Patent US5255986A successfully refreshed from Google Patents.
Patent US4919044A successfully refreshed from Google Patents.
Patent US3833905A successfully refreshed from Google Patents.
US3833905A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Proximity fuze
Assignee: United States Department of the Army
•
Filing: 1971-12-17
•
Granted: 1974-09-03
•
Expires: 1991-12-17
Abstract
Abstract A proximity fuze employs a push-pull oscillator to generate an r-f signal, to be transmitted and to detect the doppler shift in the received r-f signal. In one embodiment the push-pull oscillator includes plural pairs of matched transistors and inductive feedback from a loop antenna. The transistors are connected to operate in series in respect to the r-f carrier and in parallel in respect to the doppler component of the received signal. As a result, the r-f carrier is cancelled out, oscillator loading is eliminated and the doppler signal appears at twice the voltage over that obtained with a single detector.
Inventors
- 👤 M Apstein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 19:08
CPC Classifications
G; G01; G01S; G01S13/00; G01S13/02; G01S13/50; G01S13/52; G01S13/56; F; F42; F42C; F42C13/00; F42C13/04
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
149 words
A proximity fuze comprising: a push-pull oscillator circuit for generating a radio frequency signal; an antenna connected to said oscillator circuit for transmitting said generated signal and receiving reflected radio frequency signals; said push-pull oscillator circuit comprising at least two matched electronic amplifiers interconnected in push-pull oscillatory configuration, said amplifiers each including: at least one input terminal connected to receive said received radio frequency signals from said antenna; a first output terminal connected to apply said generated radio frequency signal to said antenna; and a second output terminal, said second output terminals of said amplifiers being connected in common to a circuit output signal terminal; whereby the difference frequency between the generated and received radio frequency signals passes through said amplifiers to said output signal terminal whereas the radio frequency components of the generated and received reflected output signals are oppositely phased and cancel at said output signal terminal.
Claim 2
Dependent Claim
149 words
A proximity fuze comprising: a push-pull oscillator circuit for generating a radio frequency signal; an antenna connected to said oscillator circuit for transmitting said generated signal and receiving reflected radio frequency signals; said push-pull oscillator circuit comprising at least two matched electronic amplifiers interconnected in push-pull oscillatory configuration, said amplifiers each including: at least one input terminal connected to receive said received radio frequency signals from said antenna; a first output terminal connected to apply said generated radio frequency signal to said antenna; and a second output terminal, said second output terminals of said amplifiers being connected in common to a circuit output signal terminal; whereby the difference frequency between the generated and received radio frequency signals passes through said amplifiers to said output signal terminal whereas the radio frequency components of the generated and received reflected output signals are oppositely phased and cancel at said output signal terminal.
Claim 3
Dependent Claim
23 words
The proximity fuze according to claim 1 wherein said antenna is a loop antenna comprising a reactive component in said push-pull oscillator circuit.
Claim 4
Dependent Claim
120 words
The proximity fuze according to claim 1 wherein: said two amplifiers comprise first and second matched transistors, each having base, emitter and collector electrodes corresponding to said input terminal, second output terminal and first output terminal, respectively; said antenna comprises a first loop antenna coil interconnecting said collector electrodes, and a second loop antenna interconnecting said base electrodes; said oscillator circuit further includes: means for DC-coupling said emitters to ground; and DC supply means for supplying operating bias voltage to said transistors; and wherein said first and second coils are positioned to permit inductive feedback from said first coil to said second coil in the necessary phase relationship for causing said transistors to alternate on and off at opposite phase.
Claim 5
Dependent Claim
28 words
The proximity fuze according to claim 3 wherein said oscillator circuit comprises further feedback means for impressing a relatively low frequency modulation signal on said radio frequency signal.
Claim 6
Dependent Claim
61 words
The proximity fuze according to claim 4 wherein said further feedback means includes a transformer having a primary winding connected to said first coil and a secondary winding connected to said second coil, said further feedback means also including a capacitor connected in parallel with said secondary winding, said capacitor and said secondary winding being tuned to said relatively low frequency.
Claim 7
Dependent Claim
99 words
The proximity fuze according to claim 1 wherein: said two amplifiers comprise first and second matched transistors, each having base, emitter and collector electrodes corresponding to said input, second output and first output terminals, respectively; said antenna comprises a loop antenna coil connected between said base electrodes; and said oscillator circuit further comprises: means for capacitively coupling the base of each of said transistors to the collector of the other of said transistors; means for DC-coupling the emitters of said transistors to ground; and means for applying DC bias voltage to the center point of said loop antenna coil.
Claim 8
Dependent Claim
102 words
The proximity fuze according to claim 1 wherein; said two amplifiers comprise first and second matched transistors, each having base, emitter and collector electrodes corresponding to said input, second output and first output terminals, respecively; and said oscillator circuit further comprises: means for DC-coupling said emitter electrodes to ground; a tank circuit tuned to said radio frequency and connected between said collector electrodes; an r-f choke connected between said base electrodes; means coupling said antenna to the center point of said r-f choke; and supply means for applying DC bias voltage to said transistors via said r-f choke and said tank circuit.
Claim 9
Dependent Claim
164 words
The proximity fuze according to claim 1 wherein said two amplifiers comprise first and second pairs of matched transistors, each transistor including a base, collector and emitter, the emitters of said second pair of transistors corresponding to said second output terminals, one transistor in said second pair having its collector connected to the emitter of one transistor of said first pair, the other transistor in said second pair having its collector connected to the emitter of the other transistor in said second pair, said circuit further comprising: a first loop antenna coil connected between the collectors of said first pair of transistors; a second loop antenna coil connected between the bases of said first pair of transistors; a third loop antenna coil connected between the bases of said second pair of transistors; wherein said second and third loop antenna coils are positioned proximate said first loop antenna coil to permit regenerative feedback from said first coil to each of said second and third coils.
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) | 1977-09-02 | 1978-03-04 | 1978-09-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-02 | 1982-03-04 | 1982-09-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-02 | 1986-03-04 | 1986-09-03 | $7700.00 | Window Closed / Lapsed |