Embodiments of the invention include a method to control an antenna pattern of a wideband array antenna wherein a wideband array antenna unit comprising the wideband array antenna and transforming means is accomplished. Embodiments of the invention further include the corresponding wideband array antenna unit and transforming means arranged to control an antenna pattern of an antenna system. The separation between antenna elements in the wideband array antenna can be increased to above one half wavelength of a maximum frequency within a system bandwidth when the array antenna is arranged to operate with an instantaneously wideband waveform.