US3803607A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Radar transponder having built-in calibration
Assignee: Individual
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Filing: 1973-02-12
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Granted: 1974-04-09
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Expires: 1993-02-12
Abstract
Abstract Calibration of a transponder is accomplished by precisely measuring the total delay time required from antenna to antenna. Stray signals from the transmitting antenna are allowed to enter the receiver and initiate a self-sustaining ''''ring-around'''' oscillation. That portion of the oscillation required for the pulse to travel internally through the transponder from the receiving antenna to the transmitting antenna is the total delay time.
Inventors
- 👤 D Robinson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 20:25
CPC Classifications
G; G01; G01S; G01S7/00; G01S7/02; G01S7/40; G01S7/4052; G01S7/406; G01S7/4069; G01S13/00; G01S13/74; G01S13/76; G01S13/767
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
162 words
In a radar transponder having built-in calibration capability, in combination: a. a receiving antenna for receiving radar signals transmitted from a radar under test, b. a radAr receiver coupled to said receiving antenna for detecting radar signals received at said receiving antenna, c. delay circuit means coupled to said receiver for generating an output signal delayed by a time interval proportional to the desired range in response to an output signal from said radar receiver, d. transmitter circuit means coupled to said delay circuit means for transmitting the delayed signal back to the radar equipment under test, e. feedback circuit means coupled from the output of said delay circuit means to the input of said delay circuit means for selectively rejecting, and accepting signals from said radar receiver when said transponder is in an operate and calibrate mode of operation, respectively, f. indicating means coupled to the output of said radar receiver for indicating the frequency of output pulses from said receiver.
Claim 2
Dependent Claim
162 words
In a radar transponder having built-in calibration capability, in combination: a. a receiving antenna for receiving radar signals transmitted from a radar under test, b. a radAr receiver coupled to said receiving antenna for detecting radar signals received at said receiving antenna, c. delay circuit means coupled to said receiver for generating an output signal delayed by a time interval proportional to the desired range in response to an output signal from said radar receiver, d. transmitter circuit means coupled to said delay circuit means for transmitting the delayed signal back to the radar equipment under test, e. feedback circuit means coupled from the output of said delay circuit means to the input of said delay circuit means for selectively rejecting, and accepting signals from said radar receiver when said transponder is in an operate and calibrate mode of operation, respectively, f. indicating means coupled to the output of said radar receiver for indicating the frequency of output pulses from said receiver.
Claim 3
Dependent Claim
48 words
The transponder of claim 1 wherein said feedback circuit means includes gate generating means responsive to an output pulse from said delay circuit for generating a blanking gate to prevent signals received by said radar receiver from entering said delay circuit for the duration of the transmitted pulse.
Claim 4
Dependent Claim
40 words
The transponder of claim 2 wherein said feedback circuit means includes disabling means for disabling said blanking gate generating means and allowing signals received by said radar receiver to enter said delay circuit during the duration of the transmitted pulse.
Claim 5
Dependent Claim
52 words
The transponder of claim 3 wherein said disabling means is a switch having a first position for coupling the output of said delay circuit means to said blanking gate generating means and a second position for coupling the output of said delay circuit means to ground in circuit with a load resistor.
Claim 6
Dependent Claim
42 words
The transponder of claim 1 wherein said feedback circuit means includes an inhibit circuit for rejecting signals from said radar receiver and an enabling circuit to insure operation of said delay circuit means when signals are being accepted from said radar receiver.
Claim 7
Dependent Claim
48 words
The transponder of claim 5 wherein said feedback circuit means includes gate generating means responsive to an output pulse from said delay circuit for generating a blanking gate to prevent signals received by said radar receiver from entering said delay circuit for the duration of the transmitted pulse.
Claim 8
Dependent Claim
40 words
The transponder of claim 6 wherein said feedback circuit means includes disabling means for disabling said blanking gate generating means and allowing signals received by said radar receiver to enter said delay circuit during the duration of the transmitted pulse.
Claim 9
Dependent Claim
52 words
The transponder of claim 7 wherein said disabling means is a switch having a first position for coupling the output of said delay circuit means to said blanking gate generating means and a second position for coupling the output of said delay circuit means to ground in circuit with a load resistor.
Claim 10
Dependent Claim
51 words
The transponder of claim 8 wherein the output of said delay circuit means is coupled to said inhibit circuit and said enabling circuit by means of a differentiating circuit having the same time constant when said switch is in the calibrate position as when said switch is in the operate position.
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) | 1977-04-08 | 1977-10-08 | 1978-04-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-08 | 1981-10-08 | 1982-04-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-08 | 1985-10-08 | 1986-04-09 | $7700.00 | Window Closed / Lapsed |