计及特性阻抗不连续性的多频带多节变换器优化设计

摘要

A dual-band two-section and tri-band three-section impedance transformers are designed,in which the characteristic impedance discontinuities of the corresponding transmission line is involved.Based on the transmission line model and microstrip line theory,design equations of the proposed transformers are derived, and the effect of the microstrip "step" is included. By the method of genetic algorithm, the design parameters of the proposed transformers are obtained for the purely resistive source and load impedances, as well as the frequency-dependent source and load impedances, respectively. Finally, electromagnetic simulations of the microstrip circuit based on the above design parameters are implemented with the commercial software ADS,and the numerical examples prove the validity of the proposed design.%本文设计了计及特性阻抗不连续性的两频两节及三频三节变换器.基于理想传输线模型和微带传输线理论,建立了计及微带线“台阶”效应的设计方程,采用遗传算法实现优化设计,取得了在纯电阻源阻抗和负载阻抗以及随频率变化的源阻抗和负载阻抗两种情况下的两频两节及三频三节阻抗变换器设计参数.用ADS(Advanced Design System)商用软件对基于上述设计参数的微带电路进行电磁仿真的数值结果显示了该设计的有效性.