A New Sub-harmonic Mixer Using Switched Gm Technique For 802.11a/b/g Dual-Band Receivers

A new prototype of sub-harmonic mixer using switched Gm technique is designed and implemented in a standard 0.18um CMOS technology. By using the PMOS active load and a switched Gm prototype at LO port, the new sub-harmonic mixer can achieve high conversion power gain and still maintain high linearity, and we can alleviate the shortage of the voltage headroom at IF output. In addition, it consumes no DC power while there is no LO input. At 5.2-GHz ISM band, this fully integrated sub-harmonic mixer achieves measured high conversion power gain of 12.8dB, -1.8dBm input third order intercept point (IIP3), and 14.0dB noise figure at 10-MHz with 4dBm LO power.