A Novel Bandpass Filter of Substrate Integrated Waveguide (SIW) Based on S-Shaped EBG

A novel S-shaped electromagnetic band gap (EBG) middling bandwidth bandpass filter based on substrate integrated waveguide (SIW) was proposed. The filter was designed based on the band-stop characteristics of EBG by etching different dimensional S-shaped on the surface of substrate integrated waveguide. The bandpass filter with a center frequency at 7.765 GHz and relative fractional bandwidth 7.31% shows good bandpass characteristics with frequency band between 7.38~7.94 GHz, while the insertion loss is less than 1.6 dB and achieve middling bandwidth in SIW by EBG and has the advantage of bandpass, low insertion loss, compacted and good selectivity etc. The good agreement between the measured results and the simulated results demonstrates that the design of this proposed filter is effective.