Selective Properties of Multistep Comb Structures with Various Methods of Their Excitation

In this paper, we study the frequency properties of the multi-step comb and counter-comb microstrip structures with various methods of their excitation. It is shown that with a combined method of its excitation, it has a significantly higher frequency selectivity. The results of a comparative analysis of two-, three-, and four-resonator structures are presented, in which a significant number of working attenuation poles at finite frequencies are formed, which deter-mines the increased frequency selectivity of microstrip filters based on these structures with a significantly limited number of resonators.