US3967220A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Variable delay equalizer
Assignee: NEC Corp
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Filing: 1975-07-31
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Granted: 1976-06-29
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Expires: 1995-07-31
Abstract
Abstract A variable delay equalizer comprises two directional couplers, each having a pair of input terminals and a pair of output terminals. A pair of variable phase shifters are inserted respectively between the output terminals of the first coupler and the input terminals of the second coupler. A third variable phase shifter is connected between the second output terminal of the second coupler and the second input terminal of the first coupler. This equalizer makes it possible to shift the peak delay frequency as well as to change the value of the peak delay itself.
Inventors
- 👤 Yoshimi Tagashira
- 👤 Masaaki Atobe
- 👤 Kazuhiro Yamamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 08:50
CPC Classifications
H; H04; H04B; H04B3/00; H04B3/02; H04B3/04; H04B3/14; H04B3/146; H04B3/148; H01; H01P; H01P9/00; H01P9/003
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
99 words
A variable delay equalizer comprising: first and second directional couplers each having a pair of input terminals and a pair of output terminals; first and second variable phase shifters inserted respectively between the first output terminal of said first directional coupler and the first input terminal of said second directional coupler and between the second output terminal of said first directional coupler and the second input terminal of said second directional coupler, and; a third variable phase shifter inserted between the second output terminal of said second directional coupler and the second input terminal of said first directional coupler.
Claim 2
Dependent Claim
99 words
A variable delay equalizer comprising: first and second directional couplers each having a pair of input terminals and a pair of output terminals; first and second variable phase shifters inserted respectively between the first output terminal of said first directional coupler and the first input terminal of said second directional coupler and between the second output terminal of said first directional coupler and the second input terminal of said second directional coupler, and; a third variable phase shifter inserted between the second output terminal of said second directional coupler and the second input terminal of said first directional coupler.
References Cited (Backward Citations)
US3487337A
Cited
US3609599A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-06-29 | 1979-12-29 | 1980-06-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-06-29 | 1983-12-29 | 1984-06-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-06-29 | 1987-12-29 | 1988-06-29 | $7700.00 | Window Closed / Lapsed |