US4100544A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Beacon system employing ramped gain receiver
Assignee: Hughes Missile Systems Co
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Filing: 1977-07-25
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Granted: 1978-07-11
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Expires: 1997-07-25
Abstract
Abstract A beacon receiver or IFF system in which the gain of the receiver is time varied to enhance the discrimination between response from transponders located ahead of the interrogator as compared with the responses from transponders in the side or rear lobe regions of the interrogator antenna pattern. The system is employed with a directional antenna and signal processing apparatus giving sum Σ and difference Δ channels. In accordance with this invention, the gain of the receiver in the sum Σ channel is increased from the minimum value to a maximum value beginning after the end of interrogation pulse. The difference Δ channel is varied in gain from the time in the beginning after the end of the interrogator pulse but the gain is varied inversely from the maximum level at the beginning of reception to a maximum level at the end of reception.
Inventors
- 👤 Royal V. Keeran
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:19
CPC Classifications
G; G01; G01S; G01S13/00; G01S13/74; G01S13/76; G01S13/762; G01S3/00; G01S3/02; G01S3/14; G01S3/28; G01S3/32; G01S7/00; G01S7/02; G01S7/28; G01S7/2813
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
153 words
In an interrogator-transponder system including a transmitting and receiving antenna system, a pulse transmitter; a pulse receiver; transmit-receive switch for selectively connecting the antenna system to the transmitter and the pulse receiver in which the pulse receiver responds to return pulses from a transponder on a remote vehicle which transponder reacts to interrogator pulses from the pulse transmitter in which the antenna system includes a plurality of antennas from which the sum and difference components of the receive signals from the transponder are derived and in which the receiver processes the sum Σ and difference Δ signals in part and in two different channels and in which the receiver includes means for comparing the level of the sum Σ channel with respect to the difference Δ channel; the improvement comprising means for simultaneously varying the gain of the receiver sum Σ signal channel inversely with respect to the receiver difference Δ signal channel.
Claim 2
Dependent Claim
153 words
In an interrogator-transponder system including a transmitting and receiving antenna system, a pulse transmitter; a pulse receiver; transmit-receive switch for selectively connecting the antenna system to the transmitter and the pulse receiver in which the pulse receiver responds to return pulses from a transponder on a remote vehicle which transponder reacts to interrogator pulses from the pulse transmitter in which the antenna system includes a plurality of antennas from which the sum and difference components of the receive signals from the transponder are derived and in which the receiver processes the sum Σ and difference Δ signals in part and in two different channels and in which the receiver includes means for comparing the level of the sum Σ channel with respect to the difference Δ channel; the improvement comprising means for simultaneously varying the gain of the receiver sum Σ signal channel inversely with respect to the receiver difference Δ signal channel.
Claim 3
Dependent Claim
43 words
The combination in accordance with claim 1 wherein said gain varying means serves to vary the receiver sum Σ channel gain from the minimum level to a maximum level while varying the difference Δ channel gain from a maximum to a minimum level.
Claim 4
Dependent Claim
29 words
The combination in accordance with claim 1 wherein said gain varying means is operative beginning at a time R° related to the first receipt of return from a transponder.
Claim 5
Dependent Claim
24 words
The combination in accordance with claim 1 wherein said gain varying means varies the gain of the sum Σ and difference Δ channels linearly.
Claim 6
Dependent Claim
24 words
The combination in accordance with claim 1 wherein said gain varying means varies the gain of the sum Σ and difference Δ portions logarithmically.
Claim 7
Dependent Claim
43 words
The combination in accordance with claim 1 wherein said gain varying means comprises an integrating circuit and means applying a pulse to said integrating circuit and means for controlling the level of gain as a function of the integrated pulse at said integrator.
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) | 1981-07-10 | 1982-01-09 | 1982-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-10 | 1986-01-09 | 1986-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-10 | 1990-01-09 | 1990-07-11 | $7700.00 | Window Closed / Lapsed |