Oscillator with constant output level over oscillation frequency range

摘要

An oscillator includes an oscillation circuit unit and an amplification circuit unit of the common-base type. The oscillation circuit unit includes an oscillation transistor and a resonance circuit, the collector of the oscillation transistor being grounded via a first capacitor. The amplification circuit unit includes an amplification transistor, the emitter thereof being directly connected to the collector of the oscillation transistor and the base thereof being grounded via a second capacitor. The resonance circuit is connected between the base of the oscillation transistor and the ground. An oscillation signal output from the collector of the oscillation transistor is input to the emitter of the amplification transistor while partially being bypassed to the ground via the first capacitor. Negative feedback is provided to the amplification transistor in association with the second capacitor.