Directivity of small antenna arrays

The linear and plane uniforms equidistant in phase antenna arrays are considered which is often used in practice. The radiation pattern in all observation space and directivity of such arrays are obtained using adaptive technique. It is shown that if the distance between radiators is larger than 0.6 - 0.95 of wavelength the antenna arrays transmitted and received of ultra-wideband signals distort their shape and spectra. Distortion is minimal when the linear antenna arrays are used, which are consisted of radiators with a minimal directivity.