Input-Reflectionless MMIC Bandpass Filter With High-Selectivity Based on GaAs IPD Technology

An input-reflectionless monolithic microwave integrated circuit (MMIC) bandpass filter (BPF) with high-selectivity using gallium arsenide (GaAs) integrated passive device (IPD) technology is proposed, which consists of bandstop section and bandpass section. Multiple transmission zeros can be obtained from capacitor and inductor in the bandpass section. The bandstop section is loaded at the input-port of the filter to realize the absorption of the reflected signal and improve the frequency selectivity and out-of-band suppression. A prototype centered at 1.94 GHz with the 3-dB fractional bandwidth of 59.4% is designed for demonstration, which exhibits excellent frequency selectivity and the minimum insertion loss of 1.9 dB.