MULTIBAND ANTENNA ASSEMBLIES WITH MATCHING NETWORKS

• US 20130069835A1
• Filed: 10/22/2012
• Published: 03/21/2013
• Est. Priority Date: 09/19/2011
• Status: Active Grant

• Current Assignee: TE Connectivity Solutions GmbH (TE Connectivity Ltd. (United Kingdom))
• Original Assignee: Laird Technologies Incorporated (DuPont de Nemours, Inc.)
• Inventors: Swais, Imad M., Antonio, Robert K., Chau, Tam Hung
• Granted Patent: US 8,988,295 B2
• Time in Patent Office: Days
• US Class Current: 343/715
• CPC Class Codes: H01Q 1/3275 mounted on a horizontal surface of the vehicle, e.g. on roof, hood, trunk
• CPC Class Codes: H01Q 5/321 within a radiating element or between connected radiating elements
• CPC Class Codes: H01Q 9/34 Mast, tower, or like self-supporting or stay-supported antennas

Abstract

An exemplary embodiment of a base assembly includes a printed circuit board and a balun coupled to the printed circuit. The printed circuit board and balun are configured to be operable for providing impedance matching via a matching network that includes a first inductor, a second inductor, and a concentric capacitance. The base assembly is operable for providing a multiband antenna assembly with impedance matching simultaneously with more than one frequency band.

Claims

1. A base assembly for a multiband antenna assembly, the base assembly comprising:

a printed circuit board;

a balun coupled to the printed circuit;

wherein;

the printed circuit board and balun are configured to be operable for providing impedance matching via a matching network that includes;

a first inductor defined by or at an electrically-conductive portion of the printed circuit board;

a second inductor defined by or at the balun, such that the first and second inductors are in parallel with each other; and

a concentric capacitance defined by or at a dielectric portion of the printed circuit board between the balun and the electrically-conductive portion of the printed circuit board, the first and second inductors concentrically capacitive to each other thereby forming the concentric capacitance between the first and second inductors;

whereby the base assembly is operable for providing a multiband antenna assembly with impedance matching simultaneously with more than one frequency band.

2. The base assembly of claim 1, wherein:

the PCB comprises a dual double sided trace representing two inductors in parallel on opposite sides of the PCB; and

the balun comprises a matching RF transformer representing the second inductor with a large mass body and surface.

3. The base assembly of claim 1, wherein the matching network further includes a capacitance from ground.

4. The base assembly of claim 3, further comprising:

a base ring portion configured for mounting the base assembly to an antenna mount, and operable for conducting a ground portion of electrical current flow; and

a contact pin configured for providing an electrical connection between a contact of the antenna mount and the printed circuit board by which electrical current is conducted between the antenna mount and the printed circuit and balun when the base assembly is mounted to the antenna mount; and

the capacitance from ground is created between the base ring portion and the contact pin.

5. The base assembly of claim 4, wherein the base ring portion is operable for controlling shunt capacitances with respect to ground and controlling resonant frequency mainly at a higher frequency range.

6. The base assembly of claim 1, wherein the base assembly is operable for providing impedance matching simultaneously with at least:

a very high frequency (VHF) band from 136 Megahertz (MHz) to 174 MHz;

an ultra high frequency (UHF) band from 380 MHz to 520 MHz; and

a 700/800 MHz frequency band from 760 MHz to 870 MHz.

7. The base assembly of claim 6, wherein:

the matching network represents a one quarter wave radiator for the upper 800 MHz frequency band; and

the matching network serves the purpose of impedance matching for the middle and low frequency bands.

8. A multiband antenna assembly including the base assembly of claim 1, and further comprising an aerial whip antenna assembly mounted to the base assembly, wherein the multiband antenna assembly is operable in at least a very high frequency (VHF) band from 136 Megahertz (MHz) to 174 MHz, an ultra high frequency (UHF) band from 380 MHz to 520 MHz, and a 700/800 MHz frequency band from 760 MHz to 870 MHz, with the base assembly being operable for providing impedance matching simultaneously with the VHF band, the UHF band, and the 700/800 MHz frequency band.

9. The multiband antenna assembly of claim 8, wherein the multiband antenna assembly is configured to have simultaneous electrical lengths of one quarter wavelength (λ

/4) for the VHF band;

five eighths wavelength (5λ

/8) for the UHF band; and

five sixteenths wavelength (5λ

/16) for the 700/800 MHz frequency band.

10. The multiband antenna assembly of claim 8, wherein the aerial whip antenna assembly comprises:

a first linear element having an upper end portion and a lower end portion mounted to the base assembly by a shock absorbing spring;

a second linear element having an upper end portion and a lower end portion spaced apart from the upper end portion of the first linear element;

a phasing coil electrically connecting the first and second linear elements and linearly joining the upper end portion of the first linear element to the lower end portion of the second linear element, the phasing coil operable; and

an aerial radio waves defusing metal ball mounted to the upper portion of the second linear element.

11. The multiband antenna assembly of claim 10, wherein:

the matching network further includes a capacitance from ground; and

the matching network together with inductance of the first linear element form a one-half wave radiator for the 700/800 MHz frequency band and five sixteenths wave radiator for the UHF band;

a one-quarter wave radiator for the VHF band is formed by elements of the multiband antenna assembly beginning with a source up to the metal ball;

inductance of the phasing coil allows the phasing coil to function for the UHF band and the 700/800 MHz band; and

inductance of the second linear element represents a one-half wave element for the 700/800 MHz band and one-quarter wave element for the UHF and, such that the multiband antenna assembly is operable and works at the 700/800 MHz band as a stacked one-have wave antenna which corresponds to the elevation pattern.

12. The multiband antenna assembly of claim 8, wherein:

the multiband antenna assembly has an overall height of 20 inches or less and/or a 2.5 inch diameter base or less; and

/or

the multiband antenna assembly is configured for use as a vehicular broadband mobile antenna; and

/or

the multiband antenna assembly is vertically polarized; and

/or

the multiband antenna assembly is omnidirectional; and

/or

the multiband antenna assembly has a voltage standing wave ratio less than 2.5;

1; and

/or

the multiband antenna assembly is operable for covering the VHF band with unity gain, the UHF band with a gain of 3 decibels relative to isotropic (dBi), and the 700/800 MHz band with a gain of 3 dBi.

13. The base assembly of claim 1, wherein the base assembly is mountable to an external mobile antenna mount, which is installed to a mounting surface of a vehicle and connected to an electronic device within the vehicle.

14. The base assembly of claim 1, wherein:

the printed circuit board includes at least one hole therethrough; and

the base assembly further comprises a contact assembly configured to provide a solderless connection between the printed circuit board and an antenna mount having a contact, the contact assembly including;

a first end portion having at least one hole therethrough aligned with the at least one hole of the printed circuit board, the first end portion fastened to the printed circuit board by at least one fastener disposed with the aligned holes;

a second end portion configured to electrically contact the contact of the antenna mount; and

a biasing member between the first and second end portions, the biasing member operable for biasing the second end portion against the contact of the antenna mount when the base assembly is mounted to the antenna mount;

whereby the printed circuit board is connected to the antenna mount via the contact assembly without solder, such that signals are transferrable via the contact assembly between the printed circuit board and an electronic device that is connected to the contact of the antenna mount.

15. The base assembly of claim 1, further comprising:

a base coupled to the base ring portion;

a housing coupled to the base ring portion such that an interior enclosure is cooperatively defined by the housing and the base, the interior enclosure including the printed circuit board therein and being sealed to thereby inhibit the ingress of water into the interior enclosure; and

one or more electrical grounding taps electrically connected to the printed circuit board, the one or more electrical grounding taps configured for establishing at least a portion of an electrically-conductive grounding pathway from outside the interior enclosure and which extends internally into the interior enclosure to the printed circuit board, whereby the one or more electrical grounding taps allow the interior enclosure to remain sealed against the ingress of water.

18. A multiband antenna assembly including the base assembly of claim 1, and further comprising an aerial whip antenna assembly mounted to the base assembly, wherein:

the multiband antenna assembly is operable in at least a very high frequency (VHF) band from 136 Megahertz (MHz) to 174 MHz, an ultra high frequency (UHF) band from 380 MHz to 520 MHz, and a 700/800 MHz frequency band from 760 MHz to 870 MHz, with the base assembly being operable for providing impedance matching simultaneously with the VHF band, the UHF band, and the 700/800 MHz frequency band; and

the multiband antenna assembly is configured to have simultaneous electrical lengths of one quarter wavelength (λ

/4) for the VHF band;

five eighths wavelength (5λ

/8) for the UHF band; and

five sixteenths wavelength (5λ

/16) for the 700/800 MHz frequency band.

16. A base assembly for mounting an aerial whip antenna assembly to an external antenna mount of a vehicle, the base assembly comprising:

a printed circuit board;

a balun coupled to the printed circuit;

a base ring portion configured for mounting the base assembly to an antenna mount; and

a contact pin configured for providing an electrical connection between a contact of the antenna mount and the printed circuit board;

wherein the base assembly is operable for providing impedance matching via a matching network that includes;

a first inductor defined by or at an electrically-conductive portion of the printed circuit board;

a second inductor defined by or at the balun, such that the first and second inductors are in parallel with each other; and

a concentric capacitance defined by or at a dielectric portion of the printed circuit board between the balun and the electrically-conductive portion of the printed circuit board, the first and second inductors concentrically capacitive to each other thereby forming the concentric capacitance between the first and second inductors; and

a capacitance from ground created between the base ring portion and the contact pin.

17. The base assembly of claim 16, wherein:

the PCB comprises a dual double sided trace representing two inductors in parallel on opposite sides of the PCB;

the balun comprises a matching RF transformer representing the second inductor with a large mass body and surface; and

the base ring portion is operable for controlling shunt capacitances with respect to ground and controlling resonant frequency mainly at a higher frequency range.

19. A multiband antenna assembly operable in at least a very high frequency (VHF) band from 136 Megahertz (MHz) to 174 MHz, an ultra high frequency (UHF) band from 380 MHz to 520 MHz, and a 700/800 MHz frequency band from 760 MHz to 870 MHz, the multiband antenna assembly comprising:

a base assembly operable for providing impedance matching simultaneously with the VHF band, the UHF band, and the 700/800 MHz frequency band; and

an aerial whip antenna assembly mounted to the base assembly,

wherein the base assembly includes;

a printed circuit board;

a balun coupled to the printed circuit;

a base ring portion configured for mounting the base assembly to an antenna mount; and

a contact pin configured for providing an electrical connection between a contact of the antenna mount and the printed circuit board when the base assembly is mounted to the antenna mount.

20. The multiband antenna assembly of claim 19, wherein the base assembly is operable for providing impedance matching via a matching network that includes:

a capacitance from ground created between the base ring portion and the contact pin;

a concentric capacitance; and

first and second inductors in parallel and concentrically capacitive to each other thereby forming the concentric capacitance between the first and second inductors.

21. The multiband antenna assembly of claim 19, wherein:

the multiband antenna assembly is configured to have simultaneous electrical lengths of one quarter wavelength (λ

/4) for the VHF band;

five eighths wavelength (5λ

/8) for the UHF band; and

five sixteenths wavelength (5λ

/16) for the 700/800 MHz frequency band; and

/or

the PCB comprises a dual double sided trace representing two inductors in parallel on opposite sides of the PCB; and

/or

the balun comprises a matching RF transformer representing the second inductor with a large mass body and surface; and

/or

the base ring portion is operable for controlling shunt capacitances with respect to ground and controlling resonant frequency mainly at a higher frequency range.