Microwave leakage shift suppression based on home made DDS

A home made DDS based on a FPGA and a DAC was designed to suppress microwave leakage shifts. The phase invariability was realized utilizing the DDS. The spectrum performance and phase noise of the DDS were measured and were good enough to be used for the microwave synthesizer. From the experiment result of fountain clock the introduced frequency shift by switch DDS output frequency should be less than 2E-16.