EP4662734A1

EP4662734A1 - Collinsia ultrawideband millimeter wave radiator for array antennas

Info

Publication number: EP4662734A1
Application number: EP23706105.6A
Authority: EP
Inventors: Marthinus Da Silveira; Neil Mcgowan
Original assignee: Telefonaktiebolaget LM Ericsson AB
Current assignee: Telefonaktiebolaget LM Ericsson AB
Priority date: 2023-02-08
Filing date: 2023-02-08
Publication date: 2025-12-17
Also published as: WO2024165894A1

Abstract

Ultra- wide band antenna elements are disclosed. According to one aspect, an antenna element includes a base dielectric multi-layer PCB structure and a spacing dielectric layer parallel to and adhered to the base dielectric layer. The antenna element includes a spacing dielectric layer being formed by a single layer of dielectric material or multiple layers of dielectric materials. A plurality of petals parallel to and above the spacing dielectric layer are configured to radiate and receive radio frequency (RF) energy. A plurality of first vias in the spacing dielectric layer are configured to form a grounded coupled transmission line. A plurality of second vias in the spacing dielectric layer are configured to form an input coupled transmission line.

Description

COLLINSIA ULTRA WIDEBAND MILLIMETER WAVE RADIATOR FOR ARRAY ANTENNAS

TECHNICAL FIELD

The present disclosure relates to wireless communications, and in particular, to ultra-wide band (UWB) millimeter wave radiators for Fifth Generation (5G) and Sixth Generation (6G) array antennas such as Collinsia ultra-wide band millimeter wave radiators.

BACKGROUND

The Third Generation Partnership Project (3 GPP) has developed and is developing standards for Fourth Generation (4G) (also referred to as Long Term Evolution (LTE)) and Fifth Generation (5G) (also referred to as New Radio (NR)) wireless communication systems. Such systems provide, among other features, broadband communication between network nodes, such as base stations, and mobile wireless devices (WD), as well as communication between network nodes and between WDs. The 3GPP is also developing standards for Sixth Generation (6G) wireless communication networks.

5G and 6G radios are expected to operate in the millimeter wave (mmWave) frequency band. A mmWave radiator with good array performance is the octal cavity backed dual stacked patch antenna (OCDPA). This radiator has been implemented using low dielectric constant printed circuit board (PCB) material with a dielectric constant around 1.6.

Sheet metal Frasera radiators give very good array performance for frequencies typically below 6GHz. But for higher frequencies such as those used for 5G and 6G transmissions an efficient Frasera radiator becomes increasingly difficult to manufacture.

The OCDPA radiators may achieve a bandwidth of 15%, which is a reasonable wide bandwidth for mmWave PCB type radiators. However, wider bandwidth is required in some cases for5G/6G mmWave antenna arrays. SUMMARY

Some embodiments advantageously provide Collinsia ultra- wide band millimeter wave radiators for Fifth Generation (5G) and Sixth Generation (6G) array antennas.

According to one aspect, an antenna element configured to radiate and receive radio frequency, RF, energy is provided. The antenna element includes: a base dielectric multi-layer printed circuit board, PCB, structure. The antenna element also includes a spacing dielectric layer parallel to and adhered to the base dielectric multilayer PCB structure, the spacing dielectric layer being formed by one of a single layer of dielectric material and multiple layers of dielectric materials. The antenna element also includes a plurality of petals adhered to the spacing dielectric layer by an intervening bonding layer, the plurality of petals being configured to radiate and receive RF energy. The antenna element also includes a plurality of first vias in the spacing dielectric layer, the plurality of first vias being configured to form a grounded coupled transmission line. The antenna element also includes a plurality of second vias in the spacing dielectric layer, the plurality of second vias being configured to form an input coupled transmission line.

According to this aspect, in some embodiments, the antenna element includes feed crossovers to connect at least one second via of the plurality of second vias to a petal of the plurality of petals. In some embodiments, at least one second via is trepanned. In some embodiments, the antenna element also includes a fencing structure formed by fencing vias in the spacing dielectric layer. In some embodiments, the fencing structure includes further a plurality of fencing elements and a slot formed in the spacing dielectric layer above each fencing element. In some embodiments, the spacing dielectric layer includes a first dielectric layer and a second dielectric layer, the first dielectric layer being between the base dielectric multi-layer PCB structure and the second dielectric layer. In some embodiments, the antenna element includes a petal tip at a distal end of each petal, the petal tip being formed by at least one of petal tip vias and tre-panning vias in the spacing dielectric layer. In some embodiments, the petal tips are configured in shape and size so that the antenna element exceeds a first level of performance over a first specified bandwidth. In some embodiments, the antenna element also includes brims at each edge of each petal of the plurality of petals, the brims being formed by at least one of brim vias and tre-panning vias in the spacing dielectric layer. In some embodiments, the brims are configured in shape and size so that the antenna element exceeds a first level of performance over a first specified bandwidth. In some embodiments, the antenna element also includes an input stripline connected to at least one second via of the plurality of second vias to conduct an RF signal to and from the petals . In some embodiments, the plurality of first vias are of different lengths. In some embodiments, the spacing dielectric layer includes a plurality of dielectric layers separated by a bonding material. In some embodiments, the plurality of petals are on a same layer of the antenna element. In some embodiments, the plurality of petals are adhered to the spacing dielectric layer by adhering the petals to a bonding layer that is adhered to the spacing dielectric layer. In some embodiments, a first two petals of the plurality of petals form a first dipole having a first polarization and a second two petals of the plurality of petals form a second dipole having a second polarization that is orthogonal to the first polarization. In some embodiments, the plurality of petals are configured in shape and size so that the antenna element exceeds a second level of performance over a second specified bandwidth. In some embodiments, first vias and tre-panning vias of the plurality of first vias and trepanning vias are spaced apart by distances to exceed a second level of performance over a second specified bandwidth. In some embodiments, a number, spacing and size of first vias of the plurality of first vias are selected to exceed a second level of performance over a second specified bandwidth. In some embodiments, the second level of performance is one of a maximum level of return loss, a minimum level of polarization isolation, a maximum level of mutual coupling, a minimum degree of pattern symmetry and a minimum polarization ratio.

According to another aspect, an antenna element includes a ground plane and a base dielectric multi-layer PCB structure adhered to the ground plane. The antenna element also includes a first dielectric layer adhered to the base dielectric multi-layer PCB structure and a second dielectric layer adhered to the first dielectric layer. The antenna element also includes a plurality of petals adhere to the second dielectric layer via bonding layer. The antenna element also includes a plurality of first vias extending at least in part into the first dielectric layer and the second dielectric layer and configured to form a grounded coupled transmission line. The antenna element also includes a plurality of second vias in the first and second dielectric layers and configured to form an input coupled transmission line.

According to this aspect, in some embodiments, the antenna element also includes a fencing structure formed by fencing vias in the first dielectric layer. In some embodiments, the antenna element also includes a petal tip at an end of each petal of the plurality of petals, the petal tip being formed by petal tip vias in the second dielectric layer. In some embodiments, the antenna element also includes a brim at edges of each petal of the plurality of petals, the brim being formed by brim vias in the second dielectric layer. In some embodiments, the antenna element also includes an input stripline on the base dielectric layer in communication with at least one second via of the plurality of second vias.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present embodiments, and the attendant advantages and features thereof, will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein:

FIG. 1 is a perspective view of an example antenna element constructed according to principles set forth herein;

FIG. 2 is a top view of the example antenna element of FIG. 1;

FIG. 3 is a side view of the antenna element of FIGS. 1 and 2;

FIG. 4 is a side view of an array of antenna elements constructed according to principles disclosed herein;

FIG. 5 is a perspective view of the array of antenna elements of FIG. 4;

FIG. 6 illustrates a step in a process of constructing an antenna element according to principles disclosed herein;

FIG. 7 illustrates another step in a process of constructing an antenna element according to principles disclosed herein;

FIG. 8 illustrates another step in a process of constructing an antenna element according to principles disclosed herein;

FIG. 9 illustrates another step in a process of constructing an antenna element according to principles disclosed herein;

FIG. 10 illustrates another step in a process of constructing an antenna element according to principles disclosed herein;

FIG. 11 illustrates another step in a process of constructing an antenna element according to principles disclosed herein; and

FIG. 12 is a graph comparing performance of a known antenna element to the performance of an antenna element constructed according to principles set forth herein. DETAILED DESCRIPTION

Before describing in detail exemplary embodiments, it is noted that the embodiments reside primarily in combinations of apparatus components and processing steps related to ultra-wide band millimeter wave radiators for Fifth Generation (5G) and Sixth Generation (6G) array antennas such as Collinsia ultra- wide band millimeter wave radiators. Accordingly, components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.

As used herein, relational terms, such as “first” and “second,” “top” and “bottom,” and the like, may be used solely to distinguish one entity or element from another entity or element without necessarily requiring or implying any physical or logical relationship or order between such entities or elements. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the concepts described herein. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes” and/or “including” when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

In embodiments described herein, the joining term, “in communication with” and the like, may be used to indicate electrical or data communication, which may be accomplished by physical contact, induction, electromagnetic radiation, radio signaling, infrared signaling or optical signaling, for example. One having ordinary skill in the art will appreciate that multiple components may interoperate and modifications and variations are possible of achieving the electrical and data communication.

In some embodiments described herein, the term “coupled,” “connected,” and the like, may be used herein to indicate a connection, although not necessarily directly, and may include wired and/or wireless connections.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the concepts described herein. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes” and/or “including” when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

Note further, that functions described herein as being performed by a wireless device or a network node may be distributed over a plurality of wireless devices and/or network nodes. In other words, it is contemplated that the functions of the network node and wireless device described herein are not limited to performance by a single physical device and, in fact, may be distributed among several physical devices.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

As used herein, term via or vias may refer to a hole passing through at least one layer of a layered structure. The via may be formed by a laser or by drilling, for example. The term via or vias may also refer to a hole that is widened by, for example tre-panning, into the layered structure. Tre -panning is a process of moving the laser transverse to an axis of a via to widen the via. As used herein, the term via or vias include vias and vias formed by trepanning. The term via or vias include micro- vias.

Referring to the drawing figures, in which like elements are referred to by like reference numerals, there is shown in FIG. 1 a perspective view of an antenna element 10 constructed according to principles set forth herein. FIG. 2 is a top view of the antenna element 10 and FIG. 3 is a side view of the antenna element 10 shown in FIG. 1. FIGS, land 2 omit the dielectric material shown in FIG. 3. Referring to FIGS. 1, 2 and 3, at the base of the antenna element 10 is a conducting bottom ground plane 12. Above, i.e., on a first side of the bottom ground plane 12 is a low-loss base dielectric multi-layer PCB structure 14. The low-loss base dielectric multi- layer PCB structure 14 may include, for example, Megtron 7N. In some embodiments, the multi-layer PCB structure 14 includes multiple PCB laminates and at least one bonding layer. Also not shown in the figures are vias which, in some embodiments, connect an input stripline 16 to a balanced broadside coupled stripline transmission line 18. The transmission line 18 may be formed by non-trepanned vias and/or trepanned vias. Above, i.e., on a first side of, the low-loss base dielectric multi- layer PCB structure 14 is a top ground plane 20. Above the top ground plane 20 is a bonding layer 22, for example, CuClad 6700 prepreg. Above the bonding layer 22 is a spacing dielectric layer 24. The spacing dielectric layer 24 may include multiple layers. In the example embodiment of FIG. 3, the spacing dielectric layer 24 includes three dielectric layers 26, 28 and 30 separated by bonding layers 32 and 34. Each of the three dielectric layers 26, 28 and 30 may be a dielectric with a low dielectric constant (close to the dielectric constant of air). Above the uppermost dielectric layer 30 is a bonding layer 36 and above the bonding layer 36 is another bonding layer 38. The bonding layers 32 and 34 may serve to adhere one dielectric layer 26, 28, 30 to another dielectric layer 26, 28, 30. The adhering may be by known techniques for layered printed circuit board construction.

A metallic fencing structure 40 is disposed about a periphery of the antenna element 10, which improves electromagnetic isolation between adjacent antenna elements 10 when a plurality of antenna elements 10 are in an antenna array, as compared to not having a fencing structure 40. The fencing structure 40 may be formed by micro-vias drilled or with via tre-panning into the first and/or second dielectric layers 16 and 18. The width, position and height of the individual fencing elements 40 of the fencing structure 40 may be formed to achieve a specified level of performance over a bandwidth of operation of the antenna element 10 or of an array of antenna elements 10. A conducting input strip line 16 is positioned above the first side of the low-loss base dielectric multi-layer PCB structure 14 and is configured to carry radio frequency (RF) signals to the transmission line 18, which may be a balanced broadside coupled strip line transmission line.

The transmission line 18 includes a grounded coupled line formed by first vias 42. The transmission line 18 also includes an input coupled line formed by second vias 44. Note that only some vias forming the transmission line 18 are shown. Each first via 42 forming the grounded coupled line may be configured to extend from a first point at or above the bottom ground plane 12 to a second point at or below a layer having petals 30 of the antenna element 10. The first vias 42 forming the grounded coupled line may have different heights and extend between different first and second points. The first vias 42 forming the grounded coupled line may be formed by drilling through the dielectric layers 26, 28 and/or 30. The drilling may be performed by a laser for location accuracy, small diameter and blind via structures. Many closely spaced first non-trepanned or tre -panned vias 42 may be employed for the grounded coupled line to achieve an impedance characteristic over a bandwidth of operation of the antenna element 10 or an array of antenna elements 10. A number and size of the first vias 42 may be selected to form a wall that may be as wide as possible without interfering with the petals 46 of the antenna element 10.

The dielectric layers 26, 28 and 30 may be selected to have low dielectric constants (close to that of air) and low loss. In some embodiments, there are more or less than three dielectric layers above the low-loss base dielectric multi-layer PCB structure 14. In some embodiments, there is only one dielectric layer above the low-loss base dielectric multi-layer PCB structure 14.The bonding layers 22, 32, 34, 36 and 38, for example, CuClad 6700 prepreg, may be used to bind or adhere the dielectric layers 26, 28 and 30 and the petals 46. In some embodiments, the petals 46 may be on the bonding layer 36. In some embodiments, the thickness of the bonding layers 22, 32, 34, 26 and 28 may be between 36 and 40 micrometers, for example, 38 micrometers. The thicknesses of the dielectric layers 26, 28 and 30may be such that a total thickness of the portion of the antenna element 10 that lies above the low-loss base dielectric multilayer PCB structure 14 may be small, e.g., 1.1 millimeters, as compared to 32 millimeters in some known antenna configurations at a frequency of 2GHz .

The second vias 44 forming the input coupled line may be configured to extend from the input strip line 16 to feed crossovers 48. The feed crossovers 48 are connected to petals 46, but are on different layers of the antenna element 10. Each petal 46 has a petal tip 50 and brims 52. In some embodiments, the four petals 46 are on the same layer of the antenna element 10 and form two orthogonally polarized dipoles that radiate or receive RF energy.

The petal tips 50 may be configured to increase an electrical length of the dipole formed by two oppositely directed petals 46. A shape and size of the petal tips 50 may be optimized by experimentation to achieve a specified level of performance over a bandwidth of operation of the antenna element 10 or of an array of antenna elements 10.

Also, the shape of the petals 46, the spacing between the petals 46 and configuration of the feed crossovers 48 may be arranged to achieve a return loss, polarization isolation, mutual coupling and array pattern over a bandwidth of operation of an array of the antenna elements 10.

The brims 52 may be configured to provide coupling between petals 46 to increase bandwidth of the antenna element 10 or an array of the antenna elements 10. The geometry of the brims 52 may be arranged achieve a specified level of performance over a bandwidth of operation of the antenna element 10 or of an array of antenna elements 10. In some embodiments, the brims 52 are above the spacing dielectric layer 24.

Note that the brims 52 and petal tips 50 may be formed by micro-vias drilled (mechanically or by laser) and tre-panning into the dielectric layer 30. The bottom ground plane 12, the input strip line 16, the petals 46 and the feed crossovers 48 may be made with standard PCB etching and plating processes. For example, the multi-layer PCB structure 14 may be a four-layer PCB structure that includes the input strip line 16. The first and second vias 42 and 44 may be filled with or lined by metal or other conductor as part of the plating process. Similarly, the vias that form the brims 52 and petal tips 50 may be filled with or lined by metal or other conductor as part of the plating process. Note that the vias 42 and 44 may be formed by a combination of single vias and trepanned vias. For example the vias 42 may include two single vias spaced apart at the bottom, then a wide trepanning via, then a narrower trepanning via above the wide trepanning via and then a single via on the top).

The antenna elements 10 may be configured to operate at millimeter wave frequencies where it becomes difficult to construct the antenna elements 10 by bending a cutout of a thin metal plate. Rather, manufacture of the antenna elements 10 use conventional printed circuit board (PCB) technology and may be constructed by layers and vias. FIGS. 4 and 5 illustrate a row of three of the antenna elements 10 to form an antenna array constructed according to principles disclosed herein. In particular, FIG. 4 shows that a slot 54 may be formed in one or both of dielectric layers 28 and 30. In some embodiments, the slot width is 206 micrometers. In some embodiments, one or more of the bottom ground plane 12, low-loss base dielectric multi-layer PCB structure 14, dielectric layers 26, 28 and 20 may be common to all three of the antenna elements 10. More or less than three antenna elements 10 may be in a row of antenna elements 10 of an antenna array. Also more than one row of antenna elements 10 may be in an antenna array to form a two dimensional antenna array. FIGS. 6-11 illustrate stages of an example process for making a multi-layer micro-via PCB structure on top of the bottom ground plane 12. Vias 56 are formed in a dielectric layer 58 (and optionally a bonding layer) above the bottom ground plane 12 (FIG. 6). Then, a conducting layer 60 may be formed on the dielectric layer 58 using a mask. The copper may also fill the vias 56 (FIG. 7). Bonding layers 62 (which may depend on a percentage of copper) may be added above the conducting layer 60 (FIG. 8). Another dielectric layer 64 may then be added above the bonding layer 62 (FIG. 9). Vias 66 may be formed in the dielectric layer 64 (FIG. 10). Then another layer of metallization 68 may be formed on the dielectric layer 64 which fills the vias 66 with metal (FIG. 11). The process of forming metallization layer 68 may include masking according to known methods in some embodiments. For example, a photo-sensitive mask process may be employed to form petals 46, feed crossovers 48, etc.

FIG. 12 is a graph of example performance of one embodiment of the antenna element 10 compared to the performance of a known octal cavity backed double stacked patch antenna (OCDP) 70. The example antenna element 10 of FIG. 12 has a - 15dB return loss over a bandwidth of 45%, whereas the OCDP 70 has a -15dB over a bandwidth of only 15%. Polarization isolation of better than -15dB over a 45% bandwidth is also achieved by some embodiments. Further, the antenna elements 10 of some embodiments have good co-polarized pattern symmetry with greater than 6dBi directivity. Also, the antenna elements 10 of some embodiments have a cross polarization ratio of 19dB at boresight and better than lOdB over +/- 60 degree angles.

Many different embodiments have been disclosed herein, in connection with the above description and the drawings. It will be understood that it would be unduly repetitious and obfuscating to literally describe and illustrate every combination and subcombination of these embodiments. Accordingly, all embodiments may be combined in any way and/or combination, and the present specification, including the drawings, shall be construed to constitute a complete written description of all combinations and subcombinations of the embodiments described herein, and of the manner and process of making and using them, and shall support claims to any such combination or subcombination.

It will be appreciated by persons skilled in the art that the embodiments described herein are not limited to what has been particularly shown and described herein above. In addition, unless mention was made above to the contrary, it should be noted that all of the accompanying drawings are not to scale. A variety of modifications and variations are possible in light of the above teachings without departing from the scope of the following claims.

Claims

What is claimed is:

1. An antenna element (10) configured to radiate and receive radio frequency, RF, energy, the antenna element (10) comprising: a base dielectric multi-layer printed circuit board, PCB, structure (14); a spacing dielectric layer (24) parallel to and adhered to the base dielectric multi-layer PCB structure (14), the spacing dielectric layer (24) being formed by one of a single layer of dielectric material and multiple layers of dielectric materials; a plurality of petals (46) adhered to the spacing dielectric layer (24) by a bonding layer (36), the plurality of petals (46) being configured to radiate and receive RF energy; a plurality of first vias (42) in the spacing dielectric layer (24), the plurality of first vias (42) being configured to form a grounded coupled transmission line; and a plurality of second vias (44) in the spacing dielectric layer (24), the plurality of second vias (44) being configured to form an input coupled transmission line.

2. The antenna element (10) of Claim 1, further comprising feed crossovers (48) to connect at least one second via of the plurality of second vias (44) to a petal (46) of the plurality of petals (46).

3. The antenna element (10) of Claim 2, wherein at least one second via (44) is trepanned.

4. The antenna element (10) of any of Claims 1-3, further comprising a fencing structure (40) formed by fencing vias in the spacing dielectric layer (24).

5. The antenna element (10) of Claim 4, wherein the fencing structure includes further a plurality of fencing elements (40) and a slot formed in the spacing dielectric layer (24) above each fencing element (40).

6. The antenna element (10) of any of Claims 1-5, wherein the spacing dielectric layer (24) includes a first dielectric layer (26)and a second dielectric layer (28), the first dielectric layer (26)being between the base dielectric multi-layer PCB structure (14) and the second dielectric layer (28).

7. The antenna element (10) of any of Claims 1-6, further comprising a petal tip (50) at a distal end of each petal (46), the petal tip (50) being formed by at least one of petal tip vias and tre-panning vias in the spacing dielectric layer (24).

8. The antenna element (10) of Claim 7, wherein the petal tips (50) are configured in shape and size so that the antenna element (10) exceeds a first level of performance over a first specified bandwidth.

9. The antenna element (10) of any of Claims 1-8, further comprising brims (52) at each edge of each petal (46) of the plurality of petals (46), the brims (52) being formed by at least one of brim vias and tre-panning via in the spacing dielectric layer (24).

10. The antenna element (10) of Claim 9, wherein the brims (52) are configured in shape and size so that the antenna element (10) exceeds a first level of performance over a first specified bandwidth.

11. The antenna element (10) of any of Claims 1-10, further comprising an input strip line connected to at least one second via of the plurality of second vias (44) to conduct an RF signal to and from the petals (46).

12. The antenna element (10) of any of Claims 1-11, wherein the plurality of first vias (42) are of different lengths.

13. The antenna element (10) of any of Claims 1-12, wherein the spacing dielectric layer includes a plurality of dielectric layers (26, 28, 30) separated by bonding layers (32, 34).

14. The antenna element (10) of any of Claims 1-13, wherein the plurality of petals (46) are on a same layer of the antenna element (10).

15. The antenna element (10) of Claim 14, wherein the plurality of petals (46) are adhered to a bonding layer that is adhered to the spacing dielectric layer (24).

16. The antenna element (10) of any of Claims 1-15, wherein a first two petals (46) of the plurality of petals (46) form a first dipole having a first polarization and a second two petals (46) of the plurality of petals (46) form a second dipole having a second polarization that is orthogonal to the first polarization.

17. The antenna element (10) of any of Claims 1-16, wherein the plurality of petals (46) are configured in shape and size so that the antenna element (10) exceeds a second level of performance over a second specified bandwidth.

18. The antenna element (10) of any of Claims 1-17, wherein first vias and tre-panning via (42) of the plurality of first vias (42) are spaced apart by distances to exceed a second level of performance over a second specified bandwidth.

19. The antenna element (10) of any of Claims 1-18, wherein a number, spacing and size of first vias (42) of the plurality of first vias (42) are selected to exceed a second level of performance over a second specified bandwidth.

20. The antenna element (10) of any of Claims 17-19, wherein the second level of performance is one of a maximum level of return loss, a minimum level of polarization isolation, a maximum level of mutual coupling, a minimum degree of pattern symmetry and a minimum polarization ratio.

21. An antenna element (10), comprising: a ground plane (12); a base dielectric multi-layer printed circuit board, PCB, structure (14) adhered to the ground plane (12); a first dielectric layer (26)adhered to the base dielectric multi-layer PCB structure (14); a second dielectric layer (28) adhered to the first dielectric layer (16); a plurality of petals (46) adhered to the second dielectric layer (18) via a bonding layer; a plurality of first vias (42) extending at least in part into the first dielectric layer (26)and the second dielectric layer (28) and configured to form a grounded coupled transmission line; and a plurality of second vias (44) in the first and second dielectric layers (26, 28) and configured to form an input coupled transmission line.

22. The antenna element (10) of Claim 21, further comprising a fencing structure (40) formed by fencing vias in the first dielectric layer (26).

23. The antenna element (10) of any of Claims 21 and 22, further comprising a petal tip (50) at an end of each petal (46) of the plurality of petals (46), the petal tip (50) being formed by petal tip vias in the second dielectric layer (28).

24. The antenna element (10) of any of Claims 21-23, further comprising a brim (52) at edges of each petal (46) of the plurality of petals (46), the brim (52) being formed by brim vias in the second dielectric layer (28).

25. The antenna element (10) of any of Claims 21-24, further comprising an input strip line (22) on the base dielectric multi-layer PCB structure (14) in communication with at least one second via (44) of the plurality of second vias (44).