Frequency Controlled Harmonic Oscillators Using Differentially Connected FETs with Automatic Oscillation Amplitude Control

Using method of shortened symbolic equations, investigation of stationary mode of operation and characteristics of phase and amplitude fluctuations of oscillations in the frequency controlled differential field effect transistor (FET) oscillator was fulfilled. It was shown that using MOS-structures in such oscillator one can provide wide band of the oscillation frequency variation. But in this band the variations of the oscillation frequency are accompanied by significant variations of the oscillation amplitude. To decrease these variations the automatic amplitude stabilization circuit was offered. Results of these circuit approximate analytic calculations were checked by calculations of particular frequency tuned oscillator by means of polyharmonic method.