Passive Wireless Platform for Resistive Sensors
Gonçalo Martins, Nuno Borges Carvalho · 2025
This article presents a versatile passive harmonic platform for resistive sensors. In contrast to the chipless sensing harmonic transponders documented in scientific literature, which are typically designed for specific single purpose applications such as humidity or temperature sensing, this research demonstrates greater flexibility by supporting a wide range of sensors. The platform is capable of monitoring a variety of physical parameters, provided that they can be expressed as a change in resistance. Such applications include, but are not limited to, temperature, light intensity, gas concentration, weight, and other measurable phenomena. The system is based on the second harmonic generated by nonlinear devices, transmitting data by varying the output signal strength in response to a variable load within the [0.2–10] kΩ range. Using a -100 dBm minimum sensitivity radio and transmitting at 30 dBm on a 2.45 GHz fundamental frequency, the system achieves a coverage of 1.5 meters.