# Fast and Accurate Simulation Technique for Large Irregular Arrays

## TL;DR

This paper introduces a fast, accurate simulation method for large irregular antenna arrays using macro basis functions, interpolatory techniques, and FFT acceleration, validated on SKA radio telescope arrays.

## Contribution

It presents a novel combination of MBF, HARP models, and FFT-based acceleration for efficient large array analysis, addressing a gap in existing simulation methods.

## Key findings

- Significant reduction in computation time for large arrays.
- Validated accuracy against commercial software and experiments.
- Effective analysis of SKA radio telescope array configurations.

## Abstract

A fast full-wave simulation technique is presented for the analysis of large irregular planar arrays of identical 3-D metallic antennas. The solution method relies on the Macro Basis Functions (MBF) approach and an interpolatory technique to compute the interactions between MBFs. The Harmonic-polynomial (HARP) model is established for the near-field interactions in a modified system of coordinates. For extremely large arrays made of complex antennas, two approaches assuming a limited radius of influence for mutual coupling are considered: one is based on a sparse-matrix LU decomposition and the other one on a tessellation of the array in the form of overlapping sub-arrays. The computation of all embedded element patterns is sped up with the help of the non-uniform FFT algorithm. Extensive validations are shown for arrays of log-periodic antennas envisaged for the low-frequency SKA (Square Kilometer Array) radio-telescope. The analysis of SKA stations with such a large number of elements has not been treated yet in the literature. Validations include comparison with results obtained with commercial software and with experiments. The proposed method is particularly well suited to array synthesis, in which several orders of magnitude can be saved in terms of computation time.