微波谐振器无载品质因素的测量方法研究

A Method for Measuring Unloaded Q-factor of Microwave Resonator

提出了一种利用微波谐振器散射参数的幅度信息测量无载品质因素的方法。该方法认为在谐振点附近,耦合电路的参数和谐振器的参数相比可以忽略,因此采用简化的等效电路模型,利用谐振点附近的标量散射参数测量值来计算无载品质因素。为了消除散射参数曲线左右不对称所产生的影响,不采用散射曲线上独立的点来计算,而是采用带宽来计算。选取无载品质因素曲线平缓部分进行平均作为测量结果,测量精度接近临界点法。

A method is presented to calculate unloaded Q-factor of microwave resonator with only amplitude of scattering parameters. Compared with resonator parameters, couple-circuit parameters can be ignored when the measurement frequency is near the resonant point. So, simplified equivalent-circuit model is used to solve the problem with the scalar data around resonant point. To eliminate the influence of asymmetry of the scattering curve, the bandwidth is used instead of isolated point. The average value of the smooth part of the Q-factor is considered to be the final result. The result shows that it almost has the same precision as critical-points method.