NOISE SOURCE FOR MILLIMETER WAVELENGTH.
Abstract
The hot load noise standard operating at 1000C produces an excess noise factor of 5.3 db above room temperature, which when reduced by waveguide losses totals 4.85 db at the waveguide switch junction of the calibration test set-up. Investigation of neon and argon filled noise tubes was completed with fill pressures varying from 5 to 60 mm of Hg. The noise tubes were calibrated against the hot load standard using a single ended mixer at 3.2 mm and a balanced mixer at 4.3 mm. The noise output from the neon tubes measured only slightly higher than the argon tubes. The operating temperature of the neon tubes, however, was very high and increased with life, causing tube failure after approximately 50 hours. The argon tubes operated relatively cool, and the noise output did not change over 350 hours operating life. Several noise tube mounts were investigated. These mounts positioned the noise tube at various angles from 0 to 17 degrees with respect to the waveguide. It was determined that the noise output from the 0 degrees mounted tube exceeded that of the 15 degrees mount by almost 2 db. However, the unfired match of the latter was better. Excess noise ratio measurements varied between 17.7 and 18.1 db, when compared to the hot load standard operating at 1000C. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1964
- Accession Number
- AD0616274
Entities
People
- Arnold M. Eklund