Wave Digital Model of Edge Coupled Filter Based on Halfwave Coupled Resonator with Dumbbell-Shaped DGS

This research investigates the application of a halfwave coupled resonator employing dumbbell placed in the ground plane (DGS) that is used to design wideband filter. A type of microstrip bandpass filter (BPF) based on edge coupled DGS resonators is designed using Chebyshev approximation. By using admittance inverters, a wave digital model of microstrip bandpass filter with only one kind of resonator can be generated more conveniently. In order to validate the theoretical predictions and simulated results, a fifth order BPF is fabricated and experimentally verified. The measured and wave-based results have shown a good agreement.