Switchable CPW-Based Band-Pass Filter into Band-Stop Filter for Broadband RF Applications

In this paper, a coplanar waveguide (CPW)-based BPF and a BSF is designed for RF applications. The BPF is designed utilizing series open-ended stubs within CPW structure. A short stub is inserted between the gap of the open-ended stubs to transform the BPF into a BSF. The CPW structure is integrated with ECE-shaped DGS resonators. Simulations and parametric analysis are carried out using the HFSS tool. The BPF demonstrates an insertion loss of −4 dB, with the filters achieving a center frequency of 21 GHz and a return loss of just −0.04 dB. The resulting bandwidth of the filter is 19 GHz. Additionally, the lower passband insertion loss remains below −4 dB. This design is compatible with K-band (13–28 GHz) applications.