Unified analysis of ridge‐waveguide slot antenna in three‐dimensional space and time

Abstract

AbstractRecently, there has been much interest in research and development of a high‐power heating system for nuclear fusion plasma heating. Since these systems deal with high power, there are several problems that are different from those in the sources for communication systems. A structure is proposed which is based on the T‐type ridge waveguide, a simple and sturdy configuration. In these systems, the complex near field due to the three‐dimensional structure including the medium conditions has a significant effect on the characteristics. Especially, in a high‐power system, the effect of higher‐order modes with relatively small power distributions cannot be neglected. Also, transient field distributions strongly affect the characteristics so that the time domain response must be analyzed. This paper applies an analysis technique for the three‐dimensional space and time based on the Bergeron method to the systematic analysis of the radiated near field from the entire system of a T‐type ridge waveguide slot antenna including the waveguide, slot and the heating regions. The power distribution of the field determining the fundamental properties of the heating system is found in terms of the Poynting vector and the fundamental properties of the system are obtained. Specifically, the effect of the dielectric material on the field distribution is found. The cutoff characteristics of the ridge waveguide and the fundamental properties of the slot are studied and their characteristics are investigated.