Slant polarized stacked patch antenna element

Abstract

A slant polarization antenna element includes a planar radiator element electromagnetically coupled through a coupling mechanism to an open center planar resonator element. The polarization of a transmitted signal is determined by the position of an input port on the open center planar resonator element. Where the coupling mechanism includes a metal layer with an iris positioned between the resonator and the radiator. In some examples, the open center planar resonator is an elliptical ring resonator within a cavity formed by a base ground plane, the ground plane with the iris, and vias connecting the ground planes.

Description

SLANT POLARIZED STACKED PATCH ANTENNA ELEMENTCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims priority to Provisional Application No. 63 / 654,608, entitled “SLANT POLARIZED STACKED PATCH ANTENNA RADIATOR FOR PHASED ARRAY APPLICATIONS” and filed May 31 , 2024, assigned to the assignee hereof and hereby expressly incorporated by reference in its entirety.FIELD

[0002] This invention generally relates to wireless communications and more particularly to slant polarized antenna elements.BACKGROUND

[0003] In wireless communication systems, antennas are used to receive and / or transmit electromagnetic signals. During transmission, electrical energy is emitted while during reception, electrical energy is captured. An antenna has an antenna polarization which is the orientation of the electric field of the electromagnetic wave that is transmitted or received by the antenna. Antenna polarizations include linear, circular and elliptical polarizations. Dual polarization antennas transmit and / or receive signals in two distinct polarization planes such as vertical and horizontal polarization planes. In some situations, it may be advantageous to utilize an antenna with a rotated polarization. For example, a slant dual polarized antenna may include a first linear polarization that is 45 degrees from vertical and a second linear polarization that is negative 45 degrees from vertical. In other words, the polarization of a conventional vertical-horizontal polarized antenna is rotated by an angle that is often 45 degrees.Phased array antennas have multiple antenna elements where the inputs signals to the antenna element can be manipulated to control the direction of the antenna beam. The scan volume is a characteristic of the phased array antenna based on the maximum angle the beam may be directed from boresight while maintaining a particular activereturn loss level. In other words, the scan volume is the volume of space in front of the array where the beam can be steered towards while maintain a particular active return loss level.SUMMARY

[0004] A slant polarization antenna element includes a planar radiator element electromagnetically coupled through a coupling mechanism to an open center planar resonator element. The polarization of a transmitted signal is determined by the position of an input port on the open center planar resonator element. The coupling mechanism may include parallel plate coupling between the resonator and the planar radiator element or a metal layer with an iris positioned between the resonator and the radiator, as well as other coupling techniques. In some examples, the open center planar resonator is an elliptical ring resonator within a cavity formed by a base ground plane, the ground plane with the iris, and vias connecting the ground planes. The slant polarization antenna element may be configured for slanted dual linear polarization with two input ports positioned such that two polarizations are orthogonal and rotated relative to vertical and horizontal polarization.BRIEF DESCRIPTION OF THE DRAWINGS

[0005] FIG. 1A is a block diagram of an antenna element including a planar radiating element electromagnetically coupled through a coupling mechanism to a planar resonator element with center opening (open center resonator element).

[0006] FIG. 1 B is an illustration of an exploded view of an example of an antenna element where the open center resonator element is an annular ring resonator element and the coupling mechanism includes a metal plate with an iris.

[0007] FIG. 2A is a block diagram of an example of a slant polarized antenna element having dual linear polarization where a radiator is formed by a planar radiator element and a radiator cavity and an open center resonator is formed with a planar open center resonator element and a resonator cavity.

[0008] FIG. 2B is an illustration of an exploded perspective view of an example of a slant polarization antenna element having dual linear polarization and including a radiator and an open center resonator.

[0009] FIG. 20 is an illustration of an example of a cross-sectional side view along A-A of FIG. 2B.

[0010] FIG. 2D is an illustration of an example of a cross-sectional top view taken along B-B of FIG. 2B and FIG. 2C.

[0011] FIG. 2E is an illustration of an example of a cross-sectional top view taken along C-C of FIG. 2B and FIG. 2C.

[0012] FIG. 3A is a block diagram of an example of a slant polarized antenna element having dual linear polarization where a radiator is formed by a planar radiator element on a dielectric and an open center resonator is formed with a planar open center resonator element and a resonator cavity.

[0013] FIG. 3B is an illustration of an exploded perspective view of an example of a slant polarization antenna element having dual linear polarization and including a radiator and an open center resonator.

[0014] FIG. 3C is an illustration of an example of a cross-sectional side view along A-A of FIG. 3B.

[0015] FIG. 3D is an illustration of an example of a cross-sectional top view taken along B-B of FIG. 3B and FIG. 3C.

[0016] FIG. 3E is an illustration of an example of a cross-sectional top view taken along C-C of FIG. 3B and FIG. 3C.

[0017] FIG. 4A is an illustration of a cross-section sideview of an example of the slant polarized antenna element with a wide angle impedance matching (WAIM) structure attached to the radiator layer.

[0018] FIG. 4B is an illustration of a cross-section sideview of an example of the slant polarized antenna element with a wide angle impedance matching (WAIM) structure attached to the radiator layer.DETAILED DESCRIPTION

[0019] As discussed above, it is often advantageous to utilize slant polarization antennas. Unfortunately, conventional techniques often do not maintain a field of view and scan volume of the slant polarization antenna that is consistent with a non-rotated polarization antenna. With a phased array antenna including multiple antenna elements, for example, physically rotating each antenna element results in increased spacing between the elements which decreases the scan volume. In addition, the field of view of each antenna element is also rotated which typically results in the field of view that is not aligned with the horizon. For the examples herein, however, the polarization of an antenna element is determined by the characteristics of one or more components of the antenna element such that an appropriate field of view and scan volume are maintained. The slant polarized antenna element includes at least a planar radiator element electromagnetical ly coupled through a coupling mechanism to a planar resonator element having an opening (open center resonator element). The polarization of the antenna element can be established by the position (location) of the input port on the planar open center resonator element. As discussed herein, “slant polarization” and “slant polarized” mean polarization at an angle to vertical or horizontal polarization where the angle can be any value. In some situations, the angle may be 45 degrees.

[0020] For the discussions herein, there is reciprocity between the antenna element as a transmission device and as a reception device. Therefore, the receive and transmit properties of the antenna element are identical for the examples. The characteristics, deign parameters, and configuration of the antenna element discussed with reference to transmission may be applied to the antenna apparatus when used as a receiving device. Therefore, the radiator captures signals and provides an output at the input port when the antenna element is used for receiving signals. More specifically, since the antenna element is a linear passive structure, the reciprocity theorem applies to its operation as a transmitter and receiver. Thus, the antenna element behaves exactly the same in transmission as in reception. In transmit mode, a signal at the input port of open center resonator element induces currents on the planar radiator element thatresult in transmission of electromagnetic fields to free space. In receive mode, an electromagnetic wave in free space that reaches the antenna element induces currents in the radiator element which, in turn, produce a signal at the input port.

[0021] The antenna layers are separated from each other by a dielectric material. In one example, printed circuit board (PCB) techniques are used to form the antenna element. Therefore, the ground layers, radiator element, and resonator elements can be formed with metallic sheets laminated on dielectric material substrates. For the examples discussed herein, a dielectric material having a dielectric constant greater than the dielectric constant of air is used and is illustrated as crosshatched sections in some of the figures. A figure with an exploded view may not show the dielectric in the interest of clarity. For the examples, the dielectric material is uniform within the structures although, in some situations, different dielectric materials may be used.

[0022] FIG. 1 A is a block diagram of an antenna element 100 including a planar radiating element 102 electromagnetically coupled through a coupling mechanism 104 to a planar resonator element with center opening (open center resonator element) 106. The open center resonator element 106 has at least one input port 108 for connecting to a signal source. The open center resonator element 106 may be part of an open center resonator that includes the open center resonator element 106 positioned within a resonator cavity. As discussed below in further detail, some examples include a planar open center resonator element 106 within a resonator cavity formed by a base ground layer and vias surrounding the open center resonator element 106 and extending from the base ground layer to a metal layer having an iris. The planar radiator element 102 radiates electromagnetic energy from the planar radiator element 102 at a polarization when an electromagnetic signal is applied to the input port 108. In some examples, the polarization is at least partially determined by an input port position 110 of the input port 108 on the open center resonator element 106. The coupling mechanism 104 may implemented in any one of numerous ways. In some examples discussed in further detail below, the coupling mechanism 104 includes a metal plate with an iris positioned between the planar radiator element 102 and the open center resonator element 106. Other components may also be used to form the coupling mechanism 104. For example, the coupling mechanism 104 may include two or more planar resonatorspositioned between the open center resonator element 106 and the planar radiating element 102 where the two or more planar resonators may be electrically connected using vias or other means or may be otherwise electromagnetically coupled. Another example of a suitable coupling mechanism 104 includes parallel plate coupling between the planar open center resonator element 106 and the planar radiator element without any additional components facilitating the coupling. In still other examples, the coupling mechanism may include multiple metal layers with irises. The characteristics of the coupling mechanism 104 depend on the shape of the center opening in the open center resonator element 106.

[0023] FIG. 1 B is an illustration of an exploded view of an example of an antenna element 120 where the open center resonator element 106 is an annular ring resonator element 122 and the coupling mechanism 104 includes a metal plate 124 with an iris 126. Accordingly, the antenna element 120 is an example of the antenna element 100 discussed with reference to FIG. 1A. FIG. 1 B is not necessarily to scale and is not intended to be more than a general illustration showing the relative positioning of elements. The annular ring resonator element 122 has an elliptical outer perimeter 130 and a center opening perimeter 132 of the center opening 134 is also elliptical for the example. In other examples, the shapes of outer perimeter 130 and the center opening perimeter 132 may be different. As discussed below in further detail, the annular ring resonator element 122 may be part of an annular ring resonator formed by a resonator cavity (not shown in FIG. 1 B) and the annular ring resonator element 122. For the example of FIG. 1 B, the planar radiator element 102 is a rectangular planar radiator element 136 that radiates electromagnetic energy at a polarization 138 when an electromagnetic signal is applied to the input port 108. The polarization 138 may be in reference to a reference polarization 140. For example, the polarization 138 may be in reference to a vertical polarization associated with the input port 108 at a reference position 142 on the annular ring resonator 122. When the electromagnetic signal is applied to the input port 108 at the reference position 142, the polarization of the antenna element 120 is the reference polarization 140. Accordingly, linearly polarized radiation is at an angle 144 of from the reference polarization 140 where the angle 144 can be established by selecting the input port position 110. The polarization angle 144is rotated about a center axis 146 extending through the center opening 134 and through the planar radiator element 102 (rectangular radiator patch 136). The polarization angle 144 may be 45 degrees in some situations. For the example, the shape of the iris 126 in the metal layer 124 and the shape of the center opening perimeter 132 at least partially establish the coupling mechanism 104. The principles and operation discussed with reference to FIG. 1 B may be applied to other configurations and structures discussed herein. For example, the general operation of the antenna element may be applied to open center resonator elements with different outer shapes and opening shapes, as well as to different coupling mechanisms. The metal plates 124 with the iris 126 is illustrated with dashed lines to indicate that this element can be omitted or replaced with another element.

[0024] FIG. 2A is a block diagram of an example of a slant polarized antenna element 200 having dual linear polarization where a radiator 202 is formed by a planar radiator element 102 and a radiator cavity 204 and an open center resonator 206 is formed with a planar open center resonator element 208 and a resonator cavity 210. Accordingly, the slant polarized antenna element 200 is an example of the antenna element 100 and the antenna element 120 discussed with reference to FIG. 1A and FIG. 1 B with dual linear polarization. The planar open center resonator element 208 includes a first input port 212 and a second input port 214. The planar open center resonator element 208, therefore, is an example of the planar open center resonator element 106 having two input ports. For the example, the polarization angle of a first polarization associated with the first input port 212 is 45 degrees from vertical and the polarization of a second polarization associated with the second input port 214 is 45 degrees from horizontal. However, angles other than 45 degrees can be used. The planar open center resonator element 208 may have any of several outer shapes such as, for example, circular, elliptical, rectangular, and square shapes. The center opening of the open center resonator element 208 may also have any of several shapes such as, for example, circular, elliptical, a rectangular, and square shapes. The outer shape may be the same as the opening shape or may be different. In addition, where the shapes are not symmetrical, the length and width of the opening shapes may be offset from the length and width of the outer shape in some circumstances.

[0025] For the example of FIG. 2A, the coupling mechanism 104 includes a metal plate with an iris 216. The iris 216 is an opening in the conductive metal plate where the shape of the iris 216 dictates the coupling between the open center resonator element 210 and the planar radiator element 102. A cross-shaped iris, such as the iris 126 in FIG. 1 B and discussed with reference to some examples below, is useful for supporting two orthogonal modes of radiation (TM11 mode). In some situations, the open center resonator element may be designed to support higher order modes which may require different aperture shapes to allow transmission of the different modes.

[0026] The two input ports 212, 214 provide a mechanism for transmission of radiation in two polarizations. The input port positions of the input ports 212, 214 may be selected to support two orthogonal modes of radiation. For example, a first linear polarization of a first radiated signal may be 90 degrees offset from a second linear polarization of a second radiated signal when a first electromagnetic signal is applied to the first input port 212 and a second electromagnetic signal is applied to the second input port 214.

[0027] FIG. 2B is an illustration of an exploded perspective view of an example of a slant polarization antenna element 220 having dual linear polarization and including a radiator 202 and an open center resonator 206. Accordingly, the slant polarized antenna element 220 is an example of the antenna element 100, the antenna element 120, and the slant antenna element 200 discussed with reference to FIG. 1A, FIG. 1 B and 2A.

[0028] FIG. 2C is an illustration of an example of a cross-sectional side view along A-A of FIG. 2B. FIG. 2D is an illustration of an example of a cross-sectional top view taken along B-B of FIG. 2B and FIG. 2C. FIG 2E is an illustration of an example of a cross-sectional top view taken along C-C of FIG. 2B and FIG. 2C. FIG. 2B, FIG. 2C, FIG. 2D and FIG. 2E are not necessarily to scale and are not intended to be more than general illustrations showing the relative positioning of elements. Some components are not illustrated in at least some of the figures in the interest of clarity. For example, not all vias between the layers are illustrated in the FIG. 2B and some of the vias behind the plane of the cross-section are not illustrated with dashed lines in FIG. 20. The slant antenna element 220 may include an outer enclosure (not shown) that surrounds the slant antenna element structure expect for openings for the input port(s) and theradiator. In addition to providing additional shielding and ground connectivity, an outer enclosure may provide structural stability. Examples of suitable techniques for forming an outer enclosure include using metal sheets, metallic vias, and combinations of the two. The outer enclosure, however, can be omitted in some situations.

[0029] For the example of FIGS. 2B-2E, a radiator cavity 204 is formed by a metal layer 222 connected to a radiator layer metal boundary 224 by vias 226 where the radiator layer metal boundary 224 surrounds the planar radiator element 102. The radiator layer metal boundary 224 and the planar radiator element 102 are on a radiator element layer 228. The number of vias 226 and the locations of the vias 226 are selected such that vias form an electromagnetic wall at the frequencies of operation. The radiator cavity forms an electromagnetic enclosure at the operating frequencies where the vias 226 form the side walls of the radiator cavity 204. The electromagnetic enclosure, however, has an opening for the planar radiator element 102 so that electromagnetic energy can be transmitted and / or received. For the example, the metal layer 222 includes a cross-shaped iris 230 and is separated from the radiator element layer 228 by a dielectric layer 232. The cross-shaped iris 230 is formed by two rectangular openings intersecting at the midpoints of the rectangles. In some situations, the intersection is the at the midpoint of one of the rectangles. Depending on the desired coupling and overall operation of the antenna element, the iris 230 may be other shapes where some examples include rectangles, squares, circles, ellipses, dog-bones, “T”-shapes, and T-shapes (two parallel rectangles connected by a longer perpendicular rectangle). The shape of the iris 232 may at least partially affect characteristics of the antenna element including frequency bandwidth, radiation pattern, antenna gain, and impedance. Accordingly, the shape of the iris 230 may be selected to obtain different combinations of such characteristics as well as to obtain a targeted scan volume, crosscoupling, and frequency response (filtering).

[0030] A resonator layer 234 includes the open center resonator element 210 and a resonator layer ground 236. For the example, the resonator cavity 206 is formed by the metal layer 222, a base ground layer 238 and a plurality of vias 240 connecting the metal layer 222 and the base ground layer 238. The number of vias 240 and the locations of the vias 240 are selected such that vias 240 form an electromagnetic wall atthe frequencies of operation. The resonator cavity 206 forms an electromagnetic enclosure at the operating frequencies where the vias 240 form the side walls of the resonator cavity 206. The open center resonator element 210 is within the resonator cavity 206. In the interest of clarity, the oval shapes representing the different vias in FIG. 2B are illustrated with different fill where the vias 226 between the metal layer 222 and the radiator layer 228 are shown with shading, the vias 240 between the base ground layer 238 and the metal layer 222 are shown with solid black fill, and ground vias 242 extending from the base ground layer 238 to the radiator layer metal boundary 224 of the radiator layer 228 do not have a fill. For the example, the resonator layer 234 is separated from the metal layer 222 by a dielectric layer 244 and from the base ground 238 by another dielectric layer 246.

[0031] The antenna element 220 is configured to be implemented as part of a Phased Array Antenna Module (PAAM) where proper grounding is important for performance. Adequate grounding provides a return path for the electromagnetic signal and reduces mutual coupling between the multiple antenna elements thereby maintaining the electrical performance of the antenna elements. Effective grounding minimizes ground plane and feed network losses and enhances beam steering. For the example, grounding between the layers in the antenna element is facilitated by ground vias 242 and the other vias between the ground sections of the layers. Any combination of through vias, blind vias, and micro vias may be used. In some situations, other grounding techniques may be implemented.

[0032] For the example, input ports vias 248, 250 provide a connection path to the input ports 212, 214 from the exterior of the antenna element structure. A first input port via 248 connects the first input port 212 of the open center resonator element 210 to a first connection pad 252. A second input port via 250 connects the second input port 214 of the open center resonator element 210 to a second connection pad 254. The connection pads 252, 254 may be connected to connections of a Radio Frequency Integrated Circuit (RFIC) or Beam Forming IC (BFIC). The connection pads 252, 254 may be connected to the RFIC by direct soldering or by electrical paths including any combination of electrical connection mechanisms such as wires, microstrip sections, and conductive traces. In some situations, the connection between the RFIC and theinput ports 212, 214 may include electrical connection mechanisms in addition to, or in the alternative to, the input port vias 248, 250 and / or connection pads 252, 254. Such electrical connection mechanisms may include any combination of wires, microstrip sections, strip line section and conductive traces.

[0033] FIG. 3A is a block diagram of an example of a slant polarized antenna element 300 having dual linear polarization where a radiator 302 is formed by a planar radiator element 102 on a dielectric 232 and an open center resonator 206 is formed with a planar open center resonator element 208 and a resonator cavity 210. Accordingly, the slant polarized antenna element 300 is an example of the antenna element 100 and the antenna element 120 discussed with reference to FIG. 1A and FIG. 1 B without the radiator cavity discussed with reference to FIGs. 2A-2E. The slant polarized antenna element 300 is similar to the slant polarized antenna element 200 except that slant polarized antenna element 300 does not include a radiator layer metal boundary 224, vias 226 connecting the metal layer to the radiator layer metal boundary 224, or vias connecting the base ground layer 238 to the radiator layer metal boundary 224.

[0034] FIG. 3B is an illustration of an exploded perspective view of an example of a slant polarization antenna element 320 having dual linear polarization and including a radiator 302 and an open center resonator 206. Accordingly, the slant polarized antenna element 320 is an example of the antenna element 100, the antenna element 120, and the slant antenna element 300 discussed with reference to FIG. 1A, FIG. 1 B and FIG. 3A.

[0035] FIG. 30 is an illustration of an example of a cross-sectional side view along A-A of FIG. 3B. FIG. 3D is an illustration of an example of a cross-sectional top view taken along B-B of FIG. 3B and FIG. 3C. FIG. 3E is an illustration of an example of a cross-sectional top view taken along C-C of FIG. 3B and FIG. 3C. FIG. 3B, FIG. 3C, FIG. 3D and FIG. 3E are not necessarily to scale and are not intended to be more than general illustrations showing the relative positioning of elements. Some components are not illustrated in at least some of the figures in the interest of clarity. For example, not all vias between the layers are illustrated in the FIG. 3B and some of the vias behind theplane of the cross-section are not illustrated with dashed lines in FIG. 3C. The slant antenna element 320 may include an outer enclosure (not shown) that surrounds the slant antenna element structure expect for openings for the input port(s) and the radiator.

[0036] Operation and design considerations for the slant polarization antenna element 300 are similar to those discussed with reference to the slant polarization antenna element 200 for FIGs 2A-2E. For the example, the slant polarization antenna element 300 includes ground vias 304 that extend from the base ground layer 238 to the metal layer 222. In some situations, one or more planar ground sections may be included on the radiator layer 302 and that are connected to other ground sections including the base ground layer 238. Even though such a structure does not form a radiator cavity, the additional grounding may improve performance in some situations.

[0037] FIG. 4A is an illustration of a cross-section sideview of an example of the slant polarized antenna element 200 with a wide angle impedance matching (WAIM) structure 402 attached to the radiator layer 228. The WAIM structure 402 provides impedance matching between the planar radiator element 102 and air. The WAIM structure 402 includes a relatively high dielectric sheet positioned at a distance from the radiator layer 228. A relatively low dielectric material may be positioned between positioned between the relatively high dielectric sheet and the radiator layer 228.

[0038] For the example of FIG. 4A, the relatively high dielectric sheet is a filled polytetrafluoroethylene (PTFE) composite laminate sheet (filled PTFE layer) 404 separated from the radiator layer 228 by a polymethacrylimide (PMI) based structural foam layer (foam layer) 406. An adhesive layer 408 secures the foam layer 406 to the radiator layer 228 where the adhesive bonds to the planar radiator element 102, the radiator layer metal boundary 224, and any exposed portions of the dielectric layer 242. Another adhesive layer 410 secures the filled PTFE layer 404 to the foam layer 406. For the example, the filled PTFE layer has a dielectric constant of 6.6 and the foam layer has dielectric constant at or near 1 .0. Although the examples discussed herein include a single foam layer and a single filled PTFE layer, additional layers may be used in some situations. The distance of the filled PTFE layer 404 to the radiator layer 228 is selectedat least partially based on the impedance profile of the radiator. Accordingly, the thickness of the foam layer and adhesive layer 408 is selected to accommodate the particular radiator in the examples of FIG. 4A and FIG. 4B. Other materials can be used to achieve the desired characteristics of the WAIM.

[0039] FIG. 4B is an illustration of a cross-section sideview of an example of the slant polarized antenna element 300 with a wide angle impedance matching (WAIM) structure 402 attached to the radiator layer 228. The WAIM structure 402 is secured to the radiator layer 302 with an adhesive layer 412. The adhesive layer 412 is affixed to the planar radiator element 102 and the exposed portions of the dielectric layer 242.

[0040] Several antenna elements may be combined to form a phased array antenna element. Phased array antennas are composed of several antennas which can be independently controlled. Working together, the individual antenna elements can be connected to individual transmitters and receivers or groups or transmitters and receivers. The electromagnetic waves radiated by each individual antenna element combine and superpose, constructively interfering (adding together) to enhance the power radiated in desired directions, and destructively interfering (cancelling) to reduce the power radiated in other directions. When used for receiving, the separate electromagnetic currents from the individual antenna elements combine in the receiver with the correct phase relationship to enhance signals received from the desired directions and cancel signals from undesired directions. Phased arrays contain components to control the amplitude and phase of each element to enable “phased” steering. In other words, the array is mechanically stationary while the electromagnetic waves are electronically steered. Active Electronically Phased Array (AESA) include active elements placed within the phased array. The phased nature and subsequent coupling of the antenna elements place additional requirements of active impedance control to the antenna elements. The requirements for phased steering determine the element spacing and are typically around a half-wavelength at the upper end of the operational spectrum. Phased array antennas allow for more efficient use of frequency spectrum and help meet the demands of conventional communication systems.Conventional techniques, however, are limited in that a desired polarization of the array cannot be achieved while meeting other requirements related to parameters such assidelobe level, active return loss, efficiency, array gain, filed of view and scan volume. The antenna elements and techniques described herein, however, enable the implementation of phased array antennas that meet these requirements.

[0041] One example of a suitable technique for designing the phased array antenna includes using an electromagnetic (EM) solver application where one or more dimensions are selected to obtain a particular characteristic and systematically setting other dimensions to adjust and compensate other characteristics. In an example of a suitable technique for designing an antenna array, design begins from the required scan volume. From the scan volume, the grid spacings in azimuth and elevation are determined, along with the maximum distance between the radiator element and the bass ground layer. A resonant structure at the desired frequency of operation must be designed to fit into this grid spacing. Then a method of excitation must be explored. This can be done using a via or through a coupling mechanism as described in a claim above. From there, S parameters are used to determine how much power is reflected back to the transceiver and how much is radiated into free space.

[0042] Clearly, other embodiments and modifications of this invention will occur readily to those of ordinary skill in the art in view of these teachings. The above description is illustrative and not restrictive. This invention is to be limited only by the following claims, which include all such embodiments and modifications when viewed in conjunction with the above specification and accompanying drawings. The scope of the invention should, therefore, be determined not with reference to the above description, but instead should be determined with reference to the appended claims along with their full scope of equivalents.

Claims

CLAIMS1 . A slant polarization antenna element comprising: a planar radiator element having a radiator shape; an open center resonator element having an outer perimeter defining an outer resonator shape and an inner perimeter defining a center opening shape of a center opening, the open center resonator element electromagnetically coupled to the planar radiator element through a coupling mechanism, and an input port connected to the open center resonator element at an input port position such that the slant polarization antenna is configured to radiate electromagnetic energy from the planar radiator element at a polarization at least partially determined by the input port position when an electromagnetic signal is applied to the input port.

2. The slant polarization antenna element of claim 1 , wherein: the planar resonator has a center axis extending through the center opening and through the open center resonator element; and the input port position is a rotated position rotated about the center axis from a non-rotated position such that the polarization is an angled polarization relative to a reference polarization associated with the non-rotated position.

3. The slant polarization antenna element of claim 1 , further comprising a metal layer between the planar resonator element and the open center resonator element.

4. The slant polarization antenna element of claim 1 , further comprising a radiator cavity forming a cavity radiator with the planar radiator element.

5. The slant polarization antenna element of claim 1 , further comprising aresonator cavity, the open center resonator element within the resonator cavity.

6. The slant polarization antenna element of claim 5, further comprising another input port connected to the open center resonator element at another rotated position rotated about the center axis from rotated position such that the slant polarization antenna is configured to radiate, when an electromagnetic signal is applied to the another input port, electromagnetic energy from the planar radiator element at another angled polarization relative to the angled polarization, the another angled polarization being offset from the angled polarization by 90 degrees.

7. The slant polarization antenna element of claim 6, wherein reference polarization is a vertical polarization, the angled polarization is a +45 degree polarization offset from the vertical polarization by 45 degrees, and the another angled polarization is a -45 degree polarization offset from the vertical polarization by -45 degrees.

8. The slant polarization antenna element of claim 7, wherein the open center resonator element is an elliptical ring resonator element.

9. The slant polarization antenna element of claim 7, wherein the outer resonator shape is rectangular and the center opening shape is rectangular.

10. The slant polarization antenna element of claim 1 , wherein the planar radiator element is part of a radiator layer, the slant polarization antenna element further comprising a wide angle impedance matching (WAIM) structure attached to the radiator layer.

11. A slant polarization antenna element comprising: a planar radiator element having a radiator shape; a resonator cavity comprising a metal layer with an iris, a base ground layer, and a plurality of resonator vias connected between the metal layer and the base ground layer, the iris having a shape; an open center resonator element within the resonator cavity and having an outer perimeter defining an outer resonator shape and an inner perimeter defining a center opening shape of a center opening, the open center resonator element electromagnetically coupled to the planar radiator element through the iris; and an input port connected to the open center resonator element at an input port position such that the slant polarization antenna is configured to radiate, when an electromagnetic signal is applied to the input port, electromagnetic energy from the planar radiator element at a polarization determined, at least partially, by the input port position.

12. The slant polarization antenna element of claim 11 , wherein: the planar resonator element has a center axis extending through the center opening and through the open center resonator element; and the input port position is a rotated position rotated about the center axis from a non-rotated position such that the polarization is an angled polarization relative to a reference polarization associated with the non-rotated position.

13. The slant polarization antenna element of claim 12, further comprising another input port connected to the open center resonator element at another rotated position rotated about the center axis from rotated position such that the slant polarization antenna is configured to radiate, when an electromagnetic signal is applied to the another input port, electromagnetic energy from the planar radiator element at another angled polarization relative to the angled polarization, the another angledpolarization being offset from the angled polarization by 90 degrees.

14. The slant polarization antenna element of claim 13, wherein the reference polarization is a vertical polarization, the angled polarization is a +45 degree polarization offset from the vertical polarization by 45 degrees, and the another angled polarization is a -45 degree polarization offset from the vertical polarization by -45 degrees.

15. The slant polarization antenna element of claim 14, wherein the open center resonator element is an elliptical ring resonator element.

16. The slant polarization antenna element of claim 14, wherein the outer resonator shape is rectangular and the center opening shape is rectangular.

17. The slant polarization antenna element of claim 11 , wherein the planar radiator element is part of a radiator layer, the slant polarization antenna element further comprising a wide angle impedance matching (WAIM) structure attached to the radiator layer.

18. The slant polarization antenna element of claim 11 , wherein the radiator shape is rectangular.

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