延迟线型无线SAW传感器的访问信号

分析了声表面波 (SAW)传感器无线测量时访问信号的宽度对回波及测量的影响。访问系统通过发射访问信号和接收回波并加以处理来获得测量信息。访问信号是一定宽度的高频脉冲 ,回波信号必然在两端存在过渡区。通过分析声表面波的激发和反射 ,给出了回波信号由多个反射差拍叠加的数学描述。计算了过渡区的宽度 ,提出了访问信号宽度必须大于过渡区的宽度并给出了确定公式 ,分析了访问信号的频率对回波信号的影响 ,给出了实测结果。该工作可以为无线声表面波传感器的设计和访问系统参数的确定提供理论依据

Interrogation signal of the wireless SAW sensor

The influence of the width of interrogation signal on echo and measurement was analyzed and the method to determine this parameter was presented. The information of surface acoustic wave (SAW) sensor is gained by interrogation unit emitting the RF interrogation signal and receiving the response signal (the echo). The interrogation signal is a limited burst, so there are both sides transitional parts in echo. The mathematics model of the echo signal is gained by analyzing SAW stimulation and reflection. The width of transitional part is calculated and the formula to determine the width of interrogation signal is presented. Besides the amplitude of echo, the frequency shift of interrogation signal affects the width of echo signal. These influences simulated are discussed. Experimental results with different widths of interrogation burst are presented. All work will provide the theoretical foundation for designing sensors and determining the interrogation unit parameters.