A 2.5 V CMOS differential active inductor with tunable L and Q for frequencies up to 5 GHz

A differential active inductor in CMOS-technology with a supply voltage of 2.5 V is presented. A self-resonant frequency of 5.6 GHz is achieved. The value of the inductance L can be controlled in the range from 10 nH up to 100 nH. The quality factor Q can be tuned independently of L to values as large as 600. The active inductor is realized with a differential gyrator. The gyrator transforms intrinsic capacitances of the MOSFETs to the emulated inductance.