THEORETICAL AND EXPERIMENTAL INVESTIGATION LEADING TO DESIGN AND CONSTRUCTION OF A BROADBAND LINE SOURCE ILLUMINATOR.
Abstract
This report describes in detail the theoretical and experimental development of a corrected line source array designed to illuminate a spherical reflecting surface of specified radius R. Spherical aberration is corrected over a wide frequency band by a corporate feed system using broadband power dividers and dispersionless feeder cables. The final line source array contains 24 biconical dipoles arranged in 5 separate groups of 8, 4, 4, 4, and 4 elements. Center frequency is 1390 Mc and the design goal in bandwidth is the octave from 1000 to 2000 Mc. Measurements indicate that satisfactory primary illumination is achieved only over the band 1200 to 1600 Mc. Within this range the phase error across the aperture does not exceed the Rayleigh limit of plus or minus 45 degrees. Secondary pattern measurements were obtained by using the array as an illuminator for the large spherical reflector (R = 60 feet). The sun and the radio stars Casseopeia A and Cygnus A were used as sources for these far field measurements. Secondary half power beamwidths are 34 minutes of arc in the H plane and 44 minutes in the E plane, as determined from the Cygnus patterns taken at 1440 Mc. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 05, 1963
- Accession Number
- AD0422370
Entities
People
- Allan W. Love