US3573643A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Frequency discriminator circuit including piezoelectric resonator providing coupled resonant circuit
Assignee: Motorola Solutions Inc
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Filing: 1969-12-15
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Granted: 1971-04-06
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Expires: 1989-12-15
Abstract
Abstract Frequency discriminator including piezoelectric element with first set of plates forming input tuned circuit and second pair of plates connected in a second tuned circuit coupled through the piezoelectric element to the first tuned circuit. The second tuned circuit includes an adjustable inductance for tuning to resonance at the center frequency of the frequency-modulated signal. The input signal is applied to the second tuned circuit and combined with opposite phases of the signal coupled through the piezoelectric element. A pair of rectifiers couple the second tuned circuit to a load across which the modulation signal is developed.
Inventors
- 👤 Corwin E Livenick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 12:00
CPC Classifications
H; H03; H03D; H03D3/00; H03D3/02; H03D3/06; H03D3/16
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
211 words
A frequency discriminator circuit for deriving modulation signals from an angle-modulated carrier wave having a given center frequency including in combination, a flat piezoelectric element, a first pair of conducting plates on opposite sides of said element and forming therewith a first tuned Circuit resonant at the given center frequency, input circuit means coupled to said first pair of plates for applying the modulated carrier wave thereto, a second pair of conducting plates on opposite sides of said element and spaced from said first pair of plates, reactance means connected to said second pair of plates and cooperating therewith and with said element to form a second tuned circuit resonant at the given center frequency, said piezoelectric element coupling signals from said first tuned circuit to said second tuned circuit with a predetermined phase relation, coupling means connecting said input circuit to said second tuned circuit for coupling signals thereto with a phase relation different from said predetermined phase relation, and a rectifier circuit including first and second rectifier means and a rectifier load circuit, said first and second rectifier means individually connecting said plates of said second pair to said rectifier load circuit, whereby a signal is developed across said load circuit in response to modulation of the carrier wave.
Claim 2
Dependent Claim
211 words
A frequency discriminator circuit for deriving modulation signals from an angle-modulated carrier wave having a given center frequency including in combination, a flat piezoelectric element, a first pair of conducting plates on opposite sides of said element and forming therewith a first tuned Circuit resonant at the given center frequency, input circuit means coupled to said first pair of plates for applying the modulated carrier wave thereto, a second pair of conducting plates on opposite sides of said element and spaced from said first pair of plates, reactance means connected to said second pair of plates and cooperating therewith and with said element to form a second tuned circuit resonant at the given center frequency, said piezoelectric element coupling signals from said first tuned circuit to said second tuned circuit with a predetermined phase relation, coupling means connecting said input circuit to said second tuned circuit for coupling signals thereto with a phase relation different from said predetermined phase relation, and a rectifier circuit including first and second rectifier means and a rectifier load circuit, said first and second rectifier means individually connecting said plates of said second pair to said rectifier load circuit, whereby a signal is developed across said load circuit in response to modulation of the carrier wave.
Claim 3
Dependent Claim
40 words
The circuit of claim 1 wherein said reactance means includes inductor means connected between said conducting plates of said second pair, and said inductor means is variable to provide precise adjustment of the resonant frequency of said second tuned circuit.
Claim 4
Dependent Claim
26 words
The circuit of claim 1 wherein said rectifier load circuit includes a capacitor for bypassing signals having frequencies in a range including the given center frequency.
Claim 5
Dependent Claim
63 words
The circuit of claim 1 wherein said signals coupled through said piezoelectric element to said second tuned circuit appear at said conducting plates of said second pair with opposite phases, and signals of said given center frequency coupled through said coupling means appear at said plates of said second pair substantially in phase quadrature with the signals coupled thereto through said piezoelectric element.
Claim 6
Dependent Claim
45 words
The circuit of claim 4 wherein said reactance means includes an inductor connected between said conducting plates of said second pair and having an intermediate tap thereon, and said coupling means is connected to said center tap for coupling signals thereto from said input circuit.
Claim 7
Dependent Claim
23 words
The circuit of claim 5 wherein said inductor is variable to provide precise adjustment of the resonant frequency of said second tuned circuit.
Claim 8
Dependent Claim
45 words
The circuit of claim 4 wherein said reactance means includes first and second capacitors connected in series between said conducting plates of said second pair, and said coupling means is connected to the connection between said capacitors for coupling signals thereto from said input circuit.
Claim 9
Dependent Claim
35 words
The circuit of claim 7 wherein said reactance means includes a variable inductor connected in parallel with said first and second capacitors to provide precise adjustment of the resonant frequency of said second tuned circuit.
References Cited (Backward Citations)
US2312079A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-04-05 | 1974-10-05 | 1975-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-05 | 1978-10-05 | 1979-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-05 | 1982-10-05 | 1983-04-06 | $7700.00 | Window Closed / Lapsed |