A Resistance-Type Sensor Based on Chipless RFID

This paper presents a novel resistance-type sensor based on chipless radio-frequency identification. It consists of a scatterer and the resistor to be detected. The scatterer is designed to be V-shaped. The angle θ between two arms is used to encode the address data of sensor. The resistor to be detected is loaded in the middle of the two V-shaped arms. The sensor is excited by the plane wave. By measuring the scattered fields in two orthogonal polarization directions, the angle θ and the value of resistor can be identified. Compared with the normal resistancetype sensor, the novel sensor can transform the resistance value and its address into the wireless signal which can be received directly by the reader. Another advantage of angle-based sensor is that every element can encode multibit data. This is helpful to achieve higher capacity. Also, for different codes of one element, the proposed sensor uses the same spectrum. This is beneficial to improve the efficiency of the spectrum. The realized sensor has the identification errors less than 3° in the angle and less than 1.5 Ω in the resistance value.