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US4596955A Expired / Lapsed US ⏱️ 0.0 years remaining

Phase-locked loop and device for demodulating frequency modulated signals, comprising such a loop

Assignee: US Philips Corp
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Filing: 1984-04-27
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Granted: 1986-06-24
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Expires: 2004-04-27
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Abstract

Abstract Phase-locked loop, comprising Hartley-type oscillator being formed with a dual-gate field effect transistor (10), whose gates (G 2 ) and (G 1 ) constitute the phase-comparison inputs of the loop and whose drain is coupled, optionally via a low-pass loop filter (35), to the input of the feedback circuit, this feedback circuit being connected to the tuning circuit of the oscillator.

Inventors

  • 👤 Philippe N. Horvat
  • 👤 Joel P. Gris

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 12:22
CPC Classifications
H; H03; H03D; H03D3/00; H03D3/02; H03D3/24; H03D3/241; H03B; H03B5/00; H03B5/08; H03B5/12; H03B5/1203; H03B5/1228; H03B5/1237; H03B5/124; H03B5/1243; H03D2200/00; H03D2200/0001; H03D2200/0007

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 51 words
A phase-locked loop, characterized in that the loop comprises an oscillator of the Hartley type, having a dual-gate field effect transistor, whose gates constitute the phase-comparison inputs and whose drain is coupled to the input of a feedback circuit, which feedback circuit is connected to a tuning circuit of the oscillator.
Claim 2
Dependent Claim 51 words
A phase-locked loop, characterized in that the loop comprises an oscillator of the Hartley type, having a dual-gate field effect transistor, whose gates constitute the phase-comparison inputs and whose drain is coupled to the input of a feedback circuit, which feedback circuit is connected to a tuning circuit of the oscillator.
Claim 3
Dependent Claim 23 words
A device as claimed in claim 1, characterized in that the tuning circuit comprises at least a varicap diode and a control capacitor.
Claim 4
Dependent Claim 27 words
A device as claimed in claim 1 characterized in that it comprises a circuit for controlling the central operating frequency, arranged in parallel with the tuning circuit.
Claim 5
Dependent Claim 27 words
A device as claimed in claim 2, characterized in that it comprises a circuit for controlling the central operating frequency, arranged in parallel with the tuning circuit.
Claim 6
Dependent Claim 106 words
A phase-locked loop for demodulating frequency modulated signals, having a Hartley-type oscillator and a feedback circuit, said oscillator including a dual-gate field effect transistor and a tuning circuit coupled thereto, in which the gates of said transistor constitute phase-comparison inputs and a drain thereof is coupled to said feedback circuit, said feedback circuit being coupled to said tuning circuit, characterized in that said frequency-modulated signal is applied to one of said gates and the other of said gates is coupled to said tuning circuit for receiving an oscillator signal therefrom, said drain being coupled to an output of said phase-locked loop for providing the demodulated signals.
Claim 7
Dependent Claim 106 words
A phase-locked loop for demodulating frequency modulated signals, having a Hartley-type oscillator and a feedback circuit, said oscillator including a dual-gate field effect transistor and a tuning circuit coupled thereto, in which the gates of said transistor constitute phase-comparison inputs and a drain thereof is coupled to said feedback circuit, said feedback circuit being coupled to said tuning circuit, characterized in that said frequency-modulated signal is applied to one of said gates and the other of said gates is coupled to said tuning circuit for receiving an oscillator signal therefrom, said drain being coupled to an output of said phase-locked loop for providing the demodulated signals.
Claim 8
Dependent Claim 27 words
A device as claimed in claim 5, characterized in that it comprises a circuit for controlling the central operating frequency, arranged in parallel with the tuning circuit.

References Cited (Backward Citations)

US3723905A Cited
US4479091A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1989-06-23 1989-12-23 1990-06-24 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1993-06-23 1993-12-23 1994-06-24 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1997-06-23 1997-12-23 1998-06-24 $7700.00 Window Closed / Lapsed

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