A CMOS transconductor for multi-mode application is presented. The transconductor includes a voltage-to-current converter and a current multiplier. Voltage-to-current conversion employs linear region MOS transistors, and the conversion features high linearity over a wide input swing range. The current multiplier, which operates in the weak inversion region, provides a wide transconductance tuning range without degrading the linearity. The transconductor was designed and fabricated in the TSMC 0.18-µm CMOS process. The results show the transconductance tuning ratio of 23 and the IM3 performance of −68.5dB.