Maximization of measurement sensitivity and reading range of passive RF sensors from complex impedance optimization

This paper reports a method to improve the performances of passive Radiofrequency sensors in terms of reading range and measurement sensitivity. More specifically the impedance profile of the sensing device that maximizes the measurement sensitivity and reading range is derived. This profile allows predicting the largest achievable reading range and the highest measurement sensitivity that can be achieved by a given sensor antenna. The proposed original method is illustrated through the design of a wireless and passive temperature sensor. Experimental results are reported for validation purposes.