WO2019204203A1

WO2019204203A1 - Patch antennas with dielectric resonator probes and vehicular antenna assemblies including the same

Info

Publication number: WO2019204203A1
Application number: PCT/US2019/027481
Authority: WO
Inventors: Gary Keith Reed
Original assignee: Molex Cvs Grand Blanc, Llc; Laird Technologies, Inc.
Priority date: 2018-04-18
Filing date: 2019-04-15
Publication date: 2019-10-24

Abstract

A patch antenna comprising: a patch dielectric substrate including an upper surface and a lower surface; an antenna structure along the upper surface of the patch dielectric substrate; and a dielectric resonator probe configured to be operable for feeding the patch antenna, wherein the dielectric resonator probe includes: an electrical conductor disposed within the patch dielectric substrate and extending generally between the upper and lower surfaces of the patch dielectric substrate; and a dielectric material disposed within the patch dielectric substrate and generally around at least a portion of the electrical conductor.

Description

PATCH ANTENNAS WITH DIELECTRIC RESONATOR PROBES AND

VEHICULAR ANTENNA ASSEMBLIES INCLUDING THE SAME

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application is a PCT International Application which claims priority to and the benefit of United States Provisional Patent Application No. 62/659,404 filed April 18, 2018. The entire disclosure of the above application is incorporated herein by reference.

FIELD

[0002] The present disclosure generally relates to patch antennas with dielectric resonator probes and vehicular antenna assemblies including the same.

BACKGROUND

[0003] This section provides background information related to the present disclosure which is not necessarily prior art.

[0004] Various different types of antennas are used in the automotive industry, including AM/FM radio antennas, Satellite Digital Audio Radio Service (SDARS) antennas (e.g, SiriusXM^® satellite radio, etc.), Global Navigation Satellite System (GNSS) antennas, cellular antennas, etc. Multiband antenna assemblies are also commonly used in the automotive industry. A multiband antenna assembly typically includes multiple antennas to cover and operate at multiple frequency ranges.

[0005] Automotive antennas may be installed or mounted on a vehicle surface, such as the roof, trunk, or hood of the vehicle to help ensure that the antennas have unobstructed views overhead or toward the zenith. The antenna may be connected (e.g, via a coaxial cable, etc.) to one or more electronic devices (e.g, a radio receiver, a touchscreen display, navigation device, cellular phone, etc.) inside the passenger compartment of the vehicle, such that the multiband antenna assembly is operable for transmitting and/or receiving signals to/from the electronic device(s) inside the vehicle. DRAWINGS

[0006] The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.

[0007] FIG. 1 illustrates a patch antenna including a dielectric resonator probe according to an exemplary embodiment.

[0008] FIG. 2, 3, and 4 are line graphs of gain in decibels (dB) versus frequency in Megahertz (MHz) at elevation angles of 0 degrees, 30 degrees, and 60 degrees, respectively, for a patch antenna with a dielectric resonator according to exemplary embodiments disclosed herein. For comparison purposes, FIGS. 2, 3, and 4 also include gain versus frequency for a conventional patch antenna without a dielectric resonator.

[0009] Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.

DETAILED DESCRIPTION

[0010] Example embodiments will now be described more fully with reference to the accompanying drawings.

[0011] Exemplary embodiments are disclosed herein of patch antennas with dielectric resonator probes. Also disclosed are vehicular antenna assemblies including patch antennas with dielectric resonator probes.

[0012] In exemplary embodiments, a patch antenna includes a dielectric ( e.g ., ceramic, etc.) resonator that replaces the conventional probe pins that are traditionally used for feeding patch antennas. The patch antenna may be a single layer patch or single non-stacked patch antenna. The dielectric resonator may be operable as a single probe feed of the feed mechanism for the patch antenna.

[0013] The dielectric resonator structure may enable the patch antenna to have a narrower bandwidth with rejection at specific frequencies. The dielectric resonator may be tuned to any frequency that the passive patch antenna needs attenuated. This allows for decreasing susceptibility to specific bands of interference and not solely relying on the natural rejection of the patch antenna based on the substrate material. [0014] Specifications for SiriusXM^® satellite radio require a certain amount of passive rejection that is difficult to attain with certain patch antenna substrates. Other use cases besides SiriusXM^® satellite radio may require additional passive rejection at out-of-band frequencies to reduce interference issues. Using the dielectric resonator instead of a conventional probe pin may allow the patch antenna and a vehicular antenna assembly including the patch antenna to meet or satisfy the specifications for SiriusXM^® satellite radio and/or other use cases.

[0015] By way of example, the dielectric resonator may be made of ceramic or other dielectric material, e.g ., a dielectric material having a dielectric constant considerably higher than the dielectric constant of air, a dielectric material having a dielectric constant greater than 20, etc. For example, the dielectric resonator may be made of a ceramic material having a dielectric constant of about 100 or more. As used herein, the term“about” indicates that the calculation or the measurement allows some slight imprecision in the value (with some approach to exactness in the value; approximately or reasonably close to the value; nearly). If, for some reason, the imprecision provided by“about” is not otherwise understood in the art with this ordinary meaning, then“about” as used herein indicates at least variations that may arise from ordinary methods of measuring or using such parameters. For example, the terms“generally”,“about”, and“substantially” may be used herein to mean within manufacturing tolerances.

[0016] The ceramic or other dielectric material of the dielectric resonator may be disposed around an electrical conductor of the dielectric resonator. The electrical conductor is part of the dielectric resonator structure.

[0017] The dielectric material may be disposed generally around or about the electrical conductor such that the electrical conductor is at about a center of and/or extends along a centerline axis of the dielectric resonator. The electrical conductor may be pretuned before the electrical conductor is added to the patch antenna and/or before the dielectric material is disposed around the electrical conductor.

[0018] The electrical conductor may be a generally straight or linear conductive element, such as a straight metal pin having a round or circular cross-sectional shape, etc. A flattened head or nail-head structure may be used at an upper or top end portion of the electrical conductor, which may be soldered to an electrically-conductive portion (e.g, antenna structure, radiating element, top plating, metallization, ground, etc.) along an upper portion of the patch antenna. [0019] The dielectric resonator including its electrical conductor and dielectric material is operable as the probe feed for the patch antenna. An electrical connection point from the patch antenna to the circuitry may be provided via the electrical conductor ( e.g ., center pin, etc.).

[0020] The dielectric resonator structure is not an inherent part of the patent antenna. For example, the dielectric material used for the dielectric resonator may be a different material(s) than the material(s) used for the dielectric substrate of the patch antenna. The dielectric resonator may be separately added to the patch antenna.

[0021] The patch antenna may be configured to be operable for receiving SDARS signals (e.g., SiriusXM^® satellite radio, etc.), other satellite signals, etc. The patch antenna includes a dielectric substrate and an antenna structure or radiating element (e.g, copper, etc.) along an upper surface of the patch dielectric substrate. The patch antenna may also include electrically-conductive portion (e.g, copper, metallization layer, ground, etc.) along a lower surface of the patch dielectric substrate. The electrical conductor of the dielectric resonator may extend through the patch dielectric substrate. The electrical conductor may provide a direct or galvanic electrical connection between the antenna structure (e.g, l/2-antenna structure, a single electrically-conductive layer, etc.) and the electrically-conductive portion (e.g, a single electrically-conductive ground layer, etc.) along the respective upper and lower surfaces of patch dielectric substrate.

[0022] The patch dielectric substrate may be thermoplastic pol ytetrafl uoroethyl ene (PTFE) based compound that is mixed with small amounts of fiberglass and ceramics. Alternatively, other suitable dielectric materials (e.g, PC board materials, etc.) may be used for the dielectric substrate of the patch antenna.

[0023] The dielectric material used for the patch dielectric substrate may be cast around the dielectric resonator. By way of example, the patch dielectric substrate may have a dielectric constant of about 20, and the dielectric material of the resonator may have a higher dielectric constant of about 100.

[0024] With reference now to the figures, FIG. 1 illustrates a patch antenna 104 embodying one or more aspects of the present disclosure. As shown in FIG. 1, the patch antenna 104 includes a dielectric substrate 108. An antenna structure or radiating element 112 (e.g, copper, etc.) is along an upper surface or top of the patch dielectric substrate 108. An electrically-conductive material 116 (e.g, copper, etc.) along a lower surface or bottom of the patch dielectric substrate 108.

[0025] The patch antenna 104 also includes a dielectric (e.g, ceramic, etc.) resonator 120 for feeding the patch antenna 104. In this exemplary embodiment, the patch antenna 104 is shown as a single layer or non-stacked patch antenna. The dielectric resonator 120 may be configured to be operable as a single probe feed of the feed mechanism for the patch antenna 104.

[0026] The dielectric resonator 120 may be made of ceramic or other suitable dielectric material 124. For example, the dielectric resonator 120 may be made of a ceramic material 124 having a dielectric constant of about 100 or more.

[0027] The ceramic or other dielectric material 124 of the dielectric resonator 120 may be disposed around an electrical conductor 128. The electrical conductor 128 is part of the dielectric resonator structure 120.

[0028] The dielectric material 124 may be disposed generally around or about the electrical conductor 128 such that the electrical conductor 128 is at about a center of and/or extends along a centerline axis of the dielectric resonator 120. The electrical conductor 128 may be pretuned before the electrical conductor 128 is added to the patch antenna 104 and/or before the dielectric material 124 is disposed around the electrical conductor 128.

[0029] The electrical conductor 128 may be a single generally straight or linear conductive element, such as a straight metal pin having a round or circular cross-sectional shape, etc. A flattened head or nail-head structure at an upper or top end portion of the electrical conductor 128 may be soldered to the antenna structure or radiating element 112 along the upper surface or top of the patch dielectric substrate 108.

[0030] The dielectric resonator 120 including its electrical conductor 128 and dielectric material 124 is operable as a probe feed for the patch antenna 104. An electrical connection point from the patch antenna 104 to the circuitry may be provided via the electrical conductor 128 (e.g, center pin, etc.).

[0031] The dielectric resonator structure 120 is not an inherent part of the patent antenna 104. The dielectric material 124 used for the dielectric resonator 120 may be different than the material(s) used for the patch dielectric substrate 108. For example, the patch dielectric substrate 108 may be thermoplastic polytetrafluoroethylene (PTFE) based compound that is mixed with small amounts of fiberglass and ceramics. The dielectric material 124 of the dielectric resonator 120 may be a ceramic. By way of example, the patch dielectric substrate 108 may have a dielectric constant of about 20, and the resonator dielectric material 124 may have a higher dielectric constant of about 100. Alternatively, other suitable dielectric materials ( e.g ., PC board materials, materials with higher or lower dielectric constants, etc.) may be used for the patch dielectric substrate 108 and/or for the dielectric resonator 120.

[0032] The dielectric resonator 120 may be separately added to the patch antenna 104. For example, the material used for the patch dielectric substrate 108 may be cast around the dielectric resonator 120.

[0033] The electrical conductor 128 of the dielectric resonator 120 may extend through the patch dielectric substrate 108. The electrical conductor 128 may provide a direct or galvanic electrical connection between the antenna structure 112 and the electrically-conductive portion 116 along the respective upper and lower surfaces of the patch dielectric substrate 108. A wide range of materials may be used for the antenna structure 112, electrically-conductive portion 116, and electrical conductor 128, including metals, metal alloys, copper, etc.

[0034] The dielectric resonator structure 120 may enable the patch antenna 104 to have a narrower bandwidth with rejection at specific frequencies. Advantageously, the dielectric resonator 120 may be tuned to any frequency that the passive patch antenna 104 needs attenuated. This allows for decreasing susceptibility to specific bands of interference and not solely relying on the natural rejection of the patch antenna 104 based on the substrate material 108.

[0035] The patch antenna 104 may be configured to be operable for receiving SDARS signals (e.g., SiriusXM^® satellite radio, etc.), other satellite signals, etc. In which case, the dielectric resonator probe 120 may allow the patch antenna 104 (and a vehicular antenna assembly including the patch antenna 104) to satisfy or meet specifications for SiriusXM^® satellite radio, etc.

[0036] FIG. 2, 3, and 4 are line graphs of gain in decibels (dB) versus frequency in Megahertz (MHz) at elevation angles of 0 degrees, 30 degrees, and 60 degrees, respectively, for a patch antenna (e.g, patch antenna 104, etc.) with a dielectric resonator (e.g, dielectric resonator 120, etc.) according to exemplary embodiments disclosed herein. For comparison purposes, FIGS. 2, 3, and 4 also include gain versus frequency for a conventional patch antenna without a dielectric resonator. Generally, FIGS. 2, 3, and 4 show that using a dielectric resonator as the patch feed can reduce gain of the patch antenna outside SiriusXM^® satellite radio frequencies at different elevation angles including 0 degrees, 30 degrees, and 60 degrees. The dielectric resonator may thus help inhibit or prevent cellular signals and other outside signals from interfering with the SiriusXM^® satellite radio. Aspects of the present disclosure may also be applied to about any other frequencies of interest, such as Global Navigation Satellite System (GNSS) signals or frequencies ( e.g ., Global Positioning System (GPS), BeiDou Navigation Satellite System (BDS), the Russian Global Navigation Satellite System (GLONASS), other satellite navigation system frequencies, etc.), Iridium, etc.

[0037] In an exemplary embodiment, a vehicular antenna assembly may include the patch antenna 104. The vehicular antenna assembly may also include one or more additional antennas operable in one or more frequencies or bandwidths.

[0038] For example, the antenna assembly may include a second patch antenna, a primary cellular antenna, and/or a secondary cellular antenna. The vehicular antenna assembly may be operable as a multiband multiple input multiple output (MIMO) vehicular antenna assembly.

[0039] As noted above, the first patch antenna 104 may be configured to be operable for receiving SDARS signals (e.g., SiriusXM^® satellite radio, etc.), other satellite signals, etc. The second patch antenna may be configured to be operable for receiving Global Navigation Satellite System (GNSS) signals or frequencies (e.g, Global Positioning System (GPS), BeiDou Navigation Satellite System (BDS), the Russian Global Navigation Satellite System (GLONASS), other satellite navigation system frequencies, etc.). The first patch antenna 104 and the second patch antenna may be in horizontally spaced apart from each other. Alternatively, the first patch antenna 104 and the second patch antenna may be in a stacked arrangement with the second patch antenna stacked on top of the first patch antenna 104.

[0040] In exemplary embodiments, the SDARS signals received by the first patch antenna 104 may be fed via a coaxial cable to a SDARS radio, which, in turn, may be located in an Instrument Panel (IP) that is independent from a Telematics Control Unit (TCU) box. By way of background, the frequency range or bandwidth of GPS(Ll) is 1575.42MHz ± l.023MHz, the frequency range or bandwidth of BDS(Bl) is 1561.098MHz ± 2.046MHz, the frequency range or bandwidth of GLONASS(Ll) is 1602.5625MHz ± 4MHz, and the frequency range or bandwidth of SDARS is 2320MHz to 2345MHz. Also, for example, the second patch antenna may be operable from about 1558 MHz to about 1608 MHz.

[0041] In an exemplary embodiment, the vehicular antenna assembly may include a first or primary cellular antenna that is a monopole antenna ( e.g ., stamped metal wide band monopole antenna mast, etc.) configured to be operable for both receiving and transmitting communication signals within one or more cellular frequency bands (e.g., Long Term Evolution (LTE), etc.). The vehicular antenna assembly may also include a second or secondary cellular antenna configured to be operable within one or more cellular frequency bands (e.g, LTE, etc.). The primary and secondary cellular antenna may be connected to and supported by a printed circuit board (PCB), for example, by soldering, etc..

[0042] The PCB may be supported by a chassis or body. The PCB may be mechanically fastened via fasteners (e.g, screws, etc.) to the chassis.

[0043] A radome or cover may be used to help protect the various components of the vehicular antenna assembly enclosed within an interior spaced defined by the radome and a chassis. For example, the radome may substantially seal the components of the vehicular antenna assembly within the radome thereby protecting the components against ingress of contaminants (e.g, dust, moisture, etc.) into an interior enclosure of the radome. In addition, the radome may have an aerodynamic shark-fin configuration. The radome may be formed from a wide range of materials, such as, for example, polymers, urethanes, plastic materials (e.g, polycarbonate blends, Polycarbonate-Acrylnitril-Butadien-Styrol-Copolymer (PC/ABS) blend, etc.), glass- reinforced plastic materials, thermoplastic materials, synthetic resin materials, etc. within the scope of the present disclosure.

[0044] The radome may be configured to fit over the first patch antenna and one or more other antennas, if any, of the vehicular antenna assembly, such that the antennas are colocated under the radome. The radome may be configured to be secured to a chassis of the vehicular antenna assembly. In an exemplary embodiment, the radome may be secured to the chassis by mechanical fasteners (e.g, screws, etc.). Alternatively, the radome may be secured to a chassis via any suitable operation, for example, a snap fit connection, mechanical fasteners (e.g, screws, other fastening devices, etc.), ultrasonic welding, solvent welding, heat staking, latching, bayonet connections, hook connections, integrated fastening features, etc. [0045] The chassis or base may be configured to couple to a roof of a vehicle for installing the antenna assembly to the vehicle. Alternatively, the radome may connect directly to the roof of a vehicle within the scope of the present disclosure. The antenna assembly may be mountable to a vehicle roof, hood, trunk ( e.g ., with an unobstructed view overhead or toward the zenith, etc.) where the mounting surface of the vehicle acts as a ground plane for the antenna assembly.

[0046] The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements, intended or stated uses, or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.

Claims

CLAIMS WHAT IS CLAIMED IS:

1. A patch antenna comprising:

a patch dielectric substrate including an upper surface and an lower surface;

an antenna structure along the upper surface of the patch dielectric substrate;

a dielectric resonator probe configured to be operable for feeding the patch antenna, the dielectric resonator probe including:

an electrical conductor disposed within the patch dielectric substrate and extending generally between the upper and lower surfaces of the patch dielectric substrate; and

a dielectric material disposed within the patch dielectric substrate and generally around at least a portion of the electrical conductor.

2. The patch antenna of claim 1, wherein the dielectric material is disposed generally around the at least a portion of the electrical conductor such that the electrical conductor is at about a center of and/or extends along a centerline axis of the dielectric resonator probe.

3. The patch antenna of claim 1 or 2, wherein the electrical conductor extends through a thickness of the patch dielectric substrate such that:

an upper end portion of the electrical conductor protrudes beyond the upper surface of the patch dielectric substrate and is electrically connected to the antenna structure along the upper surface of the patch dielectric substrate; and/or

a lower end portion of the electrical conductor protrudes beyond the lower surface of the patch dielectric substrate, the lower end portion of the electrical conductor is electrically connected to an electrically-conductive material along the lower surface of the patch dielectric substrate and/or provides an electrical connection point for connecting the patch antenna to circuitry.

4. The patch antenna of any one of the preceding claims, wherein:

the dielectric material of the dielectric resonator probe has a dielectric constant that is higher than a dielectric constant of the patch dielectric substrate; and/or

the patch dielectric substrate has a dielectric constant of about 20, and the dielectric material of the dielectric resonator probe has a dielectric constant of about 100.

5. The patch antenna of any one of the preceding claims, wherein:

the dielectric material of the dielectric resonator probe comprises a ceramic material having a dielectric constant of about 100 or more; and/or

the dielectric material of the dielectric resonator probe comprises a thermoplastic polytetrafluoroethylene based compound mixed with fiberglass and/or ceramics.

6. The patch antenna of any one of the preceding claims, wherein:

the dielectric material of the dielectric resonator probe and the patch dielectric substrate are made from different materials; and/or

the patch dielectric substrate comprises a dielectric material cast around the dielectric resonator probe.

7. The patch antenna of any one of the preceding claims, wherein the electrical conductor comprises a generally linear electrically-conductive element.

8. The patch antenna of claim 7, wherein the generally linear electrically-conductive element comprises a metal pin having a round cross-sectional shape and a flattened head at an upper portion of the electrical conductor soldered to the antenna structure of the patch antenna.

9. The patch antenna of any one of the preceding claims, wherein:

the patch antenna is configured to be operable for receiving Satellite Digital Audio Radio Service (SDARS) signals; and/or

the dielectric resonator probe is configured to be operable as a single probe feed of a feed mechanism for the patch antenna.

10. The patch antenna of any one of the preceding claims, wherein the electrical conductor is tunable for one or more out-of-band frequencies before the electrical conductor is added to the patch antenna and/or before the dielectric material is disposed generally around the electrical conductor, to thereby enable the patch antenna to have a narrower bandwidth with passive rejection at the one or more out-of-band frequencies and decrease susceptibility to specific bands of interference.

11. A vehicular antenna assembly including the patch antenna assembly of any one of the preceding claims.

12. The vehicular antenna assembly of claim 11, wherein:

the patch antenna is a first patch antenna configured to be operable for receiving first satellite signals; and the vehicular antenna assembly further comprises a second patch antenna configured to be operable for receiving second satellite signals different than the first satellite signals, the second patch antenna horizontally spaced apart from the first patch antenna or in a stacked arrangement with the second patch antenna stacked on top of the first patch antenna.