In this letter, a highly linear wideband up-conversion differential CMOS micromixer with a linearized transconductor employing a third order intermodulation (IMD3) cancellation technique for a digital TV tuner IC is proposed and designed. It is fabricated in a 0.18 mu m CMOS process and draws 22 mA from a 1.8 V supply voltage. It shows it voltage gain of more than 6 dB, a noise figure lower than 11.9 dB, an IIP2 of more than 57 dBm, and an IIP3 of more than 18 dBm for the entire input band from 48 to 860 MHz.