| With the enhancement of optimization algorithm level swarm intelligence algorithm has been widely used and researched in optimization design field.Power amplifier is an important component of communication system,which affects the power,efficiency and linearity of the whole system.The optimal design of the traditional power amplifier usually optimizes the input and output matching circuit,but the performance of the matching circuit cannot fully characterize the performance of the power amplifier.Therefore,the overall optimization of power amplifier through optimization algorithm becomes another feasible solution.Based on the improvement of the traditional particle swarm optimization algorithm,a collaborative optimization method combining optimization algorithm and simulation software is proposed in this thesis.The objective function is determined by power and efficiency,and the overall optimization of power amplifier is carried out.The main research works are as follows:1.In order to improve the optimization effect of power amplifiers,improvements have been made to the traditional particle swarm optimization algorithm.Firstly,considering the problem of the algorithm easily falling into local optima,a simulated annealing strategy was introduced to improve the algorithm’s global search ability.Secondly,to avoid the inflexibility caused by fixed weights,sine adaptive weights are introduced,because of which,this algorithm has a good ability to solve multidimensional complex optimization problems.Then,adaptive mutation strategy and conflict improvement method are used to improve the diversity of the algorithm.Finally,the convergence performance of the improved algorithm was verified through testing functions.2.In order to meet the design requirements of high efficiency power amplifier,a collaborative simulation optimization method combining improved particle swarm optimization algorithm and Advanced Design System(ADS)simulation software is proposed.The entire power amplifier is treated as a black box,and its performance indicators are optimized to achieve automatic design of power amplifiers.First,the ADS simulation software is called by the optimization algorithm through the interface function for the overall simulation of the power amplifier,and its power and efficiency are obtained for the calculation of the objective function.Then,based on individual fitness,the particle swarm optimization algorithm which has been improved is used to generate the next generation of population and conduct individual evaluation until the optimization goal is achieved.In order to verify the above method,the power amplifier with different single frequency points such as 0.5,1.5,2.2 and 3.5GHz was designed using class F amplifiers as the optimization object.The optimization results show that the saturated output power and efficiency of the above high efficiency power amplifier are higher than 40 d Bm and 80%,respectively.the improved optimal algorithm can solve the optimal design problem of efficient power amplifier better.Finally,a 1.5 GHz high efficiency power amplifier is selected for processing and testing verification.The results show that the optimized design of the power amplifier has an output power of 41 d Bm at saturation and a maximum efficiency of 80%,proving the correctness of the proposed method.3.In order to improve the success rate of wideband power amplifier optimization,an objective function strategy based on piecewise function is introduced into the proposed power amplifier cosimulation optimization method.The objective function strategy used uses different objective function calculation formulas based on the different ratio of power amplifier efficiency/power to target efficiency/power during the optimization process.Based on this,an optimization design process for broadband power amplifiers is proposed and applied to the optimization design of 0.5-4.3 GHz broadband high efficiency power amplifiers.The test results show that after optimization process,high efficiency broadband power amplifier has an output power of 40-42 d Bm at saturation and a corresponding efficiency of 60.8-68.8% over the entire operating bandwidth(relative bandwidth of 158%).In order to further expand the application of collaborative simulation optimization methods,an objective function strategy for Doherty power amplifier optimization was proposed to optimize performance indicators such as saturation power and backoff efficiency.The optimization simulation results show that the optimized 1.65-2.85 GHz broadband Doherty power amplifier has a saturation power of 42.6-44.5 d Bm,of Efficiency about54-65% at saturation,and of efficiency about 50-60% at 6 d B back-off.The optimization method used improves the overall performance of the Doherty power amplifier. |
PDF Full Text Request