共查询到20条相似文献,搜索用时 15 毫秒
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介绍了阿基米德螺旋天线的原理与设计方法,仿真了背腔式阿基米德螺旋天线,并与实际测试结果吻合;研究了一种新颖的光子带隙平面螺旋天线,这种天线用光子带隙代替金属反射腔作为反射面以得到单向波束,仿真与实验发现,光子带隙阿基米德螺旋天线的增益提高约有2dB,后瓣降低了10dB,在有效的工作带宽内天线的性能得到了改善. 相似文献
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针对宽带射频识别系统和3G系统的要求,将阿基米德螺旋结构、陶瓷介质基板和光子带隙结构相结合,设计了一款三频光子带隙陶瓷阿基米德螺旋天线。仿真和实测结果显示,该款天线具有小尺寸、大工作带宽、良好的回波损耗性能和全向辐射特性。该款天线能够同时覆盖射频识别系统的868~870 MHz,902~928 MHz,2.400 0~2.483 5GHz频段和3G系统的1.710~1.785GHz频段,实现射频识别系统和3G系统移动终端的兼容。 相似文献
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新型光子带隙微带贴片天线 总被引:2,自引:1,他引:1
提出一种新型光子带隙(PBG)结构微带贴片天线。在同轴线馈电型微带贴片天线的接地板上蚀刻出新颖PBG结构,通过数值仿真得到有效提高增益的结构。实际制作了PBG结构微带天线,并实测了天线特性参数。数值结果和实验结果进行了比较,取得了较为一致的结果.实测天线增益达8.8dB,比无PBG时提高约3dB,验证了该PBG结构的有效性。 相似文献
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本文从正方形网格型PBG结构出发提出了新型的具有PBG结构的微带天线,讨论了在金属地板上蚀刻圆形孔的PBG结构微带天线,对其进行仿真,并对仿真结果进行分析,分析表明具有PBG结构的微带天线能够有效地抑制高次模,提高天线的性能. 相似文献
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For wideband RFID systems, a dual-frequency printed folded dipole antenna is designed with a photonic bandgap (PBG) structure carved in the antenna's arms. Simulated results show that this antenna has good return loss characteristic and hemisphere direction radiation characteristic, at two working centre frequencies of 0.90 and 2.24'GHz. Compared to other improved structures, the new PBG structure has special advantages in simplifying the antenna structure. Considering engineering processes, the influences of antenna arm width, dielectric loss, the PBG structure bore size and substrate on the performance of an antenna are particularly studied. 相似文献
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Harmonic suppression with photonic bandgap and defected ground structure for a microstrip patch antenna 总被引:3,自引:0,他引:3
Haiwen Liu Zhengfan Li Xiaowei Sun Junfa Mao 《Microwave and Wireless Components Letters, IEEE》2005,15(2):55-56
This letter presents a microstrip patch antenna integrated with two-dimensional photonic bandgap (PBG) and one-dimensional defected ground structure (DGS) jointly in ground plane. It is demonstrated that application of both PBG and DGS eliminates the second and third harmonics and improves the return loss level. Moreover, the combination use of PBG and DGS decreases the occupied area by 70% compared to the conventional PBG patch antenna. 相似文献
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PBG结构分析及其在柱面共形微带天线中的应用 总被引:1,自引:1,他引:0
利用光学Bragg反射条件,设计了两种曲面光子带隙结构,并将其应用于柱面共形微带贴片天线中,分析了光子带隙结构的结构参数对微带贴片天线性能的影响。计算仿真表明,利用合适的PBG结构可以增强微带贴片天线的前向增益,抑制高次谐波,减小旁瓣,减小表面波损耗。 相似文献
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设计了一种基于光子带隙(PBG)高阻表面的宽带双极化微带天线。将PBG高阻表面地板应用到设计的缝隙耦合微带天线上,实现了C波段阻抗带宽为22%(VSWR<2)的宽带双极化天线单元。仿真结果表明,与加金属地板的情况相比较,设计得到的PBG高阻表面在减缩剖面的同时,改善了天线的阻抗带宽、增益、端口隔离度和交叉极化,其中端口隔离度最大可以提高约8dB、轴向交叉极化可以提高约4dB。 相似文献
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分析了一种在高介电常数基板上周期性挖孔的PBG结构的阻带特性,然后在提出一种宽带圆极化天线的基础上,将这种PBG结构应用于天线底板,选择合适的栅格周期和孔半径,使得天线的谐振频率落在它的阻带范围内,可以很好地抑制表面波的传播,进一步改善天线的圆极化度。当天线工作于12.5GHz时,加载PBG结构的圆极化天线阻抗带宽达到20.6%(VSWR<2),3dB轴比带宽达到27.4%,这样的结果相对于普通圆极化天线而言,带宽有近10倍的增加。这种结构的圆极化天线在卫星通信等领域应用前景广阔。 相似文献
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以高介电常数介质为基底,利用辐射贴片开槽和微带馈电技术,设计了一款尺寸仅为16mm×12.45mm的小型微带天线。通过在此天线微带贴片周围加载高阻抗表面型光子晶体,有效抑制了表面波,改善了以高介电常数介质为基底的贴片天线的性能,实现了一款多频小型化PBG天线。HFSS仿真结果表明,加载高阻抗表面结构后的微带天线出现了三个谐振频点,分别为2.74、2.86和3.80GHz,其对应的增益分别达到6.02、8.38和5.69dB。所设计的光子晶体天线物理尺寸较小,方向性良好且具有多频特性,因此可为实际通信天线的应用提供参考。 相似文献
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The microstrip patch antenna is a low-profile robust planar structure. A wide range of radiation patterns can be achieved with this type of antenna and, due to the ease of manufacture, is inexpensive compared with other types of antennas. However, patch-antenna designs have some limitations such as restricted bandwidth of operation, low gain, and a potential decrease in radiation efficiency due to surface-wave losses. In this paper, a photonic-bandgap (PBG) substrate for patch antennas is proposed, which minimizes the surface-wave effects. In order to verify the performance of this kind of substrate, a configuration with a thick substrate is analyzed. The PBG patch antenna shows significantly reduced levels of surface modes compared to conventional patch antennas, thus improving the gain and far-field radiation pattern 相似文献
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Harmonic suppressed active antenna integrated with power amplifier yields improved efficiency, higher output power and reduced harmonic radiation from transmitter front end. This paper presents different harmonic suppression techniques of active antenna integrated with power amplifier. This paper also proposes and demonstrates novel PBG engineered structures to suppress higher order harmonics of integrated active antenna. 相似文献
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Directive photonic-bandgap antennas 总被引:15,自引:0,他引:15
This paper introduces two new photonic bandgap (PBG) material applications for antennas, in which a photonic parabolic reflector is studied. It is composed of dielectric parabolic layers associated to obtain a PBG material. The frequency gap is used to reflect and focus the electromagnetic waves. This device has been designed using a finite-difference time-domain (FDTD) code. FDTD computations have provided the theoretical reflector's directivity. These results are in good agreement with measurements, and it appears that the PBG reflector presents the same directivity as a metallic parabola. A second application uses a defect PBG material mode associated with a metallic plate to increase the directivity of a patch antenna. We explain the design of such a device and propose experimental results to validate the theoretical analysis 相似文献
18.
A spiral antenna backed by a conducting plane reflector 总被引:5,自引:0,他引:5
Nakano H. Nogami K. Arai S. Mimaki H. Yamauchi J. 《Antennas and Propagation, IEEE Transactions on》1986,34(6):791-796
An Archimedean planar spiral antenna is numerically analyzed in the presence of a conducting plane reflector. The analysis shows that the spiral antenna backed by the plane reflector has two distinct regions in the current distribution, which explain the radiation of a circularly polarized wave for the outer circumferenceC ranging over about1.3 lambda < C < 1.5 lambda andC > 2.9 lambda , wherelambda is a free-space wavelength. Further consideration is given to a truncated spiral antenna whose outer circumference is on the order of1.4 lambda . The truncated spiral antenna maintains a decaying current distribution and radiates a circularly polarized wave over a 1:1.2 frequency bandwidth. It is also demonstrated that a power gain on the order of 8.5 dB is realized over the same frequency range. 相似文献
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Truong Khang Nguyen Haewook Han Ikmo Park 《Journal of Infrared, Millimeter and Terahertz Waves》2011,32(6):763-777
In this paper, a full-wavelength dipole antenna, supported by a GaAs membrane structure, is examined. The antenna was designed
with both high input resistance and high radiation efficiency to improve the overall efficiency of a terahertz photomixer
design. The geometrical effects of the GaAs membrane structure on the overall antenna performance were investigated through
an optimization process. To supply DC bias to the antenna, a bias line with a photonic bandgap (PBG) structure was designed
and optimized. The resulting antenna had a 2742-Ω input resistance and a 65% radiation efficiency, corresponding to an approximately
44% total efficiency at the 1.05-THz resonance frequency. The proposed antenna is expected to efficiently generate THz waves
and be applicable to many practical applications where large coverage (detection area), easy alignment, and high scanning
speed, rather than high-resolution, are preferred. 相似文献