Measurement of polarization properties of ECRH polarizers at 170 GHz

A combination of circular polarizer and polarization rotator at 170 GHz were designed and constructed by General Atomics (GA) and tested at MIT for Electron Cyclotron Heating in ITER. Cold test measurements were performed using a Vector Network Analyzer to determine the relative amplitudes and phase shifts between two orthogonal components of the reflected field. Measured polarization parameters, ellipticity and rotation, are compared with the numerical simulations done using High Field Structure Simulator (HFSS) software for the designed groove shapes.