Photonic Band Gap Lattice Cavities

70801S02-II Photonic band gap (PBG) structures have been proposed for applications as particle accelerators or high power microwave/millimeter wave sources. PBG structures have unique modal properties that cause some modes to be ¿trapped¿ within a portion of the lattice while other modes exist throughout the whole structure and can be attenuated away from the trapped mode. This project will investigate the applicability of single-defect and multiple-defect PBG structures to klystrons and accelerating structures. Phase I performed design, analysis, and simulations of a variety of both single-defect and multi-defect PBG structures, with both cylindrical and planar symmetries, for use in pulsed power sources and linear accelerators. Algorithms for calculating the coupling strength of waveguide-loaded cavities were developed. In Phase II, a newly discovered, planar, PBG-like cavity will be demonstrated. An X-band, planar, flat field cavity with multiple rods in a rectangular array, complete with a power coupler, will be designed, fabricated, and tested for use in a proposed Planar Lasertron. Commercial Applications and Other Benefits as described by awardee: As operating frequencies increase and device sizes decrease commensurately, the photonic band gap cavity should provide a significant advantage because of its ability to use "oversized" cavities and to isolate the desired mode from the higher order modes. The targeted application is for high energy physics, especially future linear colliders. In addition, the oversized cavities also may be able to produce microwaves in the terahertz range, thereby impacting high-resolution medical imaging, radar, and high-speed communication.