中文摘要：

针对目前声表面波（SAW）传感器检测电路的缺点，通过对SAW传感器信号的特征分析，设计了一种简单实用的SAW传感器检测电路，降低了硬件成本。该电路利用直接数字频率合成技术产生不同的频率信号，用以激励不同谐振频率的声表面波敏感元件，在间歇收发周期从SAW传感器输出信号中提取出反映被测量的频率信号，通过对该频率的测量得到被测物理量的变化。通过对SAW传感器的温度实验，获得了传感器的温度一频率特性，在较低频率（20MHz）时检测灵敏度可达1．36kHz／℃，具有较好的一致性；在较高频率（75MHz）时检测灵敏度可达2．03kHz／℃，存在一定偏差。

英文摘要：

Aiming at the shortcoming of the present SAW sensor testing circuits, a simple and practical SAW sensor test circuit which saves hardware cost was designed by analyzing the features of the SAW sensor signals. In this circuit, the different frequency signals were produced by direct digital synthesis technology, and were applied to excite SAW sensors with different resonance frequencies. At the intermittent cycle, the frequency signal which reflects the measurement was extracted from the output signal of SAW sensor, and the change of the measured physical quantity was obtained by testing this frequency. The temperature-frequency characteristic was concluded by the SAW sensor temperature experiment. The test sensitivity is 1.36 kHz/℃ at the lower frequency （20 MHz）, and the circuit has the better consistency. The test sensitivity is 2.03 kHz/℃ at the higher frequency （75 MHz）, and the circuit has a little warp.