NUMERICAL STUDY OF MATCHING STRUCTURE FOR INFINITE WAVEGUIDE PHASED ANTENNA ARRAY BY FINITE ELEMENTS METHOD

Abstract

In this paper a numerical study of an infinite plane rectangular waveguides PAA with the proposed matching structure has been performed in the form of a modified matching structure with an extra layer of dielectric (foam) by the finite element method.To analyze the antenna array mode l by the finite element method, a program package of HFSS 14 has been used. An infinite waveguide PAA analyzed by the HFSS program, is approximated by an infinite number of emitters placed periodically with geometry identical to the real antenna array. When constructing a triangular grid arrangement of emitters for the correct description of a central single cell, one must determine the shift between the boundary conditions of the Master and the Slave, which determines the ratio of the breakdown of the Master and Slave boundary conditions along the coordinate meshes. This procedure should take into account the grid angle and the transverse geometric dimensions of the "Flock channel" and the waveguide.The purpose of the modification of the matching structure (MS) consisting of the dielectric layer, which is located above the antenna aperture, is to remove the defect in the form of a air layer between the aperture and the dielectric layer, which may lead to the bending of the dielectric layer, which, in turn, can cause heterogeneity of the dielectric value permeability along the MS. To remove this air layer, it has been suggested to use an extra layer that will not allow bending the upper dielectric layer. The foam was chosen as an dielectric, which, firstly, has a small density that essentially does not change the mass of the MS, and secondly, it is cheap and well-treated, and its relative permittivity is close to the air (ε = 1.1). The results of the theoretical study of the use of foam in the CS were carried out in a wide range of values of the thickness of dielectric layers.The numerical results of the calculations allow us to conclude that the model of the MS, which is being investigated, allows to improve the mechanical properties of the PAA while maintaining the operating parameters: reflection coefficient, frequency range and range of angles of scanning.