A 25–75 GHz Broadband Gilbert-Cell Mixer Using 90-nm CMOS Technology

A compact and broadband 25-75-GHz fully integrated double-balance Gilbert-cell mixer using 90-nm standard mixed-signal/radio frequency (RF) CMOS technology is presented in this letter. A broadband matching network, LC ladder, for Gilbert-cell mixer transconductance stage design is introduced to achieve the flatness of conversion gain and good RF port impedance match over broad bandwidth. This Gilbert-cell mixer exhibits 3plusmn2dB measured conversion gain (to 50-Omega load) from 25 to 75GHz with a compact chip size of 0.30mm². The OP_{1 dB} of the mixer is 1dBm and -4dBm at 40 and 60GHz, respectively. To the best of our knowledge, this monolithic microwave integrated circuit is the highest frequency CMOS Gilbert-cell mixer to date