Frequency-azimuth dependence of the sidelobe structure in the radiation pattern of phased equidistant single-ring antenna ar-rays

A method is proposed for representing the radiation patterns of phased equidistant single-ring antenna arrays as a series expansion in integer-order Bessel functions, with a substitution of arguments that enables the factorization of variable parameters in the radiation patterns. The results of the study on the frequency-angular dependence of the sidelobe structure in the radiation patterns of phased equidistant single-ring antenna arrays are presented. It is established that at large values of the array’s electrodynamic radius, which determine the upper boundary of the direction finder’s operating range, several sidelobes of near-maximum amplitude are formed. The angular dependence of the orientation of the highest-amplitude sidelobe relative to the main lobe is found to be a piecewise linear function with segments of varying steepness. An algorithm for computing integer-order Bessel functions is proposed, enabling the calculation of radiation patterns for phased equidistant single-ring antenna arrays with low computational complexity. The obtained frequency-angular dependencies of the sidelobe structure in the radiation patterns of equidistant single-ring antenna arrays improve the accuracy of calculating the probability of anomalous direction-finding errors and, consequently, enhance the capability to estimate the potentially achievable characteristics of wideband direction finders with equidistant single-ring antenna arrays.