arrangement, such as at a school, church, or kosher church), and rock concerts, may have thousands of people passing a security check in a short period of time. Metal detectors are commonly employed, but they also create bottlenecks in the event, may be impractical and costly to deploy, and may fail to detect all items that may threaten public safety. Some locations, such as churches and jewish churches, are contradictory to the concept of public security screening, and the adoption of metal detection and other security screening methods may not be desirable.

In addition, sites with thousands of participants may have many entrances and exits, and screening all areas is impractical. For example, a school may have only a few security personnel to manage overall security. It may not be practical to hire a sufficient number of screeners, and so alternatives may include limiting the number of entrances and exits, or limiting operating time. In any case, the overall purpose of the school may be limited, and the school may not be able to fully exploit its potential, since access is restricted for public safety purposes.

More generally, many public events and locations open to the public face similar or related challenges and do not have sufficient budgets or funds to effectively minimize the associated and ever changing risks faced. Increasing safety may ultimately result in safer activities and facilities, while at the same time reducing the enjoyment or nature of the activity.

Accordingly, other and more covert screening systems and methods have been developed. One known approach includes an ultra-wideband (UWB) screening system that employs several radar transceivers arranged in a planar array to transmit UWB pulse signals. UWB pulses are transmitted and the simultaneous reflections are received and combined to construct an image of the subject. Due to image reconstruction requirements and other functions of the system, such systems may be computationally intensive, and obtaining sufficient imaging data may include: several transceivers obtain sufficient resolution to properly detect and identify threats.

Another known method may include identifying an object by the resonant frequency of the object in a UWB system. In a given angular orientation, an object such as a weapon may emit a unique signature (signature) and/or an increase in amplitude at its resonant frequency, which is then identified as the frequency sweeps to detect a particular resonant frequency in the UWB system. However, the resonant frequency of an object may be highly dependent on its angular orientation relative to the UWB transceiver, and a given object may be "calibrated" to identify its resonant frequency-not only in terms of its angular orientation, but also in a wider orientation within the 3-dimensional space. Each weapon may then be associated with a table or mathematical structure that relates the resonant frequency to the object orientation. While such systems may be suitable for individual weapons or firearms, it may be necessary to develop or calibrate separate tables and mathematical constructs for each of a number of individual weapon types and models, which may be burdensome and impractical. In addition, the system may not be calibrated for a particular weapon and therefore may not be able to detect or identify.

Yet another known system includes an ultra-wideband (UWB) array having a transmitter that transmits electromagnetic waves as UWB pulses to a region of interest (ROI) and having a receiver that receives reflected electromagnetic waves from an object in the ROI and generates object data, and a pattern recognition device having a processor configured to provide operations. The processor is configured to provide instructions that obtain scan data from reflected electromagnetic waves from the ROI until an event is triggered, when the event is triggered, the processor accesses a heuristic function created from calibration data previously obtained using the ROI with an object of interest (OOI) present and the OOI absent and using the UWB array, analyzes the scan data with the heuristic function to determine whether an OOI pattern is identified within the scan data, and generates an alert if an OOI pattern is identified.

However, these known UWB-based systems may rely on a high signal-to-noise ratio (SNR) for normal operation, however in some systems the SNR may be low due to its nature. Various factors may also result in a low SNR. For example, in an RF enclosure housing transmit and/or receive antennas, energy transmitted from the side and back lobes of the transmitter (e.g., not in the intended direction) can result in unacceptable noise levels. One example is in patch antennas, which are directional in that most of the transmitted energy is transmitted as a main lobe from the front of the antenna. However, the emitted radiation may include a back lobe that is emitted in a direction opposite the main lobe, or side lobes that may be emitted in random directions that are offset from the main lobe or the back lobe. An object placed in the RF enclosure or the RF enclosure itself may cause unwanted off-directional radiation to be reflected back to the antenna, which may appear as noise in the antenna, thus resulting in a reduced SNR. Not only can the reduced SNR reduce the effectiveness of the UWB system, it can actually compromise the ability of the UWB system to correctly identify weapons and other objects.

Accordingly, there is a need for an improved system architecture in UWB-based systems for weapons and object detection.

Brief Description of Drawings

FIG. 1 illustrates exemplary steps for predicting the presence of an object of interest (OOI);

FIG. 2 illustrates an exemplary system of the present disclosure;

FIG. 3A illustrates a basic hardware configuration of the exemplary system of FIG. 2, in which no object of interest (OOI) is present;

FIG. 3B illustrates the basic hardware configuration of FIG. 3A, in which an OOI is present;

FIG. 4 illustrates the steps followed for object of interest (OOI) pattern recognition;

FIG. 5 illustrates an exemplary system and configuration that would benefit from the disclosed subject matter;

FIG. 6 illustrates exemplary attenuation data for various materials that may form a barrier;

FIG. 7 shows a housing that houses or encloses an array of UWB transmitters;

FIG. 8 is a graphical illustration of a main lobe, a back lobe and side lobes of an ultra-wideband (UWB) transmitter;

FIG. 9 is a graphical illustration of waves incident on a Radiation Absorbing Material (RAM) and their reflection and transmission characteristics;

FIG. 10 is a schematic view of a first radiation absorber and a second absorber laterally offset from each other;

FIG. 11 is a schematic view of the emitter as viewed from its back;

12A and 12B illustrate exemplary paths of transmitted and reflected emissions through an absorber material and corresponding locations of a ground plane;

FIG. 13 shows a portion of a housing and having an array of UWB transmitters located therein;

FIG. 14 shows a UWB transmitter array with a first wing with transmitter elements and two absorbers and a second wing with receiver elements and two absorbers;

FIG. 15 shows the complete housing as a first part and as a second part; and

fig. 16 shows the complete housing in assembled form.

Detailed Description

A system includes an ultra-wideband (UWB) array having a transmitter that transmits electromagnetic waves as UWB pulses to a region of interest (ROI) and having a receiver that receives reflected electromagnetic waves from an object in the ROI and generates object data, and a pattern recognition device having a processor configured to provide operations. The processor is configured to provide instructions that: obtaining scan data from reflected electromagnetic waves from the ROI until an event is triggered, accessing heuristics created from calibration data previously obtained using the ROI with an object of interest (OOI) present and an OOI absent when the event is triggered, analyzing the scan data with the heuristics using a pattern recognition function derived from the calibration data to determine whether an object of interest (OOI) pattern is recognized within the scan data, and generating an alert if the OOI pattern is recognized.

An exemplary ultra-wideband (UWB) system includes a housing and an ultra-wideband (UWB) transmitter array within the housing having a transmitter component that transmits electromagnetic waves toward a region of interest (ROI), the UWB array having a receiver component that receives reflected electromagnetic waves from an object in the ROI and generates object data. The system also includes a radar-absorbing material positioned to receive electromagnetic waves emitted from the transmitter component that are not directed toward the ROI, and a pattern recognition device having a processor configured to process the electromagnetic waves reflected from the ROI and determine whether an object of interest (OOI) pattern is identified within the object data.

Fig. 1 illustrates exemplary steps for deploying a UWB system and predicting the presence of an object of interest (OOI) pattern. The method or process 100 includes defining a region of interest (ROI) at step 102. At step 104, an ultra-wideband (UWB) system is deployed or otherwise arranged to screen the ROI. The ROI may include a walkway or channel through which the individual passes, or any area in which the individual may gather. At step 106, a pattern recognition calibration or "prediction function" is generated using the pre-processed data from the UWB system, which is fed to the pattern recognition device. The system is based on a Convolutional Neural Network (CNN) architecture. The pattern recognition system includes a calibration step that includes determining a "prediction function" created in a "learning environment," which in one example may include a region of interest (ROI) in which the disclosed system is deployed.

After deployment of the UWB system at step 104, a prediction function is generated at step 106 to calibrate the system for operation. That is, in the learning environment, UWB systems are taught a known "ground truth" data pattern consistent with two main conditions:

1) an individual having a weapon Or Object of Interest (OOI);

2) the individual does not carry a weapon or (OOI).

The "ground truth" data patterns are obtained later for use in detecting the presence of known objects or OOIs. For example, in the example above, the "ground truth" calibration data pattern was obtained in two cases: one is the presence of OOI on the individual, and the second is the presence of the individual but not the presence of OOI. The OOI may be a weapon or pistol, but is not limited to such a device, but may include any substance capable of being identified with a unique identifier that may be held on an individual. Thus, OOIs may include contraband (such as wine bottles for carrying wine), rifles, or any equipment that may be considered dangerous or illegal at a particular location. For both cases, the UWB scan data is obtained by projecting electromagnetic waves from the UWB to the ROI, and reflections from objects within the ROI are collected as data and analyzed to generate "ground truth" data patterns. In one example, the calibration pattern is obtained on a test stand and no one is present. Additionally, it is contemplated that when screening individuals against a calibration background, the environment in which the calibration occurs or the ROI itself may change. When in use and screening occurs, the ROI may change due to movement of items within the ROI, such as movement of background items (such as trash cans) or one or more other items forming a background signature.

The resulting "training set" of calibration data thus includes two primary data sets obtained during the calibration step, one data set (in this example) including weapon or pattern OOI data, and the second data set being devoid of weapon or pattern OOI data. Both data sets are labeled or otherwise identified as "ground truth" data sets that operate through training or calibration heuristics based on the CNN architecture. The heuristic is a multi-layer heuristic that performs a convolution process on a data set to ultimately produce a "prediction function.

Once the "prediction function" is set and calibration data is determined for a given environment deployed, screening in the actual environment begins. At step 108, ROI scan data is obtained in the ROI, and at step 110, an event trigger occurs when the individual passes through the ROI. That is, when scan data is obtained and pre-processed, if no event is triggered (i.e., a change in data mode) at step 112, control returns to step 108 and scan data for the ROI is obtained. An event is triggered when the acquired scan results in a change in pattern recognition that exceeds a certain threshold. In other words, in one example, in addition to noise and other background events, an event is not triggered until a change in pattern recognition meets a threshold above background.

When an event is triggered (such as an individual passing through the ROI, step 114), then at step 116 the scanned and pre-processed data is fed to the pattern recognition system and the scan data is compared to the calibration data, and at step 118 if the appropriate threshold 120 relative to the calibration data is not met, the OOI pattern is not recognized and control returns to step 108. Thus, step 116 includes at least accessing heuristics created from calibration data when an event is triggered, and analyzing scan data using a pattern recognition function derived from calibration data at the ROI that was previously obtained using the ROI and using the UWB array, and using the UWB array. That is, when an event is triggered, a prediction scheme created from calibration data previously obtained using the ROI and using the UWB array is invoked, and the scan data is compared to the calibration data using a pattern recognition function derived from the calibration data.

However, if the threshold 122 for determining the OOI mode in the scan data is met, an OOI may be present and an alert is sent at step 124. Typically, further intervention occurs to confirm whether the OOI pattern is indeed a true OOI, or whether a "false positive" has occurred. The alarm may include any number of mechanisms, such as a silent alarm, a signal sent to a monitoring device, or a loud alarm to alert others who may be present nearby.

In one example, the average of the individual interval predictions may be evaluated against established thresholds to make a final prediction. As will be discussed further, the disclosed UWB system may include a single array of UWB transmitters and receivers, or a plurality of UWB transmitters and receivers. In an exemplary environment including multiple arrays, predictions may also be made of the weapon or OOI location of an individual.

Further, although the disclosed system includes an OOI as a weapon or contraband, it is contemplated that any pattern recognizable using scan data may be employed. For example, the disclosed system and "predictor function" step 106 may be used by training to include facial recognition or other patterns that may be input into a pattern recognition system. Moreover, the OOI patterns that are subsequently recognized as weapons or handguns are not limited to the particular items used to obtain the "training set". Thus, a training set may be obtained using a pistol (such as a revolver), but subsequent use identifies other types of pistols, such as semi-automatic pistols, which are identified using UWB data calibrated for e.g. a pistol.

Fig. 2 illustrates an exemplary system 200 for operating one or more radar transceiver arrays, for example. Each radar transceiver array operates independently of the other arrays and can therefore operate in an asynchronous manner. That is, each radar transceiver array may operate independently and in an independent arrangement to detect OOI patterns (i.e., for weapons such as handguns), and no information from another radar transceiver array is included or required to detect or identify OOI patterns, and no additional information from other imaging systems such as image-based systems is required. Also, while multiple radar transceiver arrays may be employed, additional radar transceiver arrays may be beneficial to provide additional or redundant coverage of a region of interest (or ROI), or to extend coverage in the ROI, but a single radar transceiver array is sufficient for OOI mode detection or identification.

The system 200 may thus take many different forms and include multiple and/or alternative hardware components and facilities. Although an exemplary system 200 is shown in fig. 2, the exemplary components shown in fig. 2 are not intended to be limiting, may be optional, and are not necessary for any other component or portion of the system 200. Indeed, additional or alternative components and/or implementations may be used.

System 200 may include or be configured for use by a user 201, such as a screening or security personnel. The system 200 may include one or more of the devices 202a, 202b and/or the server 205, which may include a processor 206 with a pattern recognition device, memory 208, a program 210, a transceiver 212, and a user interface 214. The system 200 may include a hub or network 220, a database 222, and a connection 224. The device may include any or all of a device 202a (e.g., a desktop, laptop, or tablet computer) and a device 202b (e.g., a mobile or cellular telephone). The processor 206 may comprise a hardware processor that executes a program 210 to provide any or all of the operations described herein (e.g., by the devices 202a, 202b, the server 205, the database 222, or any combination thereof), and these operations are stored as instructions on the memory 208 (e.g., of the devices 202a, 202b, the server 205, or any combination thereof). The processor 206 in the server 205 includes a pattern recognition heuristic that can learn from the data, and can enhance its learning by heuristics or other "rules of thumb" that are presented or recognized based on its learning capabilities, and can write its own heuristics or prediction functions. Additionally, the systems and identified OOI patterns disclosed herein may not be limited to physical OOIs, such as weapons or contraband. OOI and OOI patterns may include not only weapons and contraband, but also facial recognition based on data that may be obtained during a "training period" or calibration period when a prediction function such as in step 106 above is performed. In fact, OOI and OOI modes may include any item or items that contain a recognizable mode, ammunition such as a cell phone, whiskey bottle, pistol, or rifle, or other items that may be prohibited for a particular location.

The exemplary system 200 may include a user interface 214, a processor 206, and a memory 208, the memory 208 having a program 210 communicatively connected to the processor 206. The system 200 may also include a transceiver 212, and the transceiver 212 may be communicatively coupled to an ultra-wideband (UWB) transmitter array 226, or to one or more UWB transmitter arrays 228. The system 200 may be configured to direct one or more UWB transmitter arrays 228 toward the ROI230 or even define the ROI 230. The UWB transmitter array 226 or a plurality of UWB transmitter arrays 228 each include a respective DC power supply 232. More specifically, only one UWB transmitter array 226 is sufficient to provide scanning. Additional or redundant UWB transmitter arrays 228 may provide additional and beneficial scanning information to provide additional coverage, or completely different ROIs. However, no additional interaction between the UWB arrays is required. This distinction is in contrast to some known systems that use multiple arrays to generate an image. The disclosed system may operate in a standalone and single UWB array.

For example, system 200 using processor 206 may provide operations that include displaying, via user interface 214, operational commands, parameters for a given or particular setting, or results of a screening process when an OOI mode is detected.

System 200 may include the entire network infrastructure through which any of devices 202a, 202b, server 205, and database 222 may communicate, for example, using connection 224 to transfer information between any portion of system 200. In general, a network (e.g., system 200) may be a collection of computing devices and other hardware to provide connectivity and carry communications. Devices 202a and 202b may comprise any computing device, such as including a mobile device, a cellular phone, a smartphone, a smartwatch, an activity tracker, a tablet computer, a next generation portable device, a handheld computer, a notebook computer, a laptop computer, a projector device (e.g., a three-dimensional holographic or holographic projector), or a virtual reality or augmented reality device. The devices 202a, 202b may include a processor 206 that executes a program 210. The devices 202a, 202b may include a memory 208 that stores system operating information and programs 210. The devices 202a, 202b may include a transceiver 212, the transceiver 212 communicating system operation information between any of the devices 202a, 202b, the server 205, and the database 222. By way of example, system operational information may include, but is not limited to, hardware setting parameters, calibration information, deep learning heuristics, and cumulative data of screening events for which system 200 is deployed for security or other screening purposes.

The server 205 may comprise any computing system. The server 205 may be generated by the processor 206 executing the program 210 and stored by the memory 206, such as system operating information. The server 205 may also generate and store a user profile for the user 201 or other information, such as the annotation and conditions of the screening event indicated by the user 201. The server 205 may be communicatively connected with the devices 202a, 202b and the database 222 and transmit information about the devices 202a, 202b and the database 222. The server 205 may be in continuous or periodic communication with the devices 202a, 202b and the database 222. The server 205 may comprise a local, remote, or cloud-based server, or a combination thereof, and may communicate with and provide system operating information to any one or combination of the devices 202a, 202b (e.g., as part of the memory 208 or database 222). The server 205 may also provide a web-based user interface (e.g., an internet portal) to be displayed by the user interface 214. The server 205 may communicate system operation information with the devices 202a, 202b using notifications including, for example, automatic telephone calls, Short Message Service (SMS) or text messages, emails, http links, web-based portals, or any other type of electronic communication. Additionally, the server 205 may be configured to store system operating information as part of the memory 208 or database 222. The server 205 may include a single or multiple centralized or geographically distributed servers. The server 205 may be configured to store and coordinate system operation information with and between any of the devices 202a, 202b, the network 220, and the database 222.

The user interface 214 of the devices 202a, 202b may include any user interface device, display device, or other hardware mechanism connected to a display or supporting a user interface to communicate and present system operating information throughout the system 200. Any inputs and outputs of the user interface 214 may be included as system operating information. The user interface 214 may include any input or output device to facilitate receiving or presenting information in audio, visual, or tactile form, or combinations thereof. Examples of displays may include, but are not limited to, touch screens, cathode ray tube displays, light emitting diode displays, electroluminescent displays, electronic paper, plasma display panels, liquid crystal displays, high performance addressed displays, thin film transistor displays, organic light emitting diode displays, surface conduction electron emitter displays, laser TV, carbon nanotubes, quantum dot displays, interferometric modulator displays, projector devices, and the like. The user interface 214 may present instructional information to any user of the devices 202a and 202 b.

Connection 224 may be any wired or wireless connection between two or more endpoints (e.g., devices or systems), for example, to facilitate the transfer of information. The connection 224 may comprise, for example, a local area network to communicatively connect the devices 202a, 202b with the network 220. Connection 224 may include, for example, a wide area network connection to communicatively connect server 205 with network 220. The connection 224 may include a wireless connection, such as Radio Frequency (RF), Near Field Communication (NFC), bluetooth communication, Wi-Fi, or a wired connection, for example to communicatively connect the devices 202a, 202b and other components of the system 200.

Any portion of the system 200 (e.g., the devices 202a, 202b and the server 205) may include a computing system and/or a device that includes a processor 206 and a memory 208. Computing systems and/or devices typically include computer-executable instructions, where the instructions may define operations and may be executed by one or more devices such as those listed herein. The computer-executable instructions may be compiled or interpreted from a computer program created using a variety of programming languages and/or techniques, including, but not limited to, the Java language, C, C + +, Visual Basic, Java Script, Perl, SQL, PL/SQL, Shell Scripts, Unity language, etc., alone or in combination. The system 200 (e.g., the devices 202a, 202b and the server 205) may take many different forms and include multiple and/or alternative components and facilities, as shown. Although the exemplary systems, devices, modules, and sub-modules are illustrated in the figures, the exemplary components illustrated in the figures are not intended to be limiting. Indeed, additional or alternative components and/or implementations may be used, and thus the above communication operation examples should not be construed as limiting.

In general, the computing system and/or devices (e.g., devices 202a, 202b and server 205) may employ any of a variety of computer operating systems, including but not limited to Microsoft WindowsVersions and/or variations of an operating system, Unix operating system (e.g., distributed by Oracle corporation of Redwood Shores, Calif.)Operating system), the AIX UNIX operating system, the Linux operating system, the Mac OS X and the iOS operating systems, the apple Inc. of Cupertino, Calif., the Research In Motion, Waterloo, Canada, issued by International Business Machines, N.Y.OS and android operating systems developed by the open cell phone alliance. Examples of computing systems and/or devices such as devices 202a, 202b and server 205 may include, but are not limited to, mobile devices, cellular phones, smart phones, super phones, next generation portable devices, mobile printers, handheld or desktop metersA computer, notebook, laptop, tablet, wearable device, virtual or augmented reality device, secure voice communication device, networking hardware, computer workstation, or any other computing system and/or device.

Further, a processor, such as processor 206, receives instructions from a memory, such as memory 208 or database 222, and executes the instructions to provide the operations herein to perform one or more processes, including one or more processes described herein. Such instructions and other instructional information may be stored and transmitted using a variety of computer-readable media, such as the memory 208 or the database 222. A processor, such as processor 206, may include any computer hardware or combination of computer hardware configured to carry out the purposes of the devices, systems, operations, and processes described herein. For example, the processor 206 may be any one of a single-core, dual-core, three-core, or four-core processor (on a single chip), a graphics processing unit, and visual processing hardware, but is not limited thereto.

Memory or database 222, such as memory 208, may generally include any computer-readable medium (also referred to as a processor-readable medium), which may include any non-transitory (e.g., tangible) medium that participates in providing instructional information or instructions that may be read by a computer (e.g., by devices 202a, 202b and processor 206 of server 205). Such a medium may take many forms, including but not limited to, non-volatile media and volatile media. For example, non-volatile media may include optical or magnetic disks and other persistent memory. Volatile media may include, for example, Dynamic Random Access Memory (DRAM), which typically constitutes a main memory. Such instructions may be transmitted by one or more transmission media, including radio waves, metal wires, optical fibers, etc., including lines that comprise a system bus coupled to a computer processor. Common forms of computer-readable media include, for example, a floppy disk, a flexible disk, hard disk, magnetic tape, any other magnetic medium, a CD-ROM, DVD, any other optical medium, punch cards, paper tape, any other physical medium with patterns of holes, a RAM, a PROM, an EPROM, a FLASH-EPROM, any other memory chip or cartridge, or any other medium from which a computer can read.

Further, the databases, data repositories, or other guidance information stores described herein (e.g., memory 208 and database 222) may generally include various mechanisms for storing, providing, accessing, and retrieving various guidance information, including a hierarchical database, a set of files in a file system, a proprietary-format application database, a relational database management system (RDBMS), and the like. Each such instructional information store can generally be included within (e.g., memory 208) or external (e.g., database 222) to a computing system and/or device (e.g., devices 202a, 202b and server 205) employing a computer operating system such as one of the above and/or accessed via a network (e.g., system 200) or connection in any one or more of a variety of ways. The file system may be accessed from a computer operating system, and may include files stored in various formats. In addition to the languages used to create, store, edit, and execute stored procedures, RDBMS typically employ Structured Query Languages (SQL), such as the PL/SQL language mentioned above. The memory 208 and database 222 may be coupled to or part of any portion of the system 200.

Fig. 3A and 3B illustrate a basic hardware layout or configuration 300 of the exemplary system of fig. 2 with corresponding elements. Fig. 3A and 3B illustrate the use of the construct 300, where fig. 3A illustrates the presence of individuals without an OOI, and fig. 3B illustrates individuals with an OOI. Fig. 3A and 3B correspond to the use of ROI230 for a training session or calibration of system 200 and its pattern recognition data and as described above at step 106, and for obtaining scan data (step 108 above) for identifying the presence of defined OOI pattern data after comparing the scan data to the calibration data, such as in step 118.

Configuration 300 includes UWB transmitter array 226 connected to network 220 via connection 224 as described above, and UWB transmitter array 226 includes DC power supply 232 (shown in fig. 2). As indicated, the configuration 300 includes one UWB transmitter array 226, but it is contemplated that a plurality of one or more UWB transmitter arrays 228 may be included, and certain additional advantages may be obtained from a system having more than one UWB transmitter array 226.

The UWB transmitter array 226 includes a transmitter 302 "TX" device (or antenna), a receiver 304 "RX" device (or antenna), and a pre-processor 306. The construct 300 includes an ROI230, for example, the ROI230 may be a hallway, a room in a building with walls, an open or semi-enclosed area, or a defined walkway for controlling the movement of a person for scanning purposes. One or more individuals 308 present within the ROI230 may be publicly scanned such that the UWB transmitter array 226 is visibly present at and near the ROI 230. Alternatively, the person 308 may be covertly scanned by placing a physical barrier 310 or other item between the ROI230 and the UWB transmitter array 226. The physical barrier 310 may be any opaque material, such as a drywall or wood wall, or a concrete or brick barrier. The physical barrier 310 may also be a transparent or reflective window or other material. In any case, the physical barrier 310 may be presented to obscure the presence of the UWB transmitter array 226, or the physical barrier 310 may simply be a separate barrier that enables the person 308 to visually see the UWB transmitter array 226. The physical barrier 310, if present, is a material that is translucent to transmission into and out of the UWB transmitter array 226. In one example, the ROI includes a walkway defined to prevent the human individual from avoiding the ROI.

The wideband and raw data streams are transmitted into and out of the UWB transmitter array 226. In operation, a subject or one or more individuals 308 to be screened passes near the UWB transmitter array 226 and when within the ROI230, triggers an event. The UWB transmitter 302 transmits short duration low energy (less than 200 microwatts) pulses over a large bandwidth and the receiver 304 captures wideband and RF data at a rate of 40 frames per second. The event data is pre-processed in a custom pipeline and the extraneous signals are removed via pre-processor 306 using one or more filters (e.g., band pass filters), background subtraction, and other methods. The processed event data may be data of person 308 potentially carrying weapon 312 or OOI, or may be a multi-path signal (i.e., instead of a direct reflection of a target, may be an additional object 314 in a reflected path from weapon 312 or person 308). In one example, the ROI includes a walkway defined with the object 314 to prevent the human individual from avoiding the ROI. Also, object 314 represents any object that may form part of the ROI and, when calibration of the ROI occurs, forms an identification of the item or items. As indicated, when screening individuals against a calibration background, the environment in which the calibration occurs or the ROI itself may change. When in use and screening occurs, the ROI may change due to movement of items within the ROI, such as movement of background items (such as trash cans) or one or more other items forming a background signature. Thus, unlike typical scanners that scan individuals against a known background, such as in walk-through scanners for metal or x-ray detection, the system allows for dynamic and changing environments that may change over time. When an object (such as object 314) changes within the ROI, the scan may be temporarily stopped so that the ROI may be recalibrated to account for different background or ROI information.

The event data is passed to the network 220 and the processor 206 with the pattern recognition device via connection 224. The analysis hardware may be a locally present computer or server (such as server 205 of fig. 2), and/or the data may be further transmitted to one or more devices, which may or may not be local to construct 300. In one example, there may be a local computer, such as server 205, to perform more computationally intensive work, accessing database 222, which may be located locally or remotely. The results of the analysis may be transmitted to the devices 202a, 202b via connection 224 for monitoring the ongoing screening process.

In one example, the UWB transmitter array 226 may operate up to 10 meters into the ROI 230. However, it is contemplated that any range may be employed such that ROIs may be established through which individuals pass and OOIs distinguishable from individual mode data. The disclosed configuration 300 provides the ability to detect objects, such as weapons 312 on person 308, through walls, clothing, bags, luggage, etc., with very low signal loss through common materials, such as drywall, glass, etc. In one example, the system provides a resolution of 1mm or less in object recognition. Further, it is contemplated that an individual carrying a concealed weapon may have a unique and identifiable gait when passing through the ROI230, which itself may be identified and identified from patterns identified in the scan data for identifying the possible presence of a weapon. Additionally, although item 312 is described as a weapon that may be concealed, any item or OOI pattern may be identified. For example, contraband (such as illegal drug gear) or other items (such as weapons and ammunition) may be identified as well, or voice or facial recognition may be identified.

In one example, the UWB transmitter array 226 uses a 7.3GHz center frequency and a 1.5GHz bandwidth. The differential RF terminals are used for low noise and low distortion, resulting in high sensitivity in both static and dynamic applications. Generally, the disclosed devices use very low power levels, well below the class B limits of Federal Communications Commission (FCC) specified electronic devices for residential space, enabling their use in most markets around the world. In one example, bi-phase or binary phase encoding is used to transmit pulses for spectral spreading. Further, a master/slave Serial Peripheral Interface (SPI) is employed, wherein the synchronous serial communication interface is used for short-range communication, wherein a four-channel SPI mode is employed for higher data rates. Digital down-conversion converts the digitized band-limited signal to a lower frequency signal at a lower sampling rate, and further filtering may be applied.

Small-sized chip scale packages are used for high-density integration. In one example, a 3 inch by 1.5 inch by 0.375 inch board with low power requirements is used to facilitate battery operation of the UWB transmitter array 226. A pulse radar transceiver system on chip (SoC) is used with commercially available UWB chips. The radar chip is mounted on a development board 316 together with a preprocessor 306 and the transmitting and receiving devices 302 and 304.

Fig. 4 illustrates steps 400 for OOI mode prediction used by the system 200 and communicated via connection 224. In general, data analysis using pattern recognition may be performed on a local server (such as server 205) and using database 222. Data reporting outputs including statistics, system performance, positive hits, etc. may be reported to the user 201 and to the devices 202a and 202 b. Thus, user 201 may be security screened, in one example, user 201 may be removed from ROI230, system 200 operates in a standalone manner, and without direct monitoring by a person. However, it is also contemplated that the disclosed system may also be used in conjunction with other known screening systems, such as metal detectors or other screening devices.

At step 402, data enters and exits the UWB array 226. At step 404, a first-in-first-out (FIFO) buffer is employed to collect and monitor data until an event trigger occurs at 406. An event trigger occurs when, for example, a learning environment defined in ROI230 is corrupted by the passage of a person or individual, such as one of humans 308. RF and wideband data is captured at step 408 and the data is filtered using band pass filters and other known filters to remove background and the like at step 410. Motion compensation is applied at step 412 and factors are determined or calculated and applied to account for gait and stride artifacts. The processed data is then fed to a pattern recognition heuristic at step 414 and the data is compared to previously obtained "ground truth" data patterns and an object of interest prediction is made at step 416. That is, based on learning performed as discussed in method 100 above, previously obtained "prediction functions" are used to identify possible OOIs via their OOI patterns. The process ends and control continues back to the beginning at step 106 and continues to monitor until another event trigger occurs at step 406.

For example, individual screening may be performed using a designated walkway. Referring to fig. 5, system 200 may be deployed in a configuration 500 as shown. The configuration 500 includes a first radar array 502, which corresponds to the UWB transmitter array 226 described above. The configuration 500 may also include a second UWB transmitter array or additional array 504, which may correspond to the UWB transmitter array 228. The arrays 502, 504 may be positioned around a walkway 506 and mounted on supports or posts 508. The radar arrays 502, 504 are positioned to emit UWB pulses to a region of interest (ROI) 507. In one example, the UWB transmitter array 504 may be positioned and hidden by a barrier (such as the barrier 310 described above and shown in fig. 5).

Once deployed, the system 200 participates in a training process so that the disclosed system can correctly predict the presence of OOI patterns or objects of interest. More specifically, because the system 200 is to be built in any environment, it may be in an environment that has not previously been used for scanning purposes. Thus, as discussed with reference to FIG. 1, a prediction function or calibration step is performed, as discussed above at step 104. The training process includes activation of the system and data acquisition that trains the system 200 to identify individuals with and individuals without an OOI pattern. Once established, the system 200 may be trained with a particular construct 500 to recognize OOI patterns by using the walkways 506 and the construct 500 as a learning environment. For example, if it is set up to perform a possible handgun screening of a person, the "ground truth" is determined by taking the two steps at step 106 above. That is, a "ground truth" can be established for two main conditions:

1) the presence of a weapon Or Object of Interest (OOI) on an individual;

2) the individual does not carry a weapon or object of interest.

Thus, a resulting "training set" of data is established that includes two primary sets of data, one including a first set of OOI data that may include weapons, and a second set that does not include OOI data.

Once trained, and as also described with respect to fig. 3A and 3B, the system 200 using the construct 500 is ready to "initiate" screening of an individual for OOIs via the obtained OOI pattern in accordance with the criteria established in step 104 above. Input data is then obtained by scanning using the first radar array 502 (and the second or additional radar arrays 504, if present). As the individual passes along the walkway 506, based on the training set and activation of the computing system, the individual is detected and identified as an individual that does not satisfy the pattern identified as OOI. The scanning continues until an individual, such as individual 510, having a pattern reflecting a weapon or pistol 512 is identified as an OOI pattern in step 118. Also, as indicated, the OOI pattern identified as item 512 is not limited to any particular model or type of pistol, but rather due to previously performed pattern recognition capabilities and calibrations, in examples where the OOI pattern is used as a pistol to perform step 104, the OOI and their patterns may then be detected as any type of pistol.

Thus, data is obtained and preprocessed using, for example, the preprocessor 306 and as at step 106. The obtained and pre-processed data is mapped to the obtained model, and pattern recognition thereby identifies patterns corresponding to OOI patterns after post-processing of any data. Suitably, any pattern that indicates the presence of an OOI pattern is predicted. The resulting data and statistical data may be monitored and reported. For example, while heavy processing and implementation may be performed on server 105, monitoring results, statistics, etc. may be reported to other users or monitors, such as devices 202a and/or 202 b.

Referring to fig. 6, exemplary normalized attenuation data for various materials that may form a barrier (such as barrier 310) is shown. Barrier materials may be used to form a physical barrier to prevent accidental or intentional abuse of components of system 200, or to disguise or mask the presence of system components (such as UWB transmitter array 226) in concealed screening arrangements. It can be seen that a nominal thickness may be used for the barrier 310, such as drywall, wood, and glass. As can be expected, bricks and concrete exhibit increased attenuation characteristics, and therefore must be considered when establishing the configuration of the system 200.

Referring to fig. 7, there is shown a housing 700 (a portion of which is shown) that houses or encloses a UWB transmitter or transmitter array 702, which generally corresponds to the UWB transmitter array 226 as previously discussed. The UWB transmitter array 702 includes a transmitter 704 "TX" device (or antenna), a receiver 706 "RX" (or antenna), both of which are coupled to a base support 708 (i.e., the development board 316 as previously described, which may include a pre-processor (not shown in fig. 7), such as the pre-processor 306) in this example. Each of the transmitter 704 and receiver 706 is shown with two corresponding elements, but each is referred to in the singular for purposes of disclosure and discussion herein. For example, transmitter 704 includes elements 704a and 704b, which generally correspond to transmitter 704. Likewise, receiver 706 includes elements 706a and 706b, which generally correspond to receiver 706. Base support 708 is located within housing 700 and provides structural support for transmitter 704 and receiver 706, while also providing attachment to housing 700 to secure base support 708.

In operation and as discussed above, wideband and raw data streams are transmitted into and out of the UWB transmitter array 226. The transmitter 704 transmits pulses and the wideband and RF signals are captured by the receiver 706. As shown in fig. 3A and 3B, the transmitter 704 is typically a directional antenna that directs its transmissions toward the intended target.

Referring to fig. 8, a 360 ° two-dimensional (2D) plot 800 includes a main lobe 802 emitted from an emitter 704 and corresponds to 0 ° in the 2D plot 800, and is directed 804 at an intended target. The back lobe 806 is generally emitted 180 ° opposite the main lobe 802, and the back lobe 806 generally has a lower intensity or amplitude than the main lobe 802. Side lobes 808 are also emitted from the emitter 704 and are at an angle of departure between the main lobe 802 and the back lobe 806. Also, although represented as 2D transmissions, it is contemplated that the transmissions may be in other "off-plane" directions, and are generally not limited to 2D only.

Thus, during operation of the transmitter 704, the main lobe 802 provides the main emission to the ROI, and reflected energy from objects in the ROI returns to the receiver 706 and is processed. Thus, in general, the transmission from main lobe 802 impinges on a target, and the reflection from the target is received at receiver 706 as the desired signal. The desired signal is processed in accordance with the above discussion to detect OOIs.

However, in general, the desired signal for detecting OOI is overwhelmed by extraneous electrical noise and requires some threshold in signal-to-noise ratio (SNR) to properly operate the UWB system. This noise may come from sources outside of the UWB system and may make OOI identification difficult.

Other sources of electrical noise may also be present. For example, if an object is in the direction of the back lobe 806 or side lobe 808, a portion of the energy from these lobes 806, 808 may be reflected back to the antenna, such as the receiver 706. That is, in application, if an object is inside of either lobe 806, 808, a portion of the energy is reflected back to the antenna, or in this example, back to the illustrated receiver elements 706a, 706 b. This reflected energy appears as noise and therefore reduces the signal-to-noise ratio (SNR) because the SNR can be reduced. Mitigating the reduction in SNR is an object of the present disclosure. In one example and as will be discussed further, the radar absorbing material may be positioned to absorb at least a portion of the energy emitted by the back and side lobes. In another example, the walls of the housing or enclosure 700 may also cause direct reflection from the walls of the enclosure back to the UWB transmitter array, and in particular back to the receiver 706. In accordance with the present disclosure, the absorbing material is a fill material that absorbs electromagnetic energy, which converts the electromagnetic energy to very low levels of heat. The incorporation of fillers into the adhesive material (which is typically an elastomer or foam-based product) aids in the production of the absorbent into sheets and other shaped products. Accordingly, the disclosed system further includes a radar-absorbing material positioned to receive electromagnetic waves emitted from the transmitter component that are not directed at the ROI and waves that are not incident on the receive antenna from the direction of the ROI, and a pattern recognition device having a processor configured to process the electromagnetic waves reflected from the ROI and determine whether an object of interest (OOI) pattern is identified within the object data.

In accordance with the present disclosure, radar absorbing material may be used to absorb at least a portion of the back and side lobe energy corresponding to back lobe 806 and side lobe 808. Thus, electrical noise generated by the housing 700 is mitigated. In general, referring to diagram 900 in fig. 9, an incident wave 902 falls on a Radiation Absorbing Material (RAM) 904. The incident wave 902 passes as a transmitted wave 906 and is absorbed to some extent when passing through the RAM904, resulting in a transmitted wave 908 having a significantly lower intensity than the incident wave 902. A portion of the incident wave 902 is reflected at the first surface 910 as a reflected wave 912. Also, a portion of the transmitted wave 906 is reflected at the second surface 914 and the absorbed wave 916 returns through the RAM904 where it passes again as a re-reflected wave 918 or a second reflected wave 920. Re-reflection, absorption and internal re-reflection will occur until the wave finally disappears.

Thus, FIG. 9 depicts RAM904, and in one example RAM904 is an electro-magnetic absorption material having a thickness of 0.89mm (0.035 inches). The thickness is determined by the frequency of interest, which in this example is in the range of 5-9GHz, corresponding to the selected thickness. In this application, an elastic adhesive is used that has a ground plane bonded to the base absorbent material.

For example, referring to fig. 10, a diagram 1000 shows a first absorber 1002 and a second absorber 1004 laterally offset from one another. Each of the first absorber 1002 and the second absorber 1004 includes a central or core absorbing material 1006, 1008, respectively, and each includes a ground plane 1010, 1012, respectively, attached thereto. That is, the first absorber 1002 comprises an absorbing material 1006 and has a first ground plane 1010 attached thereto on one side of the first absorber 1002 (on the front side as shown). The second absorber 1004 comprises an absorbing material 1008 and has a second ground plane 1012 attached thereto (on the back side as shown). Thus, according to the present disclosure, the first absorber 1002 and the second absorber 1004 are positioned to have opposite orientations to each other, as it is desirable that the first ground plane 1010 and the second ground plane 1012 be properly positioned with respect to any incident waves, as will be further explained.

Referring back to fig. 7, the transmitter 704 and receiver 706 are shown on the front side 710 of the transmitter array 702. The transmitter 704 is located on a first wing 712 and on the front side 710 of the transmitter array 702, and the receiver 706 is located on a second wing 714 of the transmitter array 702 and also on the front side 710. The emitter array 702 includes a back side 716.

Fig. 11 shows the emitter array 702 of fig. 7 from the back side (and additional structural elements are not shown for illustrative purposes only). The first wing 712 includes emitters 704, with emitter elements 704a and 704b located in front of the emitter array 702 and thus not visible in FIG. 11. Likewise, second wing 714 includes receiver 706, with receiver components 706a and 706b located in front of transmitter array 702, and thus also not visible in FIG. 11. As such, a back side 716 of the emitter array 702 is visible in fig. 11. However, fig. 11 also includes a first absorber 1002 on the rear side 716 of the first wing 712 and includes a second absorber 1004 on the rear side 716 of the second wing 714.

According to the present disclosure and in one example, the ground planes of the absorbers are located on their respective absorbing materials so as to be remote from any incoming waves to be attenuated, as further illustrated in fig. 12A and 12B. Fig. 12A shows an emitter illustration 1200 with an emitter element 704a, by way of example, the emitter element 704a being located on the first wing 712. The first absorber 1002 is located on the back side 716 and the first absorber 1002 comprises a first absorbing material 1006 and a ground plane 1010 located thereon. FIG. 12B shows a receiver illustration 1202 with a receiver element 706a, by way of example, the receiver element 706a located on the second wing 714. The second absorber 1004 is located on the back side 716 and the second absorber 1004 includes a second absorbing material 1008 and a ground plane 1012 located thereon. Thus, the first and second ground planes 1010, 1012 are in opposite orientations with respect to their respective first and second wings 712, 714.

In operation and as discussed with reference to fig. 8, the transmitter 704 includes a main lobe 802, a back lobe 806, and a side lobe 808. In fig. 12, the main lobe 802 thus corresponds to transmission from transmitter element 704a in direction 1204, the back lobe 806 corresponds to direction 1206, and the side lobe 808 is transmitted in an offset direction and as shown in one exemplary direction 1208. As discussed, the back and side lobe emissions can cause undesirable noise after reflection from walls within the housing in which the emitter array 702 is located. As such, the first absorber 1002 is positioned to intercept the back lobe 806 and the side lobe 808 through the wall of the housing and attenuate the back lobe 806 and the side lobe 808. And as shown, the first ground plane 1010 is located on a surface located away from the first absorber 1002. That is, the emissions from the emitter element 704a pass first through the first absorbing material 1002 and then through the first ground plane 1010.

Also in operation and as discussed, emissions may also reflect off the walls of the enclosure. Thus, although the undesired back and side lobe emissions are attenuated, and as discussed with reference to fig. 12A, some of the emissions still pass through the surrounding housing and are reflected back. Referring to fig. 12B, the reflected wave may be reflected back directly from the walls of the enclosure, such as in direction 1210 (which may be due to back lobe emission from direction 1206) or may be off direction 1212 due to reflection from exemplary direction 1208. Likewise and as discussed, emissions in directions 1210 and 1212 are directed toward receiver element 706a by first passing through the second absorbing material 1008 of the second absorber 1004 before reaching the second ground plane.

Thus, according to the present disclosure, the absorbent material is positioned such that any unwanted emissions pass first through the absorbent material itself and then through their respective ground planes. Further, it is contemplated that the ground planes discussed herein may remain electrically floating and not electrically connected to any additional ground or bias voltage. However, it is contemplated that the ground planes may be grounded to ground, grounded to other devices, or grounded to each other. It is also contemplated that the ground plane may be electrically biased.

Furthermore, although the illustration and corresponding discussion refer to the ground plane being away from the direction of the transmission such that the transmission first passes through the absorbing material before encountering the ground plane, it is also contemplated that the opposite may be true for one or both of the respective transmit and receiver ground planes. That is, while, empirically, a greater improvement in undesirable attenuation may be observed with the disclosed arrangement (i.e., first through the absorber before encountering the ground plane), attenuation also occurs when the situation is reversed and the ground plane is encountered before reaching the absorber material.

Referring now to fig. 13, a diagram 1300 shows a portion of a housing 700 and having an array of UWB transmitters 702 located therein, which generally corresponds to fig. 7. However, also shown in fig. 13 is a first wing 712 having a transmitter 704 and a second wing 706 having a receiver 706. The illustration 1300 shows a first absorber 1002 and its corresponding first ground plane 1010, and a second absorber 1004 and its corresponding ground plane 1012, consistent with the description. According to the present disclosure, the ground planes are thus attached to their respective absorbent material and positioned within the housing. However, it is contemplated that additional ground planes (not shown) located within the housing 700 further mitigate or reduce extraneous electrical noise. Such a ground plane may be located at a different location within the housing and may be electrically connected to the other ground plane, biased in a similar manner, biased separately or kept electrically floating apart from the other ground plane.

It is contemplated in accordance with the present disclosure that more than one absorber may be employed to attenuate the undesired emissions. For example, referring to fig. 14, the illustration 1400 includes a UWB transmitter array 702 having a first wing 712 and a second wing 714, the first wing 712 having transmitter elements 704a, 704b including two absorbers 1402, 1404, and the second wing 714 having receiver elements 706a, 706b including two absorbers 1406, 1408. The absorbers 1402, 1404 and the absorbers 1406, 1408 likewise include respective ground planes 1412, 1414 and 1414, 1416 that are, as disclosed, located away from their respective incident wave sources. Thus, in each case, the radiation passing therethrough first passes through the absorbing material and then reaches the ground plane. However, encountering the second absorbing material and the ground plane in this case produces a further attenuation of the noise-generating wave emissions.

According to the present disclosure, attenuation of electrical noise is obtained not only by absorbing reflected radiation via the absorbing materials and their respective ground planes, but also by the inclined surfaces of the housing. In one example, the housing itself is an absorptive material that absorbs the electromagnetic energy and converts it to heat, as discussed. Referring back to fig. 7 and 13, the housing 700 includes an outer wall 718. Fig. 7 and 13 show only a portion of the housing 700, while fig. 15 shows the entire housing as a first portion 1500 and a second portion 1502. The first portion 1500 and the second portion 1502 are joined to each other and include additional structural elements such that the two fit together and enclose the emitter array 702 (not shown in fig. 15). The outer walls of the first 1500 and second 1502 portions include sloped surfaces so that emissions falling substantially perpendicular to the sloped surfaces do not reflect back in the same direction. For example, referring back to fig. 8, the back lobe 806 includes a relatively strong emission level compared to the emission level of the side lobe 808. Moreover, although the back lobe 806 has a generally much lower intensity than the main lobe 802, the back lobe 806 also represents a type of emission that may fall on the receiver and cause unwanted noise if reflected back directly from the walls of the housing. Thus, according to the present disclosure, and in order to prevent the back lobe 806 from being reflected directly back to the receiver, the housing portions 1500, 1502 include walls with inclined surfaces. Upper wall 1504, front wall 1506, side walls 1508, lower wall 1510, and rear wall 1512 include sloped surfaces that are generally not aligned with a plane passing through the outer perimeter of each wall. In other words and by way of example, the walls are formed as generally rectangular structures, and if the walls are formed (as in conventional structures, such as boxes), the walls will be generally perpendicular to the main lobe 802 and the back lobe 806. However, in accordance with the present disclosure, some or all of the walls 1504-1512 include surfaces that are inclined relative to the overall structure. The walls 1504-1512 thus include indentations that result in a surface orientation that is oblique to the overall structure of the portions 1500, 1502.

As such and as shown in fig. 9, the reflected emissions not only include lower intensities, but if directed in different directions and away from the receiver, they will have minimal further impact on the receiver, thereby reducing noise. Thus, emissions from emitters such as emitter elements 704a, 704b are not directly reflected back to receiver elements 706a, 706 b. Conversely, emissions reaching the walls are advantageously emitted in an off-set direction and away from the receiver elements 706a, 706b, further reducing noise generated within the housing due to the back lobe 806 and side lobes 808.

Fig. 16 shows housing 1500 in an assembled form with UWB transmitter array 702 (not visible) located therein, and with angled surfaces 1504, 1506, and 1508 visible in this perspective view.

Thus, in accordance with the present disclosure, an ultra-wideband (UWB) system includes a housing and an ultra-wideband (UWB) transmitter array within the housing having transmitter means that transmits electromagnetic waves toward a region of interest (ROI), the UWB array having receiver means that receives reflected electromagnetic waves from an object in the ROI and generates object data. The system also includes a radar-absorbing material positioned to receive electromagnetic waves emitted from the transmitter component that are not directed toward the ROI, and a pattern recognition device having a processor configured to process the electromagnetic waves reflected from the ROI and determine whether an object of interest (OOI) pattern is identified within the object data.

Also in accordance with the present disclosure, a method of assembling an ultra-wideband (UWB) system includes positioning an array of ultra-wideband (UWB) transmitters within a housing, the array of UWB transmitters having transmitter components that transmit electromagnetic waves toward a region of interest (ROI), the array of UWB transmitters having receiver components that receive reflected electromagnetic waves from objects in the ROI and generate object data, positioning a radar-absorbing material to receive the electromagnetic waves transmitted from the transmitter components that are not directed toward the ROI, and configuring a pattern recognition device to process the electromagnetic waves reflected from the ROI and determine whether an object of interest (OOI) pattern is identified within the object data.

With respect to the processes, systems, methods, heuristics, etc. described herein, it should be understood that, although the steps of these processes, etc. have been described as occurring according to a certain ordered sequence, such processes may be practiced with the described steps performed in an order other than the order described herein. It is also understood that certain steps may be performed simultaneously, that other steps may be added, or that certain steps described herein may be omitted. In other words, the description of the processes provided herein is for the purpose of illustrating certain examples and should in no way be construed as limiting the claims.

Accordingly, it is to be understood that the above description is intended to be illustrative, and not restrictive. Many examples and applications other than those provided will be apparent upon reading the above description. The scope should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled, rather than to the foregoing description. It is anticipated and intended that future developments will occur in the arts discussed herein, and that the disclosed systems and methods will be incorporated into such future examples. In sum, it should be understood that the application is capable of modification and variation.

All terms used in the claims are intended to be given their broadest reasonable constructions and their ordinary meanings as understood by those skilled in the art to which the claims are entitled, unless an explicit indication to the contrary is made herein. In particular, use of the singular articles such as "a," "the," "said," etc. should be read to recite one or more of the indicated elements unless a claim recites an explicit limitation to the contrary.

The Abstract of the disclosure is provided to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Furthermore, in the foregoing detailed description, it can be seen that various features are grouped together in various examples for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claims require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed example. Thus, the following claims are hereby incorporated into the detailed description, with each claim standing on its own as a separately claimed subject matter.