Wireless Sensing based on Variable Axial Ratio
Résumé
In this paper, we report a novel wireless technique to remotely interrogate passive sensors and wirelessly estimate a physical or chemical quantity of interest. The technique consists in making the axial ratio of the sensor antenna dependent on a complex impedance itself related to the physical quantity to be read. We numerically illustrate the principle with a single-port patch antenna loaded by a varying resistance. A constant axial ratio sensitivity of -0.2 dB/Ohm is obtained within the resistance range and we achieve a bijective axial ratio variation as a function of the loaded resistance.