Stripline Microwave Filters with Increased Frequency Selectivity Based on Counter-Comb Structures

This paper investigates the design specifics of compact highly selective stripline filters based on counter-comb structures with a limited number of resonators. The selective properties of basic two-resonators counter-comb strip structures are examined. It is shown that in such structures it is possible to form a significant number of working attenuation poles at finite frequencies. The possibilities to use these structures for creating four-resonator stripline filters with additional galvanic connection between adjacent resonators, that have increased frequency selectivity without creating electromagnetic coupling between non-adjacent resonators, are shown.