Pravda Vladimir I.

Development of multichannel transmitters short-centimeter-wave systems for multiple radio access

Theoretical study of intermodulation distortion in nonlinear power amplifier has been done. It relates to a generation of second harmonics of input signal and allowed to present a new linearization principle of these devices, which is based on use of mentioned harmonics energy as a feedback signal. Calculations of impact of described mechanism upon signals of different digital modulation types have been conducted. Significant reduce (up to 25 dB) in crosstalk level has been reached. And 1dB compression level of amplifier output power has almost reached saturation point.

Development of integrated Receiver & Transmitter module in millimeter-wave band for wide band wireless access system

The new constructions of millimeter wave band pass and band stop filters were designed. Filters are builded on the cheap plastic metalized substrates and are suitable for integration into the all-planar millimeter wave transceivers. The new constructions of hybrid integrated low-noise millimeter wave oscillators for frequency up- and down converters were designed. Oscillators can be used in the wireless broadband access system. The new constructions of all-planar orthomode transducers were designed and investigated both theoretically and experimentally.