Electromagnetic coupling reduction in dual-band microstrip antenna array using ultra-compact single-negative electric metamaterials for MIMO application

In this paper, an ultra-compact single negative(SNG) electric waveguided metamaterial(WG-MTM) is first investigated and used to reduce the mutual coupling in E H planes of a dual-band microstrip antenna array. The proposed SNG electric WG-MTM unit cell is designed by etching two different symmetrical spiral lines on the ground, and has two stopbands operating at 1.86 GHz and 2.40 GHz. The circuit size is very compact, which is only λ_0/33.6 ×λ_0/15.1(where λ_0 is the wavelength at 1.86 GHz in free space). Taking advantage of the dual-stopband property of the proposed SNG electric WG-MTM, a dual-band microstrip antenna array operating at 1.86 GHz and 2.40 GHz with very low mutual coupling is designed by embedding a cross shaped array of the proposed SNG electric WG-MTM. The measured and simulated results of the designed dual-band antenna array are in good agreement with each other, indicating that the mutual coupling of the fabricated dual-band antenna array realizes 9.8/11.1 d B reductions in the H plane, 8.5/7.9 d B reductions in the E plane at1.86 GHz and 2.40 GHz, respectively. Besides, the distance of the antenna elements in the array is only 0.35 λ_0(where λ_0 is the wavelength at 1.86 GHz in free space). The proposed strategy is used for the first time to reduce the mutual coupling in E H planes of the dual-band microstrip antenna array by using ultra-compact SNG electric WG-MTM.     

脉冲积累对双点源干扰影响分析

双点源干扰是一种针对单脉冲雷达的有效角度欺骗干扰技术。现有文献均在单次回波情况下分析双点源相干及非相干情况下的干扰效果。而实际情况下,雷达在进行数据处理时,会进行脉冲积累处理,此时双点源干扰两点源信号间的相位会受到脉冲积累的影响,进而影响干扰效果。通过仿真分析,得出了脉冲积累处理下,单脉冲雷达受双点源干扰欺骗的角度不再稳定,而是在一定范围内波动的结论。     

双点源干扰对抗主动寻的导弹的有效新方法

双点源干扰对抗主动寻的导弹过程中,两点源和导引头形成的张 角由小变大,这种变化导致偏离角度减小。通过分析当张角等于分辨角时的偏离角度,得出 拖曳式诱饵和交叉眼两种典型的双点源干扰有效对抗寻的导弹的新方法,该方法主要通过改 变两点源功率比来增大偏离角度。仿真与分析验证了该方法的有效性。     

对NETD表达的红外热像仪探测距离的讨论

红外热像仪对目标的探测距离的计算方法已有多种,本文对基于目标与背景温差△T0和等效噪声温差NETD而推导出的公式进行了分析,对大气透过率τa对△T0的衰减作用提出了不同的看法,并据此对基于△T0和NETD的热像仪探测距离公式进行了修正,对影响NETD参数的诸多因素进行了分析.在此基础上,推导出了热像仪对含有不同温度的多个红外辐射源的同一目标的距离计算公式.     

雷达诱饵的干扰仿真及分析

雷达诱饵可与目标一起对跟踪雷达形成双点源干扰，从而造成测角偏差，使武器系统失去对目标的进攻能力。为了更为确切地揭示雷达诱饵的干扰效果，本文以雷达天线波束参数为基础，对雷达诱饵的干扰效果进行了仿真，得到了较为确切的仿真结果，并对仿真结果进行了分析。     

一种基于T型缺陷微带结构低通滤波器

提出了一种T型微带缺陷结构(DMS),并分析了其传输特性,设计并制作了一款基于T型DMS低通滤波器,仿真和实测结果表明,所设计的新型低通滤波器3 dB截止频率为2.9 GHz,通带插入损耗小于0.15 dB,回波损耗最大旁瓣优于15 dB。该滤波器设计方法简单,电磁泄漏小,体积小,并且易于与其他电路集成。     

Metamaterial beam scanning leaky-wave antenna based on quarter mode substrate integrated waveguide structure

In this paper, we first propose a metamaterial structure by etching the same two interdigital fingers on the upper ground of quarter mode substrate integrated waveguide(QMSIW). The simulated results show that the proposed QMSIWbased metamaterial has a continuous phase constant changing from negative to positive values within its passband. A periodic leaky-wave antenna(LWA), which consists of 11 QMSIW-based metamaterial unit cells, is designed, fabricated,and measured. The measured results show that the fabricated antenna achieves a continuous beam scanning property from backward-43° to forward +32° over an operating frequencyrange of 8.9 GHz–11.8 GHz with return loss better than 10 d B.The measured antenna gain keeps consistent with the variation of less than 2 d B over the operating frequency range with a maximum gain of 12 d B. Besides, the measured and simulated results are in good agreement with each other, indicating the significance and effectiveness of this method.     

拖曳式诱饵对单脉冲雷达的干扰分析

拖曳式诱饵是一种在实战中得到检验、可有效对付防空导弹的电子战装备。本文对拖曳式诱饵的设计原则及其对单脉冲雷达的干扰机理进行了分析,并提出了防空雷达分离拖曳式诱饵的技术条件。