A double‐balanced subharmonic passive mixer with an integrated quadrature local oscillator in 0.18 μm CMOS

Abstract

This letter presents a double‐balanced subharmonic passive mixer designed in a 0.18 μm CMOS technology.The biasing condition of the passive mixer is analyzed to optimize its conversion loss and local oscillator (LO) to RF/IF leakage performances. The four phases required for the mixer were generated using an on‐chip LO and a divide‐by‐two circuit. The mixer converts an RF signal ranging from 3.5 to 6.7 GHz to an IF signal using an LO of 2.5 GHz with a voltage conversion loss of 7.2 ± 1.5 dB. The measured 1 × LO and 2 × LO leakages to the RF/IF port are −25/−60 dBm and −35/−65 dBm, respectively. The measured input third‐order intercept point (IIP3) of the mixer is −2 dBm. The circuit operates from a 1.8 V supply and consumes 45 mW of power. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2617–2619, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27156