Sector-mode beamforming of a 2.4-GHz electronically steerable passive array radiator antenna for a wireless ad hoc network

An electronically steerable passive array radiator (ESPAR) antenna features a simple hardware structure, which enables the use of adaptive array techniques in user terminals, especially in an ad hoc network. We propose the sector-mode beamforming of a 2.4-GHz ESPAR antenna. A single source power maximization technique is presented to find a control voltage vector of the antenna that provides a sector-pattern toward the source direction. Experiments in a radio anechoic chamber give 12 bias voltage vectors and, correspondingly, 12 sector-patterns at every 30°.