Interaction of Antenna, Human and Channel at 28 GHz

This master's thesis studies millimetre-wave antenna arrays at 28 GHz under realistic operational conditions, taking into account the interaction of the Antenna, the Body of the human user and the propagation Channel (A-B-C). The main goal of the thesis is to develop a framework in MATLAB that uses a numerical approach to evaluate the total array gain and the spherical coverage of two modular sub-array designs on a mobile phone chassis. State-of-the-art numerical methods, such as simulations of scattered fields from antenna elements near a full-size human body and polarimetric ray-optical multipath radio channel simulations from an in-house ray-tracer, are used to generate the channel data for an outdoor and an indoor small-cellular site. The method was applied, showing that sub-arrays that point in opposite directions have 3 dB better median (50 per cent) link performance and 8-12 dB better outage performance (1 per cent or 10 per cent respectively), and similar peak performance, compared to sub-arrays that point into the same direction. Further, results showed that beam steering in co-located sub-arrays offered the best peak performance and that the median performance is about 6 dB better than the distributed array. The outage performance (10 per cent) of the co-located array and the distributed array modules was similar, while the distributed array had a 2-3 dB advantage. This insight differs from those obtained in spherical coverage, where the distributed array is inferior to the co-located array at outage levels. Results showed that median and outage total array gain reveals additional insights compared to spherical coverage, where the former shows equally capable gains of the co-located array and the distributed array, while the latter justifies only the co-located array and does not support the distributed array. It was shown that the performance of phased-antenna configurations should be evaluated based on empirical statistics of two types of antenna gains, i.e., spherical coverage and total array gain, as antenna and link gain metrics, respectively. It is thereby demonstrated that the inter-play of antenna beams and multipath channels needs to be quantified through the link gain metric, i.e., total array gain, and the antenna gain metric, i.e., spherical coverage, when evaluating, comparing and ranking different phased antenna array designs