Reconfigurable amplifier with tunable impedance matching networks based on CMOS-MEMS capacitors in 0.18-µm CMOS technology

An integrated RF microelectromechanical systems (MEMS) tunable impedance matching network is presented for use in CMOS adaptive amplifiers. The matching network is based on high quality factor (Q) parallel-plate MEMS tunable capacitors implemented by standard 0.18-µm CMOS technology. A reconfigurable amplifier for WLAN applications operating at 5.2 GHz is designed and implemented. The amplifier achieves maximum power gain under variable load and source impedance conditions. The amplifier has a measured gain of 14.3 dB and a noise figure of 2.3 dB at 5.4 GHz and consumes 26 mW dc power. To our knowledge this is the first single-chip implementation of a reconfigurable amplifier using high-Q MEMS parallel-plate capacitors.