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US3747102A
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Electronically modulated tacan antenna
Assignee: Westinghouse Electric Corp
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Filing: 1971-12-15
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Granted: 1973-07-17
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Expires: 1991-12-15
Abstract
Abstract A TACAN antenna array comprising a central radiating element, providing carrier frequency fc radiation omnidirectionally in the azimuth plane, which is surrounded by two or more concentric arrays of 15Hz and 135Hz modulation radiating elements. The first concentric array is preferably comprised of 4 elements used to provide a fc + OR - 15Hz modulation and is comprised of two orthogonally disposed antiphased subarrays which are excited with the suppressed carrier sideband energy of a 15Hz modulated carrier frequency fc with the two orthogonally arranged subarrays being excited in phase quadrature with one another. The second concentric array is preferably comprised of 36 radiating elements divided into two subarrays of 18 elements each, which are excited with 135Hz modulated suppressed carrier fc sideband energy. The elements of the two 18 element subarrays are alternately dispersed in a circular pattern. The two subarrays respectively are fed in phase quadrature with adjacent elements of each subarray being fed in antiphase relationship so that as the circumference is traversed a +l, +j, -l, -j phase relationship exists in consecutive sets of four elements around the 36 radiating elements.
Inventors
- 👤 H Cooper
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 06:06
CPC Classifications
G; G01; G01S; G01S1/00; G01S1/02
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
304 words
An electronically modulated TACAN antenna system for providing a rotating radiation pattern, comprising in combination: a TACAN transmitter generating and providing at least three output signals having frequencies of fc, fc + OR - 15Hz, and fc + OR - 135Hz, respectively, where fc is the carrier frequency; central radiation means coupled to said fc output signal and providing an omnidirectional radiation pattern in the azimuth plane thereby; an array of at least four elements containg two pairs of mutually orthogonal active radiation elements centrally located with respect to said central radiation means; circuit means coupling said array of at least four radiation elements to said fc + OR - 15Hz output signal and including circuit means feeding said fc + OR - 15Hz output signal to said at least four radiation elements with respective fc + OR - 15Hz output signals phased +1, +j, -1, and -j, consecutively where +1 corresponds to 0* phase shift, +j corresponds to 90* phase shift, -1 corresponds to 180* phase shift and -j corresponds to 270* phase shift whereby said +1 phase and -1 phase excited radiation elements are located on a common axis on opposite sides of said central radiation means and said +j phase and -j phase excited radiation elements are located on a common orthogonal axis on opposite sides of said central radiation means; another array of 4 n radiation elements, where n>1, circularly arranged concentrically with respect to said central radiation means; and circuit means coupling said circular array of 4n radiation elements to said fc + OR - 135Hz output signal and including circuit means feeding said fc + OR - 135Hz output signal to repetitive sets of four radiation elements each with respective fc + OR - 135Hz output signals phased +1, +j, -1, and -j, consecutively around the entire array.
Claim 2
Dependent Claim
304 words
An electronically modulated TACAN antenna system for providing a rotating radiation pattern, comprising in combination: a TACAN transmitter generating and providing at least three output signals having frequencies of fc, fc + OR - 15Hz, and fc + OR - 135Hz, respectively, where fc is the carrier frequency; central radiation means coupled to said fc output signal and providing an omnidirectional radiation pattern in the azimuth plane thereby; an array of at least four elements containg two pairs of mutually orthogonal active radiation elements centrally located with respect to said central radiation means; circuit means coupling said array of at least four radiation elements to said fc + OR - 15Hz output signal and including circuit means feeding said fc + OR - 15Hz output signal to said at least four radiation elements with respective fc + OR - 15Hz output signals phased +1, +j, -1, and -j, consecutively where +1 corresponds to 0* phase shift, +j corresponds to 90* phase shift, -1 corresponds to 180* phase shift and -j corresponds to 270* phase shift whereby said +1 phase and -1 phase excited radiation elements are located on a common axis on opposite sides of said central radiation means and said +j phase and -j phase excited radiation elements are located on a common orthogonal axis on opposite sides of said central radiation means; another array of 4 n radiation elements, where n>1, circularly arranged concentrically with respect to said central radiation means; and circuit means coupling said circular array of 4n radiation elements to said fc + OR - 135Hz output signal and including circuit means feeding said fc + OR - 135Hz output signal to repetitive sets of four radiation elements each with respective fc + OR - 135Hz output signals phased +1, +j, -1, and -j, consecutively around the entire array.
Claim 3
Dependent Claim
38 words
An antenna system according to claim 1 wherein n is equal to 9 whereby the phase of fc + or - 135Hz signal goes through a 360* linear phase variation for each 40* of direction angle in azimuth.
Claim 4
Dependent Claim
28 words
The apparatus as defined in claim 1 wherein said output signals of fc + or - 15Hz and fc + or - 135Hz comprise suppressed carrier sideband signals.
Claim 5
Dependent Claim
174 words
The invention as defined by claim 1 wherein said feeding means for said array of at least four radiation elements includes: a fc + or - 15Hz signal buss; signal coupling means coupled from said signal buss to a first radiation element of said four radiation elements and providing the +1 phase radiation; signal coupling means including a phase inverter coupled between said signal buss and a second radiation element, said second element being located on said common axis with said first radiation means and providing the -1 phase radiation; quadrature phase shifter means coupled to said signal buss; signal coupling means coupled from the output of said quadrature phase shifter to a third radiation element, said third radiation element being located on said orthogonal axis and providing the +j phase radiation; and signal coupling means including a phase inverter coupled from the output of said quadrature phase shifter to a fourth radiation means, said fourth radiation means being located on said orthogonal axis opposite said third radiation element and providing the -j radiation.
Claim 6
Dependent Claim
160 words
The invention as defined by claim 4 and wherein said feeding means for each set of 4n radiation elements of said circular array includes: a fc + or - 135Hz signal buss; signal coupling means coupling said last recited circuit buss to the first radiation element of each set of elements and thereby providing the +1 phase radiation; signal coupling means including a phase inverter coupling said last recited circuit buss to the third radiation element of each set of elements and thereby providing the -1 phase radiation; a quadrature phase shifter coupled to said last recited circuit buss; signal coupling means coupling the output of said quadrature phase shifter to the second radiation element of each set of elements and thereby providing the +j phase radiation; and signal coupling means including a phase inverter coupling the output of said quadrature phase shifter to the fourth radiation element of each set of elements and thereby providing the -j phase radiation.
Claim 7
Dependent Claim
15 words
The apparatus as defined in claim 5 wherein said 4n radiation elements comprise 36 elements.
Claim 8
Dependent Claim
27 words
The apparatus as defined in claim 6 wherein said fc + or -15Hz and fc + or - 135Hz output signals each comprise suppressed carrier sideband signals.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-16 | 1977-01-15 | 1977-07-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-16 | 1981-01-15 | 1981-07-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-16 | 1985-01-15 | 1985-07-17 | $7700.00 | Window Closed / Lapsed |