Influence of a parasitic aerial in a rectangular array

A rectangular aerial array has a parasitic element placed at its centre. All the aerials making up the array are symmetrical half-wave dipoles parallel to one another and not displaced in. the sense of their axes, and the system radiates in free space. The aerials are assumed to be thin and in the form of wires. Radiation diagrams and the gain of the network are considered from the double standpoint of the influence of the parasitic element and of the geometric configuration of the rectangle. The formulae produced are developed in the form of graphs. Some comments relative to the case of earthed dipoles are given.