US3585513A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Frequency modulation discriminator having first branch with resonator and second branch providing voltage and temperature compensation
Assignee: Motorola Solutions Inc
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Filing: 1969-05-02
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Granted: 1971-06-15
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Expires: 1989-05-02
Abstract
Abstract A discriminator for a frequency modulated receiver, having slope detector and reference portions, with each portion developing a signal from the input signal. The slope detector portion signal varies in accordance with the frequency and amplitude of the input signal, and varies with temperature. The reference portion signal varies in accordance with the amplitude of the input signal and also varies in accordance with temperature. Signals from the two portions are combined at the output to produce a resultant signal which varies in amplitude according to the frequency of the input signal and is substantially unaffected by temperature variations and changes in supply voltage.
Inventors
- 👤 Alfred R Lucas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 03:27
CPC Classifications
H; H03; H03D; H03D3/00; H03D3/28; H03D3/34; H03D3/26; H03D2200/00; H03D2200/0041; H03D2200/0094; H03D2200/0098
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
192 words
A discriminator for the detection of a frequency modulated signal having a particular center frequency including in combination, input means for receiving the signal, a first discriminator portion coupled to said input means and including piezoelectric means responsive to said frequency modulated signal to develop a first output signal varying in accordance with the frequency of said frequency modulated signal, said piezoelectric means being responsive to variations in temperature to vary the first output signal in accordance therewith, a second reference portion coupled to said input means and responsive to said frequency modulated signal to develop a second output signal, said second output signal being substantially independent of the frequency of said frequency modulated signal, said second reference portion including first circuit means being responsive to variations in temperature to vary said second output signal in accordance therewith, output means coupled to said first and second portions for combining said first and second output signals to cancel said first and second output signal variations due to temperature and to develop a resultant signal of varying amplitude proportional to the modulation of the frequency modulated signal and substantially independent of variations in temperature.
Claim 2
Dependent Claim
192 words
A discriminator for the detection of a frequency modulated signal having a particular center frequency including in combination, input means for receiving the signal, a first discriminator portion coupled to said input means and including piezoelectric means responsive to said frequency modulated signal to develop a first output signal varying in accordance with the frequency of said frequency modulated signal, said piezoelectric means being responsive to variations in temperature to vary the first output signal in accordance therewith, a second reference portion coupled to said input means and responsive to said frequency modulated signal to develop a second output signal, said second output signal being substantially independent of the frequency of said frequency modulated signal, said second reference portion including first circuit means being responsive to variations in temperature to vary said second output signal in accordance therewith, output means coupled to said first and second portions for combining said first and second output signals to cancel said first and second output signal variations due to temperature and to develop a resultant signal of varying amplitude proportional to the modulation of the frequency modulated signal and substantially independent of variations in temperature.
Claim 3
Dependent Claim
41 words
The discriminator of claim 1 wherein said output means includes first and second resistance means coupled together and to said first and second portions, and third resistance means coupled to said first nd second resistance means and to a reference potential.
Claim 4
Dependent Claim
131 words
The discriminator of claim 1 wherein said first discriminator portion includes, first resistance means coupled to said input means for receiving the frequency modulated signal therefrom said piezoelectric means being coupled to said first resistance means and to a reference potential and responsive to said frequency modulated signal to develop a first signal thereacross varying in accordance with the frequency of said frequency modulated signal, said piezoelectric means being responsive to variations in temperature to vary the first signal in accordance therewith, diode means coupled to said resistance means and to said piezoelectric means, and reactance means coupled to said diode means and to the reference potential, said diode means rectifying said first signal developed across said piezoelectric means and charging said reactance means to develop said first output signal thereacross.
Claim 5
Dependent Claim
13 words
The discriminator of claim 3 wherein said piezoelectric means is a ceramic resonator.
Claim 6
Dependent Claim
29 words
The discriminator of claim 3 wherein said first discriminator portion further includes resistance means coupled in parallel with said piezoelectric means for linearizing the response of said piezoelectric means.
Claim 7
Dependent Claim
29 words
The discriminator of claim 3 wherein said first discriminator portion further includes inductance means coupled in parallel with sad piezoelectric means for widening the response of said piezoelectric means.
Claim 8
Dependent Claim
136 words
The discriminator of claim 1 for use in a frequency modulated receiver wherein the frequency modulated signal may vary in amplitude in accordance with the supply voltage of the receiver, and herein said first discriminator portion is further responsive to said variation in amplitude of said frequency modulated signal coupled thereto to vary the first output signal in accordance therewith, said second reference portion further including circuit means responsive to the amplitude of said frequency modulated signal and interacting with said first circuit means to develop a second output signal varying in accordance with the amplitude of said frequency modulated signals and in response to variations in temperature, whereby said resultant signal varies in amplitude in proporTion to the modulation of the frequency modulated signal and is substantially independent of variations in temperature and supply voltage.
Claim 9
Dependent Claim
107 words
The discriminator of claim 7 wherein said second portion includes, first resistance means coupled to said input means for receiving the frequency modulated signal therefrom, second resistance means coupled to said first resistance means and to a reference potential, said first and second resistance means being responsive to the amplitude of said frequency modulated signal to develop a second signal across said second resistance means, diode means coupled to said first and second resistance means, and reactance means coupled to said diode means and to the reference potential, said diode means rectifying said second signal and charging said reactance means to develop said second output signal thereacross.
Claim 10
Dependent Claim
81 words
The discriminator of claim 8 wherein said second resistance means includes, variable resistance means and fixed resistance means serially connected, and temperature responsive resistance means coupled across said fixed resistance means, said variable resistance means enabling the voltage developed across said second resistance means to be adjusted in value, and said temperature responsive resistance means causing the voltage developed across said second resistance means to vary in accordance with temperature, so that said second output signal varies in accordance with temperature.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-06-14 | 1974-12-14 | 1975-06-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-14 | 1978-12-14 | 1979-06-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-14 | 1982-12-14 | 1983-06-15 | $7700.00 | Window Closed / Lapsed |