Patent US3765020A successfully refreshed from Google Patents.
US3765020A
Expired / Lapsed
US
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Digitally controlled attenuator
Assignee: Raytheon Co
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Filing: 1972-04-14
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Granted: 1973-10-09
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Expires: 1992-04-14
Abstract
Abstract A digitally controlled attenuator adapted for use with radio frequency signals is disclosed. The digitally controlled attenuator includes a radio frequency bus having connected thereto, at proper points therealong, a number of coupling and switching networks, each one thereof including a different attenuating shunt element of a ladder network. Each switching element, in turn, is responsive to a different digital control signal. The coupling and switching networks are connected to the radio frequency bus such that the signals passing through the shunt elements selected by any digital control signal are in proper relative phase relationship at various nodes of the ladder network. Unwanted radio frequency signals, leaking through a switching element which has been placed in its ''''off'''' condition, are cancelled by radio frequency signals having a relative 180* phase shift from the radio frequency signals being attenuated.
Inventors
- 👤 R Seager
- 👤 D Lonigro
- 👤 O Lowenschuss
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:49
CPC Classifications
H; H03; H03H; H03H11/00; H03H11/02; H03H11/24; H03H11/245; G; G01; G01S; G01S7/00; G01S7/02; G01S7/28; G01S7/285; G01S7/34
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
101 words
In a radar system wherein radio frequency signals produced by various objects in response to a series of pulses of radar energy are processed in the receiver of such system, such receiver including apparatus comprising: a. means for producing digital signals indicative of the radio frequency signals as such signals are received; b. attenuator means, responsive to the digital signals, for varying the attenuation of the radio frequency signals as such radio frequency Signals pass through the attenuator means including means for compensating for variations in the phase of the radio frequency signals as such signals pass through the attenuator means.
Claim 2
Dependent Claim
101 words
In a radar system wherein radio frequency signals produced by various objects in response to a series of pulses of radar energy are processed in the receiver of such system, such receiver including apparatus comprising: a. means for producing digital signals indicative of the radio frequency signals as such signals are received; b. attenuator means, responsive to the digital signals, for varying the attenuation of the radio frequency signals as such radio frequency Signals pass through the attenuator means including means for compensating for variations in the phase of the radio frequency signals as such signals pass through the attenuator means.
Claim 3
Dependent Claim
100 words
The apparatus recited in claim 1 wherein the attenuator means comprises: a. a radio frequency bus; b. a ladder network having a plurality of shunt elements; c. a plurality of switching means, responsive to the digital signals, each one of such switching means being connected between a different one of the shunt elements and a different point on such radio frequency bus, for coupling the radio frequency signals through selected ones of the shunt elements in accordance with the digital signals and for equalizing the phase of the radio frequency signals passing through the selected ones of the shunt elements.
Claim 4
Dependent Claim
69 words
The apparatus recited in claim 2 including additionally: a. compensator means; b. means for coupling a portion of the radio frequency signals to the radio frequency bus and another portion thereof to the compensator means; c. means for combining the signals out of the compensator means with the signals out of the ladder network to cancel unwanted radio frequency signals coupling through an unselected one of the shunt elements.
Claim 5
Dependent Claim
148 words
In a radar system wherein radio frequency signals produced by various objects in response to each one of a series of pulses of radar energy are processed in the receiver of such system, a sensitivity time controller, for processing such radio frequency signals and for adjustingg the sensitivity of such receiver, comprising: a. means, initiated in accordance with each one of the series of pulses for producing a set of digital signals, each one of the digital signals in such set having a value related to the desired sensitivity of the receiver; and b. attenuator means, responsive to each one of the digital signals for varying in accordance with the digital signals the attenuation of the radio frequency signals as such radio frequency signals pass therethrough including means for compensating for variations in the phase of the radio frequency signals as such signals pass through the attenuator means.
Claim 6
Dependent Claim
148 words
In a radar system wherein radio frequency signals produced by various objects in response to each one of a series of pulses of radar energy are processed in the receiver of such system, a sensitivity time controller, for processing such radio frequency signals and for adjustingg the sensitivity of such receiver, comprising: a. means, initiated in accordance with each one of the series of pulses for producing a set of digital signals, each one of the digital signals in such set having a value related to the desired sensitivity of the receiver; and b. attenuator means, responsive to each one of the digital signals for varying in accordance with the digital signals the attenuation of the radio frequency signals as such radio frequency signals pass therethrough including means for compensating for variations in the phase of the radio frequency signals as such signals pass through the attenuator means.
Claim 7
Dependent Claim
102 words
The sensitivity time controller recited in claim 4 wherein the attenuator means comprises: a. a radio frequency bus; b. a ladder network having a plurality of shunt elements; c. a plurality of switching means, responsive to the digital signals, each one of such switching means being connected between a different one of the shunt elements and a different point on such radio frequency bus, for coupling the radio frequency signals through selected ones of such shunt elements in accordance with the digital signals and for equalizing the phase of the radio frequency signals passing through the selected ones of the shunt elements.
Claim 8
Dependent Claim
71 words
The sensitivity time controller recited in claim 5 including additionally: a. compensator means; b. means for coupling a portion of the radio frequency signals to the radio frequency bus and another portion thereof to the compensator means; c. means for combining the signals out of the compensator means with the signals out of the ladder network to cancel unwanted radio frequency signals coupling through an unselected one of the shunt elements.
Claim 9
Dependent Claim
106 words
A digitally controlled attenuator responsive to digital signals and suitable for use with radio frequency signals comprising: a. a radio frequency bus; b. a ladder network having a plurality of shunt elements; c. a plurality of switching means, responsive to the digital signals, each one of such switching means being connected between a different one of the shunt elements and a different point on such radio frequency bus, for coupling the radio frequency signals through selected ones of the shunt elements in accordance with the digital signals and for equalizing the phase of the radio frequency signals passing through the selected ones of the shunt elements.
Claim 10
Dependent Claim
106 words
A digitally controlled attenuator responsive to digital signals and suitable for use with radio frequency signals comprising: a. a radio frequency bus; b. a ladder network having a plurality of shunt elements; c. a plurality of switching means, responsive to the digital signals, each one of such switching means being connected between a different one of the shunt elements and a different point on such radio frequency bus, for coupling the radio frequency signals through selected ones of the shunt elements in accordance with the digital signals and for equalizing the phase of the radio frequency signals passing through the selected ones of the shunt elements.
Claim 11
Dependent Claim
71 words
The digitally controlled attenuaTor recited in claim 7 including additionally: a. compensator means; b. means for coupling a portion of the radio frequency signals to the radio frequency bus and another portion thereof to the compensator means; c. means for combining the signals out of the compensator means with the signals out of the ladder network to cancel unwanted radio frequency signals coupling through an unselected one of the shunt elements.
Claim 12
Dependent Claim
37 words
The digitally controlled attenuator recited in claim 8 wherein each one of the plurality of switching means includes a pair of FET''s and the compensator means is coupled to the combining means through an ''''off'''' biased FET.
References Cited (Backward Citations)
US3305859A
Cited
US3590366A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-08 | 1977-04-09 | 1977-10-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-08 | 1981-04-09 | 1981-10-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-08 | 1985-04-09 | 1985-10-09 | $7700.00 | Window Closed / Lapsed |