GAIN OF DIRECTIVE ANTENNAS 



73 



important factor in determining the gain. Furthermore, minimum 

 area diagrams are frequently attended by fairly large spurious lobes 

 which are undesirable particularly on receiving antennas. Also the 



6 8 10 12 14 



LENGTH OF ARRAY IN WAVELENGTHS 



Fig. 9 — Approximate gains to be expected from arrays of couplets for spacings of 

 approximately X/4 and X/2. 



2 4 6 8 10 12 14 16 18 20 



LENGTH OF ARRAY IN WAVELENGTHS 



Fig. 10 — Approximate gains to be expected from arrays of couplets for spacings of 

 approximately X/4: and X/2. 



cost of an antenna system of a given height is more or less proportional 

 to its length, and in many cases is not materially affected by the number 

 of conductors present. These considerations, together with the fact 



