Technique to increase directivity of a reconfigurable array antenna for wireless sensor network

In this paper, a technique to maximize the directivity of an antenna array is presented. It consists of a fed monopole and a loaded parasitic one. The nature and value of the load are obtained using the Uzkov equations that calculate the current weighting coefficients in the case of two separately fed antennas to maximize the gain and the directivity in one direction. Reconfigurability is achieved by using reflectors and directors activated by pin diodes to reduce the back radiation and pointing in the desired direction. Thus a system of two elements, one fed and the other loaded with an inductor, having a maximum gain of 5.2 dBi at 2.45GHz in azimuthal directions 90° and 270° is obtained. The system is compared with a system of two antennas fed separately.