Millimeter-Wave Dual-Band, Bidirectional Amplifier and Active Circulator in a CMOS SOI Process

This paper presents a reconfigurable dual Q- and W-band bidirectional amplifier and a V-band active circulator in a 45-nm CMOS silicon-on-insulator (SOI) technology. The circuits rely on reconfigurable feedback networks to manipulate the traveling wave along a transmission line. The dual Q- and W-band bidirectional amplifier operates at 40 and 81 GHz, with peak gain of more than 4.2 dB in all modes of operation. The V-band active circulator is reconfigurable to operate in four different modes of operation: clockwise, counter-clockwise, quasi-circulation, and as a thru between port 1 and port 2. The circulator is measured to have an insertion loss of 7.4 dB with isolation between any pair of isolated ports better than 18 dB from 62-75 GHz. The circuit technique proposed here can easily be adapted to operate at different millimeter-wave frequency bands.