A 500-mW high-efficiency Si MOS MMIC amplifier for 900-MHz-band use

A 500-mW monolithic-microwave integrated-circuit (MMIC) amplifier using a 0 .6-mu m Si MOSFET for 900-MHz-band use has been developed. The input matchi ng network, which consists of a spiral inductor and an MOS capacitor, was i ntegrated onto the chip using a low-cost mass-production large-scale-integr ation process. A new spiral-inductor model, taking into account the dielect ric loss and skin effect of the Si substrate, was introduced. We analyzed t he stability and gain dependence on the gate structure of the MOSFET and op timized the gate finger length and the loss of the matching network to achi eve high gain and stability. The fabricated MMIC amplifier achieved a linea r gain of 15.2 dB and an output power of 27.1 dBm,vith a PAE of 60% under a supply voltage of 4.8 V.