HIGH FREQUENCY TUNNEL DEVICE STUDY
Abstract
The work reported is aimed at investigating the feasibility of achieving low-noise microwave amplification - specifically: 20 db gain, 6 db noise figure at 10 kmc, and 1 kmc bandwidth by using tunneling. It was concluded that the most promising approach to achieving these objectives is through the use of a thin film cathode operating in conjunction with a micro wave structure. At present, it is possible to build tunnel cathodes which exhibit sufficient current density to permit their use in a 10 kmc traveling- wave tube. However, the life of the cathodes under both dc and pulsed operation is by no means satisfactory. For this reason, efforts were directed towards obtaining better stability and life by improving the uniformity and dielectric strength of the thin insulating layer. To demonstrate the usefulness of tunnel cathodes in a traveling-wave tube, some prototype cathodes were built and incorporated in a suitable gun structure. The focused electron beam was imaged on a phosphor screen. The emission appeared to be uniform in this structure as well as in a projection tube image. Work was continued towards controlling the n sulator thickness by ellipsometry. A tunnel cathode and a 10 kmc traveling-wave tube were designed. Exposure to air appears to be deleterious to the performance of tunnel cathodes. Although no efforts were made to actually construct a 10 kmc tunnel cathode TWT, on the basis of our work to date it appears that such a TWT is feasible. A difficult life problem still exists.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1963
- Accession Number
- AD0406444
Entities
People
- W. Feist
Organizations
- RTX