共查询到19条相似文献,搜索用时 203 毫秒
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本文利用光子晶体带隙(PBG)结构的特点,将特殊设计的 PBG 结构应用于圆柱形微带贴片天线中。在同轴线馈电的圆柱形微带贴片天线的介质上蚀刻出按一定规律排列的 PBG 结构,并基于 HFSS 对特殊设计的 PGB 结构圆柱形微带贴片天线和普通的圆柱形微带贴片天线进行仿真和优化,仿真结果表明,按照一定规律排列的 PBG 结构可以有效抑制天线表面波的传播,明显提高圆柱形微带贴片天线的带宽和增益,有效改善圆柱形微带贴片天线的辐射方向图,实现天线性能的优化设计。 相似文献
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提出了一种加载S型缝隙的方形切角毫米波微带天线。该天线的辐射贴片采用方形切角,在贴片中央进行非对称S型缝隙开槽,实现了双频点圆极化。在接地板上进行阶跃型缝隙开槽,改变了微带天线的辐射特性及阻抗特性。同时采用加载调谐支节的耦合馈电方式,实现了微带贴片天线频带的展宽。 相似文献
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针对用于气体绝缘组合电器(GIS)局部放电特高频(UHF)在线监测的天线传感器应具有宽频带、高增益和小尺寸等性能要求,设计了一种外置小型四频段微带单极子特高频天线传感器。采用多个辐射单元技术,展宽了特高频天线的检测频段,实现了传感器的多频信号传感特性,运用HFSS仿真软件对天线结构尺寸进行优化设计,选取一组最优参数进行特高频天线实物制作。理论计算和实验室天线特性实测表明,研制的外置四频段微带单极子特高频天线性能优异,在实验室GIS装置上,用已有的微带贴片特高频天线与所设计的特高频天线传感器对模拟缺陷产生的局放信号进行了对比检测,进一步证明了微带单极子特高频天线具有良好的检测灵敏度。 相似文献
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为克服合成孔径雷达中现有微带天线带宽窄、效率低、成本高的缺陷,提出了一种在低成本FR4基板上实现的X波段宽带高效堆叠微带贴片天线。天线通过多层FR4基板堆叠方式构成,通过空气腔的引入,天线的有效介电常数和介质损耗得到降低,天线的效率和带宽得到提升。利用寄生贴片在带内增加了谐振点,使得天线的带宽得到进一步增大。同时为补偿馈电探针的寄生电感,利用微带匹配器对天线的输入阻抗进行匹配。实测表明,天线输入驻波低于2.0的频率范围为7.7~11.7GHz,相对带宽大于40%。天线的增益为7.6dBi,效率为83%。与传统微带贴片天线相比,具有宽带、高效、低成本的特点,具有一定应用前景。 相似文献
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一种新型双频微带天线的设计与仿真 总被引:1,自引:0,他引:1
本文研究了一种新型结构的可同时工作在S/X波段的双频微带贴片天线.该天线的S波段单元和X波段单元印制在同一层介质基板上,S波段单元是一在边长40 mm方形贴片内对称开出4个边长12 mm方形槽的"田"字形贴片天线,4个边长为8 mm的方形贴片对应布置于"田"字形贴片槽内.这种结构可以实现天线的孔径复用,有利于减小天线的尺寸重量,便于设计制造.最后借助Ansoft 公司的Designer仿真软件对此天线进行仿真计算,讨论了两种情况下天线的辐射特性. 相似文献
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微带贴片天线的基板材料的相对介电常数和介质板厚度是影响天线性能的重要因素.为了验证在相同相对介电常数的情况下,改变介质基板的不同的厚度时微带矩形贴片天线的阻抗带宽的变化,通过HFSS软件设计和仿真了工作频率为1.95 GHz的4个矩形微带贴片天线,相对介电常数均为2.2,介质基板厚度分别设计为0.8、1.6、2.4、3.2 mm,比较其各自的S参数、方向图,通过仿真结果验证了相关文献所述的对于在给定的频率下,选用相同的基板材料时,厚度增大时阻抗带宽会变大的说法. 相似文献
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设计了一种层叠圆极化微带贴片天线,采用宽带功分网络形成四馈点馈电,实现右旋圆极化接收,工作带宽覆盖L波段内多个卫星导航频点,具有优良的方向图特性及轴比特性。利用Ansoft HFSS对天线模型进行了优化分析,制作了天线实物,对天线轴比进行了实测,结果表明天线设计达到了设计要求。 相似文献
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为了实现宽频带天线指定方向的高性能辐射,设计了一种宽频带的微带等角螺旋天线。为实现阻抗匹配,天线馈电部分设计了一种指数渐变式微带巴伦结构。经过实物测试参数,结果表明加入了指数渐变巴伦结构后天线实现了良好的阻抗匹配并具有良好的宽频带特性,其工作带宽为1.74~4.82 GHz,回波损耗最低达- 30 dB。同时设计了一个平底型金属反射腔用于反射背向电磁波,在保持宽频带工作特性的同时,使天线具有了良好的单向辐射特性,天线在整个工作频段内的增益均大于6 dB,与传统的螺旋天线相比,具有宽频、定向、高增益的特点,具有一定应用前景。 相似文献
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A generalized method of lines algorithm is presented for characterizing unbounded and bounded circuits. Finite substrate extent and inhomogeneous dielectric layers are rigorously considered in this field‐based model. Radiating properties of unbounded regular and irregular microstrip patch resonators and arrays are studied with emphasis on effects of mutual coupling and finite dielectric extent on complex resonant frequencies. In addition, unbounded loss effects for microstrip open‐end and 90° angular bend deposited on finite substrate as well as chip‐to‐chip discontinuities are also investigated. Our developed algorithm incorporates an absorbing boundary condition using the Padé approximation to simulate any potential radiation and leakage losses for resonator structures while an improved lossy absorbing boundary condition (LABC) that can handle both propagating and evanescent waves is used to determine the unbounded effects for waveguiding structures. Results indicate interesting properties of the finite extent of dielectric substrate on resonance and radiation characteristics, and also on unbounded radiation and leakage losses. Copyright © 2000 John Wiley & Sons, Ltd. 相似文献
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In this work, the resonance and radiation characteristics of a superconducting cylindrical-rectangular microstrip antenna covered with a dielectric layer are studied using an electric field integral equation and the spectral-domain Green’s function. The effect of superconductivity of the patch is modeled by including surface complex impedance in the formulation. In order to validate the present method, numerical results for the cylindrical microstrip antenna with a perfectly conducting patch are presented and very good agreement has been demonstrated between our computed data and those found in the literature. Once the validity of the method is checked, the effect of the superconducting patch on resonance frequency, half-power bandwidth and radiation pattern of cylindrical rectangular microstrip patch is studied. It is found that the resonant frequency is affected significantly by the superconductivity property of the patch and the half-power bandwidth is considerably increased, which improves the narrow bandwidth characteristics of the microstrip structure. Further results show that a thin superconductor patch has a significant effect on the E-plane radiation pattern. 相似文献
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The effect of the substrate structure on the radiation properties of microstrip array feed networks is investigated with the space-domain integral equation approach. Numerical and analytical techniques are employed to produce efficient computer algorithms. Results for space and surface wave losses are presented for corner discontinuities printed on substrate/superstrate, and two-layer substrate structures. Comparisons are made with the single-layer case. 相似文献
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汽轮机蒸汽湿度的在线测量,对汽轮机的安全、经济运行具有重要的理论意义和实用价值。根据微扰法的基本理论,提出一种结构简单、灵敏度高的倒置微带贴片谐振器,实现汽轮机湿度的准确在线测量。湿蒸汽的湿度变化反应为谐振器介质层介电常数的变化,根据微带贴片谐振器的基本原理,仿真计算不同介电常数下的谐振频率,得到其变化关系曲线;讨论样本厚度、基质厚度和基质介电常数对频率偏移量的影响;设计微带贴片谐振器模型,并分别在HFSS和CST软件下进行仿真。研究及仿真结果表明,微带贴片谐振器模型适用于汽轮机蒸汽湿度的在线测量,蒸汽湿度每变化1%,谐振器频偏约为18 k Hz,约为微带缝隙谐振器频偏的3.6倍,有利于蒸汽湿度的准确测量。 相似文献
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In this paper we present a new theoretical model for the modelling of the microstrip line as well as two types of discontinuities: regular (open end, step, bend and T‐ and cross‐junctions) and irregular (stub and bent‐stub). The two‐dimensional exact dyadic Green function of a grounded dielectric slab has been used with the Galerkin's technique. The subdivision of the discontinuity in a network of juxtaposed unit cells, characterized by their own longitudinal and transversal current distributions, allowed the treatment of a large class of irregular discontinuities in addition to the regular discontinuities. The obtained results have been commented and compared with those of different approaches and with experimental results where a good concordance has been observed. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
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Analysis and design of rectangular microstrip antenna on two-layer substrate materials at terahertz frequency 总被引:1,自引:0,他引:1
In this paper, an effective permittivity of the two-layer dielectric substrate material has been analyzed to enhance the electrical
performance of the rectangular microstrip patch antenna at terahertz frequency. The frequency dependent effective dielectric
permittivity of the substrate materials has been evaluated and result has been compared with finite integral technique based
CST Microwave Studio a commercially available simulator. The input impedance characteristic with electrical performance of
the rectangular microstrip patch antenna on two-layer substrate materials has also been analyzed at 600 GHz. Manipulation
in the input impedance characteristic of the antenna has led to a slow wave structure. This slow wave structure has been examined
at 542 GHz, and improvement in the performance has been observed without increasing the overall dimension of the proposed
antenna. 相似文献
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Dual-band rectangular microstrip patch antenna at terahertz frequency for surveillance system 总被引:1,自引:0,他引:1
In this paper, a rectangular microstrip patch antenna on two-layer substrate materials has been analyzed and simulated at
the terahertz frequency regime for the surveillance system. The proposed antenna has been simulated at 600 and 800 GHz frequencies
by using CST Microwave Studio a commercially available simulator based on finite integral technique. This antenna structure
is also simulated by using finite element method based simulator Ansoft HFSS and the results are compared with former. 相似文献
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Felix A. Miranda Carl H. Mueller Fred W. Van Keuls Guru Subramanyam Sivaruban Vignesparamoorthy 《Integrated ferroelectrics》2013,141(1):121-131
The inclusion of voltage-tunable barium strontium titanate (BSTO) thin films into planar band pass filters offers tremendous potential to increase their versatility. The ability to tune the passband so as to correct for minor deviations in manufacturing tolerances, or to completely reconfigure the operating frequencies of a microwave communication system, are highly sought-after goals. However, use of ferroelectric films in these devices results in higher dielectric losses, which in turn increase the insertion loss and decrease the quality factors of the filters. This study explores the use of patterned ferroelectric layers to minimize dielectric losses without degrading tunability. Patterning the ferroelectric layers enables us to constrict the width of the ferroelectric layers between the coupled microstrip lines, and minimize losses due to ferroelectric layers. Coupled one-pole microstrip bandpass filters with fundamental resonaces at ~7.2 GHz and well-defined harmonic resonances at ~14.4 and ~21.6 GHz, were designed, simulated and tested. For one of the filters, experimental results verified that its center frequency was tunable by 528 MHz at a center frequency of 21.957 GHz, with insertion losses varying from 4.3 to 2.5 dB, at 0 and 3.5 V/ w m, respectively. These data demonstrate that the tuning-to-loss figure of merit of tunable microstrip filters can be greatly improved using patterned ferroelectric thin films as the tuning element, and tuning can be controlled by engineering the ferroelectric constriction in the coupled sections. 相似文献