Extra high efficiency power amplifier for satellite and mobile communication system

Abstract

Three newly developed methods are derived in this thesis to design the class E amplifier and simulate its output performance. These three methods include The Alternor Method, The Analytical Method with zero Ron and The Modified Analytical Method with non-zero Ron. For the alternor technique method, it can fast simulate the output performance of the class E amplifier accurately. Non-zero Ron is integrated in the alternor model which can match the practical consideration. The collector efficiency and power loss of the amplifier can then be evaluated accurately. Secondly, an analytical method is developed to design the class E amplifier to obtain the desired output performance. The finite DC choke inductor is used in this method, so an inductive compensation technique can be obtained to extend the operation frequency of the amplifier. Some important characteristics of the class E amplifier, such as maximum available output power, maximum and minimum shunt capacitance, maximum operation frequency are also obtained based on the analytical method. Thirdly, the analytical method is modified by the use of non-zero ON resistance in the class E amplifier. This modified analytical method can also be used to evaluate the required circuit components to achieve the desired performance. With the use of non-zero ON resistance, the output power, power loss and collector efficiency of the designed class E amplifier can also be predicted very accurately. Finally, a 100 kHz class E amplifier is designed and constructed. A good agreement between the experimental and theoretical waveforms of the circuit parameters in the class E amplifier is obtained. In addition, a high power 5 W and high frequency 406 MHz class E amplifier was designed and constructed by the proposed method. The collector efficiency of the amplifier can reach 93%, which have also an excellent agreement with the predicted one.