Research On Low Phase Noise And Low Spurious Frequency Diverse Array Signal Synthesis Method

Frequency diverse array is an emerging technology in recent years.Its main difference from phased array technology lies in the fact that each element of the array transmits signals at different frequencies.In a frequency diverse array,each element’s transmitted signal is accompanied by a small frequency offset.Its transmitted beam pattern exhibits characteristics that vary with distance,angle,and time in the far field.Therefore,many scholars also refer to it as frequency controlled array.Due to its unique distance-dependent characteristics,frequency diverse array has been widely used in radar and communication fields.The signal source,as a key component of the frequency diverse array system,has a significant impact on the system.This places higher demands on the performance and flexibility of the signal source.A frequency diverse array signal synthesis simulation system was designed and implemented in this thesis,incorporating the concept of hierarchical design.Simulations and comparative analyses were conducted on various architectures for synthesizing low phase noise and low spurious frequency diverse array signals.Subsequently,a frequency diverse array signal synthesis validation system was constructed,and synthetic signal testing and analysis were performed on the DDS driven PLL loop mixing architecture.The main work of this thesis are as follows:(1)The requirements of the frequency diverse array signal synthesis system were studied,and a simulation framework for the frequency diverse array signal synthesis system was established using the idea of hierarchical design.The specific frequency synthesis components were simulated and modeled on relevant platforms based on the theory.The established simulation model was tested,and the test results indicated that all the frequency synthesis components functioned properly and their phase noise performance aligned with theoretical analysis.Furthermore,the basic functionality of the system was designed and implemented.(2)The design and simulation implementation of the frequency diverse array signal synthesis architectures were conducted,including the DDS-PLL cascaded architecture,DDS driven PLL mixing architecture,PLL driven DDS mixing architecture,PLL loop mixing architecture,and triple-regulation architecture.The synthesized simulation system for frequency diverse array signal synthesis was tested,indicating that the system’s fundamental functionalities were operating normally.Additionally,the generated simulation model of the frequency diverse array met the design requirements.Furthermore,tests were conducted on the simulation models of the frequency diverse array signal synthesis architectures,and the performance of each architecture was analyzed and summarized.The results demonstrated that the PLL loop mixing architecture,DDS driven PLL loop mixing architecture,and triple-regulation architecture exhibited favorable phase noise and spurious performance.(3)A frequency diverse array signal synthesis validation system was established,and synthetic signal testing was performed on the DDS-driven PLL loop mixing architecture.A comparison was made between the test results,theoretical analysis,and simulation results,confirming the consistency of the functionalities of various modules within the simulation system and the performance of the frequency diverse array signal synthesis architecture with the actual validation results.The simulation models of the frequency diverse array signal synthesis architecture provided by the simulation system can serve as effective references for practical system design.