利用开放谐振腔在68.5GHz精密测量电介质参数

The Accurate Measurement of Dielectric Parameters at 68.5 GHz Using an Open Resonator

本文介绍了一个工作在68.5 GHz、以开放谐振腔为核心的电介质参数测试系统。其工作原理是,以锯齿波对4mm速调管进行扫频,1.25cm体效应管振荡器的注入锁定信号作为本振;改变腔长使开放腔谐振于68.5 GHz;检测从三次谐波混频器输出的中频信号得开放腔的谐振曲线。作者利用这个系统测量了聚四氟乙烯、石英玻璃和TPX等材料的介电常数ε_r,和损耗角正切tan δ;分析表明,系统的ε_r和tan δ测量精度分别为10^(-3)和10^(-5)量级。

For measuring dielectric parameters at 68.5 GHz, an open resonator measurement system has been constructed. The system employs a frequency-sweeping as its source, and the signal is detected through a triple-frequency harmonic mixer together with a centimeter wave band phase-locked source. Using this system, measurements have been made for teflon, fused silica and TPX. The analysis shows that the measurement errors of dielectric constant εr and loss tangent tan δ are 10-3 and 10-5 in order of magnitude, respectively.