ANN-based design of a versatile millimetre-wave slotted patch multi-antenna configuration for 5G scenarios

This paper addresses the modelling of a dual-band (28 and 38 GHz), circularly-polarised slotted-patch-antenna for highly demanded millimetre-wave MIMO-systems in 5G-networks. A computer-aided-design model is derived by means of an artificial-neural-network (ANN) which allows obtaining the physical dimensions of a single-fed antenna, satisfying both near- and far-field goals, without resorting to time-consuming electromagnetic-simulation. This mathematical-model can be implemented in any CAD-tool, as demonstrated within the framework of Advanced-Design-System. This allows, for the first time, to carry out optimizations of strategic importance for future 5G nonlinear-radiating-systems, especially operating at millimetre-wave, directly addressing their far-field behaviour. The model performance is validated by some examples and measurement results. A further important advantage of this approach is that the trained ANN-model can be further adopted to fast, but accurately, investigate the complex relationships between antenna layout and its near-field and far-field performance, such the resonance conditions and the polarisation behaviour. Indeed arbitrary orthogonal-polarisations (LHCP/RHCP) have been achieved by the aid of the ANN-model of the same topology. This result can be adopted to implement a combination of two independent radiation patterns for the antenna-pair: this feature is attractive for MIMO applications. This is confirmed by measurements showing antenna-coupling reduction with the MIMO-array exploiting polarisation-diversity.