Spatio-frequential filtering considerations on antenna array

The need for efficient transmissions in mobile communication systems has led to the development of optimized radiation pattern antennas. The paper presents a study of the feasibility of spatio-frequential filtering using beamforming array antennas. We propose a graphic visualization tool, spatio-frequential graphs, to estimate qualitatively both spatial and frequency filtering capabilities. This tool has been used with a 4-omnidirectional-element phased array antenna. Different kinds of phase shifters and configurations have been studied. Some of these configurations give frequency filtering while keeping beamforming properties at the working frequency. It is believed that it will generate a set of new investigations into multiband beamforming techniques. Indeed, combining spatio-frequency filtering, due to the array factor, with elementary antenna radiation patterns could be a solution to multi-standard beamforming requirements.