Low‐loss and highly‐selective differential bandpass filter on integrated passive device process

Abstract

AbstractThis letter presents a low‐loss and highly‐selective differential bandpass filter (BPF) with high common‐mode rejection ratio (CMRR). The presented integrated passive device process provides high quality lumped elements, and therefore a low insertion loss of the BPF can be obtained. The circuit also uses series‐shunt resonators for controlling its differential‐ and common‐mode transmission zeros. Moreover, with a proper choice of circuit component values, a high common‐mode rejection can be controlled at a specific frequency without alternating properties of the filter. The chip area of the filter is 3.74 mm2 including all testing pads. Additionally, the differential BPF achieves a 1.5‐dB insertion loss and 11‐dB return loss with a 73% 3‐dB bandwidth at 2.2 GHz. Finally, the peak CMRR at the frequency of interest is up to 50 dB.