A Transistor Oscillator Frequency Stability Study

The problem of oscillator frequency instability arising from environmentally induced changes in the active element is treated with respect to a particular transistor oscillator. Variations in frequency are related to those changes in collector capacitance and cutoff frequency which are due to temperature and supply voltage variations. Measurements show that the analysis is a useful basis for the estimation of frequency stability, and indicate correct identification of the major sources of instability. Consideration of the nonlinear aspects of operation is used to simplify the analysis and design of the oscillator. A useful order of frequency stability can be realized with the oscillator.