US4053889A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Non-linear spread spectrum transmitter/receiver for a homing system
Assignee: Motorola Solutions Inc
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Filing: 1976-07-27
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Granted: 1977-10-11
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Expires: 1996-07-27
Abstract
Abstract A spread spectrum transmitter/receiver in a pulse ranging system including surface acoustic wave devices with a nonlinear transducer to reduce frequency shift errors due to doppler effects.
Inventors
- 👤 Robert H. Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:43
CPC Classifications
G; G01; G01S; G01S13/00; G01S13/02; G01S13/06; G01S13/08; G01S13/10; G01S13/26; G01S13/28; G01S13/282
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
124 words
In a detection, track and homing system including a spread spectrum transmitter adapted to transmit signals to a remotely located target and a spread spectrum receiver adapted to receive signals reflected from the target in response to the transmitted signals impinging thereon where the velocities between the transmitter/receiver and the target are relatively high, surface acoustic wave apparatus providing doppler invariant pulse compression/expansion comprising: a. a piezoelectric base; b. a plurality of spaced apart interdigitated fingers formed on a surface of said base and interconnected to provide an input transducer and an acoustically coupled output transducer; and c. the fingers forming the output transducer having spacings therebetween which vary nonlinearly in a generally hyperbolic function for reducing frequency shift errors due to doppler effects.
Claim 2
Dependent Claim
124 words
In a detection, track and homing system including a spread spectrum transmitter adapted to transmit signals to a remotely located target and a spread spectrum receiver adapted to receive signals reflected from the target in response to the transmitted signals impinging thereon where the velocities between the transmitter/receiver and the target are relatively high, surface acoustic wave apparatus providing doppler invariant pulse compression/expansion comprising: a. a piezoelectric base; b. a plurality of spaced apart interdigitated fingers formed on a surface of said base and interconnected to provide an input transducer and an acoustically coupled output transducer; and c. the fingers forming the output transducer having spacings therebetween which vary nonlinearly in a generally hyperbolic function for reducing frequency shift errors due to doppler effects.
Claim 3
Dependent Claim
86 words
A detection, track and homing system for use where the velocities between the system and a target are relatively high, said system comprising: a. a spread spectrum transmitter and receiver; b. expansion filter means and compression filter means connected in said transmitter and receiver, respectively, for providing the spread spectrum signals, each of said filter means including a surface acoustic wave device having a nonlinear transducer with interdigitated fingers having spacings therebetween which vary in a generally hyperbolic function for reducing errors due to doppler effects.
Claim 4
Dependent Claim
86 words
A detection, track and homing system for use where the velocities between the system and a target are relatively high, said system comprising: a. a spread spectrum transmitter and receiver; b. expansion filter means and compression filter means connected in said transmitter and receiver, respectively, for providing the spread spectrum signals, each of said filter means including a surface acoustic wave device having a nonlinear transducer with interdigitated fingers having spacings therebetween which vary in a generally hyperbolic function for reducing errors due to doppler effects.
References Cited (Backward Citations)
US3430241A
Cited
US3875571A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-10-10 | 1981-04-11 | 1981-10-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-10-10 | 1985-04-11 | 1985-10-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-10-10 | 1989-04-11 | 1989-10-11 | $7700.00 | Window Closed / Lapsed |