A new microwave antenna system

Abstract

Rapid expansion of radio relay facilities requires the development of new radio relay systems in the higher frequency b a n d s a s s i g n e d by the FCC for common-carrier use. To help meet this need, a horn-reflector antenna w a s developed. Its a p plication, transmission characteristics, a n d g e n eral design requirements are set forth. R A D I O R E L A Y i n the B e l l System n o w provides over 7 m i l l i o n miles of two-way message circuits, a p p r o x i m a t e l y 1/6 of all the long-distance tele p h o n e circuits i n this country. It also provides about 50,000 miles of b r o a d b a n d radio c h a n n e l s w h i c h m a k e network television available to over 365 televisionFig. 1. Horn-reflector antenna installation at Terrell, Texas. broadcasting stations in 240 cities. T h i s r a p i d e x p a n s i o n of r a d io relay facilities i n d i c a t e d s o m e t i m e a g o t h a t by1955 portions of the central transcontinental a n d other b a c k b o n e routes w o u l d b e l o a d e d to their capacity of six b r o a d b a n d c h a n n e l s in each direction of transmis sion.

Impact of Microwave Depolarization During Multipath Fading on Digital Radio Performance

“…7 For successful isolation of the two information channels of a dualpolarized digital radio system, it is reasonable to expect that Κ = 20 log l0 k s -20 dB.…”

Transmission systems for trunk and junction circuits

“…In the case of the 3770-4220 Mc/s and 5850-6425 Mc/s bands, the feeders are combined by bandbranching units 18 to feed a common parabolic horn aerial. 19 An alternative arrangement is to combine half the transmitters and receivers on one aerial and the other half on the second aerial.…”

URSI National Committee Report: Commission 6. Radio Waves and Circuits. Part 1. Information Theory and Coding

“…The bowl should be useful at 21 cm, and if the tolerances can be achieved, this bowl will have at 21 cm the highest gain of any antenna, over 6 db , allmving 2 db for gain loss due to spherical aperture. Also to be mentioned is the very low sidelobe parabolic horn d eveloped at B ell Laboratories [Friis, May, 1958], with first sidelobes below -40 db and back loves below -70 db.…”

“…Hogg [1959] gives the effect of oxygen and water vapor absorption upon antenna temperature. D e Grasse et al [1959] report very careful measurements of antenna effective noise temperature at .5,600 Mc/s using a parabolic horn antenna with v ery low side and back lobes (see Friis, May, 1958).…”