A GaAs IPD Dual-Port Ultra-Wideband Quasi-Reflectionless Bandpass Filter with Compact Structure

In this paper, a compact dual-port ultra-wideband reflectionless bandpass filter (BPF) is implemented in gallium arsenide (GaAs)-based integrated passive device (IPD) technology. By integrating absorption resistors into conventional series/parallel resonators, a novel class of resonant structures with inherent out-of-band interference absorption capability is proposed. The reflectionless BPF architecture employs cascaded series/parallel absorptive stages, co-optimized through component value adjustment. Experimental results confirm exceptional dual-port performance: 10-dB reflectionless range across 0–6 octaves and over 20 dB stopband rejection, validating the effectiveness of the proposed absorptive stages methodology in the reflectionless BPF design.