Leakage suppression in stripline circuits using a 2-D photonic bandgap lattice

A novel method for suppressing leakage due to parallel-plate mode in stripline circuits using a uni-planar compact 2-D PBG lattice is proposed and demonstrated. The leakage is suppressed by the stopband of the PBG lattice, which is easily etched in the ground planes with standard planar process. Good agreements between simulation and measurement results verify the effectiveness of this novel concept which suppresses leakage coupling by over 30 dB in the PBG stopband.