US3676785A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High gain, ultra linear detector for frequency modulation
Assignee: Bull HN Information Systems Italia SpA
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Filing: 1970-12-10
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Granted: 1972-07-11
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Expires: 1990-12-10
Abstract
Abstract A detector for providing quadrature detection of frequency modulated signals is disclosed. An FET (Field Effect Transistor) device having two gates, a source and a drain, has one gate coupled to the frequency modulated incoming signal and the other gate coupled through a 90* phase shifter to the incoming signal. The demodulated signal appears at the drain electrode of the FET.
Inventors
- 👤 Henri T Pichal
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:33
CPC Classifications
H; H03; H03D; H03D3/00; H03D3/02; H03D3/06; H03D3/14
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
130 words
A solid state detector for detecting frequency modulated electromagnetic wave signals comprising: a. a first tank circuit means; b. a second tank circuit means; c. an FET (Field Effect Transistor) device having a source and a drain and a first and second gate, with said first tank circuit means coupled to said first gate and said second tank circuit means coupled to said second gate; d. biasing means coupled to said FET device for providing bias to said FET device; e. phase delay means coupled to said first and second tank circuit means for introducing a phase difference between signals in said first and second tank circuit means; f. and input and output means coupled to said FET device for introducing and abstracting electric signals to and from said detector.
Claim 2
Dependent Claim
130 words
A solid state detector for detecting frequency modulated electromagnetic wave signals comprising: a. a first tank circuit means; b. a second tank circuit means; c. an FET (Field Effect Transistor) device having a source and a drain and a first and second gate, with said first tank circuit means coupled to said first gate and said second tank circuit means coupled to said second gate; d. biasing means coupled to said FET device for providing bias to said FET device; e. phase delay means coupled to said first and second tank circuit means for introducing a phase difference between signals in said first and second tank circuit means; f. and input and output means coupled to said FET device for introducing and abstracting electric signals to and from said detector.
Claim 3
Dependent Claim
18 words
A solid state detector as recited in claim 1 wherein said phase delay means is an external capacitor.
Claim 4
Dependent Claim
34 words
A solid state detector as recited in claim 2 wherein said capacitor has a capacitance sufficient to provide Qk factor up to unity where: Qk x/R x reactance at resonance R resistance at resonance.
Claim 5
Dependent Claim
30 words
A solid state detector as recited in claim 1 wherein said delay means introduces a phase difference of substantially 90* between signals in said first and second tank circuit means.
Claim 6
Dependent Claim
22 words
A solid state detector as recited in claim 1 wherein said phase delay means comprises capacitance means internal to said FET device.
Claim 7
Dependent Claim
22 words
A solid state detector as recited in claim 1 including biasing means coupled to said source and drain of said FET device.
Claim 8
Dependent Claim
21 words
A solid state detector as recited in claim 1 wherein said drain is positively biased and said source is negatively biased.
Claim 9
Independent Claim
113 words
A method of detecting frequency modulated electromagnetic wave signals, comprised of a carrier frequency and audio frequency electromagnetic waves, comprising the steps of: a. imparting a phase shift to the frequency modulated electromagnetic wave signals; b. converting the frequency modulated electromagnetic wave signals into first voltage variable electric signals and converting the phase shifted frequency modulated electromagnetic wave signals into second voltage variable signals said first and second voltage variable signals responsive to frequencies above and below the center frequency of the carrier frequency respectively; c. introducing the voltage variable electric signals into a FET (Field Effect Transistor device; and, d. abstracting the audio voltage variable electromagnetic wave signals from said FET device.
Claim 10
Independent Claim
113 words
A method of detecting frequency modulated electromagnetic wave signals, comprised of a carrier frequency and audio frequency electromagnetic waves, comprising the steps of: a. imparting a phase shift to the frequency modulated electromagnetic wave signals; b. converting the frequency modulated electromagnetic wave signals into first voltage variable electric signals and converting the phase shifted frequency modulated electromagnetic wave signals into second voltage variable signals said first and second voltage variable signals responsive to frequencies above and below the center frequency of the carrier frequency respectively; c. introducing the voltage variable electric signals into a FET (Field Effect Transistor device; and, d. abstracting the audio voltage variable electromagnetic wave signals from said FET device.
Claim 11
Dependent Claim
34 words
A method of detecting frequency modulated electromagnetic wave signals as recited in claim 8 wherein the phase imparted to the audio frequency electromagnetic wave signals relative to the carrier frequency electromagnetic signals is 90*.
Claim 12
Independent Claim
127 words
A method of detecting frequency modulated electromagnetic wave signals comprised of a carrier frequency and audio frequency electric wave signals comprising the steps of: a. converting the frequency modulated electromagnetic wave signals having frequencies below the center frequency of the carrier wave into first voltage variable signals responsive to the frequencies below the carrier frequency; b. introducing a phase shift to the frequency modulated electromagnetic wave signals; c. converting the phaSe shifted frequency modulated electromagnetic wave signals having frequencies above the center frequency of the carrier wave into second voltage variable signals responsive to the frequencies above the carrier frequency; d. applying the first and second voltage variable signals to a FET device; e. and abstracting the audio voltage variable electromagnetic wave signals from said FET device.
Claim 13
Independent Claim
127 words
A method of detecting frequency modulated electromagnetic wave signals comprised of a carrier frequency and audio frequency electric wave signals comprising the steps of: a. converting the frequency modulated electromagnetic wave signals having frequencies below the center frequency of the carrier wave into first voltage variable signals responsive to the frequencies below the carrier frequency; b. introducing a phase shift to the frequency modulated electromagnetic wave signals; c. converting the phaSe shifted frequency modulated electromagnetic wave signals having frequencies above the center frequency of the carrier wave into second voltage variable signals responsive to the frequencies above the carrier frequency; d. applying the first and second voltage variable signals to a FET device; e. and abstracting the audio voltage variable electromagnetic wave signals from said FET device.
Claim 14
Dependent Claim
114 words
A solid state detector for detecting frequency modulated electromagnetic wave in (FM) signals comprising: a. an FET (Field Effect Transistor) device having a source and a drain and a first and second gate; b. input means coupled to said FET device, said input means for applying electronic signals to said FET device; c. quadrature tank circuit means coupled to said FET device and to said input means said quadrature tank circuit means for converting the FM signal to phase delayed voltage variable signals; d. bias means coupled to said FET device for providing bias to said FET device; and, e. output means coupled to said FET device for abstracting electric signals from said detector.
Claim 15
Dependent Claim
114 words
A solid state detector for detecting frequency modulated electromagnetic wave in (FM) signals comprising: a. an FET (Field Effect Transistor) device having a source and a drain and a first and second gate; b. input means coupled to said FET device, said input means for applying electronic signals to said FET device; c. quadrature tank circuit means coupled to said FET device and to said input means said quadrature tank circuit means for converting the FM signal to phase delayed voltage variable signals; d. bias means coupled to said FET device for providing bias to said FET device; and, e. output means coupled to said FET device for abstracting electric signals from said detector.
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) | 1975-07-11 | 1976-01-10 | 1976-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-11 | 1980-01-10 | 1980-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-11 | 1984-01-10 | 1984-07-11 | $7700.00 | Window Closed / Lapsed |