Narrow band Fabry-Perot based EBG bandpass filter

Narrow band Fabry-Perot (F-P) based electromagnetic bandgap (EBG) bandpass filter is designed, fabricated and measured. This narrow bandpass characteristic is due to the defect cavity formed in the bandgap structures by the insertion of a transmission line resonator in between the two bragg reflectors. The parametric analyses of the FP-EBG filter are investigated by considering; i) effect of EBG cells on Q factor and ii) change in the defect length and the slot dimension to influence the filter performance characteristics. The Fabry-Perot EBG filter is fabricated on silicon substrate using surface micromachining process. The measurement result of the F-P filter shows a 3dB bandwidth of around 250MHz with an insertion loss of 4dB.