A Wideband Wearable Antenna Based on Metasurface

This paper presents a design of a wideband antenna based on metasurface for wearable applications. The operating band of the proposed antenna can cover the industrial, scientific, and medical (ISM) 2.45 GHz band, and the resonant frequencies can be tuned simply by adjusting the dispersion curve of the metasurface through the calculation of a single unit cell. In this design, the metasurface consists of a 3×3 array of unit cells, which are fed by a printed coplanar waveguide (CPW) monopole antenna. By modeling the metasurface as a two dimensional composite right/left-handed transmission line (CRLH TL), the negative modes can be excited in this design, which can miniaturize the dimension of the antenna significantly. Then two negative modes are combined to extend the working band. The footprint of the proposed antenna is 50.6×43.5 mm2 (0.14λ02), and the impedance matching band ranges from 2.2 GHz to 2.65 GHz, with a fractional bandwidth of 18.3%. The maximum gain is 4.35 dBi and 2.57 dBi in free space and on the human body, respectively. This design provides a new approach to realize wideband miniaturized antennas for wearable applications.