Design of the compact multimode feeds with high power capacity

With the rapid development of the high power microwave source, the power levels have steadily increased. The breakdown of the feed output window is often found in the reflector antennas system. It seriously affects the service life and radiation efficiency of the feed. The paper analyzes the relationship between the max electric intensity in near-field and the field distribution on the aperture. Based on the analysis, the method to reduce the electric field intensity at the surface of output window by the diffraction mechanism is presented instead of work on reduce intensity of aperture. It can greatly reduce the physical size of the feed. The high efficiency multimode feed prototype has been designed by the MMT (Mode Matching Technology) and manufactured. The excellent correspondence between the experimental result and theory is demonstrated.