Wideband mixer exploiting gm and gm" compensation technique

A novel wideband down-conversion mixer is proposed for multi-standard wireless applications between 100 MHz and 2.5 GHz. A transconductance stage with two pairs of compensatory transistors is adopted for high linearity. Differing from the ordinary differential multi-gated transistor technique utilised in Gilbert mixer, the design proposed concerns about both g(m)'' and g(m) compensation of the transconductance stage in order to improve both input-referred third-order intercept point (IIP3) and 1 dB gain compression point (CP1 (dB)). Realising in Taiwan Semiconductor Manufacturing Company (TSMC) 180 nm RF CMOS process, the mixer provides a gain of 8.9 dB, a maximum IIP3 of 5.8 dBm, a maximum CP1 dB of -4 dBm and a minimum noise figure (NF) of 9.6 dB.