A novel substrate integrated waveguide broadband bandpass filter

A novel broadband substrate integrated waveguide bandpass filter is presented based on the highpass characteristics of substrate integrated waveguide (SIW) and the bandstop performance of photonic band gap (PBG) structure.In order to verify it,a wideband bandpass filter with center frequency of 5.0 GHz and fractional bandwidth of 60% is designed.The electromagnetic simulation results show its good passband characteristics from 3.5 GHz to 6.5 GHz,and the maximun insertion loss is about 0.64 dB.An experimental filter prototype is fabricated with standard PCB technics and measured with the vector network analyzer.The measured results show the passband is from 3.8 GHz to 6.8 GHz,the fractional bandwidth is about 56%,and the minimal insertion loss is about 1.6 dB.The measured results are in good agreement with the simulated results.