基于声表面波传感器的新型频率测量法的研究

Study on a new method of frequency measurement based on SAW sensor

传统的频率测量方法不足之处较多,即使用单一测频法在频率的上下限处测量的误差较大。在此设计了一种新型测频法及其测量电路。即利用声表面波带通滤波器对被测频率进行预选,高于中界频率的信号用测频法,低于中界频率的信号用侧周法,试验结果表明新型测频法的硬件电路在辅以高速数字器件后,系统测量精度比传统测频法有相对提高,具有在各个行业推广应用的价值。

The shortcomings of the traditional frequency measuring methods are discussed in this paper. A new method of frequency measurement based on SAW sensor and a measuring circuit are designed. The frequency is preselected by SAW bandpass filter. The signal which is higher than intermediate frequency is measured by the method of frequency measurement and period measurement for others. The hardware circuit is composed of high speed digital devices. The system has high accuracy and is worth to spread.