Harmonic suppression of a bandpass filter using binomially distributed photonic bandgap structures

Binomially distributed photonic band gap (B-PBG) structures are applied to a 4-section asymmetric coupled line band pass filter (BPF) at 15 GHz for harmonics suppression. The frequency response of the BPF on B-PBG is compared with that for the same BPF on uniform PBGs (U-PBGs). It is seen that B-PBG structures provide complete harmonic suppression in both transmission and return loss responses. BPF on B-PBGs produces 18 dB more harmonics suppression with zero return loss at 15 GHz compared to those for the same BPF on UPBGs. The proposed B-PBG structure finds promising applications for complete harmonics suppression in filters and patch antennas and saves space and packaging cost in HMICs and MMICs.