WO2024141984A1

WO2024141984A1 - Antenna reflector

Info

Publication number: WO2024141984A1
Application number: PCT/IB2023/063339
Authority: WO
Inventors: Amir ABRAMOVICH; Asaf BAROM; Daniel ROZBAN; David ROTSHILD; Ariel ETINGER; Gil KEDAR
Original assignee: Ariel Scientific Innovations Ltd.; Ceragon Networks Ltd.
Priority date: 2022-12-28
Filing date: 2023-12-28
Publication date: 2024-07-04

Abstract

Disclosed is a reconfigurable antenna reflector that, in some embodiments, is particularly suitable for transmitting or receiving millimeter waves. In some embodiments the reconfigurable antenna reflector comprises: a flat antenna-array defining an antenna plane, a ground layer defining a ground plane the ground plane substantially parallel to the antenna plane, a dielectric layer located between the antenna-array and the ground layer thereby physically separating the antenna-array from the ground layer, the array, the individual patch antennas and the ground layer configured so that a reflecting surface of the antenna-array is a parabolic reflector for millimeter waves having a steering angle at which incident millimeter waves are reflected from the reflecting surface; and at least one piezoelectric component configured to change an angle between the antenna plane and the ground plane, wherein a change of the angle between the antenna plane and the ground plane changes the steering angle.

Description

Antenna Reflector

RELATED APPLICATION

The present application gains priority from US Provisional Patent Application 63/435,581 filed 28 December 2022 which is included by reference as if fully set-forth herein.

FIELD AND BACKGROUND OF THE INVENTION

The invention, in some embodiments, relates to the field of wireless communication and, more particularly but not exclusively, to antenna reflectors that, in some embodiments, are particularly suitable for use transmitting or receiving millimeter waves.

Millimeter wave (MMW, 30-300 GHz) wireless communication channel requires very accurate alignment between a transmitter parabolic dish antenna associated with an MMW transmitter and a receiver parabolic dish antenna associated with a MMW receiver due to line-of-sight behavior of the radiation having these frequencies. Even a slight displacement in the relative orientation of the antennas from optimum leads to a significant degradation in the performance of the MMW communication channel. Thus, a real time mechanism to keep optimal alignment between the transmitter and receiver antennas is required. Currently, such antenna are mounted on mounts comprising accurate step motors. As a consequence, the antenna mounts are complicated and heavy.

It would be useful to have methods and devices that allow accurate alignment of a transmitter antenna and a receiver antenna to allow effective communication between the associated transmitter and receiver.

SUMMARY OF THE INVENTION

Some embodiments of the invention relate to an antenna reflectors that, in some embodiments, are particularly suitable for transmitting or receiving millimeter waves. In some embodiments, the antenna reflector comprises a flat parabolic metasurface which is reconfigurable using a piezoelectric component.

According to an aspect of some embodiments of the teachings herein, there is provided a reconfigurable antenna reflector suitable for reflecting millimeter waves, comprising: a flat antenna-array defining an antenna plane, the flat antenna-array comprising a reflecting surface and a backing surface; a ground layer defining a ground plane, the ground plane substantially parallel to the antenna plane, the ground layer having an upper surface facing the backing surface of the antenna-array; a dielectric layer located between the backing surface of the antenna-array and the ground layer, thereby physically separating the antenna-array from the ground layer, wherein the flat antenna-array comprises multiple coplanar patch antennas arranged in an array on the reflecting surface, the patch antennas devoid of electrical connection to the ground layer, wherein the array, individual patch antennas and the ground layer are configured so that the reflecting surface is a parabolic reflector for millimeter waves having a steering angle at which incident millimeter waves are reflected from the reflecting surface; and at least one piezoelectric component configured to change an angle between the antenna plane and the ground plane when an electrical potential is applied thereto, wherein a change of the angle between the antenna plane and the ground plane changes the steering angle.

In some embodiments, the antenna-array comprises a planar PCB.

In some embodiments, the reflecting surface is a parabolic reflector for E-band millimeter waves.

In some embodiments, the reflecting surface is a parabolic reflector for 80 GHz millimeter waves.

In some embodiments, the configuring of the individual patch antennas is different relative sizes of the patch antennas. Specifically, the patch antennas have different sizes, the sizes selected to provide the desired phase shift to achieve the desired reflecting surface.

In some embodiments, at least one piezoelectric component is a piezoelectric bending element, so that when an electric potential is applied to leads of the piezoelectric bending element, the piezoelectric bending element changes shape in order to change the angle between the antenna plane and the ground plane.

In some embodiments, the dielectric layer between the backing surface and the ground layer comprises a gas.

In some embodiments, the dielectric layer between the backing surface and the ground layer comprises a vacuum of not more than 50 kPa. In some embodiments, the vacuum of not more than 10 kPa and even not more than vacuum of not more than 5 kPa.

In some embodiments, the upper surface of the ground layer is not flat so that the distance between the upper surface of the ground layer and the backing surface of the antenna-array is smaller closer to a periphery of the antenna-array and greater closer to a center of the antenna-array. In preferred such embodiments, the ground layer is stepped.

BRIEF DESCRIPTION OF THE FIGURES

Some embodiments of the invention are described herein with reference to the accompanying figures. The description, together with the figures, makes apparent to a person having ordinary skill in the art how some embodiments of the invention may be practiced. The figures are for the purpose of illustrative discussion and no attempt is made to show structural details of an embodiment in more detail than is necessary for a fundamental understanding of the invention. For the sake of clarity, some objects depicted in the figures are not to scale.

In the Figures:

FIG. 1A (prior art) schematically depicts a parabolic mirror in side view where parallel incoming rays LI, L2, and L3 are reflected to a focal point F due to the mirror geometry.

FIG. IB schematically depicts an embodiment of a antenna reflector in side cross section where parallel incoming rays LI, L2, and L3 are reflected to a focal point F due to the phase shift provided by each unit cell of the antenna reflector.

FIGS. 2 A, 2B and 2C schematically depict the design of a unit cell (a patch antenna) of a antenna reflector: Figure 2A, front view of the unit cell, Figure 2B, side view of the unit cell; and Figure 2C is Table 1 which lists physical parameters of the unit cell of Figures 2A and 2B.

FIGS. 3A and 3B: Figure 3A schematically depicts a piezoelectric bending element. Figure 3Bs a graph showing a displacement of a typical piezoelectric bending element as a function of the potential applied to the leads, including hysteresis.

FIGS. 4 A and 4B show results of a simulation of the effect of different dielectric thicknesses (g= 1.4, 1.6, 1.85, 2.1 and 2.3) on the Si l magnitude in dB (Figure 4A) and sl l phase shift in degrees (Figure 4B) as a function of frequency on a unit cell of Figures 2.

FIGS. 5A and 5B depict an embodiment of a antenna reflector. Figure 5A schematically depicts the antenna reflector in side cross section and Figure 5B is Table 2 which lists physical parameters of the antenna reflector of Figure 5 A.

FIGS. 6A and 6B show results of a simulation of a antenna reflector of Figures 5A and 5B. Figure 6A is a graph of gain as a function of reflected phase of the antenna reflector compared to a flat copper plate of the same size. Figure 6B is Table 3 which is a summary of the far-field radar cross section (RCS) results at 80 GHz with no beam steering (a_r = 0°) for the flat copper plate and for the antenna reflector.

FIG. 7 schematically depicts the reflector of Figures 5 A and 5B in side cross section with a a_r = 0.5° tilt of the ground layer.

FIGS. 8 A and 8B show results of a simulation of the antenna reflector with tilted ground layer of Figure 7. Figure 8A is a graph of gain as a function of reflected phase of the antenna reflector compared to a flat copper plate of the same size that is tilted in the same way as the ground layer of the antenna reflector. Figure 8B is Table 4 which is a summary of the far-field radar cross section (RCS) results at 80 GHz with a_r = 0.5° beam steering for the two cases: the tilted flat copper plate and the antenna reflector.

FIGS. 9 A, 9B, 9C and 9D schematically depict an embodiment of a antenna reflector (comprising an intelligent reflecting surface) according to the teachings herein that in some embodiments is suitable for transmitting and receiving 80 GHz millimeter waves. Figure 9a shows the ground layer causing to different phase reflection from each discrete step depending on the distance between the step to the patch above. In Figure 9B a ring-shaped dielectric spacer is shown attached to the ground layer. In Figure 9C (perspective view towards the front surface) and Figure 9D (side view) is shown a round flat antenna-array placed over the ring-shaped dielectric layer, the antenna-array being multiple patch antennas arranged in array, printed on a Rogers 5880LZ PCB.

FIGS. 10A and 10B schematically depict a simulation performed to study the antenna reflector of Figures 9. Figure 10A depicts the physical setup of the simulation. Figure 10B is Table 5 which lists parameters used in a simulation for studying the antenna reflector of Figures 9.

FIG. 11 show results of the simulation of the antenna reflector reflector depicted in Figures 9 under the conditions depicted in Figures 10.

DESCRIPTION OF SOME EMBODIMENTS OF THE INVENTION

The invention, in some embodiments thereof, relates to reconfigurable antenna reflectors that, in some embodiments, are particularly suitable for transmitting or receiving millimeter waves. In some embodiments, the antenna reflector comprises a flat parabolic metasurface which is reconfigurable using a piezoelectric component.

The principles, uses and implementations of the teachings herein may be better understood with reference to the accompanying description and figures. Upon perusal of the description and figures present herein, one skilled in the art is able to implement the invention without undue effort or experimentation. In the figures, like reference numerals refer to like parts throughout.

Before explaining at least one embodiment in detail, it is to be understood that the invention is not necessarily limited in its application to the details of construction and the arrangement of the components and/or methods set forth herein. The invention is capable of other embodiments or of being practiced or carried out in various ways. The phraseology and terminology employed herein are for descriptive purpose and should not be regarded as limiting.

According to an aspect of some embodiments of the teachings herein is provided a antenna reflector. In some embodiments, the antenna reflector comprises an intelligent reflecting surface. The antenna reflector comprises a flat antenna-array defining an antenna plane functionally associated with a ground layer defining a ground plane separated from the antenna-array by a dielectric layer, where the angle between the antenna plane and the ground plane can be changed using a piezoelectric component. Simulations of an antenna reflector according to the teachings herein show excellent performance and high accuracy compared to prior art parabolic dish antennas. In preferred embodiments, the antenna-array comprises a PCB that can be manufactured using known PCB technology.

As known in the art, as the gain of an antenna increases, the beamwidth of the antenna decreases. Optimal operation of a parabolic antenna (both for transmission and reception) is achieved when the illumination at the center of the antenna is greater at the center of the antenna than at the edges. More specifically, it is known that optimal performance of a communication channel that uses parabolic antennas is achieved when illumination at the center of the parabolic antenna is at least 10 dB greater than at the edges. The lower the illumination at the antenna edges, the lower the side-lobe level is. Thus, in such a communication channel it is important that the transmitting (Tx) and receiving (Rx) parabolic antenna be continuously aligned to provide high quality MMW wireless communication. Misalignment of Rx and Tx parabolic antennas yields a sever degradation in the channel performance especially at E-band (60 Ghz - 90 GHz) and greater frequencies. In practice, such misalignment can be caused by any reason, including wind or by temperature differences between the two sides of a parabolic antenna caused by the sun. To overcome the misalignment due to such environmental factors, current parabolic antennas for MMW are tunable by ±3°. Currently, 80 GHz communication links typically use a 1 foot (0.3 m) diameter dish antennas having a directivity (the ratio of the radiation intensity in a given direction from the antenna to the radiation intensity averaged over all directions) of about 45 dBi. A three-foot (0.9 m) antenna has a directivity of about 54 dBi. The beamwidth of such antennas is not more than about ±0.5° so real time steering of such antennas to maintain alignment to counteract environmental changes is necessary.

According to an aspect of some embodiments of the teachings herein there is disclosed a reconfigurable antenna reflector vaguely similar ot a Flat Parabolic Surface (FLAPS™) antenna such as disclosed by Communications & Power Industries (Camarillo, California, USA), in some embodiments the antenna reflector is particularly suitable for E- band communication, especially at 80 GHz. In some embodiments, the antenna reflector comprises a flat antenna array defining an antenna plane and a ground layer defining a ground plane, where the antenna-array and the ground layer are separated by a dielectric layer. The antenna-array comprises multiple coplanar patch antennas arranged in an array on the reflecting surface of the antenna-array. Preferably, the antenna-array is a PCB, e.g., copper patterns printed on a planar dielectric substrate using PCB technology. The patch antennas are electrically connected to the ground layer by vias as known in the art of PCBs.

The individual patch antennas are configured so that the reflecting surface of the antenna reflector is a parabolic reflector for millimeter waves, in some embodiments for E- band millimeter waves, in some preferred embodiments 80 GHz millimeter waves. For example, in some embodiments such configuration of the individual patch antennas is the relative size of each patch antenna in the planar antenna-array is such that the antenna-array is a parabolic reflector as described above.

The antenna reflector comprises at least one piezoelectric component configured to change the angle between the antenna plane and the ground plane when an electrical potential is applied thereto. In some embodiments, at least one such piezoelectric component is a piezoelectric bending element, so that when an electric potential is applied to leads of the piezoelectric bending element, the piezoelectric bending element changes shape in order to change the angle between the antenna plane and the ground plane. For example, in some embodiments at least part of a piezoelectric component such as as a piezoelectric bending element is physically located between the antenna-array and the ground layer. By applying a selected electric potential to such a piezoelectric component, the angle In Figure 1 A is schematically depicted an optical parabolic mirror in side view where parallel incoming rays LI, L2, and L3 are reflected to a focal point F due to the parabolic geometry of the mirror.

In Figure IB is schematically depicted a antenna reflector analogous to the optical mirror depicted in Figure 1A, in side cross section The antenna reflector depicted in Figure IB comprises multiple unit cells arranged in an array on the reflecting surface of the antenna reflector, wherein the individual unit cells are configured so that the reflecting surface is a parabolic reflector. As a result, parallel incoming rays LI, L2, and L3 are reflected to a focal point F due to the phase shift provided by each unit cell of the antenna reflector. In Figure IB, the phase shift of each unit cell XQ, X . . . X_n is designed to collectively provide the parabolic reflection. As known in the art, one preferred manner of setting the phase shift of a unit cell is by setting the physical dimensions of the unit cells on the reflecting surface.

Figures 2A, 2B and 2C schematically depict a unit cell, i.e., a patch antenna, design of a antenna reflector of Figure IB. In Figures 2A, the front view of the unit cell as seen from viewing the reflecting surface. Figure 2B is a side view of the unit cell, and Figure 2C is Table 1 which lists the parameters of the unit cell of Figures 2A and 2B. On the reflecting surface, the unit cell is a 0.8 mm square with a 0.5 mm square 0.035 mm thick conductive metal (copper) patch centered therein. The patch is deposited on a 0.254 dielectric substrate (e.g., a PCB substrate, such as RT5880LZ by ROGERS Inc. having a dielectric coefficient of sr = 2.2). The bottom of the substrate is separated from a conductive ground layer of 0.254 mm thick copper by a (variable) g = 1.4 - 2.3 mm thick layer of dielectric (e.g., air, a gas, vacuum). The exact dimension g of the dielectric layer (e.g., of the vacuum) is determined using a piezoelectric component.

Figure 3A schematically depicts a piezoelectric bending element that changes shape as a function of potential applied to the leads of the bending element. Figure 3B is a graph showing a displacement of a typical piezoelectric bending element as a function of the potential applied to the leads, including hysteresis. Suitable piezoelectric bending elements are commercially-available. In the studied design, a commercially-available piezoelectric bend element was used, a PB4NB2W (TORLABS Inc.). The maximal displacement of the bending element is 0.9 mm controlling the size of the dielectric layer. The piezoelectric crystal enables a displacement of 0.9 millimeter as function of the apply DC voltage in the range 0-150V. Considering that the maximal displacement using the selected piezoelectric bending element is 0.9 mm, a simulation of the designed unit cell was carried out for different g values. Figure 4 shows the reflection magnitude and the reflection phase for several values of the parameter g in the frequency range of 60-110 GHz. Note that the designed operation frequency is 80 GHz.

FIGS. 4 A and 4B show results of a simulation of the effect of different dielectric thicknesses (g= 1.4, 1.6, 1.85, 2.1 and 2.3) on the Si l magnitude in dB (Figure 4A) and sl l phase shift in degrees (Figure 4B) as a function of frequency. From Figure 4A is seen that the reflection losses are very low around 80 GHz. From Figure 4B the phase dynamic range between g=1.4mm to g=2.3mm is about 300 degrees which is sufficient for the design of the an antenna reflector according to the teachings herein, especially for use for 5 and 6 generation of the wireless communication.

Based on the simulation results of the designed unit cell discussed with reference to Figure 4. A schematic antenna reflector having two piezoelectric components located on opposite sides of antenna reflector was simulated, allowing changing the angle a_r between the x-axis of the antenna plane and the x-axis of the ground plane ("tilting"). For the simulation, the dimensions of the antenna-array was 80 mm square with 10000 unit cells arranged in a 100 by 100 square matrix. In Figure 5 A, the antenna reflector is schematically depicted in side cross section. In Figure 5B, Table 2 lists the physical parameters of the antenna reflector: the distance between the horn antenna (a commercially-available W-band horn antenna by MI-WAVE Inc.) and the reflecting surface is 85 mm, the thickness of the dielectric substrate supporting the antenna-array (a PCB board) is 0.388 mm, the thickness of the conductive metal patches that constitute the patch antennas and the ground layer is 0.035 mm. The separation between the bottom of the PCB board and the ground layer g = 1.85 mm (e.g., vacuum) and the angle between the antenna plane and the ground plane can be varied between -0.5° and +0.5° by using the two piezoelectric components.

The results of the simulation of the antenna reflector of Figures 5 are shown in Figures 6 compared to a flat copper plate. Figure 6A is a graph of gain as a function of reflected phase of the antenna reflector compared to a flat copper plate of the same size. Figure 6B is Table 3 which is a summary of the far-field radar cross section (RCS) results at 80 GHz with no beam steering (a_r = 0°) for the two cases: the flat copper plate and the antenna reflector. The results show that the reflected beam is wide (±13° copper plate, ±14° antenna reflector) and the antenna gain (21.49 dBi copper plate, 20.95 dBi antenna reflector) is relative low. There is no substantial different between reflection by the antenna reflector and by the copper plate.

Changing of the angle between the antenna plane and the ground plane using the piezoelectric components was simulated, as depicted in Figure 7 with a a_r = 0.5° tilt of the ground layer.

Figures 8A and 8B show results of a simulation of changing the angle of the antenna plane and the ground plane, and demonstrate the resulting beam steering. Figure 8A is a graph of gain as a function of reflected phase of the antenna compared to a flat copper plate of the same size that is tilted in the same way as the ground layer of the antenna. Figure 8B is Table 4 which is a summary of the far-field radar cross section (RCS) results at 80 GHz with a_r = 0.5° beam steering for two cases: tilted flat copper and the antenna reflector. The results show that the reflected beam is wide (-14° to +15° copper plate, -14° to +17° antenna reflector) and the antenna gain (20.57 dBi copper plate, 20.13 dBi antenna reflector) is relative low. However, reflected beam steering for the copper plate is 0.2° compared to 0.9° for the antenna reflector.

The simulation results summarized in Figures 8 indicate that the reflected beam angle of the antenna reflector is 5 times greater than the reference flat copper plate for the same tilting angle a_r = 0.5°. In addition, it can be seen that the reflected beam when the tilting is performed does not behave according to the ray equation as expected. Without wishing to be held to any one theory, it is currently believed that this unexpected results occurs because the incident wave that was transmitted from the horn antenna that reaches the reflecting surface of the antenna reflector has a Gaussian propagation and the beamforming of a Gaussian beam is different from the beamforming of a normal beam. In addition, this can be explained due to the use of high frequency waves and the beamforming of wave propagation according to the ray equation is correct for waves in the optical range.

Figures 9A, 9B, 9C and 9D schematically depict an embodiment of a antenna reflector according to the teachings herein.

Figure 9A schematically depicts a ground plate that bears a conductive ground layer defining a ground plane. The upper surface of the ground layer that faces the backing surface of the antenna array is not flat but is stepped with concentric bands so that the distance between the upper surface of the ground layer and the backing surface of the antenna-array is smaller closer to the periphery of the antenna-array and greater closer to the center of the antenna-array. This non-flat stepped surface changes the phase reflection of the patch antennas, assisting in configuring the reflecting surface to be a parabolic reflector for millimeter waves.

Figure 9B schematically depicts the ground plate together with a ring-shaped dielectric spacer attached to the periphery of the ground plate. The spacer helps define the thickness of the dielectric layer located between the backing surface of the antenna-array and the ground layer and also defines a central dielectric portion that includes a gas or vacuum.

Figure 9C (perspective view towards the reflecting surface) and Figure 9D (side view) of the antenna reflector show a round flat antenna-array placed over the ring-shaped dielectric spacer, the antenna-array being multiple patch antennas arranged in array, printed on a Rogers 5880LZ PCB.

Not depicted in Figures 9 is a chassis. The chassis holds the antenna array and the ground plate in the correct relative orientation and distance, as well as the piezoelectric component or components in the desired physical association with the other components to allow the piezoelectric components to change the angle between the antenna plane and the ground plane as desired. Further, in some embodiments the chassis defines an empty volume which constitutes the dielectric layer located between the backing surface of the antennaarray and the ground layer, that physically separates the antenna-array from the ground layer. The empty volume can be filled with a gas or, alternatively, gas can be evacuated therefrom to a vacuum.

Figures 10A and 10B show the physical parameters used for a simulation performed to study the antenna reflector of Figures 9. Figure 10A depicts the physical setup of the simulation. Figure 10B is Table 5 which lists parameters used in a simulation for studying the antenna of Figures 9. In Figure 10B, Table 5 lists the physical parameters of the antenna reflector including that the focal length of the reflecting surface is 80 mm so the horn antenna was located at the focal point of the reflecting surface.

Figure 11 show results of the simulation of the antenna reflector depicted in Figures 9 under the conditions depicted in Figures 10 when the ground plane and the antenna plane are parallel a_r = 0.0°, compared to a typical known prior art parabolic dish antenna with the same aperture dimension of the antenna reflector and substantially the same set-up depicted in Figure 10A. The results depicted in Figure 11 show a significant improvement compared to the results depicted in Figures 6. The gain of the antenna reflector in Figure 11 is 30 dBi compared to 20 dBi for the antenna reflector in Figures 6. This indicates that the configuration of the antenna reflector depicted in Figures 9 increases the antenna gain by an order of magnitude compared to the depicted in Figures 5. Furthermore, the beamwidth is around ±5 which is significantly better than the beamwidth of ±15 in Figures 6.

Changing of the angle between the antenna plane and the ground plane using the piezoelectric components was simulated, as depicted in Figure 12 with a a_r = 0.35° tilt of the ground layer.

Figures 13 A and 13B show results of a simulation of changing the angle of the antenna plane and the ground plane, and demonstrate the resulting beam steering. Figure 13 A is a graph of gain as a function of reflected phase of the antenna compared to a typical known prior art parabolic dish antenna with the same aperture dimension of the antenna reflector that is tilted in the same way as the ground layer of the antenna reflector. Figure 13B is a summary of the far-field radar cross section (RCS) when a_r = 0.35° for beam steering at 80 GHz for two cases: a dish antenna and the antenna reflector of Figure 12.

The results in Figures 13 indicate that changing the angle between the antenna plane and the ground plane focuses the reflected beam. The steer angle of the beam by the antenna reflector according to the teachings herein is five times larger than the beam reflected by the dish antenna for the same a_r value. Furthermore, the greater degree of focusing of the reflected beam by the antenna reflector according to the teachings herein compared to that of the dish antenna is noticeable and the beamwidth is comparable. Compared to the antenna reflector depicted in Figures 5, the antenna reflector depicted in Figures 9 has an improved main beam to side lobe ratio.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. In case of conflict, the specification, including definitions, takes precedence.

As used herein, the terms “comprising”, “including”, "having" and grammatical variants thereof are to be taken as specifying the stated features, integers, steps or components but do not preclude the addition of one or more additional features, integers, steps, components or groups thereof. As used herein, the indefinite articles "a" and "an" mean "at least one" or "one or more" unless the context clearly dictates otherwise.

As used herein, when a numerical value is preceded by the term "about", the term "about" is intended to indicate +/-10%. As used herein, a phrase in the form “A and/or B” means a selection from the group consisting of (A), (B) or (A and B). As used herein, a phrase in the form “at least one of A, B and C” means a selection from the group consisting of (A), (B), (C), (A and B), (A and C), (B and C) or (A and B and C).

It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination or as suitable in any other described embodiment of the invention. Certain features described in the context of various embodiments are not to be considered essential features of those embodiments, unless the embodiment is inoperative without those elements.

Embodiments of methods and/or devices described herein may involve performing or completing selected tasks manually, automatically, or a combination thereof. Some methods and/or devices described herein are implemented with the use of components that comprise hardware, software, firmware or combinations thereof. In some embodiments, some components are general-purpose components such as general purpose computers, digital processors or oscilloscopes. In some embodiments, some components are dedicated or custom components such as circuits, integrated circuits or software.

For example, in some embodiments, some of an embodiment is implemented as a plurality of software instructions executed by a data processor, for example which is part of a general-purpose or custom computer. In some embodiments, the data processor or computer comprises volatile memory for storing instructions and/or data and/or a non-volatile storage, for example, a magnetic hard-disk and/or removable media, for storing instructions and/or data. In some embodiments, implementation includes a network connection. In some embodiments, implementation includes a user interface, generally comprising one or more of input devices (e.g., allowing input of commands and/or parameters) and output devices (e.g., allowing reporting parameters of operation and results.

Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the scope of the appended claims.

Citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the invention. Section headings are used herein to ease understanding of the specification and should not be construed as necessarily limiting.

Claims

CLAIMS:

1. A reconfigurable antenna reflector suitable for reflecting millimeter waves, comprising: a flat antenna-array defining an antenna plane, said flat antenna-array comprising a reflecting surface and a backing surface; a ground layer defining a ground plane, said ground plane substantially parallel to said antenna plane, said ground layer having an upper surface facing said backing surface of said antenna-array; a dielectric layer located between said backing surface of said antenna-array and said ground layer, thereby physically separating said antenna-array from said ground layer, wherein said flat antenna-array comprises multiple coplanar patch antennas arranged in an array on said reflecting surface, said patch antennas devoid of electrical connection to said ground layer, wherein said array, individual said patch antennas and said ground layer are configured so that said reflecting surface is a parabolic reflector for millimeter waves having a steering angle at which incident millimeter waves are reflected from said reflecting surface; and at least one piezoelectric component configured to change an angle between said antenna plane and said ground plane when an electrical potential is applied thereto, wherein a change of said angle between said antenna plane and said ground plane changes said steering angle.

2. The antenna reflector of claim 1, wherein said antenna-array comprises a planar PCB.

3. The antenna reflector of any one of claims 1 to 2, wherein said reflecting surface is a parabolic reflector for E-band millimeter waves.

4. The antenna reflector of any one of claims 1 to 2, wherein said reflecting surface is a parabolic reflector for 80 GHz millimeter waves.

5. The antenna reflector of any one of claims 1 to 4, wherein said configuring of said individual patch antennas is different relative sizes of said patch antennas.

6. The antenna reflector of any one of claims 1 to 5 wherein at least one said piezoelectric component is a piezoelectric bending element, so that when an electric potential is applied to leads of said piezoelectric bending element, said piezoelectric bending element changes shape in order to change the angle between said antenna plane and said ground plane.

7. The antenna reflector of any one of claims 1 to 6, wherein said dielectric layer between said backing surface and said ground layer comprises a gas.

8. The antenna reflector of any one of claims 1 to 7, wherein said dielectric layer between said backing surface and said ground layer comprises a vacuum of not more than 50 kPa.

9. The antenna reflector of any one of claims 1 to 8, wherein said upper surface of said ground layer is not flat [preferably stepped] so that the distance between said upper surface of said ground layer and said backing surface of said antenna-array is smaller closer to a periphery of said antenna-array and greater closer to a center of said antenna-array.