Abstract: The subject of the present invention is a set of SAW (surface acoustic wave) based sensor tag device embodiments system for remotely sensing and/or providing identification information. These sensor/tag devices would operate in a system which consists of one or more uniquely identifiable sensor/tag devices and a wireless interrogator. The sensor device incorporates an antenna for receiving incident RF energy and re-radiating the tag identification number and the sensor measured parameter(s). Since there is no power source in or connected to the sensor, it is a passive sensor. As such the device is elegantly simple, low-cost, and rugged. The device is wirelessly interrogated by the interrogator which is described elsewhere.