Finger effect on 60 GHz user device antennas

In this paper, the loading effect and far-field pattern degradation caused by a finger is studied for antennas that can be considered for future user devices operating at 60 GHz. It is found that if a finger is located closer than 2 mm to the antenna, the antenna matching is severely detuned and the antenna radiation efficiency is degraded. For patch and dipole antennas, the far-field radiation behind the finger is attenuated by 10-24 dB with the finger 10 mm from the antenna, and up to 18-25 dB for finger distance of 3 mm. For a 2×2 patch array, the attenuation is slightly higher at 12-25 dB with the finger distance of 10 mm, increasing to 25-34 dB with the finger distance of 3 mm. If the array is beam-steered when the finger is close to the antenna, it is shown that the broadside gain can be improved by directing the beam towards the sides of the finger.