Improved Magnitude Weighting Technique for Wireless Sensor Network Beamformer

Abstract

The wireless sensor node consumes maximum energy for data communication which calls for highly directive beams for point to point communication applications to reduce its energy consumption in a Wireless Sensor Network (WSN). This paper presents the synthesis of a wideband beamformer, which is highly directive with reduced sidelobe level (SLL). It supports wide-angle beam steering which makes it suitable for Uniform Linear Array (ULA) WSN. An expression is obtained for weighting the array factor (AF) of the wideband beamformer to achieve beampattern model with desired SLL and Half Power Beam-Width (HPBW) specifications. Compared to Taylor and DPSS techniques, the proposed beamformer shows higher directivity for a given number of elements. It has lower and tapered sidelobes, hence better First Null to Last Null (FNLN) ratio. The proposed beamformer shows improved performance in wideband of interest i.e. 1-3GHz and basically, it is a non-optimization approach.