Improvement of gain of the phased array antenna by the parasitic elements

The gain of a phased array antenna decreases as the scanning angle becomes large. This phenomenon is explainable from characteristics of the array element directivity. This paper shows theoretically that the decrease of gain according to scanning angle can be controlled by means of the parasitic elements, which are located in front of each of the antenna elements. The analysis is based on the EMF method and circuit theory. Parameters of the parasitic elements have been decided by computer simulation. In the area of radar and radio communication systems using the phased array antenna, efficiency of power can be improved remarkably by applying this technique.