A Half-Watt CW Traveling-Wave Amplifier for the 5-6 Millimeter Band

The traveling-wave tube here described represents the first practical CW power amplifier with broadband performance in the millimeter wave band. More than 30 db of gain has been achieved over a bandwidth of 10,000 mc centered at 55,000 mc. A maximum CW output power of ½ watt has been obtained in this band. This combination of high power output and broadband performance represents a significant advance in the millimeter art. The electrical and mechanical techniques are described which were found successful in solving the problems peculiar to the high operating frequency. These problems are focusing, heat dissipation, intrinsic RF loss and structural precision. Experimental data on an operating tube are presented which show good agreement with predicted performance. These data suggest that the techniques described may be extended to allow either an increase in power to several watts at the present operating frequency or an increase in operating frequency to 150 kmc for output powers of a hundred milliwatts.