Quasi-Omnidirectional Millimetre Wave 5G Handset Antenna

This paper presents a handset antenna array operating within approved millimetre-wave 5G (mmWave) 3GPP n257 band 26.5-29.5 GHz and providing quasi-omnidirectional radiation characteristics. A 4 x 1 linear antenna array is placed into 3 distinct locations within a handset for testing against a numerical hand model which allows simulation of the effects of a user in a specific handset holding scenario. Blockages can cause significant degradation of the performance of the antenna, however, the optimized antenna locations presented achieved 52% coverage for gain values greater than 0 dBi, achieved using a 3bit phase shifter. Single 4x1 array characteristics were confirmed by far-field measurements. Beam steering characteristics are thoroughly investigated, showcasing how signal coverage can be improved in the event of a blockage. Study was also carried out into the effectiveness of increasing the size of multi-bit phase shifters and it is shown how improvement is negligible beyond a certain point.