The Design of Microstrip Band-Selective Filter with Narrow Stopband for UWB Application

협대역 저지 특성을 가지는 UWB용 마이크로스트립 필터 설계

  • Roh, Yang-Woon (Department of Electrical and Computer Engineering, Hanyang University) ;
  • Hong, Seok-Jin (Department of Electrical and Computer Engineering, Hanyang University) ;
  • Jung, Kyung-Ho (Department of Electrical and Computer Engineering, Hanyang University) ;
  • Jung, Ji-Hak (Department of Electrical and Computer Engineering, Hanyang University) ;
  • Choi, Jae-Hoon (Department of Electrical and Computer Engineering, Hanyang University)
  • 노양운 (한양대학교 전자통신컴퓨터공학과) ;
  • 홍석진 (한양대학교 전자통신컴퓨터공학과) ;
  • 정경호 (한양대학교 전자통신컴퓨터공학과) ;
  • 정지학 (한양대학교 전자통신컴퓨터공학과) ;
  • 최재훈 (한양대학교 전자통신컴퓨터공학과)
  • Published : 2005.11.05

Abstract

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 bandstop 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% reduction in footprint compared to the traditional bandstop 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 7.42 % (5.32 GHz to 5.73 GHz) for 3-dB bandwidth. The measured group delay is less than 0.7 ns within the passband except the rejection band.

Keywords

Band-selective filter;Meandered resonators;Microstrip;Narrow stop band;UWB