UWB용 대역 저지 필터 설계

초록

A compact microstrip band-selective filter for ultra-wideband(UWB) radio system is proposed. The filter combines the traditional short-circuited stub highpass filter and coupled resonator band-stop filter on both sides of the mitered 50-ohm microstrip line. To realize the pseudo-highpass filtering characteristic over UWB frequency band(3.1 GHz to 10.6 GHz), a distributed highpass filter scheme is adopted. Three coupled resonators are utilized to obtain the band stop function at the desired frequency band. By meandering the coupled resonators, there is 29 % size reduction in footprint compared to the traditional band-stop filter using L-shaped resonators. The measured results show that the filter has a wide passband of 146.7 %(2.1 GHz to 10.15 GHz) with low insertion loss and the stop band of 10.04 %(5.2 GHz to 5.75 GHz) for 3-dB bandwidth. The measured group delay is less than 0.7 ns within the passband except the rejection band.

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