Patent ID: 8179045

Claim:
A traveling wave amplifier circuit to receive an RF wave and an electron sheet beam and to effect synchronized interaction therebetween, the circuit comprising: a wave guide comprising at least a first wall and a second wall opposite the first wall, wherein the first wall and the second wall are connected to define an axis of propagation and a rectangular wave guide cross-section that is normal to the axis of propagation; a plurality of first projections located on and extending from an interior surface of the first wall of the wave guide, wherein the first projections are pitched in a direction of the axis of propagation; a plurality of second projections located on and extending from an interior surface of the second wall of the wave guide, wherein the second projections are pitched in the direction of the axis of propagation; wherein a number of the second projections are located on and extending from the interior surface of the second wall in a staggered configuration in the direction of the axis of propagation relative to a number of corresponding first projections located on and extending from the interior surface of the first wall; and wherein one or more of the first and second projections comprise a composite stack of a dielectric material and a metal material.