The RF characteristics of the JET-ITER Like (JET-IL) antenna relevant for operation on plasma have been assessed using full wave three Dimensional (3D) electromagnetic CST® Microwave Studio (MWS) simulations, measurements of the full 8-port antenna strap array S/Z-matrix, and RF circuit modeling. These efforts are made in parallel with the high voltage testing of the antenna inside a vacuum tank and the hardware implementation of a RF (Radio Frequency) matching feedback control system prior to installation of the antenna on the JET tokamak.