X-band frequency synthesizer with high frequency resolution

A high frequency resolution X-band frequency source composed of a direct digital synthesizer (DDS) and a phase locked loop (PLL) is proposed in the paper. The DDS provides signals as the reference of the PLL, which generates a stable and low phase noise X-band signal. Hardware design is given with an ADF4002 and an AD9858. Experimental measurements of the frequency synthesizer demonstrate the excellence performance is achieved with the output range of 9.7GHz-10.2GHz, a high frequency resolution of 10Hz, and phase noise better than -100dBc/Hz@10kHz.