Simulation And Implementation Of Wideband High Linearity And Low Spurious Chirp Signal

Chirp signal is named for its audio sounds similar to the chirping of birds.It's widely used in microwave communications,synthetic aperture radar imaging,sonarand othermilitary fields,As a typical nonstationary signal.In radar measurement and electronic countermeasure system,Bandwidth,linearity,and the degreeof chirp signal Is one of the most critical factors that restrict the measurement precision and the ability to resist.By the increasing demand of broadband signal and nonlinear system,the technology of chirp signal synthesis with wide bandwidth,high linearity and low dispersion has become an Hot research topic.Many researchers and scholars have done a lot of theoretical research on the high quality synthesis of chirp signal,and put forward a variety of solutions for chirp signal synthesis,however,With the progress of science and technology,the requirement of high quality chirp signal is more and more severe,including bandwidth,agility,capture time and so on.The innovation of the existing technology,the application of new electronic devices,can be applied to the needs of the current stage of scientific research projects of high quality chirp signal.In this paper,we study the theory of real-time bandwidth,spurious and phase noise in chirp signal synthesis,then,A chirp signal generation method for wideband fast lock-in phase-locked loop is proposed,point at The main problem for the existence of S-band wideband chirp signal,Direct digital frequency synthesis technology,phase-locked loop technology,and programmable logic devices for research and design.at present the chirp signal synthesis link in the large loop bandwidth design,low spurious design,broadband VCO design and digital design research workis completed.And the simulation was carried out for system design key links such as Phase locked loop lock time,logic functions of control letterNumberand many more.The simulation results show that the system design can meet the actual needs of scientific research projects to achieve the desired objectives.Chirp signal frequency is 2560MHz-2960 MHz bandwidth can reach 400 MHz,lock time is less than 0.5uS;and with thepulse recurrence periodof 100us;single pulse duty cycle 14/15,linearity of chirp signal is less than 10^-4.