Millimeter Wave Wearable Modified Yagi Antenna

A miniaturized wideband millimeter-wave (mm-wave) modified Yagi antenna is investigated for off-body communications of wearable devices. The proposed antenna is based on the principle of Yagi antenna due to the merit properties of wide operating bandwidth, simple structure and good directivity. In the structure of the antenna, a microstrip patch antenna (MPA) is employed as driven element because of its directionality. Five disks acting as the director are stacked above the MPA, achieving high gain and intense directivity. Moreover, the antenna has a complete ground as a reflector, and occupies the dimensions of 3.24 mm ×2 mm ×3.5 mm. The simulation results reveal that the proposed antenna yields an impedance bandwidth of 18% (57.58-68.97 GHz), the realized gain varies from 10 dBi to 10.9 dBi in the mm-wave band of 57.99-68.23 GHz and half-power beamwidth is 52.9° at 60 GHz as the antenna is attached to the human phantom.