Oscillator of the butler improved

摘要

An amplitude limiting amplifier followed by a filter network is interposed between the voltage amplification stage and the impedance matching stage in a Butler oscillator. This allows both the voltage amplification stage and the impedance matching stage to be operated in a linear mode at all times which assures that a piezoelectric crystal connected between the stages is connected in a relatively low, constant impedance path and is driven by a sinusoidal waveform, free of distortion, to assure maximum frequency stability.