Design of test kits for the RF characterization of the PAM antenna of LHCD system for Aditya-upgrade Tokamak

The Lower Hybrid Current Drive (LHCD) system of the ADITYA-Upgrade tokamak will employ a Passive Active Multijunction (PAM) antenna to launch 250 kW of RF power at 3.7 GHz to drive plasma current non inductively in the tokamak. To evaluate the RF performance of the designed PAM antenna, it is characterized with the help of VNA measurements. The performance of the PAM antenna is mainly decided by the integrated performance of the entire antenna (with a differential phase shift of 270° and equal power distribution between each of the output waveguides) and the performance of mode converter, which transforms input TE₁₀ mode to TE₃₀ mode (with a mode purity of 98.5% at the output). This poster thus reports the design and analysis of these testing kits. Also, the test results of PAM antenna obtained by using these test kits would also be presented and discussed in this poster