ONE-WATT CW S-BAND TRAVELING-WAVE TUBE WITH 6 DB NOISE FIGURE.
Abstract
Activity of oxide-coated cathodes for use in a high-power low-noise tube is studied. Several diodes have been built employing active cathodes and have exhibited very encouraging data. Current densities on the order of 1.5 amps/sq.cm. (CW) have been obtained at normal operating temperatures (700 C). Since the cathode is one of the most important factors in low-noise tubes, careful attention must be given to processing and techniques if cathode activity is to be increased from that of a conventional oxide-coated emitter. Revised techniques for processing tubes with active cathodes have been instituted. Four vacuum envelope assemblies were fabricated. Two assemblies developed vacuum leaks at the pin seal. The third assembly developed a vacuum leak at the tube pinch-off after removal from the exhaust station. RF data were taken on the fourth tube, which exhibited a minimum noise figure of 5.3 db (uncorrected) at 2.8 Gc, at 5 ma cathode current. The saturated power output at 4 ma was 200 mW. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1963
- Accession Number
- AD0428056