High-power Microwave Effects And Protection Design Of Fuz

Fuze is a device that uses the electromagnetic characteristics of the target and the environment to guide precisely and control the combat department under predetermined conditions,which determines the killing effectiveness of the weapon system.In modern warfare,the electromagnetic environment is increasingly complex.As the "brain" of intelligent ammunition,fuze is the focus of high-power microwave weapons.With the popularization of high-power microwave weapons in various countries,studying on the attack effect of high-power microwaves on fuzes and their protective measures has become an urgent problem.It is very expensive to use the experimental method to study the attack effect of high-power microwaves.Therefore,software numerical simulation is an important research direction to study the response of fuze to high-power microwaves and taking reinforcement measures.This thesis addresses the current widely used millimeter-wave FMCW fuze,and studies the coupling effect,interference effect and damage effect of it in the attack of high-power microwave weapons,and designs a passive reflective limiter as its front-end protection.The main work and achievements of the thesis are as follows:1.This thesis clarifies the long-range killing efficiency of HPM weapons and the way to attack the fuze are explains the destruction process of the fuze and the nonlinear damage effect during the power coupling process are explained.2.This thesis uses the microstrip array antenna on the fuze to simulate the coupling effect,and studies the coupling effect of a variety of HPM weapon attack scenarios on the fuze antenna,including various HPM illumination power,attack angle,attack frequency band,attack signal rising edge and attack Bandwidth,and founds the strong coupling characteristics and coupling laws outside the antenna working frequency band.By combining the simulation data and the fuse’s damage and interference threshold criterion,the damage and interference area range of the HPM weapon during direct,oblique and vertical irradiation are obtained.3.This thesis clarifies the design scheme and framework of the FM fuze,builds the fuze radio frequency front-end circuit model,and adds the nonlinear gain compression of the LNA in the simulation;after the link simulation of the fuze front-end,the antenna coupling is combined with the circuit to carry out the field-Road joint simulation,focusing on the interference effect experiments of the HPM weapon on the fuze under low-power irradiation,which uses three typical waveforms inject the fuze.The experiment shows that the point-frequency long-pulse-width attack waveform can raise the interference level of the fuze to-45 d Bm and compress the signal-to-noise ratio below 11 d B.4.In order to prevent the fuze from being damaged under the field intensity of 400 k V/m,after selection,a narrow-band passive reflective microstrip limiter was designed using a cascaded symmetrical structure to achieve good frequency selectivity and power capacity;Its bandwidth is controlled by the microstrip line width,and the 4mm epitaxial microstrip lines are used to control the resonant frequency point of the layout,making the bandwidth of the limiter concentrated in the Ka-band;the simulated limiter is processed into a physical object,and assembled and tested.The operating frequency of the measured limiter is34.32~36.19 GHz,covering the fuze operating frequency(34.5~35.5GHz),and the in-band insertion loss is less than 2d B.In the 17.5d Bm power injection experiment,the threshold power is less than 8d Bm,and the flat power leakage is less than 6.2d Bm.