Compact coplanar waveguide low-pass filter using a novel electromagnetic bandgap structure

In the present paper, a new electromagnetic bandgap (EBG) structure is proposed to design and fabricate low-pass filters on coplanar waveguide (CPW). Using the novel EBG structure, the filter prototypes exhibit sharp cutoff and low insertion loss in the passband. An equivalent lumped L-C circuit mode is introduced to describe the proposed EBG structure, which manifests an elliptic-function low-pass frequency response. Using only three units of this novel EBG cell, a compact low-pass filter device has been fabricated, which achieved sharp cutoff and deep attenuation levels on the stop band. The measured results showed consistency with the simulation using the method of momentum (MoM).