Development of high-power rf vector modulator employing tem ferrite phase shifters

Construction and installation of a cavity radio frequency (RF) power distribution system in a high power superconducting RF accelerator can have cost savings if a fan-out configuration that feeds many cavities with a single high power klystron is realized. The configuration, however, requires independent control of RF amplitudes and phases to the cavities to perform properly. A prototype high power RF vector modulator for the control is built and tested. The vector modulator employs a quadrature hybrid and two fast ferrite phase shifters in square coaxial transverse electro-magnetic (TEM) transmission lines. The square coaxial format can provide the power handling capability and thermal stability. RF properties of the design and results of high power system testing of the design are presented.