基于PSO的多级反馈放大器的设计与仿真

采用粒子群优化算法,在高电压增益、低输出电阻的要求下,选择电压增益与输出电阻的比作为适应度函数,对两级直接耦合负反馈放大电路电阻的参数进行优化设计.对结果的电阻值经EWB软件仿真,闭环电压增益与优化理论计算的平均误差为1.65%,说明理论的正确性.优化结果显示,输出电阻总是趋于设定值的底限,以使适应度函数为最大,符合算法的要求.同时根据对放大器指标的不同需求,可以改变适应度函数,找到的最好效果.

Designing and simulatingmultistage feedback amplifier based on PSO

The parameters of resistances in two levels direct coupled negative feedback amplifying circuit are optimized by particle swarm optimization with the requirements of highvoltage gain and low output resistance, the ratio of voltage gain and output resistance is chosen as fitness function of algorithm. The optimal results of resistance are simulated by EWB, the average relative error between close loop voltage gain and theory value is 1.65%, the result indicate that the theory is correct. The optimal results also indicated that the output resistance always tends to the set value and make the fitness function is the maximum, this state consistent with the requirements of the algorithm. In addition, the best result can be found with changing of fitness function according to the different needs of the amplifier index.