US3961331A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Lossy cable choke broadband isolation means for independent antennas
Assignee: United States Department of the Army
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Filing: 1975-05-21
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Granted: 1976-06-01
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Expires: 1995-05-21
Abstract
Abstract A broadband isolation section comprised of a plurality of series connectedable chokes having respective damping resistors shunted thereacross located between at least two dipole antennas mounted one above the other in a generally vertical plane. The isolator section is particularly adapted to be utilized with dipole antennas having respective pairs of radiating elements substantially aligned in a common vertical axis and being fed from respective radio signal sources by feedlines directed along the common vertical axis through the various radiating elements. The cable chokes included in the isolator section are formed from coaxial cable feedlines and the respective damping resistors shunted thereacross are connected to the sleeve or outer conductor of the feedline(s) feeding the upper antenna(s). Thus adjacent antennas have intermediate broadband isolator sections separating them. Additionally, it is preferable to also include cable chokes at the top and bottom of the particular dipole antenna for determining the electrical length of the respective antennas.
Inventors
- 👤 Donn V. Campbell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 14:11
CPC Classifications
H; H01; H01Q; H01Q1/00; H01Q1/52; H01Q1/521; H01Q21/00; H01Q21/06; H01Q21/08; H01Q21/10
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
123 words
In a broadband antenna system including at least two dipole antennas respectively coupled to first and second radio apparatus, said antennas being mounted one above the other and having a predetermined spacing therebetween with respective pairs of antenna elements being aligned generally along a common vertical axis and having a first feedline coupling said first radio apparatus to the upper dipole antenna and a second feedline coupling said second radio apparatus to the lower dipole antenna, the improvement comprising: the first feedline being configured to include an isolator section in said predetermined spacing between said at least two dipole antennas, said isolator section being comprised of a plurality of series connected cable choke sections, each having a respective electrical damping resistor shunted thereacross.
Claim 2
Dependent Claim
123 words
In a broadband antenna system including at least two dipole antennas respectively coupled to first and second radio apparatus, said antennas being mounted one above the other and having a predetermined spacing therebetween with respective pairs of antenna elements being aligned generally along a common vertical axis and having a first feedline coupling said first radio apparatus to the upper dipole antenna and a second feedline coupling said second radio apparatus to the lower dipole antenna, the improvement comprising: the first feedline being configured to include an isolator section in said predetermined spacing between said at least two dipole antennas, said isolator section being comprised of a plurality of series connected cable choke sections, each having a respective electrical damping resistor shunted thereacross.
Claim 3
Dependent Claim
39 words
The system as defined by claim 1 wherein said first feedline comprises a coaxial cable having an inner conductor and an outer conductor and wherein each damping resistor is coupled to said outer conductor across the respective cable choke.
Claim 4
Dependent Claim
19 words
The system as defined by claim 2 where said plurality of cable choke sections are tuned to different frequencies.
Claim 5
Dependent Claim
23 words
The system as defined by claim 3 wherein each electrical damping resistor has an electrical resistance value equal to or approximately 1000 ohms.
Claim 6
Dependent Claim
27 words
The system as defined by claim 3 wherein said plurality of cable choke sections are comprised of a predetermined number of self-supported turns of said first feedline.
Claim 7
Dependent Claim
15 words
The system as defined by claim 5 wherein said turns are generally circular in shape.
Claim 8
Dependent Claim
34 words
The system as defined by claim 3 wherein said plurality of cable choke sections are each comprised of a predetermined number of turns of said first feedline wound on a core of plastic material.
Claim 9
Dependent Claim
35 words
The system as defined by claim 3 wherein said plurality of cable choke sections are comprised of a predetermined number of turns of said first feedline wound on a generally cylindrical core of plastic material.
Claim 10
Dependent Claim
32 words
The system as defined by claim 3 wherein each of said cable choke sections are comprised of a predetermined number of turns of said first feedline wound on a respective magnetic core.
Claim 11
Dependent Claim
13 words
The system as defined by claim 9 wherein said core comprises ferrite material.
Claim 12
Dependent Claim
97 words
The system as defined by claim 3 wherein said first feedline runs through the lower dipole antenna and is additionally configured to provide an additional cable choke section adjacently below the lower element of the upper dipole antenna and a cable choke section adjacently above the upper radiating element of the lower dipole antenna and a cable choke section adjacently below the lower radiating element of the lower dipole antenna, said cable choke adjacently below the lower radiating element of the lower dipole antenna, also being formed from said second feedline coupled to the lower dipole antenna.
References Cited (Backward Citations)
US3879735A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-06-01 | 1979-12-01 | 1980-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-06-01 | 1983-12-01 | 1984-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-06-01 | 1987-12-01 | 1988-06-01 | $7700.00 | Window Closed / Lapsed |