LOCAL OSCILLATION APPARATUS

Disclosed is a local oscillator using a dielectric coaxial resonator (27), which is availably used as a fixed local oscillator in double-spot tuners and CATV converters, and which is arranged so that an AFC voltage is applied to a variable-capacitance diode (23) from an output terminal (E) of a freq...

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Bibliographic Details
Main Authors AKIRA USUI, HIROYUKI NAGAI, TETSUO KUTSUKI, HIDEYUKI IKUHARA, KAZUHIKO KUBO
Format Patent
LanguageEnglish
Published 13.07.1988
Edition4
Subjects
BASIC ELECTRONIC CIRCUITRY
DEMODULATION OR TRANSFERENCE OF MODULATION FROM ONE CARRIER TOANOTHER
ELECTRICITY
GENERATION OF NOISE BY SUCH CIRCUITS
GENERATION OF OSCILLATIONS, DIRECTLY OR BY FREQUENCY-CHANGING,BY CIRCUITS EMPLOYING ACTIVE ELEMENTS WHICH OPERATE IN ANON-SWITCHING MANNER
SELECTING RESONANT CIRCUITS
TUNING RESONANT CIRCUITS
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Summary:Disclosed is a local oscillator using a dielectric coaxial resonator (27), which is availably used as a fixed local oscillator in double-spot tuners and CATV converters, and which is arranged so that an AFC voltage is applied to a variable-capacitance diode (23) from an output terminal (E) of a frequency control circuit through a first resistor (35), the variable-capacitance diode having its one end being connected to a center conductor of a dielectric coaxial resonator (27) through a capacitor (25) and its other end being AC grounded, and that a first reference potential (VA) lower than a source voltage (VCC) by a predetermined value is given to the variable-capacitance diode (23), the one end of the variable-capacitance diode (23) being connected to the source voltage (VCC) through a second resistor (22), whereby the voltage impressed across the variable-capacitance diode (23) can be kept constant regardless of a variation in the source voltage to thereby prevent the oscillation frequency from fluctuating.
Bibliography:Application Number: GB19880003235