Modulators – Amplitude modulator – Suppressed carrier double sideband type
Patent
1985-03-29
1986-12-16
Grimm, Siegfried H.
Modulators
Amplitude modulator
Suppressed carrier double sideband type
331116R, 331177V, 332 18, 332 26, 332 30V, H03C 322
Patent
active
046300082
ABSTRACT:
A direct frequency modulation crystal-controlled oscillator circuit is provided having a configuration which minimizes the number of parts required for modulation while maintaining a linear relationship between the incoming modulation voltage and the outputted frequency. The circuit includes a tuning diode in a parallel arrangement with a tank circuit connected to the collector of a transistor. In the preferred embodiment, the tank circuit includes only an inductor. The crystal of the circuit operates in the anti-resonant mode and its impedance is much greater than that of the tank circuit. Direct frequency modulation results from the frequency change of the crystal in responding to a phase change caused by the modulation voltage applied to the tuning diode, which subsequently results in a change in the phase of a transistor collector voltage. The desired linear relationship is achieved over a frequency range by proper selection of the tuning diode wherein the non-linearity that exists between voltage and capacitance associated with the tuning diode is compensated for by the offsetting non-linearity that exists between capacitance and frequency associated with the tank circuit.
REFERENCES:
patent: 3256498 (1966-06-01), Hurtig
patent: 3528032 (1970-09-01), Tahmisian, Jr. et al.
patent: 3747023 (1973-07-01), Hoft et al.
patent: 3916344 (1975-10-01), Enderby
patent: 3995233 (1976-11-01), Waku
patent: 4088968 (1978-05-01), Pradal et al.
patent: 4134085 (1979-01-01), Driscoll et al.
patent: 4224580 (1980-09-01), Yoshisato et al.
patent: 4442415 (1984-04-01), Ashida
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