Abstract
Today, with the growth of wireless technology, the endless demand is required for achieving low-cost, small-voltage, and high-integration wireless transceivers. It is necessary to use CMOS technologies for the purpose of system on a chip. However, it is still a great challenge to integrate high-efficiency and high-linearity power amplifiers with CMOS technologies. This thesis addresses the challenges of CMOS integrations and demonstrates a radio frequency (RF) class A power amplifiers for OFDM modulations using TSMC 0.18μm CMOS technology. A novel two-stage cascode common-source amplifier and a load-pull output matched power amplifier are designed for the WiMAX application of 2.5GHz transmitting frequency. The designed power amplifier exhibits 19.8dBm of 1-dB compression point, 24.1dBm of output power, 35% power-added-efficiency (PAE), and 23.3dB of power gain under 3.3V and 1.8V power supplies. The power consumption is about 827.34mW. A small chip size of 0.81x0.65 mm2 is achieved including all the matching networks. A predistorter CMOS power amplifier is also presented in this work. It is based on the class A configuration using diode-connected MOSFET as predistorter. The compensation topology extends P1dB to 11dBm and has a 15dBm improvement of IIP3. However, an undesired 8% power-added-efficiency decrease is observed.