共查询到19条相似文献,搜索用时 156 毫秒
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基于NURBS建模的椭圆波束赋形天线设计 总被引:1,自引:0,他引:1
基于非均匀有理B样条曲面建模,提出一种低剖面椭圆波束赋形天线设计方法。利用馈源喇叭的辐射方向图和主反射面口面场分布函数,对φ=0°面的主副反射面曲线赋形,计算任意φ平面的主副反射面赋形曲线,利用非均匀有理B样条曲面建模技术对主副反射面建模并用全波仿真软件进行仿真优化。仿真结果表明,用该方法设计的椭圆波束天线在12.5 GHz和14.5 GHz时效率分别为67.82%和65.38%,第一副瓣电平均小于-14 dB,该天线实现了低剖面和高效率的优良性能。 相似文献
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针对双频段低剖面椭圆波束天线的需求,该文提出了一种新型混合结构椭圆波束天线的设计技术。该混合结构由主、副反射面内环部分构成的椭圆波束环焦天线和外环部分构成的椭圆波束卡塞格伦天线组成。该文描述了椭圆波束天线的设计思路、设计步骤和赋形计算公式,给出一个600 mm×1200 mm椭圆波束天线的设计实例,并进行了容差分析,该天线的工作频率覆盖了Ku/Ka双频段,效率达到56%以上,电压驻波比(VSWR)低于1.27,俯仰面第1旁瓣低于–12.2 dB,方位面第1旁瓣低于–14.6 dB。商业软件Grasp和CST全波仿真的结果吻合很好,证明了该新颖结构和设计方法的有效性。 相似文献
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为提高反射面天线的照射均匀性,利用波束赋形技术设计一款工作在15 GHz的高性能偏置反射面天线.该天线由一个非均匀有理B样条(non-uniform rational B-splines,NURBS)反射面和一个介质棒馈源组成,NURBS反射面通过物理光学法结合Nelder-Mead优化算法来赋形,从而获得理想的天线辐射场.仿真结果表明,赋形后的反射面天线相对旁瓣电平低于-20 dB,增益在-2.7°~2.7°的波束范围内超过20 dBi,且浮动不超过1 dB.该天线具有结构简单、旁瓣低、增益均匀的特点,在卫星通信等领域具有重要作用. 相似文献
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针对传统切换式多馈源的低剖面反射面天线结构复杂,不能多频段同时工作的问题,介绍了一款四波段单馈源低剖面环焦反射面天线及设计方法。该天线工作在四波段14~14.5 GHz, 11.45~12.75 GHz,19.6~21.2 GHz,29.4~31 GHz。整体天线采用双槽深波纹喇叭单馈源、通过口面场分布和多项式拟合过渡函数的方法构造的赋形副反射面和主反射面。用电磁仿真软件进行了建模仿真和验证。实测结果表明,整体天线较传统天线的效率提高12%以上,第一旁瓣<-14 dB,指标满足设计要求。 相似文献
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本文研究了双频段双极化赋形环焦网状TVRO天线。其核心是新型介质管加载引向的圆同轴波导馈源.Ku频段馈源由圆同轴波导内导体加介质引向器组成.C频段由圆同轴波导外导体延伸成圆锥喇叭组成.针对这种新式馈源,又探讨了双频段相心一致问题,双频段之间的耦台和干忧抑制方法,以及正交极化的隔离措施,文中还叙述了四连杆极轴式转台的特点和应用。最后,经CAD优化设计的双频段双极化赋形环焦Ф3m网状TVRO天线,又经CAM,其测试结果与理论分析十分吻合,在C/Ku频带内都达到并优于国际电联规定的入网旁瓣包络和正交极化隔离度的要求。 相似文献
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给出了用几何光学法计算双反射面天线方向图的求解过程,这种方法不但可以用于计算普通的反射面天线,而且可以用于计算特殊形状的双反射面天线。作为实例,用这种方法计算了环焦型椭圆波束天线和多波束抛物环面天线的方向图,实测结果和理论计算基本一致,从而验证了这种方法的正确性。 相似文献
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给出了在焦环 (ringfocus)上配置点馈源的环焦抛物面天线的增益与副瓣电平的计算方法与计算值 ,计算结果表明 :焦环上配置适当个数和位置适当的点馈源的环焦抛物面天线比馈源偏焦的普通抛物面天线有较高的增益和较低的副瓣电平 ,这些特性与馈源个数和位置有显著的关系。文中还利用上述特性设计了一个大口径的焦环卡塞格伦天线 ,结果显示 :它有较高的增益和较低的副瓣电平 相似文献
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Genetic algorithm is used to optimize a base station antenna in order to achieve ashaped beam in a frequency band. During the optimization process5 different antenna models havebeen evaluated using the Method of Moment (MoM). As a result of this optimization, a shapedbeam antenna with suppressed sidelobe smaller than-18dB, backlobe smaller than-30dB and 相似文献
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本文利用遗传算法对不等间距阵列天线进行优化,实现了一种赋形波束基站天线。天线模型用矩量法分析,并采用遗传算法综合天线方向图.在优化过程中通过合适的目标函数,保证了天线较好的频段特性,并压制干扰区副瓣、填充服务区零值、控制后瓣。优化后天线在整个工作频段上实际性能为:上副瓣小于-18.32dB,填充零点大于-14.71dB,前后比小于-26dB.与以前的方法相比,本文的结果更接近实际情况,并且该方法可应用于较复杂的天线.本文中的结果对工程和理论研究都有重要意义. 相似文献
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Isabelle Kossiavas 《电信纪事》1992,47(3-4):142-152
To facilitate the design of dual reflector antennas, the interactive, graphic CA2R software package handles centrally or offset-fed structures with quadric or shaped reflectors. Surface shaping, based on geometrical optics, improves the antenna’s efficiency and the sidelobe level. Existing techniques are applied to an offset-fed antenna with an elliptical projected aperture. An original numerical method to minimize crosspolar components is also presented. 相似文献
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本文设计了W 波段CW 雷达TR 高增益低副瓣天线,该天线采用偏馈切割反射面,天线尺寸带到400 个
波长,实现了高增益、低旁瓣、扇形波束,从而避开馈源及其支杆的遮挡,消除了由于遮挡造成的旁瓣电平上升,
又改善了馈源的输入电压驻波比;为了测试出准确的天线参数,研制了用于该天线使用和测量的高角度分辨率的天
线转台、角度精密指示器、天线转台控制器和测试数据采集系统。解决了窄波束(0.2°)高增益天线远场测试问题,
得到了较好的天线实测结果,满足了总体对天线设计的要求。 相似文献
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A complete procedure for the design and optimization of arbitrarily shaped integrated lens antennas 总被引:1,自引:0,他引:1
This paper proposes a new design methodology of arbitrarily shaped integrated lens antennas (ILAs). First, we describe the design principles and numerical techniques of the optimization iterative loop. The starting lens shape, deduced from a general synthesis method based on geometrical optics principles, is optimized so that the radiation pattern of the ILA complies with an arbitrary amplitude-shaped template. The optimization procedure is local and is based on a multidimensional conjugate gradient method. Then, the capabilities and potentialities of this approach are demonstrated numerically using two examples. In the first one, an ILA radiating a secant-squared beam in one principal plane and a flat-top beam in the orthogonal plane is designed for indoor communications in V-band. In the second example (Gaussian/flat-top beam), we show for the first time that the joint optimization of the feed together with the lens shape is a very promising design methodology. Finally, our design tools are validated experimentally in Q-band through the synthesis and optimization of a peculiar small shaped ILA (28 mm/spl times/28 mm/spl times/15 mm) fed by an aperture-coupled microstrip patch antenna. 相似文献
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Ashraf A. Adam Sharul Kamal Abdul Rahim Kim Geok Tan Ahmed Wasif Reza 《Wireless Personal Communications》2013,69(2):535-549
This paper presents a new design of an elliptical disc monopole antenna for ultra wideband (UWB) applications. The antenna is fed by a 50 Ω microstrip line and printed on a dielectric FR4 substrate of permittivity ε r = 4.7 and height h = 1.6 mm. The optimization on the planar elliptical disc monopole has been presented to accomplish an ultra wide 10 dB return loss bandwidth. The design includes a half-modified circular ground plane with two short I-shaped sleeves in the middle to enhance the S-parameter characteristics across the whole UWB frequency band. Furthermore, compared to a simple rectangular shaped ground plane, the proposed design enhances the bandwidth and improves input return loss. The obtained results confirm that the proposed antenna achieves greater than 90 % radiation efficiency, better than 10 dB return loss, and 0.1 ns group delay in the frequency range of 3.1–12 GHz. The parameters, which affect the performance of the antenna with respect to frequency domain and time domain characteristics, are investigated also. In addition, the proposed antenna is fabricated and the simulation results are compared to the measurement results to prove the superiority of the antenna. 相似文献
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本文设计了一种 K 频段低副瓣波导缝隙驻波阵天线,给出了实现低副瓣的方法。设计副瓣电平为-27dB,缝隙幅度分布按-30dB 泰勒分布计算,结合高频仿真软件 Ansoft HFSS 对各缝隙归一化导纳进行计算,建立仿真模型并优化天线各参数。依据设计结果加工实物并测试其方向图及增益。测试结果表明,该天线在工作频带内波束宽度约 3°,副瓣电平小于-27dB,工作频带内增益大于 30.8dB,仿真结果与实测结果相符,设计满足指标要求。 相似文献