# US 8,786,503 B2 · Dual UHF dipole quadrafiler helix antenna > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,786,503 B2 - Document ID: US8786503B2 - Status: Granted - Kind: B2 - Application number: 13/473,723 - Filed: 2012-05-17 - Published: 2013-01-10 - Granted: 2014-07-22 - Earliest claimed: 2011-07-07 - Assignees: BAE Systems Information and Electronic Systems Integration Inc. - Applicants: John T. Apostolos; Benjamin G. McMahon - Inventors: John T. Apostolos; Benjamin G. McMahon - Web page: https://patentgrep.com/patent/US8786503B2 ## CPC - H01Q 1/273: {Adaptation for carrying or wearing by persons or animals} - H01Q 1/3275: {mounted on a horizontal surface of the vehicle, e.g. on roof, hood, trunk} - H01Q 5/40: Imbricated or interleaved structures; Combined or electromagnetically coupled arrangements, e.g. comprising two or more non-connected fed radiating elements - H01Q 5/50: Feeding or matching arrangements for broad-band or multi-band operation - H01Q 9/22: Rigid rod or equivalent tubular element or elements - H01Q 11/08: Helical antennas - H01Q 21/10: Collinear arrangements of substantially straight elongated conductive units - H01Q: ANTENNAS, i.e. RADIO AERIALS (radiators or antennas for microwave heating H05B6/72) ## Abstract A dual purpose antenna is provided with the UHF antenna in the form of a pair of copper tubes to provide an off center fed dipole, with a pair of quadrafiler helix L1 and L2 GPS antennas stacked on top of the UHF antenna, and with the top section of the UHF dipole providing a ground plain for the GPS antenna. The antennas are fed internally by two coaxial feeds, one feeding the UHF antenna, the other passing through the UHF antenna to feed the GPS antennas. In one embodiment, a tuning coil is provided at the base of the UHF antenna by the coiling of the two coaxial feeds around a non-conductive mandrel, with copper taping placed on top of the coiled coaxial sections to provide an LC circuit to lower the resonant frequency of the UHF antenna to 225 MHz. ## Claims ### Claim 1 A dual UHF/GPS antenna system comprising: a UHF dipole antenna structure comprising an upper tubular section and a lower tubular section; a lower coaxial feedline wherein the outer conductor of the lower coaxial feedline is configured to feed the upper section of the dipole antenna structure and the inner conductor of the lower coaxial feedline is configured to feed the lower section of the dipole antenna structure; an upper coaxial feed line configured to access the upper section through the lower section of the dipole antenna structure, said coaxial feedlines coiled at the bottom of said lower section of said dual dipole structure and overlain with a strip of conductive tape; and a GPS antenna stacked on top of said dipole antenna structure and fed with the upper coaxial feedline, wherein said GPS antenna includes a stacked pair of L1 and L2 band GPS antennas. ### Claim 2 (depends on 1) The antenna system of claim 1, wherein the upper section of the dipole antenna structure includes said GPS antenna. ### Claim 3 (depends on 1) The antenna system of claim 1, wherein the upper coaxial feedline passes through the lower section without affecting the operation of the lower section of the dipole antenna structure. ### Claim 4 (depends on 1) The antenna system of claim 1, wherein the coil includes at least seven turns of the upper and lower coaxial feedlines around a nonconductive part of the dipole antenna structure. ### Claim 5 (depends on 1) The antenna system of claim 1, further including a spring structure fixed to the base of the dipole antenna structure. ### Claim 6 (depends on 1) The antenna system of claim 1, wherein said coiled coaxial feedlines and said strip form an LC circuit for lowering the operating frequency of said dipole. ### Claim 7 (depends on 6) The antenna system of claim 6, where said dipole is tuned to the center of the UHF band at 300 MHz. ### Claim 8 (depends on 7) The antenna system of claim 7, wherein the lower end of the UHF band at which said dipole operates is 225 MHz. ### Claim 9 (depends on 1) The antenna system of claim 1, wherein said GPS antennas include quadrofiler helix antennas. ### Claim 10 (depends on 1) The antenna system of claim 1, and further including a diplexer and low noise amplifiers interposed between the end of said upper coaxial feedline and said L1 and L2 band GPS antennas. ### Claim 11 (depends on 1) The antenna system of claim 1, wherein the upper section of said dipole antenna structure serves as a ground plane for said GPS antenna. ### Claim 12 A dual UHF/GPS antenna system comprising: a UHF dipole antenna structure comprising an upper tubular section and a lower tubular section; a lower coaxial feedline wherein the outer conductor of the lower coaxial feedline is configured to feed the upper section of the dipole antenna structure and the inner conductor of the lower coaxial feedline is configured to feed the lower section of the dipole antenna structure; an upper coaxial feed line configured to access the upper section through the lower section of the dipole antenna structure, and a GPS antenna stacked on top of said dipole antenna structure and fed with the upper coaxial feedline, said GPS antenna having said upper tubular section as a ground plane, wherein there is a coil which include at least seven turns of the upper and lower coaxial feedlines around a nonconductive part of the dipole antenna structure. ### Claim 13 (depends on 12) The antenna system of claim 12, wherein the said coaxial feedlines are coiled at the bottom of said dipole structure. ### Claim 14 (depends on 13) The antenna system of claim 13, and further including a strip of conductive tape over said coiled feedlines. ### Claim 15 (depends on 14) The antenna system of claim 14, wherein said coiled coaxial feedlines and said strip form an LC circuit for lowering the operating frequency of said dipole. ### Claim 16 (depends on 15) The antenna system of claim 15, where said dipole is tuned to the center of the UHF band at 300 MHz. ### Claim 17 (depends on 16) The antenna system of claim 16, wherein the lower end of the UHF band at which said dipole operates is 225 MHz. ### Claim 18 A dual UHF/GPS antenna system comprising: a UHF dipole antenna structure comprising an upper tubular section and a lower tubular section; a lower coaxial feedline wherein the outer conductor of the lower coaxial feedline is configured to feed the upper section of the dipole antenna structure and the inner conductor of the lower coaxial feedline is configured to feed the lower section of the dipole antenna structure; an upper coaxial feed line configured to access the upper section through the lower section of the dipole antenna structure, said coaxial feedlines coiled at the bottom of said lower section of said dual dipole structure and overlain with a strip of conductive tape, wherein there is a coil which includes at least seven turns of the upper and lower coaxial feedlines around a nonconductive part of the dipole antenna structure; and a GPS antenna stacked on top of said dipole antenna structure and fed with the upper coaxial feedline. ### Claim 19 A dual UHF/GPS antenna system comprising: a UHF dipole antenna structure comprising an upper tubular section and a lower tubular section; a lower coaxial feedline wherein the outer conductor of the lower coaxial feedline is configured to feed the upper section of the dipole antenna structure and the inner conductor of the lower coaxial feedline is configured to feed the lower section of the dipole antenna structure; an upper coaxial feed line configured to access the upper section through the lower section of the dipole antenna structure, said coaxial feedlines coiled at the bottom of said lower section of said dual dipole structure and overlain with a strip of conductive tape; and a GPS antenna stacked on top of said dipole antenna structure and fed with the upper coaxial feedline, wherein said coiled coaxial feedlines and said strip form an LC circuit for lowering the operating frequency of said dipole. ### Claim 20 A dual UHF/GPS antenna system comprising: a UHF dipole antenna structure comprising an upper tubular section and a lower tubular section; a lower coaxial feedline wherein the outer conductor of the lower coaxial feedline is configured to feed the upper section of the dipole antenna structure and the inner conductor of the lower coaxial feedline is configured to feed the lower section of the dipole antenna structure; an upper coaxial feed line configured to access the upper section through the lower section of the dipole antenna structure, said coaxial feedlines coiled at the bottom of said lower section of said dual dipole structure and overlain with a strip of conductive tape; and a GPS antenna stacked on top of said dipole antenna structure and fed with the upper coaxial feedline, wherein the upper section of said dipole antenna structure serves as a ground plane for said GPS antenna.