US3701949A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Wideband frequency scanning radio receiver
Assignee: Cutler Hammer Inc
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Filing: 1971-03-22
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Granted: 1972-10-31
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Expires: 1991-03-22
Abstract
Abstract A superheterodyne system utilizing successive harmonics of an electrically tunable local oscillator, which is repeatedly swept over a frequency range of about one octave or less, to scan throughout a radio frequency range of several octaves in a substantially continuous manner.
Inventors
- 👤 Sidney Turkish
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 19:51
CPC Classifications
H; H03; H03J; H03J7/00; H03J7/18; H03J7/20; H03J7/28; H03J7/32
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
165 words
A superheterodyne system for frequency scanning throughout a radio spectrum of more than one octave, including, in cascade, a mixer, an intermediate frequency amplifier and a detector, and further comprising: a. an electrically tunable local oscillator coupled to said mixer and capable of fundamental frequency operation only over a limited range of less than said spectrum, b. an electrically tunable preselector, preceding said mixer, c. a sweep signal generator for tuning said preselector to sweep cyclically throughout said spectrum, d. a sweep signal generator for tuning said local oscillator to sweep repeatedly within said limited frequency range during each preselector sweep cycle, e. a source of timing signals for controlling the timing of said preselector and local oscillator sweeps, and f. means responsive to said timing signals for controlling the slope and offset of the local oscillator sweep to maintain a predetermined intermediate frequency difference between the tuning of said preselector and respective harmonics of said local oscillator during successive sweeps of said local oscillator.
Claim 2
Dependent Claim
165 words
A superheterodyne system for frequency scanning throughout a radio spectrum of more than one octave, including, in cascade, a mixer, an intermediate frequency amplifier and a detector, and further comprising: a. an electrically tunable local oscillator coupled to said mixer and capable of fundamental frequency operation only over a limited range of less than said spectrum, b. an electrically tunable preselector, preceding said mixer, c. a sweep signal generator for tuning said preselector to sweep cyclically throughout said spectrum, d. a sweep signal generator for tuning said local oscillator to sweep repeatedly within said limited frequency range during each preselector sweep cycle, e. a source of timing signals for controlling the timing of said preselector and local oscillator sweeps, and f. means responsive to said timing signals for controlling the slope and offset of the local oscillator sweep to maintain a predetermined intermediate frequency difference between the tuning of said preselector and respective harmonics of said local oscillator during successive sweeps of said local oscillator.
Claim 3
Dependent Claim
46 words
The invention set forth in claim 1, further including means responsive to said timing signals for controlling said sweep signal generator means to produce a brief miniature retrace of said preselector sweep at the beginning of each local oscillator sweep that starts during a preselector sweep.
Claim 4
Dependent Claim
52 words
The invention set forth in claim 1, further including means for applying a d-c bias to said mixer, and means responsive to said timing signals for controlling said bias to maximize the conversion efficiency of said mixer with said respective harmonics of said local oscillator during said successive sweeps of said oscillator.
Claim 5
Dependent Claim
62 words
The invention set forth in claim 3, further including gain control means in the signal channel following said mixer, and means responsive to said timing signals for adjusting said gain control means to compensate change in the conversion efficiency of said mixer with said respective local oscillator harmonics to maintain the overall amplitude response of the system substantially constant through said spectrum.
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) | 1975-10-31 | 1976-05-01 | 1976-10-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-31 | 1980-05-01 | 1980-10-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-31 | 1984-05-01 | 1984-10-31 | $7700.00 | Window Closed / Lapsed |