摘要
针对SAR系统的前门耦合电磁敏感特性,通过等效注入试验方法,系统研究了单频连续波对机载SAR成像的影响规律及作用机理,并采用融合皮尔逊相关系数、结构相似度和峰值信噪比的SAR图像质量评价因子作为干扰效果评估指标。研究结果表明:当干扰频率落入接收机硬件通带(8.5~9.5 GHz)范围内,且干信比≥15 dB时干扰效应显著;干扰信号在射频前端虽未诱发显著非线性效应,但会导致模数转换(ADC)采样芯片中的内部金属氧化物半导体场效应晶体管(MOSFET)产生非线性响应,其产生的额外直流分量和谐波成分是造成SAR图像中出现特征性干扰条纹及质量下降的根本物理成因。
[Background]Airborne synthetic aperture radar(SAR)is vulnerable to continuous wave(CW)interference in complex electromagnetic environments,leading to significant degradation in imaging quality.Itssusceptibility to front-door coupling electromagnetic effects is a critical concern.[Purpose]This study aims tosystematically investigate the impact patterns and physical mechanisms of single-frequency CW interference onairborne SAR imaging through equivalent injection experiments.It further seeks to establish a robust evaluationmethod for interference effects.[Methods]Equivalent injection testing was employed to simulate CW interferencesusceptibility.The interference effect was evaluated using a composite SAR image quality factor integrating thePearson correlation coefficient(PCC),Structural Similarity Index(SSIM),and Peak Signal-to-Noise Ratio(PSNR).Detailed analysis of the radio frequency(RF)front-end response and Analog-to-Digital Converter(ADC)behaviorunder interference was conducted.[Results]Significant interference effects were observed when the interferingfrequency fell within the receiver's hardware passband(8.5−9.5 GHz)and the jammer-to-signal ratio(JSR)reached15 dB.While the RF front-end exhibited no significant nonlinearity,the interference induced a nonlinear responsespecifically within the internal Metal-Oxide-Semiconductor Field-Effect Transistor(MOSFET)of the ADC samplingchip.This nonlinearity generated additional DC components and harmonics,identified as the fundamental physicalcause of characteristic interference stripes and overall SAR image quality degradation.[Conclusions]The generationof DC offsets and harmonic distortion within the ADC’s MOSFET circuitry is the root physical mechanism behindSAR image degradation under CW interference within the specified band and JSR threshold.This research provides asolid theoretical foundation for designing electromagnetic interference(EMI)countermeasures in airborne SARsystems,thereby enhancing their robustness and imaging capability in challenging complex electromagneticenvironments.
作者
沈衍
陈亚洲
王玉明
马立云
王耀北
Shen Yan;Chen Yazhou;Wang Yuming;Ma Liyun;Wang Yaobei(Shijiazhuang Campus of Army Engineering University,Shijiazhuang 050003,China)
出处
《强激光与粒子束》
北大核心
2026年第1期140-152,共13页
High Power Laser and Particle Beams
基金
电磁环境效应国家级重点实验室基金项目(6142205210301)。
关键词
合成孔径雷达
连续波干扰
电磁干扰机理
非线性效应
synthetic aperture radar
continuous wave
electromagnetic interference
nonlinear effect
