The Sectoral Electromagnetic Horn

An electromagnetic horn radiator two of whose opposite sides are flared, the other two being parallel, was studied experimentally at wavelengths between 40 and 100 centimeters. For comparison, measurements on parabolic reflectors and broadside arrays were also made. By virtue of its unusual freedom from secondary lobes and stray radiation, its ability to operate well over a broad band width, its simple construction, and its ease and stability of operation, the electromagnetic horn offers unique possibilities as a directive radiating system for microwave applications. These results and the application to a straight-line blind-landing system for airplanes are discussed.