Slow wave structure having offset projections comprised of a metal-dielectric composite stack

1. 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.

2. The traveling wave amplifier circuit of claim 1 ,

wherein each of the first projections comprises a first vane normal to the interior surface of the first wall, the first vane defining: a substantially constant thickness T 1 measured in the direction of the axis of propagation, a substantially constant height H 1 measured in the direction normal to the interior surface of the first wall, and a substantially constant width W 1 measure in a direction transverse to the axis of propagation; and

wherein each of the second projections comprises a second vane normal to the interior surface of the second wall, the second vane defining: a substantially constant thickness T 2 measured in the direction of the axis of propagation, a substantially constant height H 2 measured in a direction normal to the interior surface of the second wall, and a substantially constant width W 2 measured in a direction transverse to the axis of propagation.

3. The traveling wave amplifier circuit of claim 2 , wherein W 1 is substantially equal to a width of the interior surface of the first wall measured in the direction transverse to the axis of propagation.

4. The traveling wave amplifier circuit of claim 2 , wherein W 2 is substantially equal to a width of the interior surface of the second wall measured in the direction transverse to the axis of propagation.

5. The traveling wave amplifier circuit of claim 2 , wherein T 1 is substantially equal to T 2 , wherein H 1 is substantially equal to H 2 , and wherein W 1 is substantially equal to W 2 .

6. The traveling wave amplifier circuit of claim 1 , wherein the pitch of the second projections is substantially equal to the pitch of the first projections.

7. The traveling wave amplifier circuit of claim 6 , wherein the pitch of the first projections and the pitch of the second projections is a constant value.

8. The traveling wave amplifier circuit of claim 6 , wherein a change in the pitch of the first projections is equal to a change in the pitch of the second projections.

9. The traveling wave amplifier circuit of claim 1 , wherein each second projection of the staggered configuration symmetrically opposes a pair of adjacent first projections located on the interior surface of the first wall.

10. The traveling wave amplifier of claim 1 , wherein each second projection of the staggered configuration asymmetrically opposes each of a pair of adjacent first projections located on the interior surface of the first wall.

11. The traveling wave amplifier circuit of claim 1 , wherein the dielectric material is selected from the group consisting of: diamond, beryllium oxide.

12. The traveling wave amplifier circuit of claim 1 , wherein the metal material is selected from the group consisting of: copper, molybdenum, tungsten.

13. A traveling wave amplifier circuit to receive an RF wave and an electron sheet beam 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 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 the interior surface of the first wall; and

wherein each second projection of the staggered configuration asymmetrically opposes each of a pair of adjacent first projections located on the interior surface of the first wall.

14. The traveling wave amplifier circuit of claim 13 ,

wherein each of the first projections comprises a first vane normal to the interior surface of the first wall, the first vane defining: a substantially constant thickness T 1 measured in the direction of the axis of propagation, a substantially constant height H 1 measured in the direction normal to the interior surface of the first wall, and a substantially constant width W 1 measure in a direction transverse to the axis of propagation; and

wherein each of the second projections comprises a second vane normal to the interior surface of the second wall, the second vane defining: a substantially constant thickness T 2 measured in the direction of the axis of propagation, a substantially constant height H 2 measured in a direction normal to the interior surface of the second wall, and a substantially constant width W 2 measured in a direction transverse to the axis of propagation.

15. The traveling wave amplifier circuit of claim 14 , wherein T 1 is substantially equal to T 2 , wherein H 1 is substantially equal to H 2 , and wherein W 1 is substantially equal to W 2 .

16. The traveling wave amplifier circuit of claim 14 , wherein W 2 is substantially equal to a width of the interior surface of the second wall measured in the direction transverse to the axis of propagation.

17. The traveling wave amplifier circuit of claim 14 , wherein W 1 is substantially equal to a width of the interior surface of the first wall measured in the direction transverse to the axis of propagation.

18. The traveling wave amplifier circuit of claim 13 , wherein each one or more of the first and second projections comprise of a composite stack of a metal material and a dielectric material.

19. The traveling wave amplifier circuit of claim 18 , wherein the dielectric material is selected from the group consisting of: diamond, beryllium oxide.

20. The traveling wave amplifier circuit of claim 18 , wherein the metal material is selected from the group consisting of: copper, molybdenum, tungsten.

21. The traveling wave amplifier circuit of claim 13 , wherein the pitch of the second projections is substantially equal to the pitch of the first projections.

22. The traveling wave amplifier circuit of claim 21 , wherein the pitch of the first projections and the pitch of the second projections is a constant value.

23. The traveling wave amplifier circuit of claim 21 , wherein a change in the pitch of the first projections is equal to a change in the pitch of the second projections.