262 BELL SYSTEM TECHNICAL JOURNAL 



It can be increased somewhat by the addition of flares. The other dimen- 

 sion can easily be made large. 



Fig. 25 — Parabolic Cylinder Bounded b>' Parallel Plates. Wave Guide Feed. 



Fig. 26. — Fxperimental 7' x 32' Antenna. 



8.6 Line Sources for Parabolic ( 'yliiulcrs 



A line source for a parabolic cylinder is physically an antenna with a long 

 narrow aperture. Any means for obtaining such an aperture can be used in 

 {)ro(lucing a line source. Parallel plate systems as described in 8.5 have 

 been used as line sources in several radar antennas. The large (7' x 32') 



