Far field simulation of antennas which have complex aperture distribution functions

In recent years there has been activity in the development of very large arrays for space applications. This has led to an interest in techniques for simulating far field patterns from models. The models developed in the past have been inadequate in that it was only practical to model the amplitude of the antenna aperture distribution function. This paper introduces a practical technique for constructing a model which correctly simulates the far field pattern of an antenna which has a complex aperture distribution function. Since the far field is known to be representable as the Fourier transform of the aperture distribution function, the aperture is considered to be a space domain and the far field the corresponding spatial frequency domain. A signal analysis point of view is taken to describe the modeling technique, and to illustrate its salient features. The simulation technique is interpreted in terms of both optical and microwave simulation. The extension of the technique to single element antennas, and arrays of small closely spaced elements is discussed.