Electronic Oscillators with Bias-Shift Limiting

Abstract

In this chapter a major, yet simple oscillator prototype is studied, together with several derivative configurations. Of particular interest is the fact that although the basic differential equation which describes the oscillator has the same form as that encountered in the last chapter, there is now a new limiting phenomenon. The essential limiting of the growth of oscillatory buildup is due to the shift of the virtual or dynamic operating point of the configuration. That is, the effective bias point of the oscillator shifts from the initial values at the quiescent state in the active region of the device(s) to equivalent bias values corresponding to a near-off state of the devices. Steady-state operation of the oscillator corresponds to Class-C operation wherein the devices are off during more than one-half of the period of the oscillation.