Six‐Beam Pattern Reconfigurable Patch Antenna Based on Yagi‐Uda Principle for Wearable Applications

ABSTRACT A six‐beam pattern‐reconfigurable patch antenna for wearable Wireless Body Area Network (WBAN) applications is proposed. Based on the Yagi‐Uda principle, the antenna features an innovative structure with a regular hexagonal driven patch as the core and six symmetrically distributed parasitic patches as switchable units, breaking through the structural limitations of traditional Yagi‐Uda antennas and enabling a low‐profile, lightweight, and integrable design. By using PIN diodes to control the parasitic patches′ function switching between reflectors and directors, combined with the combinatorial coding control of the six units, precise beam steering in six discrete directions in the azimuthal plane is achieved. Compared with existing Yagi‐Uda‐based reconfigurable antennas, it offers more beams with simpler switching logic and no need for complex feeding networks. A physical prototype was fabricated and measured, with the measured results showing good agreement with simulations. The antenna demonstrates stable performance around 2.8 GHz, and its extremely low simulated specific absorption rate (SAR) values comply with international safety standards, confirming its viability and safety for wearable applications.