LOCAL OSCILLATOR

摘要

A local oscillator used for communication equipment or a double superheterodyne tuner. The local oscillator comprises a coaxial resonator (1), an amplifier circuit (26) of which the output terminal is connected to a central conductor of the coaxial resonator (1) via a first capacitor (2) and of which the input terminal is connected to the central conductor via a second capacitor (3), and a variable-capacity diode (5) of which one terminal is connected to the central conductor of the coaxial resonator (1) via a third capacitor (4) and of which the other terminal is grounded in an alternating current manner, and wherein the oscillation frequency changes depending upon the voltage applied to the variable-capacity diode (5). Factors of temperature drift in the oscillation frequency can be substantially eliminated, and stable oscillation can be obtained by simply compensating the temperature characteristics of the coaxial resonator (1).