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BELL SYSTEM TECHNICAL JOURNAL 



average elevation as the remainder of the antenna. The eHmination 

 of this sharp rise over rocky ground serves principally to remove an 

 irregularity in the constants of the wave-antenna near the end, so 

 that the entire antenna may be considered more nearly a smooth line. 

 This makes the antenna function more satisfactorily as a unit of an 

 array in connection with other antennas constructed nearby. 



Fig. 9. 



6. Wave- Antenna Arrays. Since 1899, when S. G. Brown ^"^ proposed 

 the use of two vertical antennas, separated in space by an appreciable 

 portion of a wave-length and excited at a half-period phase difference, 

 as a means of directional transmission, the use of arrays of antennas 



1^ R. M. Foster, "Directive Diagrams of Antenna Arrays," Bell System Tech. 

 Jour., 5, 292; April, 1926. Also see references listed in F"oster's paper. 



