Annular shape interdigital filter with increased frequency selection design

The design of the interdigital bandpass filter annular shape with increased frequency selectivity due to convergence input and output lines introduction additional between them is suggested. This allows amplitude-frequency characteristic such a be formed attenuation poles on edges its bandpass, which significantly increases steepness slopes. A model four-resonator made results experimental investigations are given. They showed that developed can successfully used in measuring channels determine signals modern microwave equipment for communication, radar telecommunications.