User effect on 60 GHz 4-port mobile terminal antenna

In this paper, the loading effect of the user finger when placed in the proximity of a planar 4-port antenna designed at 60 GHz is studied. The proposed array antenna operates in wideband mode from 53.3 to 65.8 GHz. The effect of user's finger is studied on four different locations on top of antenna elements, with six distances between antenna and user's finger. Losses due to the increased shadowing of the index finger are studied in terms of radiation efficiency (RE) and matching efficiency (ME). Minimum frequency shift is observed when the finger is placed at 1.5 mm distance from the antenna. A maximum RE loss of up to around 80 % is observed when the finger is placed at 0 mm from the antenna, as compared to the case without user (WU) which decreases RE to 10 % with the finger distance of 1.5 mm. Results also indicate that ME losses are insignificant regardless of the antenna and finger variations.