Volodymyr Stepanovych Osadchuk

The generator of superhigh frequencies on the basis silicon germanium heterojunction bipolar transistors

Investigations of the hyperfrequency generator presented on the basis of the transistor structure consisting from two silicon - germanium heterojunction of bipolar transistors. The opportunity of electrical adjustment of an oscillation frequency is shown.

Optical transducers with frequency output

In this work the characteristics research of microelectronic transducers of optical radiation with a frequency output signal on the basis of a hybrid integrated circuit consisting of a bipolar and a field-effect transistor with a Schottky barrier is presented. The connection of an external inductance to electrodes a collector - drain allows to implement the auto generating device. The frequency of the device generation depends on power of optical radiation falling on photosensing elements as a photoresistor, photodiode and photosensing transistors switched on in a circuit of the self-excited oscillator. The impedance on electrodes the collector - drain of bipolar and field transistors has capacitive reactive part and negative active resistance, which compensates power losses in a tuning circuit of the device. On the base of a nonlinear equivalent circuit of the transducer on an alternating current the analytical expressions of function of transformation and equation of sensitivity are obtained. The sensitivity of optical transducers lays in a range from 25 kHz/μWt/cm2 up to 150 kHz/μWt/cm2.