C-band Frequency Synthesizer Developed

Frequency synthesizer has played an important role in the electronic systems, and it can be widely used in such fields as radar, communications, electronic warfare and electronic measurement instruments. The way of DDS+PLL can take good advantage of both their merits: the high resolution, high accuracy, convenient control of frequency variance for DDS and the excellent character of narrow band tracing filtering for PLL. We introduce the arrangement and realize the circuits.This thesis focuses on the realization of signal source based on DDS and PLL, proposes a design plan of frequency synthesizer for the C-band high-range-resolution radar, display the design parameters and the simulation results as well.Phase noise and spur are two important factors to the performance of PLL. Simulation is completed by the ADISIMPLL for the PLL part, which we choose ADF4360-7, and studies also carried out to ensure its feasibility. The results of phase noise, spur and lock time are analyzed that the plan is feasible.We analyze the output spectrum of DDS and adopt the method of time-domain waveform to analyze these influence generated by the phase noise and spur in the output spectrum. Design and complete the DDS part which we choose AD9954 of the circuit. After debug, the results of testing indicate that we achieve the target.