Dudnyk V. Synthesis of distributed filtering structures for increasing the efficiency of radioengineering and telecommunication systems based on inhomogeneous lines

The dissertation solves the scientific and technical task of improving the synthesis methods of distributed filtering structures, which are part of high-speed telecommunications equipment, by determining the parameters and developing new types of equivalent circuits based on non-homogeneous lines. Obtaining the best characteristics of the devices is achieved by selecting the law of change of the wave resistance of the NL sections. For the first time, analytical expressions for determining the characteristic parameters of NL were obtained, according to which the four-pole parameters of new types of NL are determined, which will allow the use of classical methods of filter synthesis theory not only on homogeneous lines but also based on the NL. The method of synthesizing filters on segments of homogeneous lines with the use of characteristic parameters for its application to the synthesis of filters based on NL received further development, as a result, the sensitivity of the electrical parameters of the filter to the spread of the structural parameters of the filter elements is reduced compared to the designs of the filter synthesized by other methods. Based on the proposed method of synthesis of filters based on NL, variants of the topology of a low-pass filter and high-pass filter implementation with characteristics superior to existing analogs have been developed. For the first time, a filter synthesis method was developed based on broadband simulation of the characteristics of lumped elements with two-stage homogeneous lines, taking into account the influence of wave resistance jumps. It is shown that the calculation of the value of the capacitance and inductance of the line junctions in the places of wave resistance jumps makes it possible to increase the accuracy of calculations and to adjust the wave resistances and the delay time of segments of homogeneous lines. It has been proven that the approximate Kohn method and other methods of filter synthesis can be used in the synthesis of band-pass filters on new types of NL. The use of NL as resonators allows the choice of wave resistance to increase the blocking band of the BPF compared to the BPF on resonators based on homogeneous lines. The practical use of such filters increases the immunity of telecommunication systems.