A prototype burst transceiver for SAW sensors interrogation

This paper describes a burst transceiver that can be used to power, interrogate and receive response from a wireless passive surface acoustic wave (SAW) sensing system. Since sensors have to measure parameters like temperature, pressure, chemical concentration, gas concentration etc., in inhospitable or inaccessible environments, it is important to establish communication with the sensor for deriving information about the parameter being sensed. The system architecture described in this paper is capable of transmitting a burst energy, receiving the RF sensor response, quadrature down converting the received RF signal, digitizing and collecting the data for processing. First, a brief introduction to a passive SAW wireless sensing system is provided after which the general design requirements for a wireless burst transceiver will be discussed. The sections that follow briefly describe the prototype transmitter and receiver architecture. Finally, the results obtained from the burst transceiver in terms of the cascaded gain and noise figure and signal power levels in the various components are presented.