Dual band reflect array and dual band unit cell for use in reflect array

Abstract

To provide a reflect array capable of supporting a wider bandwidth, and a method for constructing the reflect array.SOLUTION: A reflect array includes multiple unit cells 100. A unit cell 100 includes: a first element 102 configured to address both a first frequency band and a second frequency band; a second element 104 configured to address the second frequency band and compensate for phase errors induced by the first element 102; and a frequency selective surface (FSS) layer 106 disposed between the first element 102 and the second element 104 and configured to reflect the first frequency band and allow passthrough of the second frequency band. The first element 102, the second element 104 and an FSS layer 106 are arranged in a stack with the first element 102 at the top and the second element 104 at the bottom.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The following relates generally to reflectarray antennas, and more particularly to dual-band reflectarray antennas that use patch elements. [Background technology]

[0002] Reflectarrays are a well-known technology for planar reflectors that allow the contours of parabolic reflectors to be mimicked using patch elements. The application of reflectarray technology for space communications has been very limited in the past due to its narrow bandwidth. Typically, reflectarray antennas have a narrow bandwidth that is only partially achievable by reflectarray antennas. Summary of the Invention [Problem to be solved by the invention]

[0003] Therefore, there is a need for a reflectarray antenna that overcomes at least some of the shortcomings of existing systems and methods. [Means for solving the problem]

[0004] A unit cell for use in a reflectarray is provided. The unit cell is configured to receive or transmit RF signals in non-overlapping first and second frequency bands. The unit cell includes a first element configured to address both the first and second frequency bands, a second element configured to address the second frequency band and to cancel phase errors induced by the first element, and a frequency selective surface ("FSS") layer disposed between the first and second elements and configured to reflect the first frequency band and allow the second frequency band to pass. The first element, second element, and FSS layer are arranged in a stack with the first element on top and the second element below.

[0005] The first frequency band may be the V-band and the second frequency band may be the Q-band.

[0006] The first frequency band may be for transmission and the second frequency band may be for reception, or the second frequency band may be for transmission and the first frequency band may be for reception.

[0007] A plurality of unit cells may be mounted in a reflector shell as a reflective array.

[0008] The reflector array and the reflector shell can form a reflector, which can be a segmented reflector including an inner region and multiple outer regions disposed around the periphery of the inner region.

[0009] In an embodiment, the interior region is a hexagon with six sides of equal length, and the number of exterior regions is six. The exterior regions are arranged such that each exterior region includes a first side that forms a common edge with one side of the interior region, a second side that forms a common edge with a first adjacent exterior region, and a third side that forms a common edge with a second adjacent exterior region.

[0010] In an embodiment, the outer areas are equally sized trapezoids and the perimeter of the reflector is a hexagon with six equal length sides.

[0011] A method is provided for constructing a reflectarray for receiving or transmitting RF signals in non-overlapping first and second frequency bands. The method includes: (i) providing a first RF band element comprising a first radiating element patch, the first RF band element configured to address both a first RF band and a second RF band; (ii) providing a second RF band element comprising a second radiating element patch, the second RF band element configured to address the second RF band and to compensate for effects that the first RF band has in the second RF band; (iii) disposing a layer of frequency selective material between the first RF band element and the second RF band element, the layer of frequency selective material configured to reject or reflect signals in the first RF band and to allow signals in the second RF band to pass or transmit signals in the second RF band; (iv) repeating steps (i)-(iii) to form a plurality of dual-band unit cells; and (v) packaging the plurality of dual-band unit cells in a single plane as an array in a reflector shell.

[0012] In an embodiment, the first frequency band is the V-band and the second frequency band is the Q-band.

[0013] In an embodiment, the first frequency band is for transmission and the second frequency band is for reception, or the second frequency band is for transmission and the first frequency band is for reception.

[0014] In an embodiment, a plurality of dual-band unit cells mounted in a reflector shell form a reflector, which is a segmented reflector including an interior region and a plurality of exterior regions disposed around the periphery of the interior region.

[0015] In an embodiment, the interior region is a hexagon with six sides of equal length, the number of exterior regions is six, and the multiple exterior regions are arranged such that each exterior region includes a first side that forms a common edge with one side of the interior region, a second side that forms a common edge with a first adjacent exterior region, and a third side that forms a common edge with a second adjacent exterior region.

[0016] In an embodiment, the outer areas are equally sized trapezoids and the perimeter of the reflector is a hexagon with six equal length sides.

[0017] A method of operating a dual-band reflectarray antenna to receive or transmit RF signals in non-overlapping first and second frequency bands is also provided. The method includes receiving or transmitting RF signals at a dual-band reflectarray, the RF signals including a first RF band signal and a second RF band signal, the dual-band reflectarray comprising a plurality of unit cells, each unit cell comprising a first RF band element, a second RF band element, and a frequency selective surface (FSS) layer disposed between the first element and the second element. The method further includes receiving or transmitting the first RF band signal using a first RF band element of the plurality of dual-band patch elements. The method further includes receiving or transmitting the second RF band signal using a second RF band unit cell of the plurality of dual-band patch elements, including addressing the second RF signal and compensating for the effect of the first RF signal on the second RF band signal. The method further includes filtering the RF signals with a layer of frequency selective material disposed between the first RF band unit cell and the second RF band unit cell of each dual-band patch element to allow passage of the second RF signal and reject or prevent passage of the first RF signal.

[0018] In an embodiment, the first frequency band is the V-band and the second frequency band is the Q-band.

[0019] In an embodiment, the first frequency band is for transmission and the second frequency band is for reception, or the second frequency band is for transmission and the first frequency band is for reception.

[0020] Other aspects and features will become apparent to those of ordinary skill in the art upon review of the following description of several exemplary embodiments.

[0021] The drawings included herein are intended to illustrate various examples of the articles, methods, and apparatus herein. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 1 is a schematic diagram of a dual-band patch element for use in a reflectarray antenna, according to an embodiment. [Figure 2] FIG. 1 is a perspective view of a dual-band patch element for use in a reflectarray antenna, according to an embodiment. [Figure 3] FIG. 3 is a schematic exploded view of the dual-band patch element of FIG. 2. [Figure 4] 1 is a top view of a QV-band reflectarray including multiple dual-band patch elements, illustrating a reflectarray geometry for QV-band applications, according to an embodiment. FIG. [Figure 5] 10 is a graph of antenna directivity at Q-band for a QV-band reflectarray including multiple dual-band patch elements, according to an embodiment. [Figure 6] 10 is a graph of antenna directivity at Q-band for a QV-band reflectarray including multiple dual-band patch elements, according to an embodiment. [Figure 7] 1 is a flow diagram of a method for constructing a dual-band reflectarray, according to an embodiment. [Figure 8] 1 is a flow diagram of a method of operating a dual-band reflectarray, according to an embodiment. [Figure 9]10 is a graph of antenna directivity versus the theta plane for a dual-band QV antenna without the dual-band reflectarray of the present disclosure (i.e., using a more conventional approach), which demonstrates poor beamforming compared to beamforming that can be achieved using the dual-band reflectarray of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0023] Various devices or processes are described below to provide examples of each claimed embodiment. The embodiments described below do not limit the claimed embodiments, and the claimed embodiments may cover processes or devices different from those described below. The claimed embodiments are not limited to devices or processes having all of the features of any one device or process described below, or to features common to more than one or all of the devices described below.

[0024] Furthermore, although process steps, method steps, algorithms, etc. may be described (in this disclosure and / or claims) in a sequential order, such processes, methods, and algorithms may be configured to operate in an alternating order. In other words, any order or sequence of steps that may be described does not necessarily dictate a requirement that the steps be performed in that order. Process steps described herein may be performed in any order that is practical. Additionally, some steps may be performed simultaneously.

[0025] It will be readily apparent that where a single device or article is described herein, two or more devices / articles (whether or not they cooperate) may be used in place of the single device / article. Similarly, where two or more devices / articles are described herein (whether or not they cooperate), it will be readily apparent that a single device / article may be used in place of the two or more devices or articles.

[0026] The following relates generally to reflectarrays, and more particularly to reflectarrays and dual-band patch elements for use in dual-band reflectarrays.

[0027] The present disclosure provides a dual-band reflectarray and unit cells (or dual-band patch elements) for use in a reflectarray. Generally, the unit cell is a shape that is re-fabricated along the reflectarray with different parameters to address the required phase slope and achieve parabolic performance. In the present disclosure, the unit cell may include a top patch element, an FSS, and a bottom patch element. The unit cell enables good performance for dual-band operation. Good performance can be measured in terms of gain, but also in terms of having a real beam. For example, while other approaches may produce very poor patterns and fail to form a beam (e.g., FIG. 9), the present disclosure provides acceptable gain and beam characteristics for dual-band operation.

[0028] The present disclosure combines the use of frequency-selective surfaces with the concept of a reflective array, which has not been done before. Existing approaches focus on combining two bands in a single element, which, due to the nature of the cell, results in large phase errors in one of the bands. The frequency-selective surface layer in the disclosed unit cell allows for decoupling of elements operating in only one band, allowing for cancellation of the phase error from the first layer. Thus, the control over the two bands in the disclosed unit cell is much better than such existing approaches. The unit cell structure also allows for independent optimization of each band (e.g., having the first band aimed at a different angle than the second band).

[0029] The dual-band reflectarrays of the present disclosure offer an improvement over existing reflectarray technology with respect to wider bandwidths. Previous work aimed at increasing the bandwidth of such elements has focused on a distinctly different approach from the present disclosure (a single element handling a wide bandwidth).

[0030] Reflectarrays are an interesting technology for satellite communications ("Satcom") because they can shorten the lead time for reflectors and enable the potential use of deployable flat panel reflectors and PCB-based antennas. The ability to support two bands simultaneously with this concept allows for wider use for Satcom.

[0031] The techniques described herein can be used to recreate parabolic reflectors, but with flat surfaces and patch elements (e.g., through introducing a phase difference to produce a phase front).

[0032] 1, there is illustrated a dual-band patch element 100 for use in a reflectarray antenna, according to an embodiment. The dual-band patch element 100 is also referred to as a unit cell 100.

[0033] Multiple dual-band patch elements 100 may be assembled to form an array of radiating elements in a reflector. Such a reflectarray may be referred to herein as a dual-band reflectarray. A dual-band reflectarray includes two non-overlapping RF bands operating simultaneously in the same array. A dual-band reflectarray may be a receive or transmit antenna. A dual-band reflectarray may be particularly suitable for space communications. A dual-band reflectarray may be implemented as part of a reflectarray antenna onboard a satellite.

[0034] In a particular embodiment, an array of dual-band elements may be implemented with a complete single offset antenna operating in non-overlapping first and second RF bands (e.g., V-band and Q-band).

[0035] In an embodiment, a dual-band reflector array may be a reflector in which the reflector RF surface is divided into multiple portions (also referred to as zones or sections). The reflector may comprise an inner zone and multiple outer zones (or "petals") arranged around the periphery of the inner zone (e.g., each outer zone forms a common edge with one edge or side of the inner zone). In an example, the reflector is hexagonal and comprises an inner hexagonal zone and six outer zones arranged around the inner hexagonal zone (an example of such a "petal-shaped reflector" is shown in FIG. 4).

[0036] The dual-band patch element 100 and reflectarrays formed from multiple dual-band patch elements 100 may be particularly well suited for applications in flat panel, deployable antennas, and reflector antennas with subreflectors, and this disclosure contemplates and covers embodiments in which the dual-band patch element and dual-band reflectarrays are used in such applications.

[0037] The dual-band patch element 100 comprises a first radio frequency (“RF”) band element 102, a second RF band element 104, and a frequency selective surface (“FSS”) layer 106 (or frequency selective spatial filter 106).

[0038] The patch element 100 also includes a first RF patch 108 that is a component of the first RF band element 102 .

[0039] The patch element 100 also includes a second RF patch (not visible in FIG. 1) that is a component of a second RF band element 104.

[0040] Although the first RF patch 108 is depicted as a rectangle in FIG. 1 , the shape of the first and second RF patches is not particularly limited, and any suitable shape or form may be used. For example, without limitation, the first and second RF patches may be rectangular, circular, or hexagonal. The first and second RF patches may also be referred to as radiating elements.

[0041] The first RF band element 102, the second RF band element 104, and the FSS layer 106 are arranged in a layered configuration with the FSS layer 106 disposed between the first RF band element 102 and the second RF band element 104. The patch element 100 as a whole, and the elements 102, 104 individually, can be considered a PCB stack-up configuration.

[0042] Thus, the first RF band element 102 may be referred to as a first or upper layer of the patch element 100 , and the second RF band element 104 may be referred to as a second or lower layer of the patch element 100 .

[0043] Furthermore, when the plurality of dual-band radiating elements 100 are arranged in a reflective array, the plurality of first RF band elements 102 can be considered to form a first layer of the reflective array layer, and the plurality of second RF band elements 104 can be considered to form a second layer of the reflective array, the first layer and the second layer being separated by an FSS layer (comprising the FSS layer 106 of the plurality of patch elements 100 in the array).

[0044] The dual-band patch element 100 comprises an upper surface 110 and a lower surface 112. The patch element 100 is mounted or positioned in a reflector shell using the lower surface 112. The upper surface 110 may also be considered and referred to as the radiating surface of the dual-band patch element 100.

[0045] The first RF band of the first RF band element 102 and the second RF band of the second RF band element 104 are non-overlapping RF bands. In a specific example, the first RF band and the second RF band are the V band and the Q band, respectively. The frequencies of the first and second RF bands are not particularly limited, and any combination of non-overlapping RF bands can be used. In general, a larger separation between the first RF band and the second RF band may be preferable because it is easier for the FSS layer 106 to filter and maintain the separation.

[0046] In general, the FSS layer 106 is configured to reflect a first RF band and allow a second RF band to pass through.

[0047] This may involve re-cancelling the phase changed by the V-band unit cell to ultimately have the correct phase dispersion.

[0048] The stacked structure of patch elements 100 with the FSS layer 106 between the first RF band element 102 and the second RF band element 104 provides the flexibility to control each band separately.

[0049] The FSS layer 106 can have any suitable structure, shape, or form. In some examples, the FSS layer 106 can be a disk or ring.

[0050] The FSS layer 106 can isolate the lower layer (element 104) from the upper layer (element 102). The lower layer 104 is dedicated to only the second RF band, allowing it to correct or cancel out phase errors induced by the first layer. The upper element 102 will affect the first and second RF bands. The FSS filters the first RF band, preventing it from reaching the lower patch 104. Signals in the second RF band pass through the FSS 106 and reach the lower patch 104. The lower patch is dedicated to the second RF band and is used to shape the phase profile in the second RF band while correcting the phase errors induced by the upper element 102 (which affect the first and second RF bands).

[0051] The first RF band element 102 is dedicated to the first RF band but affects both the first and second RF bands. The phase of the reflection is determined by the size of the patch element, which will vary depending on the reflector array. The top patch 102 affects both bands because signals in the first and second RF bands reflect off the top patch 102. The first RF band element 102 is "dedicated" to the first RF band in that it is sized for best performance in the first RF band.

[0052] 2 and 3, a dual-band patch element 200 is illustrated in accordance with one embodiment. Patch element 200 may also be referred to as unit cell 200. Patch element 200 is an example of patch element 100 that is operable in the QV band. Similar components are given similar reference numbers incremented by 100 (i.e., 1xx, 2xx).

[0053] The patch element 200 includes a V-band element 202 (or a V-band radiating element 202 ), a Q-band element 204 (or a Q-band radiating element 204 ), and an FSS layer 206 disposed between the elements 202 , 204 .

[0054] The patch element 200 comprises multiple substrate layers 214, 220, 224, 230, 236. The substrate layers are made of a dielectric material suitable for use in a printed circuit board (PCB stack-up). In some embodiments, the substrate material may be Kevlar or Kapton with etched copper. The substrate layers 214, 220, 224, 230, 236 are arranged in a stacked configuration.

[0055] The patch element 200 comprises a plurality of bonding layers 218, 222, 228, and 232. The bonding layers 218, 222, 228, and 232 are used to bond the substrate layers 214, 220, 224, 230, and 236. Thereby, each of the bonding layers 218, 222, and 228 is disposed between two substrate layers.

[0056] The patch element 200 further comprises copper patches 208, 216, and 234. The copper patches 208, 216, and 234 are depicted as circles. In other embodiments, the copper patches 208, 216, and 234 may have any other suitable shape. The copper patch 208 is disposed on the top surface of the substrate layer 214 of the V-band element 202. The copper patch 216 is disposed between the bonding layer 218 and the bottom surface of the substrate layer 214. The copper patch 234 is disposed on the top surface of the substrate layer 236 of the Q-band element 204. The copper patches are designed or configured (e.g., sized) based on frequency. The copper patches may be larger or smaller depending on the position of the dual-band patch element 200 in the reflective array. In FIG. 3 , it can be seen that the copper patches 208, 216, and 234 become larger moving from top to bottom (i.e., 208 is smaller than 216, which is smaller than 234). This size variation can be specifically designed for the particular position that the dual-band patch element 200 will occupy in the reflective array, and therefore, generally speaking, the size of the copper patch can vary depending on where the patch element 200 is positioned in the reflective array.

[0057] Patch element 200 further comprises copper FSS elements 223 and 226. Copper element 223 is disposed on the upper surface of substrate layer 224 of FSS layer 206. Copper element 226 is disposed between the lower surface of substrate layer 224 and bonding layer 228. The shapes of copper elements 223 and 226 are just an example, and the shapes may be different in other embodiments and are not particularly limited.

[0058] The patch element 200 further comprises a copper layer 238. The copper layer 238 is bonded to the bottom surface of the bottom substrate layer 236.

[0059] Referring now to Figure 4, there is shown a dual-band reflector array 400 comprising a plurality of dual-band patch elements, such as patch element 100 of Figure 1, according to one embodiment. Figure 4 shows the final reflector array comprised of one embodiment of a unit cell of the present disclosure.

[0060] The dual-band reflector array 400 is a petal reflector that includes an inner or central hexagonal area 402 and six outer "petal" areas 404-1, 404-2, 404-3, 404-4, 404-5, and 404-6 arranged around the perimeter of the inner hexagonal area 402. The manner in which the outer petal areas are shaped and arranged around the inner hexagonal area 402 creates the overall hexagonal shape of the reflector. Each petal area 404 shares one edge with the inner hexagonal area 402 and two other edges with adjacent petals.

[0061] 5 and 6, graphs 500, 600 illustrating antenna directivity in the Q-band and V-band, respectively, for a QV-band reflectarray including a plurality of dual-band patch elements are shown, according to an embodiment.

[0062] Graphs 500 and 600 show the radiation patterns of reflectarrays comprised of unit cells of the present disclosure configured for Q-band and V-band. Good gain performance is seen for both frequency bands. In contrast, FIG. 9 is a graph of antenna directivity versus the theta plane for a QV antenna without the dual-band reflectarray of the present disclosure (i.e., using a more conventional configuration / approach), and the graph shows poor beamforming compared to that which can be achieved using the dual-band reflectarray of the present disclosure.

[0063] Referring now to FIG. 7, a method 700 of constructing a reflective array for receiving or transmitting RF signals in non-overlapping first and second frequency bands is illustrated, according to an embodiment.

[0064] The method 700 includes, at step 702, providing a first RF band element comprising a first radiating element patch, the first RF band element configured to address both a first RF band and a second RF band.

[0065] The method 700 includes, at step 704, providing a second RF band element comprising a second radiating element patch, the second RF band element configured to address a second RF band and to compensate for effects that the first RF band has on the second RF band.

[0066] The method 700 includes, at step 706, disposing a layer of frequency selective material between the first RF band element and the second RF band element, the layer of frequency selective material configured to reject or reflect signals in the first RF band and to allow passage of or transmit signals in the second RF band.

[0067] Steps 702-706 form the dual-band patch element.

[0068] The method 700 includes, at step 708, repeating steps 702-706 to form a plurality of dual-band patch elements.

[0069] The method 700 includes, at step 710, mounting a plurality of dual-band patch elements in a single plane as an array in a reflector shell.

[0070] The reflector comprising a dual-band patch element mounted on a reflector shell may be a segmented reflector.

[0071] The segmented reflector may include an inner region and multiple outer regions disposed around the periphery of the inner region.

[0072] In an embodiment, the interior region is a hexagon with six sides of equal length, and the number of exterior regions is six. The exterior regions are arranged such that each exterior region includes a first side that forms a common edge with one side of the interior region, a second side that forms a common edge with a first adjacent exterior region, and a third side that forms a common edge with a second adjacent exterior region.

[0073] In an embodiment, the outer areas are equally sized trapezoids and the perimeter of the reflector is a hexagon with six equal length sides.

[0074] 8, a method 800 of operating a dual-band reflectarray is illustrated, according to an embodiment. The dual-band reflectarray can operate simultaneously in non-overlapping first and second RF bands. The dual-band reflectarray comprises a plurality of dual-band patch elements, such as patch element 100 of FIG. 1.

[0075] In step 802, the method 800 includes receiving or transmitting RF signals at a dual-band reflectarray, the RF signals including a first RF band signal and a second RF band signal.

[0076] In step 804, the method 800 includes receiving or transmitting a first RF band signal using a first RF band element of the plurality of dual-band patch elements.

[0077] In step 806, the method 800 includes receiving or transmitting a second RF band signal using a second RF band element of the plurality of dual-band patch elements, including addressing the second RF signal and compensating for an effect of the first RF signal on the second RF signal.

[0078] In step 808, the method 800 includes filtering the RF signals with a layer of frequency selective material disposed between the first RF band element and the second RF band element of each dual-band patch element to allow passage of the second RF signal and reject or prevent passage of the first RF signal.

[0079] Although the foregoing description provides examples of one or more devices, methods, or systems, it will be understood that other devices, methods, or systems may be within the scope of the claims as interpreted by one of ordinary skill in the art. [Explanation of symbols]

[0080] 100 Dual-band patch elements, unit cells, dual-band radiating elements 102 first radio frequency (RF) band element, upper layer, upper element, upper patch 104 second radio frequency (RF) band element, lower layer, lower patch 106 Frequency Selective Surface (FSS) Layer, Frequency Selective Spatial Filter 108 First RF Patch 110 Top surface 112 Bottom surface 200 Dual-band patch elements, unit cells 202 V-band element, V-band radiating element 204 Q-band element, Q-band radiating element 206 FSS layer 208, 216, 234 Copper Patch 214, 220, 224, 230, 236 Base layer 218, 222, 228, 232 bonding layer 223, 226 Copper FSS elements 238 Copper layer 400 Dual-Band Reflector Array 402 Internal hexagonal area 404, 404-1, 404-2, 404-3, 404-4, 404-5, 404-6 Outer Petal Area

Claims

1. 1. A unit cell for use in a reflectarray, the unit cell for receiving or transmitting RF signals in non-overlapping first and second frequency bands, the unit cell comprising: a first element configured to accommodate both the first frequency band and the second frequency band; a second element configured to address the second frequency band and to cancel the phase error induced by the first element; a frequency selective surface ("FSS") layer disposed between the first element and the second element and configured to reflect the first frequency band and allow the second frequency band to pass; Equipped with The first element, the second element, and the FSS layer are arranged in a stack with the first element on top and the second element below a unit cell.

2. 2. The unit cell of claim 1, wherein the first frequency band is a V-band and the second frequency band is a Q-band.

3. 2. The unit cell of claim 1, wherein the first frequency band is for transmission and the second frequency band is for reception, or the second frequency band is for transmission and the first frequency band is for reception.

4. A reflector array comprising a plurality of unit cells of claim 1 mounted in an array in a reflector shell.

5. 5. The reflective array of claim 4, wherein the reflective array and the reflector shell form a reflector, the reflector being a segmented reflector including an inner section and a plurality of outer sections disposed around a periphery of the inner section.

6. 6. The reflective array of claim 5, wherein the inner region is a hexagon with six sides of equal length, the number of outer regions is six, and the plurality of outer regions are arranged such that each outer region includes a first side that forms a common edge with one side of the inner region, a second side that forms a common edge with a first adjacent outer region, and a third side that forms a common edge with a second adjacent outer region.

7. 7. The reflective array of claim 6, wherein the outer areas are equally sized trapezoids and the periphery of the reflector is a hexagon with six sides of equal length.

8. 1. A method of constructing a reflectarray for receiving or transmitting RF signals in non-overlapping first and second frequency bands, comprising: (i) providing a first RF band element comprising a first radiating element patch, the first RF band element configured to accommodate both a first RF band and a second RF band; (ii) providing a second RF band element comprising a second radiating element patch, the second RF band element configured to address the second RF band and to compensate for effects that the first RF band has on the second RF band; (iii) disposing a layer of frequency selective material between the first RF band element and the second RF band element, the layer of frequency selective material configured to reject or reflect signals in the first RF band and to allow passage of or transmit signals in the second RF band; (iv) repeating (i)-(iii) to form a plurality of dual-band unit cells; (v) packaging the plurality of dual-band unit cells in a single plane as an array in a reflector shell; A method comprising:

9. 9. The method of claim 8, wherein the first frequency band is a V-band and the second frequency band is a Q-band.

10. 9. The method of claim 8, wherein the first frequency band is for transmission and the second frequency band is for reception, or the second frequency band is for transmission and the first frequency band is for reception.

11. 10. The method of claim 8, wherein the plurality of dual-band unit cells mounted in the reflector shell form a reflector, the reflector being a segmented reflector including an interior region and a plurality of exterior regions disposed around a periphery of the interior region.

12. 12. The method of claim 11, wherein the interior region is a hexagon with six sides of equal length, the number of exterior regions is six, and the plurality of exterior regions are arranged such that each exterior region includes a first side that forms a common edge with one side of the interior region, a second side that forms a common edge with a first adjacent exterior region, and a third side that forms a common edge with a second adjacent exterior region.

13. 13. The method of claim 12, wherein the exterior areas are equally sized trapezoids and the perimeter of the reflector is a hexagon with six sides of equal length.

14. 1. A method of operating a dual-band reflectarray antenna for receiving or transmitting RF signals in non-overlapping first and second frequency bands, comprising: receiving or transmitting RF signals at a dual-band reflectarray, the RF signals including a first RF band signal and a second RF band signal, the dual-band reflectarray comprising a plurality of unit cells, each unit cell comprising a first RF band element, a second RF band element, and a frequency selective surface (FSS) layer disposed between the first RF band element and the second RF band element; receiving or transmitting the first RF band signal using the first RF band elements of a plurality of dual-band patch elements; receiving or transmitting the second RF band signal using second RF unit cells of the plurality of dual-band patch elements, including addressing the second RF band signal and compensating for effects of the first RF band signal on the second RF band signal; filtering the RF signals with a layer of frequency selective material disposed between the first RF unit cell and the second RF band unit cell of each dual-band patch element to allow the second RF band signals to pass and reject or prevent the first RF band signals from passing; A method comprising:

15. 15. The method of claim 14, wherein the first frequency band is V-band and the second frequency band is Q-band.

16. 15. The method of claim 14, wherein the first frequency band is for transmission and the second frequency band is for reception, or the second frequency band is for transmission and the first frequency band is for reception.

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