Unequally‐excited linear totally random antenna arrays for multi‐beam patterns. Issue 10 (30th April 2018)

• Record Type: Journal Article
• Authors: Buonanno, Giovanni; Solimene, Raffaele
• Is Part Of: IET microwaves, antennas & propagation. Volume 12:Issue 10(2018)
• Page Start: 1671
• Page End: 1678
• Publication Date: 2018-04-30
• Subjects: linear antenna arrays -- multibeam antennas -- antenna radiation patterns -- random processes -- antenna theory -- antenna feeds -- higher order statistics -- Monte Carlo methods; unequally‐excited linear totally random antenna arrays -- multibeam patterns -- uniform excitations -- linear phase shift -- feeding network -- Hermitian function -- mean array pattern -- excitation currents -- random variables -- element positions -- second‐order statistic characterisation -- first‐order statistic characterisation -- Monte Carlo study -- symmetric arrays -- up‐crossing theory -- random processes -- mean radiation pattern -- multibeam array factors; Microwaves -- Periodicals; Microwave antennas -- Periodicals; Antennas (Electronics) -- Periodicals; Radio wave propagation -- Periodicals; Microwave communication systems -- Periodicals; 621.381305
• DOI: 10.1049/iet-map.2017.1206
• Languages: English
• ISSNs: 1751-8725

Abstract

Abstract : Linear random antenna arrays are usually studied in conjunction with uniform excitations with, at most, a linear phase shift in order to steer the main beam. This offers some advantages in terms of the feeding network but puts limitations on the array factor that can be obtained. The authors introduce unequally excited random arrays whose excitation currents are obtained by suitable transformations of the random variables related to the element positions. Besides, the first‐ and second‐order statistic characterisation, the uniform norm (i.e. the supremum) of difference between the mean (the desired one) and the actual array factors is estimated. In particular, while in the general case, this is achieved only via a Monte Carlo study, for the case of symmetric arrays (where the elements are randomly deployed symmetrically with respect to the array aperture centre) that norm is analytically estimated using the up‐crossing theory for random processes. It is shown that the proposed unequally excited random arrays, unlike some other previous approaches, allow shaping the mean radiation pattern. However, the procedure in general yields reduced achievable performance. Therefore, the theoretical findings are checked through some numerical examples only for the important class of multi‐beam array factors.