Array antennas and radomes for millimetre-wave 5G applications

The deployment of the millimetre-wave (mmWave) band for 5G wireless communication has attracted significant attention and support from government, industry, and academic institutions over the past years due to the large chunks of available bandwidth. Nonetheless, for 5G mmWave communication systems to be successful for commercial applications, several fundamental issues in hardware development must be addressed. Here of particular relevance, is the development of mmWaveantenna systems. Fundamental challenges in mmWaveantenna system design include substantial losses such as material and propagation path losses and hardware implementation costs. To mitigate propagation path loss, a directive antenna is required. An array antenna is among the techniques used to realise directive antennas. Nonetheless, with the directive beam, the array antenna's coverage area will be reduced. However, a wide coverage area feature is one of the essential characteristics required by the base station to provide high throughput to individual users. Therefore, the antenna beam of an array antenna must be able to be steered in various directions covering up to 120°. In practical deployments of antenna systems, antennas are typically covered with a dielectric radome that serves to protect the antenna system or to provide additional spatial and/or frequency filtering to the antenna system. Conventional dielectric radomes have demonstrated satisfactory performance at low microwave frequencies. Nonetheless, at the mmWave band, the dielectric radome deployment has become an additional source of losses for the mmWave antenna system.
Considering the issues above of mmWave antenna systems for 5G wireless communications, this doctoral dissertation objective is twofold: (I) to design and characterise wideband mmWave array antennas and (II) to design and characterise antenna radomes for 5G applications. This dissertation therefore consists of two Parts.