Antenna model for conformal array performance prediction

Abstract

A physical modeling method for the calculation of characteristic electromagnetic parameters of small conformal arrays is presented. The antenna array model is based on the interaction between special antenna elements composed of electrically small dipoles and loop antennas. It allows for the approximate calculation of mutual coupling effects inside the antenna array. While some system aspects (such as subarray structures, T/R-module quantization, bandwidth, driving point impedance etc.) are taken into account, the numerical complexity of exact EM modeling software (e.g. integral equation methods) is avoided. Of special interest with respect to SMART antenna structures are investigations on array bandwidth and influences of static deformations on array performance: Array performance over an increased frequency range is studied. Static deformations of the array may occur in airborne applications and can cause element dislocation and disorientation. As an effect, the resulting array far field pattern is distorted. In both cases compensation is (at least partially) possible using adapted array coefficients. The results of these calculations lead to the conclusion that in SMART antenna systems the array excitation coefficients need to be modified to increase array bandwidth and to compensate for static deformations.