基于同轴开槽的阻抗调谐器研究

Study on Impedance Tuner Based on Slotted Coaxial Line

在通信系统提高通信性能的研究中,现代大信号微波功率放大器的设计,广泛应用负载牵引测量法来优化源和负载,阻抗调谐器是负载牵引测量系统中必不可少的部分。通过同轴线开槽内插探针滑块结构的阻抗调谐器,优化通信质量,为提高带宽,建立了传输线等效模型来描述调谐器的工作原理,并用传输线网络理论进行了分析,验证了影响调谐器性能的主要参数。对800M～6GHz的阻抗调谐器进行了设计和仿真,利用HFSS的优化功能对调谐器优化后,得出了设计的详细尺寸。仿真结果显示,在频率范围内驻波比超过25,相应的反射系数超过0.89,证明设计的调谐器不仅满足带宽要求,而且在频带内阻抗调谐范围足够大。

In the design of large signal power amplifier,load pull measurement is used widely to optimize the load and source.Impedance Tuner is an indispensable part of load pull measurement systems.This paper presents an Impedance Tuner based on a slotted coaxial transmission-line with a probe in it.According to the physical structure of the Tuner,the paper establishes an equivalent transmission-line model to describe the Tuner ＇s working principle,analyzes the theory of the Tuner using transmission-line network theory and presents the main influence parameters to the Tuner.A 800M-6GHz Impedance Tuner has been designed and simulated.After the optimization design of the size using the optimization function of HFSS,the resulting design is detailed.The simulation data shows that the proposed design has a Voltage Standing Wave Ratio（VSWR） in excess of 25,and the corresponding reflection coefficients in excess of 0.89 over the bandwidth ranging from 800M to 6GHz.It shows that not only the Tuner designed satisfies the bandwidth requirements,but also the tuning range is large enough over the band.