Efficient Rf Switching Class E Power Amplifier

The Class E power amplifier is well-known switching-mode power amplifier topology that has demonstrated high efficiency at microwave frequencies.In this thesis, the principles and design methodology of the Class E amplifier have been analyzed in detail. The main contents of the dissertation are listed as follows:First, the design procedure of classic Class E power amplifiers is proposed, and two practical transmission-line amplifiers using GaAs and GaN transistor are built. Both amplifiers operate at 2.14GHz. The GaAs Class E amplifier achieves drain efficiency of 66.93%, exhibits 10dB power gain, 37dBm output power when operated from a 10.2V supply voltage. The GaN inverse Class E amplifier obtains drain efficiency of 70.2%, exhibits 11dB power gain, 40.45dBm output power when the supply voltage is 23V.Secondly, comprehensive theoretical analysis and design methodology of inverse Class E amplifiers with finite DC blocking capacitance is presented. The proposed amplifier not only offers 100% efficiency in theory, but also brings in some improvements, such as lower peak switching voltage and higher power output capability. The amplifier obtaining an output power 40.07dBm at 155MHz with drain efficiency of 83.87% and power-added efficiency of 82.57% is also presented.The final contribution of this work is the analysis of operation about a modified inverse class E power amplifier. The proposed amplifier, which has a series tunable parallel resonant tank, is similar to a hybrid of class F and inverse class E. The principles and design equations required to determine the optimum operation of the amplifier are analyzed in detail. The practical circuit is shown to be able to deliver 40.02dBm outpout power at 155MHz. The amplifier achieves PAE of 78.18% and drain efficiency of 78.42% and exhibits 25.02dB power gain when operates from a 21V supply voltage. Comparisons of simulated and measured results are given with good agreement.