Modulation of the output power of semiconductor microwave oscillators by changing the voltage in bias circuit

The use of the scheme of coherent signals subtraction (the synchrosignal and the synchronized oscillator output signal) for realization of the simple method of control of the output power of semiconductor microwave oscillators on the example of Gunn oscillator by the changing the bias of an active element has been proved theoretically and experimentally. The change up to 40 dB of the oscillator output power at the constant output frequency, when bias changes on 2.7%, has been achieved.

Introduction

The control of the of the output power of semiconductor microwave oscillators by the bias changing on the one hand is the attractive one because of its simplicity [1], but on the other hand there is several difficulties. For example, to achieve hard-driving amplitude modulation the bias variation must be comparable to the active element bias voltage. At that the change of the stationary electrical and thermal mode of an active element [2]–[5], which can accompany with the rise of the complicated dynamic operation modes, namely: subharmonics generation, frequency and amplitude modulation, chaotic oscillations [6]–[12].