ARTICLE | doi:10.20944/preprints202201.0048.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: Radiation pattern synthesis; Almost periodic structures; Mutual coupling effects; Artificial neural network ANN algorithm; Early stoping method.
Online: 6 January 2022 (09:30:59 CET)
This paper proposes a radiation pattern synthesis of the almost periodic antenna arrays including mutual coupling effects (that extracted by the Floquet analysis according to our previous work), which principally has a high directivity and large bandwidth. For modeling the given structures, the moment method combined with the Generalized Equivalent Circuit (MoM-GEC) is proposed. The artificial neural network (ANN) as a powerful computational model has been successfully applied to the antenna array pattern synthesis. The results showed that the multilayer feedforward neural networks are rugged and can successfully and efficiently resolve various distinctive complex almost periodic antenna patterns (with different source amplitudes) (in particular, both periodic and randomly aperiodic structures are taken into account). However, the artificial neural network (ANN) is capable of quickly producing the synthesis results using generalization with the early stopping (ES) method. A significant time gain and memory consumption are achieved by using this given method to improve the generalization (called early stopping). To justify this work, several examples are developed and discussed.
ARTICLE | doi:10.20944/preprints202111.0409.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: Floquet analysis; MoM method; Almost periodic antenna arrays; Fourier analysis; strong mutual coupling; Dense massive MIMO; MM and THz waves; 5G and 6G applications
Online: 22 November 2021 (15:11:58 CET)
In this paper, we introduce a new formulation based on Floquet (Fourier) spectral analysis combined with a spectral modulation technique (and its spatial form) to study strongly coupled sublattices predefined in the infinite and large finite extent of almost periodic antenna arrays (e.g metasurfaces). This analysis is very relevant for dense massive MIMO, intelligent surfaces, 5G, and 6G applications (used for very small areas with a large number of elements such as millimeter and terahertz waves applications). The numerical method that is adopted to model the structure is the method of moments simplified by equivalent circuits MoM GEC. Other numerical methods (as the ASM array scanning method and windowing Fourier method) used this analysis in their kernel that to treat periodic and pseudo-periodic (or quasi-periodic) arrays.