X-band phase calibration generator coupler

A new type of phase calibration generator (PCG) coupler was developed for the Deep Space Network (DSN) X-band antennas that can be located directly behind the feedhorn. The advantage of this is that the calibration includes more of the system. The disadvantage is that the overmoded waveguide at this location must be coupled in a mode-selective manner. Low-power and high-power PCG couplers have been successfully produced, and the RF test results from a PCG coupler are given.