阅读说明：本技术 具有用于宽带频率调谐的可重新配置辐射器的电子可控全息天线 (Electronically controllable holographic antenna with reconfigurable radiator for broadband frequency tuning ) 是由 瑞安·G·夸福斯 卡尔森·R·怀特 于 2019-07-23 设计创作，主要内容包括：一种全息天线包括：传输线结构,具有沿着传输线结构的长度的行波模式；和多个可重新配置的辐射元件,沿着传输线结构的长度定位。(A holographic antenna comprising: a transmission line structure having a traveling wave mode along a length of the transmission line structure; and a plurality of reconfigurable radiating elements positioned along the length of the transmission line structure.)

1. A holographic antenna, comprising:

a transmission line structure having a traveling wave mode along a length of the transmission line structure; and

a plurality of reconfigurable radiating elements positioned along a length of the transmission line structure.

2. The holographic antenna of claim 1, further comprising:

at least one tuning device coupled to at least one of the plurality of reconfigurable radiating elements, the tuning device being capable of reconfiguring the reconfigurable radiating element to control radiation from the antenna in a desired direction and to tune an operating frequency of the antenna.

3. The holographic antenna of claim 2, further comprising:

a bias line coupled to the at least one tuning device for controlling the tuning device to be shorted to the transmission line structure or not shorted to the transmission line structure to reconfigure the reconfigurable radiating element.

4. The holographic antenna of claim 1, wherein the transmission line structure comprises:

rectangular waveguides, ridge waveguides, coaxial transmission lines or parallel plate waveguides.

5. The holographic antenna of claim 1, wherein the transmission line structure comprises:

dielectric waveguides, microstrip lines or surface wave impedance waveguides.

6. The holographic antenna of claim 1, wherein each of the plurality of reconfigurable radiating elements comprises:

straight slots, curved slots, grommets, split rings, or slots having any geometry.

7. The holographic antenna of claim 2, wherein the tuning means comprises:

a field effect transistor FET, a micro-electromechanical system MEMS switch or a phase change material PCM switch.

8. The holographic antenna of claim 1, further comprising:

a plurality of tuning devices coupled to respective reconfigurable radiating elements of the plurality of reconfigurable radiating elements;

wherein the plurality of tuning devices coupled to the respective reconfigurable radiating elements are evenly or unevenly spaced across a width of the respective reconfigurable radiating elements.

9. The holographic antenna of claim 8, further comprising:

a plurality of bias lines, each respective bias line coupled to a respective tuning device for controlling the respective tuning device to be shorted to the transmission line structure or not to be shorted to the transmission line structure to reconfigure the reconfigurable radiating element.

10. The holographic antenna of claim 8, further comprising:

a plurality of integrated circuits, each respective integrated circuit coupled to a respective reconfigurable radiating element, each respective integrated circuit comprising:

a tuning control input;

a decoder coupled to the tuning control input; and

a plurality of outputs of the decoder coupled to respective ones of the plurality of tuning means coupled to the respective reconfigurable radiating elements for controlling the respective tuning means to be shorted to or not shorted to the transmission line structure.

11. The holographic antenna of claim 3, further comprising:

a dielectric;

wherein the transmission line structure comprises:

a first metal layer on a top layer of the dielectric;

a second metal layer on the inner layer of dielectric; and

a plurality of metal vias coupled between the first metal layer and the second metal layer.

12. The holographic antenna of claim 11,

wherein the bias line extends below the second metal layer.

13. A holographic antenna, comprising:

a rectangular waveguide;

a plurality of radiating elements positioned along a length of the rectangular waveguide;

a plurality of tuning devices, respective sets of the plurality of tuning devices coupled to respective ones of the plurality of radiating elements,

wherein each respective group of the plurality of tuning arrangements has uniform or non-uniform spacing across the width of the respective radiating element.

14. The holographic antenna of claim 13, further comprising:

a plurality of bias lines, each respective bias line coupled to a respective tuning device for controlling the respective tuning device to be shorted to the transmission line structure or not.

15. The holographic antenna of claim 13,

wherein the reconfigurable radiating element comprises a slot; and is

Wherein the tuning means comprises a field effect transistor.

16. The holographic antenna of claim 13, wherein the rectangular waveguide comprises:

a first metal layer on a top layer of the dielectric;

a second metal layer on the inner layer of dielectric; and

a plurality of metal vias coupled between the first metal layer and the second metal layer.

17. The holographic antenna of claim 14,

wherein the plurality of bias lines extend below the second metal layer.

18. A method of providing a holographic antenna, comprising:

providing a printed circuit board having a plurality of layers;

forming a metal top layer of a transmission line structure on top of the printed circuit board;

forming a metal bottom layer of the transmission line structure on an inner layer of the printed circuit board;

forming a plurality of metal vias coupled between the top layer of the transmission line structure and the bottom layer of the transmission line structure;

forming a plurality of radiating elements in the top layer of the transmission line along a length of the transmission line; and

providing a plurality of tuning devices, respective sets of the plurality of tuning devices coupled to respective ones of the plurality of radiating elements,

wherein each respective group of the plurality of tuning arrangements has uniform or non-uniform spacing across the width of the respective reconfigurable radiating element.

19. The method of claim 18, further comprising:

providing a plurality of bias lines, each respective bias line coupled to a respective tuning device for controlling the respective tuning device to be shorted to the transmission line structure or not.

20. The method of claim 18, wherein the first and second portions are selected from the group consisting of,

wherein the radiating element comprises a slot; and is

Wherein the tuning means comprises a field effect transistor.

[ technical field ] A method for producing a semiconductor device

The present disclosure relates to antennas, and in particular to holographic antennas and electronically scanned phased array antennas.

[ background of the invention ]

Prior art holographic antennas have an operating bandwidth of less than 30%, which is limited by the bandwidth of the radiating element, and depending on the size of the antenna, the instantaneous bandwidth is typically less than 3%.

The electronically scanned phased array antenna or beam forming array antenna of the prior art can achieve a wide bandwidth by using a wide-band antenna element. However, in order to use the element in an array, the element must have a length on each side that is less than half the wavelength. Therefore, to achieve broadband operation, the antenna elements must be larger in the vertical direction, which has disadvantages in terms of cost, array fabrication, and weight. Broadband phased arrays can be 5 times higher than holographic arrays and have more complex fabrication and electronics, both of which add cost.

In contrast, holographic antenna architectures have shown cost savings on the order of 3-5 times. The small thickness of the holographic array is typically in the order of 2mm, which provides the possibility of folding and subsequent unfolding of the sub-array panels, e.g. by an operator. Further, holographic arrays have the potential to use significantly less power in the receive mode, as they have far fewer antenna elements. Phased arrays use significantly more power in receive mode because they have 15-20 times as many receive modules as holographic arrays.

Prior art holographic antenna designs can be fixed beam and electronically steerable. Leaky Wave Antennas (LWA) with slotted waveguides have been studied as early as 1940, as described in the following reference [1], which is incorporated herein by reference, and precursors of these antennas were patented in 1921, as described in the following references [2, 3], which are incorporated herein by reference. LWA is a non-resonant antenna in which waves propagate along the structure and radiate due to the characteristics of the modes supported by the antenna. LWAs can be divided into two categories, uniform and periodic, as described in reference [4] below, which is incorporated herein by reference. The uniform antenna supports a fast wave mode, where the phase velocity of the antenna is greater than the speed of light. For this case, the wave radiates based on the wavenumber of the modes along the antenna according to equation (1):

β＝k₀sinθ (1)

where β is the wavenumber of the wave propagating along the antenna, k₀Is the wave number in free space, and θ is the radiation angle relative to the surface normal of the antenna. Quasi-uniform antennas operate similarly to uniform antennas, but with sub-wavelength periodic loading in order to improve antenna characteristics. Composite left-right-handed (CRLH) transmission line antennas use capacitive and inductive loads to allow improved beam scanning, as described in the following reference [5]]This document is hereby incorporated by reference. However, these architectures often obtain beam scanning by varying their operating frequency, and this approach is not compatible with a variety of applications that require a fixed operating frequency, such as mobile satellite communications. The periodic LWA uses a slow-wave guiding structure whose wave number is modulated. In this case, the antenna radiates an infinite number of spatial harmonics defined by equation (2):

β＝k₀sinθ+mk_p (2)

where m is an integer representing the spatial modulus, k_pIs the modulated wave number. The m-1 mode is generally the most accessible modulation, and other spatial modes have mostly very little coupling or complex radiation angles when the m-1 mode is excited. In this document, the terms "periodic LWA" and "holographic antenna" are used interchangeably. An early method for producing holographic antennas was the Artificial Impedance Surface Antenna (AISA), as in the following reference [6]]-[8]These documents are hereby incorporated by reference. These passive structures exhibit high gain beams and polarizationAnd (5) controlling. Surface wave waveguides are used as a way to confine the traveling wave mode and allow easier biasing, as in the following reference [9]]-[11]These documents are hereby incorporated by reference. AISA may be electronically scanned by loading the structure with a tunable element such as a varactor, as described in the following reference [12]]-[21]These documents are hereby incorporated by reference. Other holographic structures have also been demonstrated, as in reference [22] below]-[26]These documents are hereby incorporated by reference.

Reconfigurable Slot Antennas of the prior art are described by H.Li, J.Xiong, Y.Yu and S.He in "A Simple configurable Slot Antenna With a Very Wide Tuning Range," IEEE Transactions on Antennas and Production, Vol.58, No. 11, p.3725-. These references are two of many examples showing reconfigurable slot architectures. These elements cannot be used as radiators for holographic antennas unless (1) coupled to a traveling wave mode, (2) tailored to the sub-wavelength separation required for a holographic antenna (- λ/10 at the highest frequency), (3) radiated at an appropriate rate to allow illumination on an electrically long traveling wave antenna, and (4) provided with an appropriate impedance to allow wave propagation. For a slot antenna element (or any other small antenna element) designed independently of the application of the holographic antenna, it is almost certain that the element will not operate as desired within the holographic antenna. Further, the innovation of using reconfigurable radiating elements within holographic antennas is not obvious and has not been previously published.

The following references are incorporated herein as if fully set forth.

Reference to the literature

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[6] Sievenpipe et al, "Holographic AIS for formal Antennas",29th Antennas Applications Symposium, 2005.

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[9] R.Quarfoth and D.Sievenpipe, "aromatic software impact Surface Waveguides," in IEEE Transactions on Antennas and Propagation, Vol.61, No. 7, p.3597-.

[10] R.G.Quarfoth and D.F.Sievenpipe, "lubricating fluids Based on resistor Impedance Surfaces," in IEEE Transactions on extensions and Propagation, Vol.63, No. 4, p.1746 and 1755, and p.2015.4.

[11] A.M.Patel and A.Grbic, "A Printed Leaky-Wave Based on a Sinussuidally-Modulated reaction Surface," in IEEE Transactions on extensions and protocols, Vol.59, No. 6, p.2087 and p.2096, 6.2011.6 months.

[12] Sieven pipe, d.; schaffner, j.; lee, j.j.; livingston, s.; "A linear leakage-wave impedance using a linear impedance ground plane," Antennas and Wireless Propagation Letters, IEEE, volume 1, No. 1, page 179-.

[13] Colburn, j.s.; lai, a.; sieven pipe, d.f.; bekaryan, a.; fong, b.h.; ottusch, j.j.; tulythan, p.; "Adaptive audio image surface compatible antipennas," extensions and Propagation Society International symposium, 2009. APPURSI' 09.IEEE, vol., No., pages 1-4, 6/month, 1-5/2009.

[14] Gregore, Daniel j, and Joseph s.colburn, "Low cost,2D, electronic-steerable, artificial-imperance-surface antenna," U.S. patent No. 9,466,887.2016, 10/11.

[15] Gregoire, Daniel J. "Two-dimensional alloy e1 electronic 11 y-stable artifica 1 imperceptible surface anti-enna." U.S. Pat. No. 9,455,495.2016, 9/27.

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[17] Patel, Amit m, and Ryan g.quartforth, "Two-dimensional electronic-dimensional organizational impedance surface antenna," U.S. patent No. 9,871,293.2018, 1/16.

[18] Gregiore, d.j.; colburn, j.s.; patel, a.m.; quarfoth, r.; sievenpipe, D., "An electronic-readable arrangement-impact-surface antenna," in Antennas and Propagation Society International Symposium. (APSURSI),2014IEEE, vol., No., p.551-552, 7/month, 6-11/2014.

[19] Gregoire, j.s.colburn, a.m.patel, r.quartforth and d.sievenpipe, "An electronic-electronic association-surface-antipna," 2014IEEE anchors and a.processing Society International Symposium (surfsi), Memphis, TN 2014, page 551-552.

[20] Gregiore, d.j.; patel, a.; quarfoth, R., "A design for an electronic design with polarization control," in extensions and Propagation & USNC/URSI National Radio Science Meeting,2015IEEE International Symposium on, vol., No., page 2203, page 2204, and 2015, 19-24 months from 7-24 days.

[21] R.g. quarfoth, a.m. patel and D.J, Gregoire, "Ka-band electronic scanned associated International future surface antipena," 2016IEEE International Symposium on Antennas and Propagation (appursi), Fajardo,2016, page 651-652.

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[27]Balanis,Constantine A."Antenna Theory:Analysis and Design.”3^rdedition, Wiley Interscience (2005), see section 6.

There is a need for an electronically steerable holographic antenna with broadband frequency tuning. Embodiments of the present disclosure meet these and other needs.

[ summary of the invention ]

In a first embodiment disclosed herein, a holographic antenna comprises: a transmission line structure having a traveling wave mode along a length of the transmission line structure; and a plurality of reconfigurable radiating elements positioned along the length of the transmission line structure.

In another embodiment disclosed herein, a holographic antenna comprises: a rectangular waveguide; a plurality of radiating elements positioned along a length of the rectangular waveguide; a plurality of tuning devices, respective groups of the plurality of tuning devices coupled to respective ones of the plurality of radiating elements, wherein respective groups of the plurality of tuning devices have uniform or non-uniform spacing across a width of the respective radiating elements.

In yet another embodiment disclosed herein, a method of providing a holographic antenna comprises the steps of: providing a printed circuit board having a plurality of layers; forming a metal top layer of a transmission line structure on top of a printed circuit board; forming a metal bottom layer of a transmission line structure on an inner layer of the printed circuit board; forming a plurality of metal vias coupled between a top layer of the transmission line structure and a bottom layer of the transmission line structure; forming a plurality of radiating elements in a top layer of the transmission line along a length of the transmission line; and providing a plurality of tuning arrangements, respective groups of the plurality of tuning arrangements being coupled to respective ones of the plurality of radiating elements, wherein respective groups of the plurality of tuning arrangements have uniform or non-uniform spacing across the width of the respective reconfigurable radiating elements.

These and other features and advantages will become more apparent from the following detailed description and the accompanying drawings. In the drawings and specification, reference numerals indicate various features, and like reference numerals refer to like features throughout both the drawings and the specification.

[ description of the drawings ]

Fig. 1A shows a perspective view of an antenna according to the present disclosure, and fig. 1B shows a slot radiating element and tuning means according to the present disclosure;

FIG. 2 shows a more detailed top view of a unit cell of a structure according to the present disclosure;

FIG. 3 shows a front view of a unit cell according to the present disclosure;

FIG. 4 shows a side view of a unit cell according to the present disclosure;

FIG. 5 illustrates a perspective view of a two-dimensional (2D) array according to the present disclosure;

fig. 6A shows an example of four tuning means according to the present disclosure, and fig. 6B shows the positions of the tuning means according to the present disclosure;

FIGS. 7A and 7B illustrate adjustment of the tuning device position of FIG. 6 to allow continuous operation between 6-18GHz according to the present disclosure;

8A, 8B, 8C and 8D illustrate device topologies related to slots and show single-transistor and multi-transistor tuning device architectures according to the present disclosure;

9A, 9B, 9C, 9D, and 9E illustrate different slot geometries according to the present disclosure;

10A, 10B, 10C, and 10D illustrate different transmission line geometries according to the present disclosure;

FIG. 11 illustrates a geometry for simulating antenna performance according to the present disclosure;

FIG. 12 shows simulation results compared to an analytical formula in accordance with the present disclosure; and

fig. 13 shows analysis results of a scan showing a modulation period of wide-angle beam steering according to the present disclosure.

[ detailed description ] embodiments

In the following description, numerous specific details are set forth in order to provide a thorough description of various specific embodiments disclosed herein. However, it will be understood by those skilled in the art that the presently claimed invention may be practiced without all of the specific details discussed below. In other instances, well-known features have not been described in order not to obscure the invention.

The described invention is for an electronically controllable holographic antenna with a reconfigurable radiating element. A preferred embodiment is a rectangular waveguide, wherein slot radiating elements are spaced along the rectangular waveguide at sub-wavelengths of the travelling wave mode of the antenna. The antenna uses conventional holographic beam steering techniques. A periodic pattern of open and short slots is applied along the length of the antenna. The beam steering direction is based on the periodicity of the open and short slots. The switches are used to control whether the slots are open or short circuited, and the periodicity can be electronically reconfigured, thereby providing electronic beam steering. The present disclosure describes a plurality of switches placed in each radiating element such that by operating the switches, the effective length of the slot can be changed. Each switch in the slot is independently controllable, and this allows the slot to assume a discrete set of lengths based on the number of switches and their positions. The operating frequency of the holographic antenna is based on the length of the slot, so the frequency of the holographic antenna can be reconfigured by shorting out portions of the slot. The preferred embodiment provides a 3:1 tuning range while still allowing wide-angle beam steering. Other embodiments may provide a wider tuning range or control range.

Four components are used together to form an electronically controllable holographic antenna with a reconfigurable radiator for broadband frequency tuning: a transmission line structure 12, a radiating element 14, tuning means 16 in the radiating element, and a bias line 20 for supplying individually controllable voltages to the tuning means. Note that in fig. 3, the bias lines 20 appear to be shorted together; however, this is a result of the perspective of the figure, in fact the bias lines 20 in fig. 3 are not shorted together. Fig. 4 clearly shows that the bias lines 20 are independently addressable.

The transmission line structure 12 supports a travelling wave mode. The radiating elements 14, including tuning devices 16, are periodically positioned along the transmission line structure to provide reconfigurability. The tuning arrangement has two purposes. The first objective is to apply the whole-body holographic pattern to the antenna so that the antenna radiates the beam in the desired direction, as described in equation (2). A second purpose is to reconfigure the length of the radiating element in order to change the operating frequency.

Fig. 1A and 1B illustrate an antenna 10 having a transmission line 12, a radiating element 14 along the transmission line 12, and a tuning device 16 along the radiating element 14, which in the illustrated embodiment is a radiating slot 14. The bias line is not shown in fig. 1A and 1B, but may be located at the edge 18 of the transmission line 12. The antenna 10 may be constructed using a printed circuit board that is a laminate of metal layers and dielectric layers. Plated metal vias may be used to provide conductive connections vertically between horizontal metal layers.

Fig. 2 shows a top view of a portion of the antenna 10 showing the slot 14 with the tuning mechanism 16 controlled by the bias line 20. The waveguide 12 may be comprised of a metal sheet in a horizontal plane creating top and bottom walls and vertical vias 22 creating side walls to form a substantially rectangular waveguide 12. The bias line 20 is connected to the tuning mechanism 16 and the metal layer below the antenna 10 using vias 24.

The red rectangle 31 in fig. 3 represents the four walls of the waveguide. The top and bottom walls are solid metal on the PCB. The sidewalls are created by the vias 22 and they contact the top and bottom layers. To be "walls," these vias are electromagnetically spaced closer than a wavelength. With such small spacing, the vias form "walls" that are impenetrable to Electromagnetic (EM) waves. Other names for walls are perforated grids, conductive grids or more generally faraday cages.

As shown in fig. 2, the tuning device 16 is connected across the slot 14. The tuning device 16 may be a switch 16 connected across the slot 14 at different locations along the slot. Each switch 16 may have one electrode contacting one side 23 of the slot and another electrode contacting the other side 25 of the slot 16. The switch 16 is controlled by a bias line 20, which controls the state of the switch 16 by applying a voltage or current. In the "short" state, the switch provides zero or low impedance between the first side 23 and the second side 25 of the slot 16, which may be less than 10 ohms. In the "off" state, the switch provides a high impedance between the first side 23 and the second side 25 of the slot 16, which may be greater than 100 ohms.

In general, a slot antenna radiates power at a given frequency if the slot antenna is appropriately sized. The tuning device or switch 16 may change the effective length of the slot 14. Thus, for example, if the appropriate slot length for radiating at frequency f is L, and if radiation of L/2 length is prevented, the slot can be switched from a radiating slot to a non-radiating slot by placing a switch in the middle of the slot 14. In the "open" state, the effective length is L, and the slot radiates. In the "short" state, the slot does not radiate. In the "short" condition, the slots do not radiate because the slots become two L/2 slots, and neither radiates at the frequency f. Fig. 8A shows switch 16 implemented with a Field Effect Transistor (FET)60 having a source 80 connected to first side 23 of slot 14 and a drain 82 connected to second side 25 of slot 14. The first side 23 and the second side 25 of the slot 14 are continuous with the waveguide 12. By controlling the gate of the FET with the bias line 20, the FET switch 60 can be controlled to be in a "short" or "open" state.

Fig. 3 shows an illustration of a front view of the antenna structure 10. The top layer 30 of the transmission line 12 may be on a top layer of a Printed Circuit Board (PCB) or dielectric 32 and the bottom layer 34 of the transmission line 12 may be on an inner layer of the PCB to provide space for the bias line 20 below the antenna 10. The bias line 20 extends from the lower base layer 36 up to the tuning device 16. The bias line 20 may be connected to conventional bias hardware, such as a digital-to-analog converter, digital input control lines, etc., using the bottom layer 36 or any number of additional layers below the antenna 10. Preferably, the horizontal extent of the unit cell is of the order of half the wavelength of the lowest operating frequency, so that the holographic antenna elements can be arranged horizontally to provide two-dimensional beam steering. Fig. 4 shows a side view of the unit cell. The horizontal extent is the horizontal direction of fig. 3, and this is also the unit cell width 46 shown in fig. 2 and discussed further below.

The antenna can be manufactured using wafer-based manufacturing and an assembly with tuning means integrated on the wafer together with the travelling wave structure and the radiator. The traveling wave structure and the radiator can also be fabricated and coupled to a circuit board or wafer using a tuning device.

Fig. 5 shows an illustration of a 2D array with 6 holographic antenna elements 10, each of which may be the same as the antenna 10 shown in fig. 1A. The individual holographic antenna elements 10 may be fed from a feed network 40 by conventional means and the input phase controlled by a phase shifter 42. This architecture allows 2D beam steering to be enabled in one dimension by the holographic antenna element 10 and in a second dimension by the phase shifter as described in references [14] to [17] above, which are incorporated herein by reference.

In a preferred embodiment, as shown in fig. 1B, 2 and 3, each unit cell of each holographic antenna element 10 may have the following parameters determined by simulation: a unit cell length 44 of 2 mm; a unit cell width 46 of 13 mm; 11mm waveguide width 48; a waveguide height 50 of 150 mils; a total unit cell height 52 of 162 mils; a slot width 54 of 9.5 mm; a slot length 56 of 0.4 mm; dielectric constant of the dielectric 6; and copper for the metal in the waveguide 12, vias 22 and 24, and bias line 20. Other lengths, widths, or materials may be used depending on the operating frequency or manufacturing method.

Electromagnetic waves (EM waves) travel along the structure through the transmission line 12. The transmission line 12 is preferably electrically long, which means that the length is a plurality of wavelengths. The preferred embodiment of the transmission line 12 may have the following characteristics: operating over the 3:1 frequency range (6-18GHz), filled with a dielectric constant of 6, is a rectangular waveguide with a length of 12.8 wavelengths in the center of the operating frequency band or 320mm at 12GHz, and is dimensioned to have a frequency cutoff just below the bottom of the operating frequency range.

The radiating elements 14 are loaded periodically along the transmission line 12 structure and one or more tuning devices 16 are coupled to each radiating element 14. The preferred embodiment of the radiating element is a slot 14 with four tuning means 16. Each tuning device 16 may be a single FET transistor. Any number of tuning devices 16 coupled to more than one of the radiating elements 14 may provide reconfigurability of the operating frequency. Increasing the number of tuning means increases the number of tuning states that the radiating element 14 can achieve. An example showing four tuning means is shown in fig. 6A. Using full wave simulations, it has been found that the optimal slot length of 6Ghz is 9.5mm, which is represented between positions a and F in fig. 6A.

The effective length of the slot radiator 14 can be varied by switching the appropriate tuning device 16 to a "short-circuit" or "on" state. For example, if the tuning device at position E is switched on or placed in a "short" state in each row of the antenna, the effective slot width is simply the distance between a and E. In this example, only the tuning devices in positions B, C and D are in an "open" or off state. The result is a 7.6mm wide slot that resonates at 7.6 Ghz.

As seen in FIG. 6B, different combinations of switches produce center frequencies ranging from 6-15 GHz. Note that the operating bandwidth of each effective slot width is approximately ± 20% of the center frequency. Thus, for the embodiment of fig. 6A, there are frequency ranges in which the antenna cannot operate efficiently. In fig. 6A, each slot 14 has four tuning devices 16 that are evenly spaced across the width of the slot 16. The four tuning devices 16 starting from one edge of the 9.5mm wide slot are at 1.9mm, 3.8mm, 5.7mm and 7.6mm positions.

By spacing the tuning devices non-uniformly, more slot lengths, and thus more center frequencies, can be achieved. Figures 7A and 7B show that by adjusting the position of the tuning means a continuous operating frequency between 6-18GHz is provided. Note again that the operating bandwidth for a particular slot length is approximately 20% of the center frequency. Thus, FIG. 7 provides a preferred embodiment. In fig. 7A, each slot 14 has four tuning devices 16 that are non-uniformly spaced across the width of the slot 16. In fig. 7A, the four tuning devices 16 starting from one edge of the 9.5mm wide slot are at 1.9mm, 3.8mm, 6.2mm and 8.6mm positions.

The bias line 20 provides independent voltage control for each tuning device 16. The metal surrounding the slot 14 is the transmission line structure 12, which may be grounded. The bias line 20 may be introduced from the lower plane of the antenna 10 as shown in fig. 2, 3 and 4.

The preferred embodiment uses multiple tuning devices 16 across the slot 14, wherein each of the multiple tuning devices 16 is a single transistor FET switch 60, as shown in fig. 8A. Fig. 8A shows switch 16 implemented with a Field Effect Transistor (FET)60 having a source 80 connected to first side 23 of slot 14 and a drain 82 connected to second side 25 of slot 14. The first side 23 and the second side 25 of the slot 14 are continuous with the waveguide 12. By controlling the gate of the FET with the bias line 20, the FET switch 60 can be controlled to be in a "short" or "open" state.

At higher frequencies, the width of the slot 14 may be narrower, and in such cases, it is challenging to fit multiple single transistor FET switches 60 across the slot 14. In this case, as shown in fig. 8B, an integrated tuning device 62 may be used for each slot 14. The integrated tuning device 62 integrates a plurality of tuning elements into an integrated tuning device, which may be an integrated circuit or a monolithic integrated circuit. Two examples of integrated tuning devices 62 are shown in fig. 8C and 8D. Fig. 8C shows a series of 3 transistors 64 that may be fed by a resistive network that controls which devices are in an on or "shorted" state based on analog voltage inputs. A pad 68 is located on the integrated tuning device 62 and is connected to the transmission line structure 12. The example of fig. 8D also has three transistors 64 controlled by a decoder 70 that decodes a digital or analog input 71 to set the state of each transistor 64 to a "short" state or an "open" state across slot 14. For example, one of the transistors 64 may be in a "short" state while the other two transistors 64 are in an "open" state. Three transistors 64 are shown within the multi-transistor tuning device example of fig. 8C and 8D; however, any number of transistors may be used for various applications. Also, more than one of these integrated tuning devices 62 may be used to control the effective width, and thus the operating frequency, of the individual slots 14. Also, the tuning devices 62 shown as transistors in fig. 8A, 8C, and 8D may also be implemented using micro-electromechanical system (MEMS) switches, Phase Change Material (PCM) switches, semiconductor switches, other switches, or any two state (on/off) or "short"/"open" device.

The preferred embodiment of the slot is a straight slot, as shown in FIG. 9A; however, other slot geometries are possible. The slots may be straight slots, curved slots, grommets, split rings, or slots of any geometry, as shown in fig. 9A, 9B, 9C, 9D, and 9E, respectively.

The preferred embodiment of the transmission line is a rectangular waveguide, as shown in fig. 10A. However, other transmission line geometries may be used, such as ridge waveguides, coaxial waveguides, or parallel plates, as shown in fig. 10B, 10C, and 10D, respectively. Each of these other geometries may provide improved bandwidth.

The preferred embodiment with straight slots and rectangular waveguides was simulated in a full-wave 3D electromagnetic resolver (ANSYS HFSS) to determine its performance. The simulated geometry of the structure is shown in fig. 11, which is an enlarged view of fig. 1A, and the structure has been simulated at multiple frequencies. Fig. 12 shows the simulation results for a center frequency of 12 GHz. The analytical formula is an array factor analysis calculated by conventional methods for antenna arrays, as described in reference [27], which is incorporated herein by reference. Fig. 13 shows the analysis result of the scanning of the modulation period, showing that the antenna 10 is capable of wide-angle beam steering. Fig. 13 shows a legend showing different modulation periods kp, kp being a spatial domain representation of the period kp-2 pi/period.

Having now described the invention in accordance with the requirements of the patent statutes, those skilled in the art will understand how to make changes and modifications to the invention to meet the specific requirements or conditions thereof. Such changes and modifications can be made without departing from the scope and spirit of the present invention as disclosed herein.

For purposes of illustration and disclosure, the foregoing detailed description of exemplary and preferred embodiments has been presented as required by the law. It is not intended to be exhaustive or to limit the invention to the precise form described, but only to enable others skilled in the art to understand how the invention may be adapted for a particular use or embodiment. The possibilities of modifications and variations will be apparent to a person skilled in the art. The description of the exemplary embodiments is not intended to be limiting, and these embodiments may have included tolerances, feature sizes, specific operating conditions, engineering specifications, etc., and may vary from implementation to implementation or from prior art to prior art, and no limitation should be implied therefrom. The applicant has made this disclosure in relation to the current state of the art, but advances are also contemplated and future adaptations may take these into account, i.e. in accordance with the current state of the art at the time. It is intended that the scope of the invention be defined by the written claims and equivalents, if applicable. Reference to claim elements in the singular is not intended to mean "one and only one" unless explicitly so stated. Furthermore, no element, component, method, or process step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, method, or process step is explicitly recited in the claims. No claim element herein is to be construed under the provisions of chapter 112, sixth, 35u.s.c. unless the element is explicitly recited using the phrase "means for …", and no method or process step herein is to be construed under these provisions unless the step is explicitly recited using the phrase "including step … …".

Concept

At least the following concepts have been disclosed.

Concept 1, a holographic antenna, comprising:

a transmission line structure having a traveling wave mode along a length of the transmission line structure; and

a plurality of reconfigurable radiating elements are positioned along the length of the transmission line structure.

Concept 2 the hologram antenna according to concept 1, further comprising:

at least one tuning device coupled to at least one of the plurality of reconfigurable radiating elements, the tuning device capable of reconfiguring the reconfigurable radiating element to control radiation from the antenna in a desired direction and to tune an operating frequency of the antenna.

Concept 3 the hologram antenna according to concept 2, further comprising:

a bias line coupled to the at least one tuning device for controlling the tuning device to be shorted to or not shorted to the transmission line structure to reconfigure the reconfigurable radiating element.

Concept 4, the hologram antenna according to concept 1,2, or 3, wherein the transmission line structure includes:

rectangular waveguides, ridge waveguides, coaxial transmission lines or parallel plate waveguides.

Concept 5, the hologram antenna according to concept 1,2, 3, or 4, wherein the transmission line structure includes:

dielectric waveguides, microstrip lines or surface wave impedance waveguides.

Concept 6, the holographic antenna according to concept 1,2, 3, 4, or 5, wherein each of the plurality of reconfigurable radiating elements comprises:

straight slots, curved slots, grommets, split rings, or slots having any geometry.

Concept 7, the holographic antenna according to concept 2, 3, 4, 5, or 6, wherein the tuning device comprises:

a Field Effect Transistor (FET), a micro-electromechanical system (MEMS) switch, or a Phase Change Material (PCM) switch.

Concept 8, the hologram antenna according to concept 1,2, 3, 4, 5, 6, or 7, further comprising:

a plurality of tuning devices coupled to respective reconfigurable radiating elements of the plurality of reconfigurable radiating elements;

wherein the plurality of tuning devices coupled to the respective reconfigurable radiating elements are evenly or unevenly spaced across the width of the respective reconfigurable radiating elements.

Concept 9 the hologram antenna according to concept 8, further comprising:

a plurality of bias lines, each respective bias line coupled to a respective tuning device for controlling the respective tuning device to be shorted to or not shorted to the transmission line structure to reconfigure the reconfigurable radiating element.

Concept 10 the hologram antenna according to concept 8, further comprising:

a plurality of integrated circuits, each respective integrated circuit coupled to a respective reconfigurable radiating element, each respective integrated circuit comprising:

a tuning control input;

a decoder coupled to the tuning control input; and

a plurality of outputs of the decoder coupled to respective ones of the plurality of tuning means coupled to respective reconfigurable radiating elements for controlling whether the respective tuning means are shorted to the transmission line structure or not.

Concept 11, the holographic antenna according to concept 3, 4, 5, 6, 7, 8, 9 or 10, further comprising:

a dielectric;

wherein, transmission line structure includes:

a first metal layer on a top layer of the dielectric;

a second metal layer on the inner layer of dielectric; and

a plurality of metal vias coupled between the first metal layer and the second metal layer.

Concept 12, the holographic antenna according to concept 11,

wherein the bias line extends below the second metal layer.

Concept 13, a holographic antenna, comprising:

a rectangular waveguide;

a plurality of radiating elements positioned along a length of the rectangular waveguide;

a plurality of tuning arrangements, respective sets of the plurality of tuning arrangements coupled to respective ones of the plurality of radiating elements,

wherein each respective group of the plurality of tuning arrangements has a uniform or non-uniform spacing across the width of the respective radiating element.

Concept 14 the hologram antenna according to concept 13, further comprising:

a plurality of bias lines, each respective bias line coupled to a respective tuning device for controlling the respective tuning device to be shorted to or not shorted to the transmission line structure.

Concept 15, the holographic antenna according to concept 13 or 14,

wherein the reconfigurable radiating element comprises a slot; and is

Wherein the tuning means comprises a field effect transistor.

Concept 16, the holographic antenna according to concept 13, 14, or 15, wherein the rectangular waveguide comprises:

a first metal layer on a top layer of the dielectric;

a second metal layer on the inner layer of dielectric; and

a plurality of metal vias coupled between the first metal layer and the second metal layer.

Concept 17, holographic antenna according to concept 14, 15 or 16,

wherein the plurality of bias lines extend below the second metal layer.

Concept 18, a method of providing a holographic antenna, comprising:

providing a printed circuit board having a plurality of layers;

forming a metal top layer of a transmission line structure on top of a printed circuit board;

forming a metal bottom layer of a transmission line structure on an inner layer of the printed circuit board;

forming a plurality of metal vias coupled between a top layer of the transmission line structure and a bottom layer of the transmission line structure;

forming a plurality of radiating elements in a top layer of the transmission line along a length of the transmission line; and

providing a plurality of tuning arrangements, respective sets of the plurality of tuning arrangements being coupled to respective ones of the plurality of radiating elements,

wherein each respective group of the plurality of tuning arrangements has uniform or non-uniform spacing across the width of the respective reconfigurable radiating element.

Concept 19 the method according to concept 18, further comprising the steps of:

a plurality of bias lines are provided, each respective bias line being coupled to a respective tuning device for controlling the respective tuning device to be shorted to or not shorted to the transmission line structure.

Concept 20, the method according to concept 18 or 19,

wherein the radiating element comprises a slot; and is

Wherein the tuning means comprises a field effect transistor.