A novel dual-plane compact electromagnetic band-gap (DPC-EBG) filter design

A novel dual-plane compact electromagnetic band-gap (DPC-EBG) microstrip structure that exhibits an ultra-wide bandwidth with high attenuation within the stopband and an excellent transmission in the passband is proposed. In this DPC-EBG structure, two conventional single-plane EBG structures with identical center frequency are superposed in order to achieve a compact dual-plane configuration. With the dual-plane arrangement, the longitudinal electromagnetic field is varied significantly and the stopband introduced by the structure can be enhanced within a small physical size. Chebyshev distribution from the low side lobe array theory is adopted to taper the dimension of circles in the ground plane. This lowers the ripple level in the passband, therefore optimizing the structure design. Multilayer substrate or via holes are not required in this novel DPC-EBG structure thus favoring fabrication. Experimental results display a passband with low ripple level and an ultra-wide stopband with high attenuation, as predicted by the method-of-moments (MOM)-based simulation result. This DPC-EBG structure is a promising structure that can find wide applications for compact and high-performance circuit components in microwave circuits.