Local oscillation apparatus

Abstract

The present invention relates to a local oscillation apparatus which is used as a local oscillator of a communication apparatus or as a fixed local oscillator of a tuner. The present invention comprises a coaxial resonator (1) and an amplifying circuit (26) having an output end connected to a central conductive member of the coaxial resonator (1) through a first capacitor (2), an input end connected to the central conductive member through a second capacitor (3), and a variable capacitance diode (5) having one end connected to the central conductive member of the coaxial resonator (1) through a third capacitor (4) and the other end grounded so as to permit an alternating current only to be flowed. The circuit is characterized by such a constitution that an oscillation frequency is varied by a voltage applied to the variable capacitance diode (5), a cause of temperature drift of an oscillation frequency can be almost eliminated, and a stable oscillation can be accomplished by only compensation of the temperature characteristics of the coaxial resonator (1).

Dependencies are inferred from the claim text.