Millimeter wave frasera (MMF) radiator with integrated broadside coupled transmission line

Abstract

Embodiments of a millimeter wave Frasera, MMF, radiator. The MMF radiator includes a radiator element having at an upper metal layer and a lower metal layer disposed on opposite sides of a dielectric substrate. The upper and lower metal layers define respective petals of the MMF Radiator and at least one broadside coupled transmission line. A dielectric support is configured to support the radiator element. The radiator element includes a plurality of bends. Each bend is defined by a portion of the dielectric substrate being at least partially removed in a vicinity of the bend, such that the at least one metal layer and any residual portion of the dielectric substrate can flex through the bend.

Description

Millimeter Wave Frasera (MMF) Radiator with Integrated Broadside CoupledTransmission lineTechnical Field

[0001] The present disclosure relates to antenna radiator elements, and in particular to a millimeter wave Frasera (MMF) radiator with integrated broadside coupled transmission line.Background

[0002] A Frasera radiator is an antenna element known, for example, from International Patent Publications Nos. W02020 / 177025 and WO / 2020 / 194188, and International Patent Application No. PCT / IB2022 / 061940 filed December 8, 2022. The Frasera radiator structure has four radiators, each located within a different quadrant of a plane. Diagonally opposite radiators form a radiator pair. In each radiator pair, a ground strip connects a first radiator of the pair to a ground conductor, and a signal strip connects the other radiator of the pair to a terminal. The ground strip and the signal strip are orientable to form a balanced transmission line.

[0003] A Collinsia radiator is an ultra-wideband mmWave antenna element known, for example, from International Patent Application No. PCT / IB2023 / 051136, filed February 8, 2023. The 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.

[0004] Performance of antenna elements made with laminated dielectric layers using drilled or micro-vias are limited by the PCB design constraints. The dielectric material also limits the achievable bandwidth.

[0005] Improved antenna elements remain highly desirable. This is particularly true for mmWave applications.Summary

[0006] This disclosure provides a millimeter wave Frasera (MMF) radiator with integrated broadside coupled transmission line that can be made from a single thin two- layer printed circuit board (PCB). The radiator is formed by bending the dipole petal tips and integrated transmission line at specific locations to form the three-dimensional radiator structure.

[0007] The bending may be performed in part by affixing the radiator with a dielectric support structure, and after bending the radiator is integrated with the support structure.

[0008] The support structure for the MMF radiator and connection to the radio board is also provided. The disclosed radiator is based on the Frasera radiator known, for example, from International Patent Publications Nos. W02020 / 177025 and WO / 2020 / 194188, and International Patent Application No. PCT / IB2022 / 061940 filed December 8, 2022.

[0009] Although the disclosed radiator can be used for millimeter wave applications, it can also be applied to lower frequency bands such as the 2 GHz band for example.

[0010] The disclosed radiator is mostly surrounded by air dielectric (except for the support structure) and thus has the capability to achieve ultra-wideband operation at millimeter wave frequency bands as well as lower frequency bands.

[0011] The whole radiator is made with a simple two-layer printed circuit board (PCB) and a plastic support structure and is very light and cost effective.

[0012] The metal dimensions can be tightly controlled by conventional PCB fabrication processes and the spacing for the balanced feed can be tightly controlled by conventional PCB material thickness dimensions and dielectric constant.Brief Description of the Drawings

[0013] The accompanying drawing figures incorporated in and forming a part of this specification illustrate several aspects of the disclosure, and together with the description serve to explain principles of the disclosure.

[0014] FIG. 1 is an orthographic view illustrating a representative array antenna module comprising eight MMF radiators in accordance with embodiments of the present disclosure;

[0015] FIG. 2 is an orthographic view illustrating an MMF radiator of FIG. 1 in greater detail;

[0016] FIG. 3 is an exploded view of the MMF radiator of FIG. 2;

[0017] FIGs. 4A and 4B are respective upper and lower views of a representative PCB layout of the MMF radiator of FIGs. 2 and 3;

[0018] FIGs. 5A and 5B are respective side and orthographic views illustrating a representative bend structure utilizing the upper metal layer of the PCB;

[0019] FIGs. 6A and 6B are respective side and orthographic views illustrating a representative bend structure utilizing the lower metal layer of the PCB;

[0020] FIGs. 7A and 7B are respective side and orthographic views illustrating a representative bend structure utilizing both upper and lower metal layers of the PCB;

[0021] FIG. 7C is an orthographic view of the bend structure of FIGs. 7A and 7B with the substrate removed to more clearly show the metal layers;

[0022] FIG. 8 is an orthographic view illustrating a second representative embodiment of an MMF radiator formed using the bend structures of FIGs. 5A-7C;

[0023] FIGs. 9A and 9B are respective upper and lower views of a representative PCB layout of the MMF radiator of FIG. 8;

[0024] FIG. 10 is an orthographic view illustrating a third representative embodiment of an MMF radiator formed using the bend structures of FIGs. 5A-7C; and

[0025] FIGs. 11 A and 1 IB are respective upper and lower views of a representative PCB layout of the MMF radiator of FIG. 10.Detailed Description

[0026] The embodiments set forth below represent information to enable those skilled in the art to practice the embodiments and illustrate the best mode of practicing the embodiments. Upon reading the following description in light of the accompanying drawing figures, those skilled in the art will understand the concepts of the disclosure and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the disclosure.

[0027] At least some of the following abbreviations and terms may be used in this disclosure.• 2D Two Dimensional• 3 GPP Third Generation Partnership Project• 5G Fifth Generation• AAS Antenna Array System• AoA Angle of Arrival• AoD Angle of Departure• ASIC Application Specific Integrated Circuit• BF Beamforming• BLER Block Error Rate• BW Beamwidth• CPU Central Processing Unit• CSI Channel State Information dB DecibelDCI Downlink Control InformationDFT Discrete Fourier TransformDSP Digital Signal Processor eNB Enhanced or Evolved Node B FIR Finite Impulse ResponseFPGA Field Programmable Gate Array gNB New Radio Base StationICC Information Carrying CapacityIIR Infinite Impulse ResponseLTE Long Term EvolutionMIMO Multiple Input Multiple OutputMME Mobility Management EntityMMSE Minimum Mean Square ErrorMFC Machine Type CommunicationNR New RadioOTT Over-the-TopPBCH Physical Broadcast ChannelPDCCH Physical Downlink Control ChannelPDSCH Physical Downlink Shared ChannelP-GW Packet Data Network GatewayRAM Random Access MemoryROM Read Only MemoryRRC Radio Resource ControlRRH Remote Radio HeadSCEF Service Capability Exposure Function• SINR Signal to Interference plus Noise Ratio• TBS Transmission Block Size• UE User Equipment• ULA Uniform Linear Array• URA Uniform Rectangular Array

[0028] Radio Node: As used herein, a “radio node” is either a radio access node or a wireless device.

[0029] Radio Access Node: As used herein, a “radio access node” or “radio network node” is any node in a radio access network of a cellular communications network that operates to wirelessly transmit and / or receive signals. Some examples of a radio access node include, but are not limited to, a base station (e.g., a New Radio (NR) base station (gNB) in a Third Generation Partnership Project (3GPP) Fifth Generation (5G) NR network or an enhanced or evolved Node B (eNB) in a 3GPP Long Term Evolution (LTE) network), a high-power or macro base station, a low-power base station (e.g., a micro base station, a pico base station, a home eNB, or the like), and a relay node.

[0030] Core Network Node: As used herein, a “core network node” is any type of node in a core network. Some examples of a core network node include, e.g., a Mobility Management Entity (MME), a Packet Data Network Gateway (P-GW), a Service Capability Exposure Function (SCEF), or the like.

[0031] Wireless Device: As used herein, a “wireless device” is any type of device that has access to (i.e., is served by) a cellular communications network by wirelessly transmitting (and / or receiving) signals to (and / or from) a radio access node. Some examples of a wireless device include, but are not limited to, a User Equipment device (UE) in a 3 GPP network and a Machine Type Communication (MTC) device.

[0032] Network Node: As used herein, a “network node” is any node that is either part of the radio access network or the core network of a cellular communications network / system.

[0033] Cell: As used herein, a “cell” is a combination of radio resources (such as, for example, antenna port allocation, time and frequency) that a wireless device may use to exchange radio signals with a radio access node, which may be referred to as a host node or a serving node of the cell. However, it is important to note that beams may be used instead of cells, particularly with respect to 5G NR. As such, it should be appreciated that the techniques described herein are equally applicable to both cells and beams.

[0034] Note that references in this disclosure to various technical standards (such as 3GPP TS 38.211 V15.1.0 (2018-03) and 3GPP TS 38.214 V15.1.0 (2018-03), for example) should be understood to refer to the specific version(s) of such standard(s) that is(were) current at the time the present application was filed, and may also refer to applicable counterparts and successors of such versions.

[0035] The description herein focuses on a 3 GPP cellular communications system and, as such, 3GPP terminology or terminology similar to 3GPP terminology is oftentimes used. However, the concepts disclosed herein are not limited to a 3 GPP system.

[0036] Systems and methods are disclosed herein that provide a millimeter wave Frasera, MMF, radiator. The MMF radiator includes a radiator element having at an upper metal layer and a lower metal layer disposed on opposite sides of a dielectric substrate. The upper and lower metal layers define respective petals of the MMF Radiator and at least one broadside coupled transmission line. The radiator element includes a plurality of bends. Each bend is defined by a portion of the dielectric substrate being at least partially removed in a vicinity of the bend, such that the at least one metal layer and any residual portion of the dielectric substrate can flex through the bend. Optionally, a dielectric support can be configured to support the radiator element.

[0037] FIG. 1 is an orthographic view illustrating a representative array antenna module 100 comprising an array of eight MMF radiators 102 in accordance withembodiments of the present disclosure. In the illustrated example, the MMF radiators 102 are mounted on a radio board 104 which provides a ground plane and RF transmission line connections (not shown) for each MMF radiator 102. Also illustrated are metal fences 106 that extend the ground plane between adjacent MMF radiators 102 and thereby help control the RF characteristics of the array antenna module 100.

[0038] FIGs. 2 and 3 respectively show orthographic and exploded views illustrating an MMF radiator 102 of FIG. 1 in greater detail. In the illustrated example, the MMF radiator 102 comprises an assembly of a radiator element 200 secured within a dielectric support structure 202. In alternative embodiments, the dielectric support structure 202 is omitted, and instead the radiator element 200 is secured directly to the radio board 104. The radiator element 200 is preferably formed as a pair of metal layers 204 and 206 (dashed lines in FIGs. 2-3) disposed on opposite sides of a dielectric substrate 208. FIGs. 4A and 4B are respective upper and lower views of a PCB 400 from which the radiator element 200 may be made. The radiator element 200 comprises the upper metal layer 204 (FIG. 4A) and the lower metal layer 206 (FIG. 4B) disposed on opposite sides of a dielectric substrate 208. The upper and lower metal layers 206 and 208 may be formed (for example using conventional PCB fabrication methods such as photoetching, milling or routing) to define respective petals 210a-d of a dual polarization dipole antenna radiator, and a respective broadside coupled transmission line 212a-b to feed each polarization of the antenna radiator. In the embodiment of FIGs. 2-4, the upper metal layer 204 is used to define the petals 210a-d of the dipole radiator.

[0039] As may be seen in FIGs. 3-4, diagonally opposite pairs of petals 210 are electrically connected to define a respective dipole of each polarization. For example, petals 210a and 210b define one dipole pair, and are connected to respective signal lines of a broadside coupled transmission line 212a. In the illustrated embodiment, the upper layer signal line 402a of transmission line 212a is directly coupled to petal 210b, while the lower layer signal line 404a of transmission line 212a is coupled to petal 210a through a via 406 and a transmission line stub 408.

[0040] Similarly, petals 210c and 21 Od define the other dipole pair, and are connected to respective signal lines of a broadside coupled transmission line 212b. In the illustrated embodiment, the upper layer signal line 402b of transmission line 212b is directly coupled to petal 21 Od, while the lower layer signal line 404b of transmission line 212b is coupled to petal 210c through vias 410a-410c and a transmission line stubs 412 and 414.

[0041] As shown most clearly in FIG. 4b, the lower metal layer 206 also includes a set of brim couplers 416a-d which are sized and positioned to facilitate a controlled capacitive coupling (through the substrate 208) between adjacent petals 210 in the upper metal layer 204. This capacitive coupling is beneficial in that it tends to broaden the bandwidth of the assembled MMF radiator 102 while avoiding excessive crosspolar interference because radiated energy due to the capacitive coupling tends to be cancelled in the far field of the radiator 200.

[0042] As will be appreciated, the dielectric substrate 208 can be machined using known techniques (such as for example milling, routing and / or laser cutting) to provide physical structures needed to support the petals 210 and transmission lines 212 of the radiator 200. For example, the transmission lines 212 may be provided on tabs 418 that are cut out from two of the petals (e.g. petals 210b and 21 Od). In order to maintain electrical symmetry, corresponding cut-outs 420 may be provided in the other petals (e.g. petals 210a and 210c).

[0043] As may be appreciated, the length of each transmission line 212 is inherently restricted by the length of the dipole petals 210. The metal length of each dipole petal is a function of the frequency and bandwidth. The petal tips need to be electrically connected around (or across) the outer ends of each cut-out by a bridge element 214. If a longer transmission line 212 and or other features at the bottom of the transmission line (e.g. at the connection to the radio board 102) is desired, the transmission line 212 may be extended, for example by the addition of a zero ohm resistor (not shown in the drawings). Alternatively, the radiator 200 may be constructed with the petal tips are not electrically connected around (or across) the outer ends of each slot or cut-out, sothat the transmission lines 212 may be constructed of any desired length. In this case, a suitable bridge element 214 may subsequently be added (e.g. by soldering or via capacitive coupling) across the open ends of each petal 210 so as to provide the necessary electrical connection to ensure proper function of the radiator 200.

[0044] As may be seen in the figures, the MMF radiator element 200 has a 3- dimentional shape. This configuration of the MMF radiator 102 can be obtained by bending the PCB after photoetching and / or machining the metal layers forming the petals 210 and transmission lines 212 of the radiator 200. In the present disclosure, the bends are formed by machining the substrate 208 to remove dielectric material in the vicinity of each bend, leaving the metal foil to form a hinge. For example, commercially available PCB material can be readily obtained with a copper foil thickness of between 50um or 137um. A copper foil “hinge” of in this range of thicknesses can be successfully bent without breaking, by removing the dielectric material in the bending region (e.g. by a laser cut or by routing / milling). Example bend structures are described below with reference to FIGs. 5A-7C.

[0045] Referring back to FIG. 3, the 3-dimentional shape of the radiator element 200 may be supported by a dielectric support structure 202, which may be formed as an injection molded plastic component. In the illustrated embodiment, the support structure 202 comprises: a set of posts 300 configured to support the radiator element 200 a selected distance above the radio board 104; clips 302 designed to hold the bentdown ends of each petal 210; and a center portion 304 configured to support the tabs 402 of each of the transmission lines 212. Preferably, each of the posts 300, clips 302 and the center portion 304 are configured to minimize overlap between the dielectric material of the support structure 202 and metallic portions of the radiator element 200, particularly of the petals 210. This arrangement means that the dielectric materials within the electric field of the radiating element 200 are predominantly air and PCB substrate 208. Minimizing interaction between the dielectric material of the support structure 202 and the electric field of the radiating element 200, in this way, supports a wide bandwidth of the assembled MMF radiator 102. As noted above, in alternativeembodiments, the dielectric support structure 202 may be omitted entirely. In such cases, the substrate 208 in the vicinity of the petal bridge portions 214 and at the free end of each tab 418 may be configured to enable a structural connection to the radio board 104.

[0046] FIGs. 5A and 5B are respective side and orthographic views illustrating a representative bend structure in which the upper metal layer 204 of the PCB is used to establish the bend 500. In this case, the lower metal layer 206 in the vicinity of the bend 500 is removed and the substrate 208 in this same region is at least partially removed. In some embodiments, a thin layer of substrate material may remain after machining, provided that any remaining dielectric material does not impose excessive stress on the upper metal layer 204 extending through the bend 500.

[0047] FIGs. 6A and 6B are respective side and orthographic views illustrating a representative bend structure in which the lower metal layer 206 of the PCB is used to establish the bend 600. In this case, the upper metal layer 204 in the vicinity of the bend 600 is removed and the substrate 208 in this same region is at least partially removed. In some embodiments, a thin layer of substrate material may remain after machining, provided that any remaining material does not impose excessive stress on the lower metal layer 204 extending through the bend 500.

[0048] FIGs. 7A and 7B are respective side and orthographic views illustrating a representative bend structure 700 in which both the upper metal layer 204 and the lower metal layer 206 of the PCB are used to establish the bend 700. In this case, the bend structure 700 is divided into two portions. In a first portion 702, the lower metal layer 206 in the vicinity of the bend 700 is removed and the substrate 208 in this same region is at least partially removed. In the second portion 704, the upper metal layer 204 in the vicinity of the bend 700 is removed and the substrate 208 in this same region is at least partially removed. In some embodiments, a thin layer of substrate material may remain after machining, provided that any remaining material does not impose excessive stress on the metal layers 204 and 206 extending through the bend 700.

[0049] As may be seen especially in FIG. 7A, the respective length of the substrate 208 and lower metal layer 206 removed in the first portion 702 is greater than the length of the substrate 208 and upper metal layer 204 removed in the second portion 704. This difference in the amount of material removed from each portion 702 / 704 of the bend 700 is selected so that the metal hinge can be bent without folding or breaking. This is beneficial in that it limits impedance discontinuity within the bend 700.

[0050] FIG. 7C is an orthographic view of the bend structure of FIGs. 7A and 7B, with the substrate 208 removed to more clearly show the upper and lower metal layers.

[0051] FIG. 8 is an orthographic view illustrating a second representative embodiment of an MMF radiator formed using the bend structures of FIGs. 5A-7C. FIGs. 9A and 9B are respective upper and lower views of a representative PCB layout of the MMF radiator of FIG. 8. In the illustrated embodiment of FIGs. 8-9B, the petals 210 are defined in the upper metal layer 204 as in the embodiments described above with reference to FIGs. 3-4B. However, in this case, the two-layer bend structure 700 described above with reference to FIGs. 7A-C is used to connect the broadside coupled transmission lines 212 to the petals using transmission line signal paths on both of the upper and lower metal layers 204 and 206.

[0052] For example, petals 210a and 210b define one dipole pair, and are connected to respective signal lines of a broadside coupled transmission line 212a. In the illustrated embodiment, the upper layer signal line 402a of transmission line 212a is directly coupled to petal 210b, while the lower layer signal line 404a of transmission line 212a is coupled to petal 210a through a via 902a and a transmission line stub 904.

[0053] Similarly, petals 210c and 21 Od define the other dipole pair, and are connected to respective signal lines of broadside coupled transmission line 212b. In the illustrated embodiment, the upper layer signal line 402b of transmission line 212b is directly coupled to petal 21 Od, while the lower layer signal line 404b of transmission line 212b is coupled to petal 210c through via 902b. As may be seen especially inFIGs. 9A and 9B, this arrangement reduces the number of vias needed to complete the electrical connections.

[0054] FIG. 10 is an orthographic view illustrating a third representative embodiment of an MMF radiator. FIGs. 11 A and 1 IB are respective upper and lower views of a representative PCB layout of the MMF radiator of FIG. 10. In the illustrated embodiment of FIGs. 10-1 IB, one pair of petals (namely, petals 210a and 210d) are formed in the upper metal layer 204, and the other pair of petals (namely, petals 210b and 210c) are formed in the lower metal layer 206. Each petal 210 is directly connected to a respective signal path 402 or 404 of a broadside coupled transmission line 212. For example, in the first dipole pair: petal 210a is formed in the upper metal layer 204 and connected to the upper signal line 402a of transmission line 212a via an upper layer bend 500 described above with reference to FIG. 5; while petal 210b is formed in the lower metal layer 206 and connected to the lower signal line 404a of transmission line 212a via a lower layer bend 600 described above with reference to FIG. 6. In the second dipole pair: petal 210c is formed in the lower metal layer 206 and connected to the lower signal line 404b of transmission line 212b via a lower layer bend 600 described above with reference to FIG. 6; while petal 210d is formed in the upper metal layer 204 and connected to the upper signal line 402b of transmission line 212b via an upper layer bend 500 described above with reference to FIG. 5.

[0055] In the embodiment illustrated in FIGs. 10-1 IB, brim contacts 416a and 416c are provided to ensure capacitive coupling between adjacent petals 210 on each side of the dielectric substrate 208. For example, brim coupler 416a is provided on the upper metal layer 204 to provide capacitive coupling between petals 210b and 210c, while brim coupler 416c is provided on the lower metal layer 206 to provide capacitive coupling between petals 210a and 210d. In order to provide equivalent capacitive coupling between petals 210a and 210c, and between petals 210b and 210d, each of these petals is provided with an extension 1002 and 1004. For example, petals 210a and 210c, respectively, are provided with extensions 1002a and 1004a. These extensions 1002a and 1004a overlap each other and thereby enable capacitive couplingthrough the dielectric substrate 208. Similarly, petals 210b and 21 Od, respectively, are provided with extensions 1002b and 1004b, which overlap and thereby enable capacitive coupling through the dielectric substrate 208.

[0056] Those skilled in the art will recognize improvements and modifications to the embodiments of the present disclosure. All such improvements and modifications are considered within the scope of the concepts disclosed herein.

Claims

ClaimsWhat is claimed is:

1. A millimeter wave Frasera, MMF, radiator (102) comprising: a radiator element (200) comprising at an upper metal layer (204) and a lower metal layer (206) disposed on opposite sides of a dielectric substrate (208), the upper and lower metal layers (204, 206) defining respective petals (210) of the MMF Radiator (102) and at least one broadside coupled transmission line (212); the radiator element (200) comprising a plurality of bends (500, 600, 700), each bend being defined by a portion of the dielectric substrate (208) being at least partially removed in a vicinity of the bend (500, 600, 700) such that the at least one metal layer (204, 206) and any residual portion of the dielectric substrate (208) can flex through the bend (500, 600, 700).

2. The MMF radiator of claim 1, wherein the radiator element is composed of a printed circuit board, PCB, and wherein a thickness of each of the upper and lower metal layers (204, 206) is 50um or greater.

3. The MMF radiator of claim 1, wherein the plurality of bends comprise at least one upper layer bend (500) in which the upper metal layer (204) is used to establish the bend 500.

4. The MMF radiator of claim 3, wherein the lower metal layer in the vicinity of the upper layer bend is removed, and the dielectric substrate 208 in this same region is at least partially removed.

5. The MMF radiator of claim 1, wherein the plurality of bends comprise at least one lower layer bend (600) in which the lower metal layer (206) is used to establish the bend 600.

6. The MMF radiator of claim 5, wherein the upper metal layer in the vicinity of the lower layer bend is removed, and the dielectric substrate 208 in this same region is at least partially removed.

7. The MMF radiator of claim 1 , wherein the plurality of bends comprise at least one dual layer bend (700) in which both the upper metal layer 204 and the lower metal layer 206 of the PCB are used to establish be bend 700.

8. The MMF radiator of claim 7, wherein: in a first portion (702) of the dual layer bend, the lower metal layer 206 in the vicinity of the bend 700 is removed and the substrate 208 in this same region is at least partially removed; and in a second portion (704) of the dual layer bend, the upper metal layer 204 in the vicinity of the bend 700 is removed and the substrate 208 in this same region is at least partially removed.

9. The MMF radiator of claim 1, wherein the respective petals (210) of the MMF Radiator (102) comprise a first pair of petals disposed opposite one another and connected to respective signal paths (402, 404) of a selected one broadside coupled transmission line (212) to define a first polarization dipole.

10. The MMF radiator of claim 9, wherein the first pair of petals are defined in the upper metal layer.

11. The MMF radiator of claim 9, wherein the first pair of petals are defined in the lower metal layer.

12. The MMF radiator of claim 9, wherein the first pair of petals comprise a first petal defined in the upper metal layer, and a second petal defined in the lower metal layer.

13. The MMF radiator of claim 10, wherein a second pair of petals are disposed opposite one another in the upper metal layer, the second pair of petals being connected to one to respective signal paths (402, 404) of a selected other broadside coupled transmission line (212) to define a second polarization dipole.

14. The MMF radiator of claim 10, wherein the second pair of petals are defined in the upper metal layer.

15. The MMF radiator of claim 9, wherein the second pair of petals are defined in the lower metal layer.

16. The MMF radiator of claim 9, wherein the second pair of petals comprise a first petal defined in the upper metal layer, and a second petal defined in the lower metal layer.

17. The MMF radiator of claim 1, further comprising a dielectric support (202) configured to support the radiator element (200).

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