Research On Rf Power Amplifier Design Technique And Fast EM-based Optimization Method

A radio frequency power amplifier?RF PA?is one of the critical modules of wireless transmitters,which directly determines the performance of wireless communication systems.In order to reduce the power dissipation of wireless communication systems and the requirements of cooling equipments,various efficiency boosting strategies have been proposed,such as Class-E,Class-F and inverse Class-F(Class-F^-1)PAs.However,the parasitic effects of the transistor and other non-ideal factors will bring great difficulties to the implementation of impedance matching with frequency increasing,thus bringing new challenges to the design of high efficiency PAs.On the other hand,during the process of designing PAs,the performance of the layout is usually lower than design specifications,which is influenced by parasitic and coupling effects of actual interconnections and devices.Therefore,the layout optimization of RF PAs becomes an indispensable step.However,the traditional electromagnetic?EM?simulation is more time-consuming and consumes a lot of CPU resources.In this dissertation,the hot issues of design methods of high-efficiency PAs and fast EM-based optimization methods of RF PAs are researched,and the main creative works of this dissertation include the following two aspects:1.In terms of the problem that the parasitic-compensation circuits and fundamental matching circuits become complicated caused by parasitic effects of transistors,the corresponding output matching circuit is proposed for Class-F^-1 and Class-E PAs respectively,which not only compensates parasitics of the fundamental wave and sub-harmonics,but also avoids separate designs of the parasitic-compensation circuits and fundamental matching circuits,greatly simplifying the design process and circuit structure.Based on the proposed method,the Class-F^-1 and Class-E PA operating at 2.5GHz are implemented respectively and achieve the maximum power added efficiency?PAE?of 79.8%and 80%separately,which proves the validity of the proposed method.2.In terms of the problem that traditional EM optimization is time consuming and CPU intensitive,this dissertation presents a fast EM-based optimization technique for RF PAs using single-point space mapping?SM?algorithm.Since the single-point SM algorithm requires neither a large amount of EM simulation as training data points nor additional device modeling of passive devices in the circuit,the proposed optimization method requires only several iterations to obtain optimal design parameters of the circuit.As an example,a 35-42 GHz MMIC PA has been designed and optimized to demonstrate the validity of this approach and all design specifications are satisfied after only two iterations.