Efficiency Enhancement of CMOS Power Amplifier for RF Applications

Abstract

This paper presented a new structure for the CMOS power amplifiers as a more effective trend to amplify radio frequency (RF) signals compared to polar power amplifiers PA's by using envelope removal and restoration (EER) technique. Polar PA offers high-efficiency RF-modulated linear signal amplification. However, these amplifiers need high uniformity between the amplitude and phase of the modulated signals. The last translates promptly into higher energy consumption. Rather than deconstructing the quadrature signals into the combination of phase and amplitude signals, it is suggested that the CMOS quadrature power amplifier (QPA's) technique had been used to amplify RF signals immediately. The linearity, bandwidth, efficiency, and power consumption of the QPA's has been improved by separate amplitude and phase quadrature signals. The quadratic geometry architecture contains two bridges from modulated PA's that are able to treat negative or positive voltages, modulation, and RF-power bundling. The design of the new structure is compared with respect to parameters such as fundamental frequency, power gain, PAE, output power, technology or fabrication process, and number of stage transistors. Simulation results for PA's design using CMOS process show an effective quadrature model by a power-added-efficiency (PAE) of 78.413% at a maximum output power of 21.619dBm. The third intermodulation IDM3 is -49.2dBc at output power driven at frequency 2.4 GHz and input power greater than 20dBm. The amplitude and phase distortion has been obtained of 1.4 and 0.26 ᵒ/dB respectively at 50MHz of bandwidth for modulated signals.