Development of a Chipless RFID Water Leakage Detecting Sensor Using Defected Ground Structure

In this paper, a fully printable low-cost chipless RFID water leakage detecting sensor is presented. The sensor comprises of 3 λ/4 stubs to encode identity information. Each λ/4 stub represents a single data bit, thus 3 bits of data can be stored. The integration of pipeline water leakage sensing is performed by utilizing the resonant frequency of a bullet-slot DGS attached with a sponge. If the water pipe leaks because of cracks or failure of socket joint, the sponge absorbs water and affects the resonate characteristic of DGS. And the identity information of the sensor is guaranteed by the natural ground of λ/4 stubs. Experiment results show that the sensor has a high sensitivity to water, and has the advantages of independent control of sensing information and identity information.