Research On High Power Microwave Coupling System For Digital Array Radar

As an entirely new concept of phased array radar,digital array radar(DAR)has made great progress in its engineering application.In the complex radar internal environment,the contradiction between the analog radio frequency circuit and the digital circuit,the contradiction between the high-power transmission signal and the low-power echo signal,resulting in the extremely complex electromagnetic environment inside the digital array radar,its high-power microwave effect is not Clearly,it is extremely vulnerable to microwave pulse interference or even damage.In order to build a high-power microwave coupling simulation system for digital array radar,to obtain the influence law of highpower microwave characteristics on the effect of the digital array radar system,and to improve the high-power microwave protection capability of the digital array radar system,this article uses theoretical guidance,simulation analysis,Experimental verification and mathematical fitting methods are used to study the characteristics and laws of high-power microwave disturbance digital array radar system.A strong electromagnetic pulse coupling effect model of digital array radar system based on modular technology is established.Targeted injection of high-power microwave interference pulses of different bandwidths,different frequencies and different energies to simulate a real strong electromagnetic environment.Through the analysis of the operating state and simulation data from components to the system,the dynamic transmission mechanism of the electromagnetic coupling effect of the digital array radar system is revealed,and the mapping relationship between the system electromagnetic effect and the characteristic parameters of the strong electromagnetic environment such as high-power microwave is established.The main content and conclusion of the paper are as follows:1.This article first describes the background,significance and development status of the digital array radar's high-power microwave coupling effect research.Secondly,it uses the theory to analyze the functional characteristics and structural characteristics of the digital array radar and the time-frequency of different high-power microwave pulses.characteristic.Aiming at the RF front-end where digital array radar is most susceptible to damage by high-power microwave,this paper calculates the changing rules of failure zone,interference zone and safety zone from the perspective of coupling power level.The non-linear working state of the RF front-end core sensitive device PIN limiter and lownoise amplifier is further analyzed,and the characteristics of the output signal of the RF device under high-power microwave environment are clarified.Finally,the timefrequency characteristics of high-power microwave pulses after pulse compression are analyzed in depth.2.Using a modular design method,the digital array radar system is divided into six modules: transceiver module,moving target module,high power microwave module,function module and system software interface for simulation modeling.First,the radar waveform and digital beamforming algorithm module are determined.Based on the previous analysis results,the low-noise amplifiers of the sixteen receiving channels are nonlinearly designed for the nonlinear state of the receiving link during strong electromagnetic pulse interference to meet the response characteristics during high-power microwave interference.The motion target module implements variable target motion status and multiple RCS type target switching.Based on digital beamforming technology,high-power microwave interference signals can achieve different angles of incidence,and the power,pulse width and pulse repetition rate can be scanned.The functional simulation module completes the mode selection and functional modeling of pulse compression,Doppler processing,moving target detection,constant false alarm detection and Monte Carlo probability detection.Finally,a visual system software interface is established through MATLAB,which realizes multi-type parameter scanning,and can display the system parameters and calculation results intuitively in real time.3.Experimentally tested the electrical performance indexes and typical parameters of the low-noise amplifier.By building a semi-physical simulation system,the simulation device and the physical device using the same parameters are loaded into the system,and the comparative analysis of the system operation status under the same interference state is performed to verify the reliability and stability of the simulation system.Secondly,for the RF receiving module,the equivalent injection experiment of the strong electromagnetic pulse to the low noise amplifier was carried out.Explore the small signal gain recovery time characteristics of low noise amplifiers.4.Utilize the advantages of the digital simulation system to calculate the operating status of the digital array radar system under a large number of different interference environments.By analyzing the law of simulation data and using a regression model for nonlinear fitting,a mathematical model of parameters such as high power microwave pulse repetition rate and pulse width and the probability of the system detecting the target is constructed.The digital array radar simulation system can better predict the working state of the radar when it is interfered by strong electromagnetic pulses,and can provide a simulation reference for radar anti-interference at the system level.