US4283693A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Amplitude tilt compensating apparatus
Assignee: Nokia of America Corp
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Filing: 1980-05-19
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Granted: 1981-08-11
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Expires: 2000-05-19
Abstract
Abstract Circuitry is disclosed for detecting signal amplitudes of a signal which is phase indicative of a digital logic level and providing a feedback signal for use in amplitude adjusting the signal to have a substantially zero slope over the relevant frequency bandwidth. The compensation is obtained by applying a voltage to variable impedance pin diodes which form part of a reactive load circuit.
Inventors
- 👤 Eliseo Saenz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:00
CPC Classifications
H; H04; H04B; H04B7/00; H04B7/005
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
180 words
Apparatus of the class described comprising, in combination: adaptive equalizer means having a gain characteristic which varies as a function of frequency over a predetermined band of frequencies, including control signal responsive variable impedance means, for passing a signal therethrough which may have an amplitude slope other than zero for the frequencies in said band, said control signal responsive variable impedance means comprising a tuned filter having only low-pass and bandpass characteristics including a pin diode as a variable resistance element in an inductive portion of the tuned filter circuit and the pin diode is utilized to vary the Q of said tuned filter circuit; detection means, connected to an output of said adaptive equalizer means, for detecting the relative amplitude of signals occurring at at least two different frequencies in the band; and first means, connected between said adaptive equalizer means and said detection means, for generating a feedback signal to vary the value of said impedance means whereby a spectrum envelope of signals output by said adaptive equalizer means is modified to have substantially a zero amplitude slope.
Claim 2
Dependent Claim
180 words
Apparatus of the class described comprising, in combination: adaptive equalizer means having a gain characteristic which varies as a function of frequency over a predetermined band of frequencies, including control signal responsive variable impedance means, for passing a signal therethrough which may have an amplitude slope other than zero for the frequencies in said band, said control signal responsive variable impedance means comprising a tuned filter having only low-pass and bandpass characteristics including a pin diode as a variable resistance element in an inductive portion of the tuned filter circuit and the pin diode is utilized to vary the Q of said tuned filter circuit; detection means, connected to an output of said adaptive equalizer means, for detecting the relative amplitude of signals occurring at at least two different frequencies in the band; and first means, connected between said adaptive equalizer means and said detection means, for generating a feedback signal to vary the value of said impedance means whereby a spectrum envelope of signals output by said adaptive equalizer means is modified to have substantially a zero amplitude slope.
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) | 1984-08-10 | 1985-02-09 | 1985-08-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-08-10 | 1989-02-09 | 1989-08-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-08-10 | 1993-02-09 | 1993-08-11 | $7700.00 | Window Closed / Lapsed |