Design of a High Power Directional Coupler with High Directivity Used in the LHCD Launcher for EAST

摘要

A high power waveguide directional coupler was designed to measure the transmitted power and reflected power in the 4.6 GHz LHCD(lower hybrid current drive) launcher for the EAST tokamak.The design principle of the coupler is assessed.Further analysis is performed by CST(computer simulating test) and Ansoft HFSS(high frequency structure simulator) software and the optimal structural parameter is obtained.In addition,finite element code ANSYS is used to determine the temperature distribution in the coupler conductively cooled by forced water. The test results of a directional coupler manufactured according to the design are close to what is expected.