Re-configurable Completely Unpowered Wireless Sensors

A methodology for remotely and wirelessly reading any type of unpowered impedance varying sensor is described. Unpowered wireless sensors, in existence for a number of years, have been limited to low impedance sensors. Techniques for reading high impedance sensors are introduced here. The resulting methodology can be used to measure a wide range of different sensors, including temperature, pressure, light level, mechanical switch, acoustic emission, and acceleration. These sensors report physically measurable data in the same manner as do similar conventional sensors, but they do it remotely and without any local power source. The sensors are measured remotely using a radar-like interrogation device, and the sensors and their related communication electronics draw all of the power needed for communicating from the radar pulse.