A three-port active circulator and an active quasicirculator (QC) based on bridged-T networks (BTNs) are designed and fabricated in a standard 0.18-?m CMOS technology. The BTN provides a notch frequency response, and therefore, the circulator is practical by connecting three BTNs in a ringtype configuration. With a power consumption of 18.2 mW, the circulator achieves 6.1?8-dB insertion loss, better than 25-dB isolation and 18.3-dB transmission ratio from 8.4 to 11.1 GHz.