Stability enhancement of radiation characteristics of dielectric covered antenna arrays

Abstract

In the design of multirange antenna arrays (AA) with a relatively thick layer of dielectric, the blinding effect suppression becomes the major design problem. A series of known suppression methods taken individually does not lead to a desired results. In this connection we consider a problem of simultaneous combining of several ways of blinding effect suppression in specific working ranges.

Based on the surface wave excitation analysis for enhancing of characteristic stability, we suggest to design two range AA as a chessboard structure with simultaneous variation of thickness and dielectric layer parameters. Chess-board structure is defined as two coincident non-equally spaced antenna arrays with periodic switching of radiators.

It is mathematically formulated and solved an optimization problem of a concurrent choice of AA step, distance between radiators and their types, and layer parameters, under restrictions of the minimum gain fall in the main lobe of directional pattern and the level of side lobes. Designs are two frequency ranges, under 30% dispersion. Total thickness of the dielectric covering is equal to two wavelengths in free space, and the number of dielectric layers is the to three.

In addition to the discussed method of frequency range expansion we have developed the algorithm of the various parameter improvement through insertion periodic as well as nonperiodic metallized dielectric inclusions.