Bandwidth Enhancement of Octagonal Patch Antenna Using Textile-Based MTM Structures for Smart Watch MM-wave Applications

This paper presents an enhancement of the operating bandwidth of textile-based smart watch printed antenna for millimeter wave (MM-Wave) applications. It enables the watch to capture the Wi-Fi signal without a connection with the mobile station. It is intended to provide bandwidth of 2 GHz or 4 GHz to equip with the standard 60 GHz Wi-Fi applications. Five different ground structures are implemented: conventional ground and four different ground with optimized etched Metamaterial (MTM) unit cell. Etched H shape, 4H, split ring resonator (SRR), and Jerusalem cross (JC) are configured. These structures are studied to investigate which one achieves the wider bandwidth for MM-wave applications. The antenna is implemented on leather textile material with a fixed dielectric constant of 1.87, loss tangent of 0.006 and thickness of 2 mm. The CST microwave studio is used for antenna design and optimization using FITD. It is found that the bandwidth is enhanced to 55.6\% with a minimum gain of 4.6 dBi.