Impact of Two-Handed Grip on Quasi-Omnidirectional Coverage of mm Wave 5G Handset

Abstract

In this study, we explore the impact of a two-handed grip on the coverage of a handset featuring three antenna arrays operating in the n257 frequency band of 26.5 GHz-29.5 GHz. We focus on beam steering, which is effectively implemented using the antenna arrays and multibit phase shifters to provide quasi-omnidirectional coverage. We investigate how different hand grips impact the handset's coverage region, including clockwise (CW) and anti-clockwise (ACW) rotation of the handset. Our findings reveal that, for the CW two-handed grip, beam steering significantly increased the coverage region (in which gain is greater than 0 dBi) from 19.7% to 42.2% of the spherical region surrounding the handset when 3-bit phase shifters are used for analogue beam steering. Similarly, for the ACW two-handed grip, coverage was increased from 10.2% to 36.9% with 3-bit beam steering. Cumulative distribution function (CDF) performance for effective isotropic radiated power (EIRP) is also considered for the handset in free space, along with both grip orientations. It is once again shown that beam steering offers a significant performance increase; however, it is also shown that introducing the user's hand grip degrades the performance. Additionally, this paper investigates the impact of varying the phase shifter resolution used to actuate beam steering on the coverage of the handset. We found that increasing the resolution increases the number of possible steering angles at each array, thereby increasing the percentage coverage of the handset. However, we also note that the relationship between resolution and coverage plateaus around 3 bits. Overall, our study highlights the importance of beam steering in improving coverage and signal strength for handsets operating in the n257 frequency band. By exploring the impact of different hand grips and phase shifter resolution, we provide valuable insights into designing future handsets that can better serve users in various settings.