A 9-50-GHz Gilbert-cell down-conversion mixer in 0.13-μm CMOS technology

A broadband microwave/millimeter-wave (MMW) Gilbert-cellmixer using standard 1P8M 0.13-μm complementary metal oxide semiconductor (CMOS) technology is presented in this letter. Two radio frequency (RF) transformer baluns are used in RF-and local oscillator (LO)-ports to convert single-ended signals to differential signals. Thin film microstrip line is employed for the matching networks and transformer design. This mixer has a conversion gain of better than 5dB from 9 to 50GHz. Between 5 and 50GHz,the RF- and LO-to-intermediate frequency (IF) isolations are better than 40dB. The RF-to-LO and LO-to-RF isolations are all better than 20dB. To the authors' knowledge, this is the first CMOS Gilbert-cell mixer operating to MMW frequency to date.