Wide-angle impedance matching of a planar array antenna by a dielectric sheet

Abstract

For wide-angle scanning array antennas, the magnitude of the reflection changes substantially with scan angle and wave polarization. Conventional matching techniques in the individual element feed lines cannot compensate for these changes. There is a method of wide-angle impedance matching (WAIM) which utilizes a thin, high- <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">k</tex> , dielectric sheet spaced in front of the array. It is capable of equalizing the reflection coefficient for <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">E</tex> and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">H</tex> polarization at any specified scan angle, or for any angle in the <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">E</tex> and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">H</tex> scan planes. This technique is applied to an array having element aperture windows flush with a metal face. It is adapted for the procedure of matching in a waveguide simulation of an infinite array.