Traveling wave tube

A method for generating or amplifying microwave energy, the method including:

• forming a generally hollow three-dimensional electrically conductive structure;
• laser micromachining the three-dimensional conductive structure to define a selected generally periodic pattern on the conductive structure;
• arranging the conductive structure inside a generally hollow barrel;
• and
• passing an electron beam through the generally hollow three-dimensional conductive structure, the electron beam interacting with the conductive structure and the hollow barrel to generate or amplify the microwave energy.

A slow wave circuit of a traveling wave tube, the slow wave circuit including:

• a three-dimensional electrically conductive shell having at least one laser micromachined gap defining a pattern selected to interact with microwaves in the traveling wave tube;
• a generally hollow barrel inside of which the conductive structure is disposed, the barrel including interior vanes;
• and
• dielectric standoff insulators arranged between the interior vanes of the barrel and the electrically conductive shell, the dielectric standoff insulators including laser micromachined gaps corresponding to the at least one laser micromachined gap of the three-dimensional shell.