Design of a compact symmetricalc-Band Micro Strip Band Pass Filter with Periodic Saw tooth Grooves

Design of a miniaturized symmetrical band pass filter (BPF) using parallel-coupled half-wavelength micro strip resonators with improved stop band characteristics and 2^nd harmonic suppression is presented. The proposed filter is designed at a center frequency of 5.25 GHz with a stop band insertion loss greater than-10dB at 5.15 GHz and fractional bandwidth of 20% (4.74–5.80GHz). The conventional parallel-coupled line band pass filter structure has been folded symmetrically about the horizontal plane and consecutive saw tooth periodic grooves are introduced to the parallel lines. Thus there has been a significant improvement in 2^ndharmonic suppression to almost-34.51dB. Size reduction of 46.73% is accomplished with respect to the conventional filter.