Rozhnovskiy M. Increase of filter selectivity of radio engineering devices with the help of expofunctional signals

3. The object is the selectivity of frequency-selective nodes of radio devices. The subject is an increase of the filter selectivity of radio devices with the help of the expofunctional signals. Research methods: methods of the electric circuit theory, methods of the mathematical modeling, simulation on the computer, analytical methods of research of the electric characteristics of circuits and environments of conductivity, methods of scientific results receipt on the basis of natural experiment with the help of a prototype. Theoretical and practical results: the method for determination of required value of parameter of expofunctional signal for asymmetrical loss compensation in LC-filters under expofunctional excitations is given. LC-filters are theoretically and experimentally researched with arbitrary losses under expofunctional excitations. The research proved that the expofunctional signals can be used for increase of frequency selectivity of the filters on 3 - 20 %. The first time mathematical expressions for the secondary parameters of homogeneous lines under expofunctional excitations are given, expressions for calculation of required value of parameter of expofunctional signals for loss compensation in the segment of homogeneous line is proposed. The analytical model of homogeneous line with frequency dependent primary parameters R and G under expofunctional excitations are given. The method of determination of value of parameter of expofunctional signal for loss compensation in strip-line filters is given. The research results prove the fact the expofunctional signal can be used to increase the frequency selectivity of 4-resonators microstrip filters on 30 %. The experimental research showed feasibility of losses compensation in piezoelectric resonators with the help of the expofunctional signals what allowed increasing of selectivity of filters built on piezoelectric resonators that allows to improve their frequency selectivity.