共查询到20条相似文献,搜索用时 31 毫秒
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提出了一款宽频带高增益的圆极化毫米波天线.该天线由一个半球形的介质透镜圆顶以及一个圆柱形极化器结合而成,将传统的扩展半球介质透镜与介质极化器融合在一起,既能将线极化波转化成圆极化波(反之亦然),又能有效提高天线的增益.该设计与传统的级联结构(透镜级联极化器)不同,它能够用一个器件同时实现两个器件的功能,并且能大大减小系统的体积,降低插入损耗,减少生产成本.此外,该天线采用3D打印技术来实现,加工精度高并且容易生产,适合于毫米波天线的应用.经过验证,该天线的阻抗带宽能达到38%,轴比带宽为36%,圆极化增益达到22 dBic. 相似文献
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Wide-angle microwave lens for line source applications 总被引:3,自引:0,他引:3
A new "time-delay" scanner consists of a constrained wide-angle two-dimensional microwave lens with a straight front face in which lens elements connect arbitrary points on the inner and outer contours. The lens can operate at very short pulse lengths and can scan more beamwidths than any previously known device of its type. A phase analysis shows that this design has very small coma aberrations and that the lens can generate fractional degree beams. Criteria developed for selecting optimum lens parameters are given. The radiation patterns of an experimental model in which the lens elements consist of coaxial cables show the expected wide-angle characteristics. In further tests incremental scanning was obtained through the use of phase shifters in the coaxial lens elements. The design of symmetrical three-dimensional lenses is briefly discussed. A table of lens contour parameters is given for an optimum lens design with scan anglealpha of30deg . 相似文献
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在现实工作中,很多人纠结于是否能使用标清镜头来替代高清镜头,或者临时在一台标清摄像机上使用高清镜头,当然,如果是同品牌的镜头,是可以安装并使用,但是混用会有什么样的影响,本文从镜头调制传递(MTF)值出发,对高标清镜头使用做了定性的分析,为正确使用高标清镜头提供了基础的理论依据。 相似文献
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为设计单个非球面扩束(缩束)透镜,由光线折射定律矢量形式和对非球面折射特性的理论分析,提出了一种设计单个非球面扩束(缩束)透镜的新方法全面学习策略的粒子群算法,并用此方法设计出了线度小于170 mm缩束14.16倍的单个非球面缩束透镜,用光线追迹方法模拟了缩束或扩束过程。模拟结果表明,单个非球面透镜可以起到缩束或者扩束作用,全面学习策略的粒子群算法可用于非球面缩束透镜的设计。单个非球面透镜作为扩束镜使扩束系统结构大大简化,大大提高了出射光斑的均匀性。 相似文献
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为了获得具有高增益特性的天线,对传统透镜天线工作原理进行了分析。因为透镜天线板间电场模式与波导中电场模式类似,以此为依据通过改变金属透镜的金属平板间距和板脊高度,设计了一种新型金属透镜天线,迥异于传统金属透镜天线的凹形曲面结构。该天线金属透镜由多片长方形侧面加脊金属板组成,能够很好地调节口径面的相位分布,以此实现口径面同相分布,从而获得高增益性能。 相似文献
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微柱阵列和两种透镜导管耦合系统的三维光线追迹与设计 总被引:2,自引:1,他引:1
微柱阵列和透镜导管组成的耦合系统在激光二极管阵列(LDA)抽运的全固态高能量激光器中起着重要的作用,其光束耦合性能直接影响激光器的最终输出能量和光束质量。为了设计微柱阵列和透镜导管耦合系统的最佳结构参数,需要研究抽运光在耦合系统内部以及在激光晶体端面的分布。利用几何光学理论,对LDA的发射光线经微柱阵列和透镜导管的传输进行三维空间追迹,并计算其能量传输效率和光束整形效果。比较了六面体导管和渐细圆台形导管的耦合性能。仿真分析结果表明,六面体导管需要长度较大,能量传输效率略高,而圆台形导管可以较短,耦合整形后的光斑更接近圆形。 相似文献
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本文介绍了短焦距离平轴全息透镜的特点、成像机制和制做方法。离轴全息透镜是用干涉原理制成的光学元件,它与普通透镜相互补充能完成某些特殊的功能。本文所研制的离轴全息透镜能使正入射的平行光经透镜后短焦距离轴会聚,适应了某些光学系统的特殊需要。 相似文献
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An iteration technique is applied to the design of a bifocal dielectric lens antenna. A bifocal lens has two conjugate off-axis focal points and offers good off-axis scanning performance. A computer model was developed to aid in the design analysis and far-field performance evaluation of a bifocal lens. The computer simulation results demonstrate that the bifocal dielectric lens can provide a higher-gain radiation pattern for multibeam antenna (MBA) applications over a large field-of-view. The computer study also indicates that the quadratic phase error can be significantly reduced by constraining the feed along an optimized focal arc 相似文献
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Jaeheung Kim Choon Sik Cho Barnes F.S. 《Microwave and Wireless Components Letters, IEEE》2005,15(5):348-350
A new form of a Rotman lens has been proposed for applications above 10 GHz, such as a collision avoidance radar. The proposed lens can be described as a dielectric slab fed by slot lines. The new form is expected to show lower loss and lower mutual coupling than the conventional Rotman lenses at higher frequency than 10 GHz. The prototype was implemented with nine beam ports and nine array ports. The measurements show that the mutual coupling can be lowered at higher frequency, and that the efficiency of the dielectric slab lens of about 30% can be obtained. We conclude that the dielectric lens is comparable to the conducting plate lens even though a spillover loss is presumed at frequency of the implementation. 相似文献
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与红外定焦镜头和红外两档变焦镜头相比,红外连续变焦镜头具有连续可变的视场,可对目标进行连续的跟踪,是未来红外成像技术的发展方向.随着光学冷加工、精密机械加工、镀膜技术等工艺水平的不断进步,以及现代科技的发展要求,红外变焦镜头向高变焦比方向发展,同时还须保持良好的成像和消热差性能.概述了国外各种高变焦比中波红外镜头的结构和设计方法,包括20高变焦比中波红外镜头、30高变焦比中波红外镜头、300高变焦比中波红外镜头,总结了一套高变焦比中波红外镜头设计经验,对国内高变焦比中波红外镜头的应用发展研究有借鉴价值. 相似文献
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本文叙述用两台光学定中心仪来观测硅、锗透镜前后表面的球心反射像,并用CCD接收电视屏显示,校正硅、锗透镜的位置,从而达到高精度双面定中心的要求。文中给出了定中心后监视系统装置及实验结果。 相似文献
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在激光系统中,伽里略球面透镜扩束器已得到广泛地应用,但是,它有许我乐足之处。本文中,研究了伽里略非球面透镜扩束器,给出了伽里略非球面透镜扩束器光学系统设计的方法和设计结果。我们得出的结论是:伽里略非球面秀镜扩束器比伽里略球面透镜扩束器好。 相似文献
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高精度光刻物镜中的光学透镜在自身重力以及装夹预紧力的作用下,面形会发生变化,从而会对光学系统各种像差造成影响。在考虑透镜自重的情况下,研究了镜片夹紧方式及夹紧力对其像差的影响规律。分别在镜片顶面和侧面施加2~6点均布、均匀载荷,且每种加载情况下夹紧力线性增大,通过有限元仿真计算出各种受力情况下的镜面变形;将变形量数据用66项标准Zernike多项式进行拟合,分析载荷均布点数以及载荷力大小对透镜像差的影响。分析结果表明:各种加载工况下透镜像差中的重要影响项皆为平移、离焦、球差和n-foil(n为均布载荷点数);重要影响项所对应Zernike多项式的系数变化与夹紧力变化呈线性关系。分析结果为补偿透镜像差提供了依据,并能指导像差校正的透镜设计。 相似文献
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The optical elements' maladjustment is a potential threaten in optical systems,thus,the transmission feature of laser beams passing through a misaligned optical system is widely studied.By using approximate expansion of circle diaphragm and generalized Huygens-Fresnel diffraction formula,a universal analytic expression is deduced for the flat-topped multi-Gaussian beams passing through a misaligned optical system with two-lens and two-diaphragm.The study on the propagating property of fundamental-mode Gaussian beams and a flat-topped multi-Gaussian beam is carried out accordingly.The expansion of complex Gauss function of misaligned optical circle diaphragm is given,as well as a group of new parameter values of the expansion of complex Gauss function.By using the new parameter values,the influence of disadjust parameters on output intensity distribution is analyzed numerically.The result shows that the diaphragms'offset can make the beams offset or covered,and the second diaphragm influences more;the angle deflection of diaphragms can make light beams compressed in the deflection direction,and the first diaphragm influences more;the offset of the first lens can weaken light intensity in the same direction of the lens offset,and the offset of the second lens can weaken light intensity in the opposite direction of the lens offset;the angle deflection of the first lens can make light beams move to the opposite direction,and the angle deflection of the second lens has no influence;when all the diaphragms and the lenses are disadjust,the angle deflection of the first lens has a vital influence to the output intensity distribution. 相似文献
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Three-dimensional bootlace lens antennas with two and four focal points can be optimized to produce high-quality scanned beams over a wide field of view. For two-dimensional scanning, the planar feed locus is replaced by a curved feed locus designed to minimize path length errors. Comparisons with previous bootlace lens designs demonstrate the advantages of this focal distribution. The bifocal lens shows good scanning performance in both principal and orthogonal planes. The quadrufocal lens performs better in its principal plane than in its orthogonal plane. It is also shown that the quadrufocal lens can be realized with a planar outer surface and a circular focal arc, and improved scanning performance is still achievable. Further optimization of the focal arc and/or relaxation of the planar outer surface condition results in quadrufocal lenses with negligible phase errors in the principal plane. 相似文献