A linear tunable transconductor is designed with the use of linear COMposite n-channel MOSFETs (COMFETs) and CMOS COMposite FETs as basic cells. With crosscoupling, a differential linear relation is achieved with a THD at 1 kHz of 0.776% for a differential voltage of ±4V. The design of the transconductor demonstrates that COMFET devices can be successfully used as standard cells in modulator analogue VLSI circuits. The transconductor performance at subthreshold is also discussed.