Enhancing the readout of passive wireless sensors by using left-handed metamaterials

Inductor-capacitor passive wireless sensors have been used in situations where wired connections are impossible. When this scheme is applied to implanted or sealed fields, the sensors are required to be scaled down to small dimensions, which results in the limited remote distance. Here we present an approach to enhance the remote readout distance of the inductor-capacitor sensors by a left-handed metamaterial. The left-handed metamaterial is an artificial planar array of double-side spirals which has a wide spectrum range of negative effective permeability to enhanced the magnetic field in the readout system. The model of left-handed metamaterial is simulated in ADS software and used to enhance the readout of the inductor-capacitor passive wireless sensor, and the results are compared with those enhanced by a resonant repeater. The results indicate that this approach with the left-handed metamaterial enables a longer detection range and broader applications in the implanted or sealed fields.