Patent ID: 7782130

Claim:
A resonant electromagnetic cavity comprising: a drift region adapted to allow the passage of an electron beam; a first lobe portion connected to the drift region and extending in a direction substantially perpendicular to a direction of the electron beam, wherein the first lobe portion is tapered such that an end proximate to the drift region has a maximum width that is smaller than that of an end that is distal to the drift region; a first post structure connected to the distal end of the first lobe portion and extending within the cavity toward the drift region; a second lobe portion connected to the drift region and extending in a direction opposite to the direction in which the first lobe portion extends, wherein the second lobe portion is tapered such that an end proximate to the drift region has a maximum width that is smaller than that of an end that is distal to the drift region; and a second post structure connected to the distal end of the second lobe portion and extending within the cavity toward the drift region.