Precision active filters at microwave frequencies implemented using Gallium Arsenide (GaAs) MESET technology offer the potential advantages'of tunable reg.wnse, small size and low weight, Realisation here is based on a transconductor-C network, where the GaAs MESFET transconductor has effective tuning by adjustment of the tail current in a differential pair. with appropriate cascoding and level-shifting techniques and Q-factor adjustment using a novel linear voltagecontrolled resistor circuit. Simulation of a 2nd order Q = 10 bandpass filter verifies filtering at 1 GHz.