Miniaturized UWB bandpass filter using hybrid techniques

This work presents a novel compact Ultra-wideband (UWB) band-pass filter (BPF) based on a hybrid technique using a short-circuited stub and a DGS (Defected Ground Structure) transition. The proposed bandpass filter characterizes by a compact size of 22 X 16.5 mm2, and it is mounted on a FR-4 substrate with a thickness of 0.8 mm. A study of the electrical equivalent circuit of the proposed BPF was carried out. Simulation results show a bandwidth range from 4 up to 17 GHz with a return loss of more than 12 dB, insertion loss of less than 2 dB, and a group delay of about 0.25ns.