共查询到17条相似文献,搜索用时 156 毫秒
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设计了一种基于电阻加载的超宽带TEM 喇叭天线。该天线由两片平滑渐变的金属曲面组成,通过在
馈电端引入微带渐变馈电结构便于同轴线馈电,同时在天线辐射片末端引入电阻加载技术消除天线口面与自由空
间失配引起的反射波能量,有效地改善低频特性,拓展带宽。在理论分析的基础上设计并制作了一副天线样机,实
验测试表明:在0. 1-5GHz 频率范围内,VSWR<2。该天线具有约50:1 的阻抗带宽,并且在0. 75-5GHz 频率范围内
具有良好传输特性。 相似文献
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在超宽带反射面天线设计中,首要问题是馈电天线的方向图与反射器匹配。以往在频域上对反射面天线的研究发现,当馈源天线方向图给出约-11 dB的边缘照射时,反射面天线可实现其最佳性能。在参数化模拟了作为馈源的透射电子显微镜(TEM)喇叭天线方向图特性的基础上,根据反射面天线的频域设计准则,相应地加入合适的超宽带反射面天线,对其远场辐射特性进行模拟计算。为了获得尽可能大的远场辐射场,采用计算机仿真技术(CST)数值模拟软件,在0 GHz~1 GHz频率范围内模拟了以不同参数TEM喇叭天线作馈源的超宽带反射面天线的远场辐射特性,并在时域上对其结果进行分析。模拟结果表明,由于其相位中心的不确定性,作为馈源的TEM喇叭天线无法与反射面天线完全匹配,其沿着反射面天线主轴移动时产生的反射面口径场相位和幅度的变化影响着远场辐射场的变化,TEM喇叭天线的遮挡效应也不容忽视。 相似文献
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恒阻抗TEM喇叭天线具有沿轴线方向特性阻抗为一恒定值的特点,所以喇叭内的反射损耗非常小,常用于超宽带电磁脉冲的辐射与接收。为了提高恒阻抗TEM喇叭天线远场主射方向脉冲峰峰值,通过数值仿真和实验测试研究了天线口径以及特性阻抗值与远场主射脉冲的关系。研究发现,天线沿主轴方向长度一定时,脉冲源通过50Ω同轴线直接向天线馈电,远场主射方向脉冲峰峰值先随天线口径增大而迅速增加,当口径达到某一值时,脉冲峰峰值达到最大值,如果继续增大口径,脉冲峰峰值开始缓慢下降。对于各个特性阻抗值不同的TEM喇叭天线,当它们分别选取上述峰峰值最大对应的口径时,280Ω的恒阻抗天线远场主射方向脉冲峰峰值最大。 相似文献
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设计了一种带有机玻璃天线罩的地平板结构横电磁波(TEM)喇叭接收天线,通过对馈入结构和辐射特性的理论分析初步确定关键结构尺寸,然后利用CST建立天线真实模型,完成相关结构参数的仿真优化,实现了快脉冲的较小馈入反射,时频特性良好。最后的天线测试结果表明,该TEM喇叭天线输入阻抗56 Ω,有效高度0.024 m,传递函数在3 GHz以内保持稳定,具备较好的时域保真度和馈入反射特性,适于作为超宽带接收天线。 相似文献
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本文设计一种共面波导馈电的超宽带天线(UWB),其阻抗带宽达到341%。所设计的天线印刷在尺寸为28×21×1.6mm3,介电常数为2.65的聚四氟乙烯介质基板上。并利用电磁仿真软件HFSS对影响天线性能的主要物理参数进行仿真、分析和优化,得到天线的理想尺寸。最后,对优化的超宽带天线进行制作,测试。实验结果表明,该天线比传统微带贴
片天线性能有了较大的提高,从而证明利用共面波导馈电的超宽带天线设计方法,能够实现兼容多种通信系统的可行性和有效性。 相似文献
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A design study for the basic TEM horn antenna 总被引:3,自引:0,他引:3
In this paper, a design study was performed for the basic TEM horn antenna. In the theoretical model, care was taken to avoid the problems associated with the use of gap sources when calculating the reflection coefficient and input impedance of the antenna. All numerical calculations were made with a program based on the method of moments, and the accuracy of the numerical calculations was established with measured results for selected antennas. The transverse electromagnetic (TEM) horn antenna is a popular broadband antenna. The basic antenna has a simple design consisting of two triangular plates and a feeding structure. The horn is described completely by only three variables: /spl alpha/, /spl beta/, and s. /spl alpha/ is the angular width of each plate, /spl beta/ is the angular separation between the two plates, and s is the length, measured from the drive point to the corner of the plate. The geometry of the basic TEM horn antenna does not require a particular choice of a feeding method. 相似文献
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提出一种电磁脉冲辐射系统设计方案,此系统由Marx发生器、短路-锐化组合开关型脉冲形成线和带低频补偿的高功率超宽带横向电磁波(TEM)喇叭天线组成.Marx发生器产生的单极脉冲经过短路-锐化组合开关型脉冲形成线锐化成双极脉冲,然后馈入天线进行辐射.仿真结果表明,在充电电压为10 kV时,电磁脉冲源可产生脉冲宽度1.41... 相似文献
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A general concept for ultrawide-band array design using interconnected transverse electromagnetic (TEM) horns is described. At high frequencies (wavelength small compared to unit cell dimensions), the mutual coupling between elements is small and, consequently, the input impedance depends only on the lattice dimensions and not on either scan angle or frequency. At low frequencies (wavelength large compared to unit cell dimensions), the mutual coupling is purposefully made large, by interconnecting the elements to maximize the low-frequency performance. This paper presents the results of analyses using a periodic hybrid finite-element approach to calculate input impedance and scanning performance of generic TEM horn arrays. The limiting case, the planar bicone, is shown to have the frequency-independent property of a self-complementary antenna, making it a useful case for establishing the effects of feed region geometry. Although it radiates bidirectionally, it has the interesting property that its broadside-scan frequency response in the array environment is absolutely flat up to the grating lobe onset limit. A TEM horn array is more unidirectional, but as a consequence suffers both oscillatory variations in the input impedance with frequency and increased limits on minimum achievable rise time 相似文献
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A simple Ultra-WideBand (UWB) exponentially-tapered Transverse ElectroMagnetic (TEM) horn antenna is presented for the asphalt detection based on Ground Penetrating Radar (GPR) In order to reduce the reflections from the antenna aperture, some absorbing material is loaded on the outer surface of the conductor. Comparing with the traditional TEM horn antenna, the proposed antenna has a small size and a large impedance bandwidth. Simulated and measured results show that the proposed TEM horn antenna has a low Voltage Standing Wave Ratio (VSWR) below 2 over the whole band from 0.35 GHz to 12 GHz, good radiation characteristics, and small late-time ringing, which can perfectly meet the requirements of the GPR application. 相似文献
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ABSTRACTA simple technique to design stable gain and low back lobe substrate-integrated waveguide (SIW) horn antenna is proposed. Matching is achieved by placing a metallised via in a specific distance from the aperture of the horn. The proposed design method is based on the analytical equivalent circuit that derived for the impedance of the antenna aperture and the matching metallic via in SIW. The aperture impedance and metallic via in SIW are studied and design curves are extracted for a specified substrate. Also, to reach a directive pattern and reduce the back lobe of the antenna, some chokes are used on the aperture of the horn. The effect of chokes on some parameters such as power flow and radiation pattern, the front to back ratio (FBR), side lobe level (SLL) and increasing directivity of the antenna is reported. The measurement results confirm simulation, appropriately. The proposed structure has high compactness due to the matching technique and design. The proposed SIW horn has compact dimensions as 18.7 * 23.34*7.62 mm (0.93 * 1.16 * 0.37 λ0) and the measured gain of the horn is about 5.5 dB at 15 GHz and bandwidth of six percent. 相似文献
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渐近线喇叭天线的传输模式为TEM波,因此不会产生色散,引起波形畸变,是辐射脉冲电磁波的理想天线。通过对渐近线喇叭天线组成各部分的设计与分析,介绍了一个应用于高能脉冲辐射条件下的渐近线喇叭天线的设计实例,具体描述了解决耐功率和驻波问题的方法,并进行了性能比较。测试和使用结果表明,所提方法切实可行,天线具有良好的阻抗特性和辐射特性,具有很好的实用价值。 相似文献