Semi-Lumped Compact Low-Pass Filter for Harmonics Suppression

  • Li Rui (Department of Radio Sciences and Engineering, Korea Maritime University) ;
  • Kim Dong-Il (Department of Radio Sciences and Engineering, Korea Maritime University) ;
  • Choi Chang-Mook (Department of Radio Sciences and Engineering, Korea Maritime University)
  • Published : 2006.09.01


In this paper, a new semi-lumped low-pass filter with three finite attenuation poles at stopband is presented. The new structure is composed of a pair of symmetrical parallel coupled-line and a shunted capacitor. With this configuration, three finite attenuation poles can be available for 2nd, 3rd, and 4th harmonics suppression. The research method is based on transmission-line model for tuning the attenuation poles. In order to examine the feasibility of the proposed structure, a low-pass filter based on microstrip structure with harmonics suppression is designed, fabricated, and measured. The experimental results of the fabricated circuit agree well with the simulation and analytical ones.


Finite Attenuation Poles;Harmonics Suppression;Low-Pass Filter;Parallel Coupled-Line


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