US3736587A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Coherent frequency hopped, phase modulated acoustic surface wave generator
Assignee: United States Department of the Air Force
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Filing: 1971-05-26
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Granted: 1973-05-29
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Expires: 1991-05-26
Abstract
Abstract An apparatus utilizing an acoustic surface wave having an ordered-code form to provide bi-phase modulation of an electromagnetic carrier frequency. A continuous stream of coded sequences is generated by utilizing a tapped delay line as a sequence generator in conjunction with a shift register which is actuated by an adjustable reference code.
Inventors
- 👤 H Bush
- 👤 J Entzminger
- 👤 W Richard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:35
CPC Classifications
G; G06; G06F; G06F7/00; G06F7/58; H; H04; H04L; H04L27/00; H04L27/18; H04L27/20; H04L27/2032
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
186 words
A switchable acoustic surface wave sequence generator apparAtus for generating a coherent frequency hopped, pseudorandom bi-phase modulated electromagnetic waveform comprising in combination: a sequence generator unit having a plurality of sequence generators, said plurality of sequence generators providing an equal number of coherent frequencies, each of said plurality of sequence generators being resonant at a desired coherent frequency, a pulse forming network to generate an input pulse and a switch control signal, a switching unit connected to said pulse forming network to receive said input pulse and said switch control signal, said switch unit provides a plurality of output lines, said plurality of output lines are respectively connected to said plurality of sequence generators, said switch control signal controls said switching unit to provide an input pulse to only that sequence generator, of said plurality of sequence generators, being resonant at the desired frequency, and a combiner unit having a plurality of input ports connected to said plurality of sequence generators, said combiner unit receiving said coherent frequencies at said plurality of input ports, said combiner unit providing a single output port for said coherent frequencies.
Claim 2
Dependent Claim
186 words
A switchable acoustic surface wave sequence generator apparAtus for generating a coherent frequency hopped, pseudorandom bi-phase modulated electromagnetic waveform comprising in combination: a sequence generator unit having a plurality of sequence generators, said plurality of sequence generators providing an equal number of coherent frequencies, each of said plurality of sequence generators being resonant at a desired coherent frequency, a pulse forming network to generate an input pulse and a switch control signal, a switching unit connected to said pulse forming network to receive said input pulse and said switch control signal, said switch unit provides a plurality of output lines, said plurality of output lines are respectively connected to said plurality of sequence generators, said switch control signal controls said switching unit to provide an input pulse to only that sequence generator, of said plurality of sequence generators, being resonant at the desired frequency, and a combiner unit having a plurality of input ports connected to said plurality of sequence generators, said combiner unit receiving said coherent frequencies at said plurality of input ports, said combiner unit providing a single output port for said coherent frequencies.
Claim 3
Dependent Claim
195 words
A switchable sequence generator apparatus as described in claim 1 wherein said sequence generator comprises: a piezoelectric substrate, an interdigital input transducer located at one end of said piezoelectric substrate, said input transducer having a predetermined number of finger pairs, an output transducer located at the other end of said piezoelectric substrate, said output transducer having a plurality of output taps, one side of each output tap is connected to ground, a switching network having a positive line and a negative line, the other side of each output tap is connected to said positive and negative line of said switching network, said negative line being connected to a phase inverter, a shift register is connected to said positive and negative line of said switching network, said shift register receives a reference code, said shift register sets the states of said switching network to correspond to the phase of the bit stored in said shift register, and, a summing network connected to said positive line of said switching network, said phase inverter of said negative line being connected to said summing network, said summing network providing an output, said output being a pseudo-random, phase modulated waveform.
Claim 4
Dependent Claim
68 words
A switchable sequence generator apparatus as described in claim 1 wherein said pulse forming network comprises: a pulse generator to provide a series of pulses at a predetermined interval, a timing unit to trigger said pulse generator at a predetermined time interval, and a pseudo-noise generator to activate said switching unit, said switching unit connecting the desired pulse from said pulse generator to one of said sequence generators.
Claim 5
Dependent Claim
72 words
A switchable sequence generator apparatus as described in claim 2 further including a delay unit connected to one output tap of said plurality of output taps, said one output tap being the same in each sequence generator, said one output tap of each sequence generator thus providing keying signals to said delay unit, said delay unit provides a constant delay, said delay provides a delayed keyed signal to key said timing unit.
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) | 1976-05-28 | 1976-11-27 | 1977-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-28 | 1980-11-27 | 1981-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-28 | 1984-11-27 | 1985-05-29 | $7700.00 | Window Closed / Lapsed |