DIRECTIVE DIAGRAMS OP ANTENNA ARRAYS 299 



is equal to or greater than this value. The area (S) relative to the 

 unit circle is given in Fig. 4 for each of the cumulative diagrams, 

 this area being equal to the area of the corresponding directive diagram. 



Sixteen Antennae, Fig. 5 



A total of (512 directive diagrams for an array consisting of sixteen 

 antennae is shown by Fig. 5. The separation between adjacent 



Fig. 6 — -Directive amplitude diagram for sixteen antennae (0.8825X, 07") having 

 the minimum area (0.0254) relative to the unit circle 



antennae varies from to 1 wave-length, in steps of 1/32 wave-length; 

 the phase difference between adjacent antennae varies from to 1/2 

 period, in steps of 1/32 period; additional sets of diagrams are included 

 with separations of 1|, 2, and 4 wave-lengths. The specihed phase 

 difference is the lag of the current in one antenna behind the current 

 in its left-hand neighbor. The diagrams are reflected about the 

 vertical axis upon changing the sign of the phase difference, and they 



