Design of Microwave Sensor Based on Rectangular Double Split Ring Resonator for Water Quality Monitoring

A rectangular microstrip fed patch antenna with complementary DSRR is proposed as a preliminary work for water quality testing. Four different designs that varies in term of the locations and number of complementary DSRR are considered and the best design will be used for water quality testing in the future work. The performance of each design is compared based on its S11 parameter and Q-factor simulated by using commercial software. The simulated results show that the addition of complementary DSRR on the patch antenna has enhanced the return loss and Q-factor of the antenna. The sensitivity of design with best performance are investigated further in term of its resonance frequency shifting by introducing water sample in the simulator. Two sample placement configurations are considered in this work and it is found that the antenna has higher sensitivity when the sample under test cover the antenna completely. The simulated results show that the proposed antenna is capable of detecting the variation step of 0.5 dielectric constant at the range from 80 to 83 with sensitivity of 8 x106.