微波谐振腔谐振频率实时测量系统的实现

The Realization of Real-Time Measurement System for the Resonant Frequency of Microwave Cavity

微波谐振腔具有很高的品质因数,因而灵敏度很高;谐振频率是谐振腔最重要的参数,通过对谐振腔谐振频率的测量是目前为止最快速、最有效的湿度测量方法。本文提出了一种对单端开口同轴微波谐振腔的谐振频率测量方法,并设计了系统的具体实现。通过实时检测谐振腔耦合出来的输出功率的最大值,测量在该最大值点对应的频率值,从而快速得到谐振频率的大小。实验证明,该系统具有高灵敏性和高精确度,适合工业的在线应用。

Microwave cavity has very high quality factor, which results in its high sensitivity. Moreover, as resonant frequency is one of the most important characteristic parameter for microwave cavity, how to realize resonant frequency measurement successfully becomes the most effective method of moisture determination nowadays. A cylindrical coaxial cavity based on method for resonant frequency measurement is presented and the measuring system is designed. By detecting the maximum output microwave power coupling from the cavity in real time, following measure the frequency corresponding to the maximum power, then we can get the resonant frequency quickly and effectively. Practical experiment validate this system has excellent performance which is suitable for industrial on-line application.