Analysis of a new 33-58-GHz doubly balanced drain mixer in 90-nm CMOS technology

A new doubly balanced drain-pumped topology for CMOS passive mixer design is proposed in this paper. In the efforts to improve the conversion loss of passive balanced mixers, the CMOS drain-pumped topology is employed. In addition, the doubly balanced architecture with the advantages of good port-to-port isolations has been combined with the CMOS drain mixer design. For the broad bandwidth and the flatness of the conversion loss, a wideband matching technique using a broadband Marchand balun network is analyzed and successfully implemented in the mixer design. This mixer is fabricated in standard 90-nm CMOS technology. According to experiment results, the mixer has a measured conversion loss of 7.5 ± 1.5 dB from 33 to 58 GHz. Based on the double-balanced architecture, the local oscillator (LO)-to-RF and LO-to-IF isolations are better than 42.7 and 51.5 dB, respectively. The mixer consumes zero dc power with a compact size of 0.55 × 0.52 mm ². To the best of our knowledge, this paper presents the first CMOS drain mixer using doubly balanced topology.