Abstract: Wireless sensor networks (WSN) technology was combined with antenna array beamforming to realize WSNs long range communication. Instead of using isotropic antennas as reported in the literatures, all nodes in this paper were equipped with directional antennas for beamforming. The influence of sensor node failure and position error on the combined beam pattern was analyzed considering the antenna beam inclination. The nodes radiation power adjustment was studied to reduce the side lobe level effectively as the main lobe remained almost unchanged. To increase the networks coverage area, node distance can be extended within a certain range which is constrained by the antenna beam pattern.

Key words: directional antenna, beamforming, antenna beam inclination, node failure, position error, radiation power adjustment, node distance extension