Intermodulation communication principle: Passive wireless sensor networks for internet-of-things

Intermodulation sensor concept is a solution for intelligent sensing: sensing is wireless and passive. It provides communication distances of several meters, high accuracy, and compliancy with the frequency regulations. The operation of the intermodulation sensor transponder is based on passive mixer diode loaded by a sensor resonator. We introduce the sensor concept, analyze the range of the system, and demonstrate wireless capacitance and voltage measurements.