A novel microstrip bandpass filter with two cascaded PBG structures

Abstract

A novel compact microstrip bandpass filter (BPF) using two cascaded strip-photonic-bandgap (PBG) structures on the ground plane is designed, simulated and demonstrated experimentally. The experimental results agree well with the simulation data, the response of this filter shows a greater than 25 dB attenuation at second and third harmonics. We found that due to the slow-wave effect, the center frequency of the BPF has been shifted to a lower frequency of about 15% corresponding to the original.