Abstract: This paper presents a tunable transconductor (Gm) cell,which is based on dynamic source degeneration and cross coupling technique,and builds a 3rd order Gm-C filter to prove the validity of this Gm cell.Simulation results reveal that,the Gm cell owns a constant transconductance (V_pp) range of around 600 mV and the Gm -C filter has a tunable -3 dB cutoff frequency from 9 M Hz to 26.4 M Hz,equivalent input referred noise of 39 nV@10 M Hz,in-band IIP3 higher than 16 dBm and a total power consumption less than 1.7 mA over all variations of process corners,supply voltage and temperature.