Design of RF amplifier with tunable active inductor

A RF amplifier with tunable active inductor for wideband wireless transceiver is proposed. The active inductor consists of a MOSFET and some resistances and capacitances, the relationship between the impedance of the active inductor and the value of the consisting elements is analyzed. In order to minimize the sensitivity to process variation and power supply variation, a centre-frequency tunable circuit and a supply-independent biasing circuit is designed. All the circuits are designed and fabricated using SMIC 0.18 ¿m CMOS technology, the measurement results show that the RF amplifier with the proposed active inductor works well, the requisite modulated RF signals can be obtained, the centre frequency of the circuit can be tunable between 0.5 G to 2 GHz, and its biasing circuit is robust even the supply variation is as high as 0.8 V.