Open AccessAffine transformation for synthesis of low sidelobe patterns in planar array antennas with a triangular element grid using the IFT method
Author(s) -
Keizer Will P.M.N.
Publication year - 2020
Publication title -
iet microwaves, antennas and propagation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.555
H-Index - 69
eISSN - 1751-8733
pISSN - 1751-8725
DOI - 10.1049/iet-map.2019.0050
Subject(s) - affine transformation , transformation (genetics) , planar array , planar , grid , optics , fourier transform , phased array , antenna array , mathematics , antenna (radio) , computer science , algorithm , topology (electrical circuits) , acoustics , physics , geometry , telecommunications , mathematical analysis , biochemistry , chemistry , computer graphics (images) , combinatorics , gene
This study deals with the affine transformation that is used to convert the triangular element grid of a planar phased array antenna into a square one. By means of this kind of transformation, it is possible to apply the iterative Fourier transform (IFT) method to synthesise low sidelobe tapers for array antennas featuring a triangular grid. Combination of the IFT method with an affine transformation allows the synthesis of low sidelobe tapers of which the peak sidelobe level does not vary with changing frequency and/or altering main beam position. The considered affine transformation was already briefly addressed in earlier publications of this author. In this study detailed information is given on its use in combination with the IFT method. Examples to demonstrate the effectiveness of the combination affine transformation and the IFT method for triangular grid array antennas are given. It will be shown that the peak sidelobe levels of the obtained tapers are invariant with frequency and scan angle when all far‐field directions of the array factor are involved in the low sidelobe taper synthesis.