USH288H
Expired / Lapsed
US
⏱️ 0.0 years remaining
Interference cancelling transmitter
Assignee: United States Department of the Army
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Filing: 1983-07-25
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Granted: 1987-06-02
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Expires: 2003-07-25
Abstract
Abstract An interference cancelling transmitter is configured which provides electagnetic compatibility (EMC) among different communications apparatus in the same area as well as providing a low probability of intercept (LPI) in a dense communications environment where secure communications is required between users. This is accomplished by means of a communications transmitter coupled to a transmitting antenna configuration comprised of an omnidirectional antenna and a notch antenna having a single deep null over a small angular beamwidth. RF power is fed equally thereto so that the radiated power from each antenna is the same but the phase is mutually inverted (180°) so that a cancellation of the radiated power occurs in all directions of space except over the angular region where the null of the notch antenna is located. The null can be varied in direction and results in a relatively narrow pencil-like radiation pattern being radiated to a predetermined receiver.
Inventors
- 👤 Frank S. Gutleber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 13:16
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/02; H01; H01Q; H01Q21/00; H01Q21/29
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
119 words
A multiple access signal communication system, comprising the combination of: means for generating an RF signal modulated with a communication signal; first antenna means, coupled to said RF signal generating means, for generating a first substantially omnidirectional antenna beam pattern; second antenna means, coupled to said RF signal generating means, for generating a second substantially omnidirectional antenna beam pattern having a single notch of narrow angular beamwidth; said first and second antenna means for generating beam patterns which interact to generate a composite antenna beam pattern of a relatively narrow angular beamwidth; at least two receiver means for receiving said RF signal; and means for selectively directing said single notch toward one of said at least two receiver means.
Claim 2
Dependent Claim
119 words
A multiple access signal communication system, comprising the combination of: means for generating an RF signal modulated with a communication signal; first antenna means, coupled to said RF signal generating means, for generating a first substantially omnidirectional antenna beam pattern; second antenna means, coupled to said RF signal generating means, for generating a second substantially omnidirectional antenna beam pattern having a single notch of narrow angular beamwidth; said first and second antenna means for generating beam patterns which interact to generate a composite antenna beam pattern of a relatively narrow angular beamwidth; at least two receiver means for receiving said RF signal; and means for selectively directing said single notch toward one of said at least two receiver means.
Claim 3
Dependent Claim
13 words
The combination of claim 1 wherein said notch comprises a beam pattern null.
Claim 4
Dependent Claim
31 words
The combination of claim 2 and additionally including means for adjusting the amplitude of said RF signal coupled between said RF signal generating means and said first and second antenna means.
Claim 5
Dependent Claim
53 words
The combination of claim 2 and additionally including means for adjusting the phase of said RF signal coupled between said RF signal generating means and at least one of said first and second antenna means for providing a mutual 180° phase difference of RF signal coupled to said first and second antenna means.
Claim 6
Dependent Claim
39 words
The combination of claim 2 and additionally including means for adjusting the amplitude and phase of said RF signal coupled between said means for generating an RF signal and at least one of said first and second antenna means.
Claim 7
Dependent Claim
65 words
The combination of claim 5 wherein said means for adjusting the amplitude and phase includes means for inverting the phase of said RF signal coupled to one of said antenna means relative to said RF signal power coupled to the other of antenna means whereby cancellation of the radiated power results in substantially all directions of space except in the region of beam pattern null.
Claim 8
Dependent Claim
21 words
The combination of claim 6 wherein said means for coupling substantially equal amplitudes of RF signal includes a power divider circuit.
Claim 9
Dependent Claim
40 words
The combination of claim 5 wherein said means for adjusting the amplitude and phase includes means for coupling substantially equal amplitudes of said RF signal from said means for generating an RF signal and said first and second antenna means.
Claim 10
Dependent Claim
49 words
The combination of claim 8 and wherein said means for adjusting the amplitude and phase additionally includes means for varying the phase of the power coupled to one of said antenna means by substantially 180° relative to the phase of the power coupled to the other said antenna means.
Claim 11
Independent Claim
114 words
A method of transmitting electromagnetic radiation in a multiple access signal communications system, comprising the steps of: generating an RF signal modulated with a communication signal; p1 coupling said RF signal to first antenna means and generating a first substantially omnidirectional antenna beam pattern; coupling said RF signal to second antenna means and generating a second substantially omnidirectional antenna beam pattern having a signal notch of narrow angular beamwidth; generating a composite antenna beam pattern of a relatively narrow angular beamwidth from said first and second beam patterns directing said single notch toward one of at least two spaced receivers; and receiving said RF signal with one of said at least two spaced receivers.
Claim 12
Independent Claim
114 words
A method of transmitting electromagnetic radiation in a multiple access signal communications system, comprising the steps of: generating an RF signal modulated with a communication signal; p1 coupling said RF signal to first antenna means and generating a first substantially omnidirectional antenna beam pattern; coupling said RF signal to second antenna means and generating a second substantially omnidirectional antenna beam pattern having a signal notch of narrow angular beamwidth; generating a composite antenna beam pattern of a relatively narrow angular beamwidth from said first and second beam patterns directing said single notch toward one of at least two spaced receivers; and receiving said RF signal with one of said at least two spaced receivers.
Claim 13
Dependent Claim
13 words
The method of claim 10 wherein said notch comprises a beam pattern null.
Claim 14
Dependent Claim
26 words
The method of claim 11 and additionally including the step of adjusting the amplitude of said RF signal coupled to said first and second antenna means.
Claim 15
Dependent Claim
42 words
The method of claim 11 and additionally including the step of adjusting the phase of said RF signal coupled to at least one of said antenna means for providing a 180° phase shift of said RF signal coupled to said one antenna.
Claim 16
Dependent Claim
32 words
The method of claim 11 and additionally including the step of adjusting the amplitude and phase of said RF signal coupled to at least one of said first and second antenna means.
Claim 17
Dependent Claim
66 words
The method of claim 14 wherein said step of adjusting the amplitude and phase further includes inverting the phase of said RF signal coupled to one of said antenna means relative to said RF signal power coupled to the other antenna of said antenna means whereby cancellation of radiated power results in substantially all directions of space except in the region of said beam pattern null.
Claim 18
Dependent Claim
31 words
The method of claim 14 wherein said step of adjusting the amplitude and phase further includes coupling substantially equal amplitudes of said RF signal to said first and second antenna means.
Claim 19
Dependent Claim
47 words
The method of claim 16 and wherein said step of adjusting the amplitude and phase further includes varying the phase of the power coupled to one of said antenna means by substantially 180° relative to the phase of the power coupled to the other said antenna means.
Claim 20
Dependent Claim
29 words
The combination of claim 1 wherein said notch comprises a relatively steep slope beam pattern null whereby said beam pattern null is of substantially equal amplitude over said notch.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-06-01 | 1990-12-01 | 1991-06-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-01 | 1994-12-01 | 1995-06-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-06-01 | 1998-12-01 | 1999-06-02 | $7700.00 | Window Closed / Lapsed |