Single chip readout electronics for SAW based gas sensor systems

This paper presents readout circuitry for surface acoustic wave (SAW) sensors based on a single chip Actel Microsemi Field Programmable Gate Array (FPGA). It measures the difference frequency output from SAW gas sensor in real time, processes the signal and transfers the data through serial port. The impulse noise filtering is done using median filtering method and the data is smoothed using moving averages technique. The peaks, resulting from detection of gases, are detected and announced. The circuitry can be used with any type of SAW sensor like gas sensor, temperature, pressure or humidity.