Design of Novel Hairpin-DGS Microstrip Bandpass and Lowpass Filters Using Coupling Matrix Method

In this paper, we present a novel compact hairpin DGS bandpass and lowpass microstrip filter employing two hairpin U-slots etched in the ground plane. A compact microstrip BPF employing coupled DGS resonators is designed using coupling matrix method. The designed BPF showed very wide stopband with two transmission zeros. Then a simple technique to transform the designed BPF to a LPF was presented. The BPF was fabricated and measured. The measurement results showed good agreement with the theoretical and simulation results.