Oleksandr Volodymyrovych Osadchuk

The UHF oscillators based on a HEMT structure with negative conductivity

The article considers a possibility of constructing microwave oscillators on a transistor structure with negative conductivity based on two HEMT. Obtained non-linear equations can be used to model microwave oscillator parameters and characteristics with an error not more than 10%.

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.

Frequency pressure transducer with a sensitivity of mem capacitor on the basis of transistor structure with negative resistance

In the article the pressure transducer with frequency output based on the structure of the bipolar-field transistors with negative resistance and tenso sensitive MEMS capacitor has been considered. A mathematical model of the frequency pressure transducer in dynamic regime has been developed that allowed to determine the voltage or current in the circuit at any given moment in time when acting this pressure. Analytical expressions of the conversion function and sensitivity equation has been received. The sensitivity of the developed device is between 0,95kHz/kPa to 1,65kHz/kPa.

Modeling the deterministic chaos microelectronic oscillator based on the bipolar transistor structure with negative resistance

The paper considers a new electric diagram of the microelectronic self-excited oscillator based on the bipolar transistor structure with negative resistance. The oscillator operates in oscillatory and relaxation modes. Chaotic mode of the self-excited oscillator was provided by installing additional components into a basic circuit. Results of the deterministic chaos microelectronic oscillator simulation were obtained. Simulation was performed with standard PSPICE models of radio components. Time and frequency characteristics of the oscillations were obtained.

Comparative analysis of radiomeasuring frequency converters of the magnetic field

In this paper three radiomeasuring frequency converters of the magnetic field are developed. Also their sensitivity characteristics are researched and compared. Besides, the advantages and disadvantages of each of the radiomeasuring frequency converters of the magnetic field are indicated.

THE RADIOMEASURING CONVERTER OF THE MAGNETIC FIELD BASED ON TRANSISTORS STRUCTURE

Вирішено завдання вимірювання напруженості магнітного поля радіовимірювальним перетворювачем магнітного поля на біполярних та польовому транзисторах. Запропоновано схемотехнічне рішення радіовимірювального перетворювача, який забезпечує перетворення напруженості магнітного поля в частоту електричного коливання, що дозволяє підвищити чутливість пристрою до напруженості магнітного поля. Проведено експеримент з дослідження розробленого радіовимірювального перетворювача магнітного поля. У результаті проведених експериментів досліджено залежності вихідної частоти та чутливості пристрою від напруженості магнітного поля.