电磁带隙结构的微带天线设计

本文设计了一种应用于无线局域网的电磁带隙结构(EBG)的微带天线。通过在微带贴片天线的辐射单元周围加载蘑菇型EBG结构,使得天线的带宽、增益性能得到了显著改善。仿真结果表明,与普通贴片天线相比,加载EBG结构时天线带宽增加了6%,主辐射方向上增益增大了1.98dB。     

基于HFSS的双层宽带微带贴片天线的研究

采用HFSS10电磁场仿真软件设计和仿真了一种新型宽频带双层微带贴片天线,本文中天线采用聚四氟乙烯和空气两层介质,通过增加空气介质层的厚度,同时利用圆形金属电容片补偿馈电探针引起的电感,对微带天线进行耦合馈电,仿真结果表明天线的阻抗带宽达到了23%（VSWR≤2）,从而实现了宽频带微带天线的设计.     

微带周期结构的仿真研究

周期结构（光子晶体结构）是电磁场与微波技术中的一种特殊结构,周期性的微带结构在相控阵天线、高性能天线、高功率微波器以及滤波器的设计等领域都有着广泛应用。分析微带周期结构的带隙特性对进行天线的设计,提高天线的性能具有十分重要的意义。用HFSS软件建立一种DGS结构的微带周期结构模型,进行仿真分析。     

微带贴片天线的仿真与测量实验设计

本文以一种典型的微带贴片天线教学为例,从理论、仿真设计以及实验测试三方面对相关教学环节和步骤进行了详细的介绍。理论设计部分重点介绍了设计贴片尺寸和进行阻抗匹配的方法。仿真环节介绍了模型、网格及收敛能量的设置。实验环节简要介绍了天线的简易测量系统和测试结果。     

电磁带隙结构反射板双面印刷偶极子天线研究

采用具有紧凑尺寸特征的高阻抗表面蘑菇状电磁带隙结构(EBG)做为双面印刷偶极子天线的反射板,利用HFSS电磁仿真软件模拟对传统金属良导体(PEC)反射板结构以及EBG反射板结构双面印刷偶极子天线的主要参数进行了对比研究。研究表明:采用EBG结构后可降低传统天线的高度约55%,同时提高天线增益约1.9dB。     

双频圆极化卫星定位系统天线设计

为了适应全球卫星定位系统的需要,采用多层重叠的贴片结构,设计了一种双频圆极化天线。其中上层贴片为圆形,下层为矩形,利用开槽技术分别在1．618GHz和2．49GHz频段处实现了圆极化,并且通过在下层贴片的四条边上分别开设矩形槽达到了缩小天线尺寸的目的。同时采用单点同轴馈电,实现了良好的阻抗匹配性能。     

双频超宽带微带天线的设计与仿真

提出了一种基于圆形缝隙结构的双频超宽带微带天线.通过在圆形缝隙内加载椭圆形贴片使得天线在获得双频超宽带特性的同时又保持了很小的物理尺寸.仿真结果表明,该天线的-10 dB阻抗带宽分别为2.1~4.0 GHz和5.2~8.8 GHz,天线的相对带宽分别达到了62.3%和51.4%,覆盖了无线局域网(WLAN)的2.45 GHz、5.20 GHz和5.80 GHz三个频段以及宽带互通微波接入(WiMAX)的2.50 GHz和5.25 GHz两个频段.在通带范围内,有良好的辐射特性,并且天线的尺寸为35 mm×35 mm×1 mm,便于集成在电路系统中.     

一种无线智能网络传感器弯曲微带天线设计

设计了一种适用于无线智能网络传感器的弯曲微带贴片天线,该天线能够满足无线智能网络传感器小型化,耗低功,高集成度等方面的要求.通过HFSS软件进行仿真优化,该天线中心频率满足ISM规定的2.45G Hz,回波损耗、带宽、方向、增益均达到了较好的效果.实验仿真结果表明此弯曲微带天线设计可以适用于无线智能网络传感器模块.     

一种用于卫星通信系统的三频天线设计

为了适应卫星通信系统终端的需求,设计了一种三频段天线,辐射贴片的基本形状为四周圆角的矩形,在贴片上分别开T形槽和L形槽,使天线产生3个工作频点。通过对辐射贴片的电流分布和槽形结构进行分析,发现开槽可使电流路径增加,在所需的频段范围内能有效降低回波损耗;同时发现,减小天线的接地面宽度,可减小天线尺寸,从而提高天线的辐射效率。实测结果表明该天线能满足设计要求。     

一种双模圆极化贴片天线设计

为满足卫星导航系统的要求,采用单点馈电叠层贴片技术,设计了一种双频圆极化宽波束天线;采用隐式的时域有限差分方法,对天线进行全波仿真,分析了影响匹配性能的结构参数,并通过在贴片的一组对边上开矩形缝隙,微调天线谐振频率,同时实现了阻抗带宽和轴比带宽相吻合;总结出改善天线双频匹配特性的方法,解决了双频段同时达到最佳匹配的问题。     

A Novel Electromagnetic Bandgap Structure for Filter

Electromagnetic bandgap (EBG) materials are periodic structures capable of prohibiting the propagation of electromagnetic waves within a certain band of frequencies. This characteristic of EBG has wide application. The structures to be studied here are mainly planar EBG materials of two dimensions, which are periodic arrays of holes etched in the ground plane of a conventional microstrip line. EBG structures are calculated with finite-difference time-domain (FDTD) method in this paper. Technique of the perfectly matched layer is used for the absorption of electromagnetic waves in FDTD. The FDTD method is programmed with the blend of C^ and Matlab languages, which makes the program both simple and fast computing. A kind of new EBG structure is brought out through a lot of experiments and analyses. A filter with wide stop-band and another filter with two stop-bands are designed.     

A Novel Electrmagnetic Bandgap Structure for Filer

Electromagnetic bandgap (EBG) materials are periodic structures capable of prohibiting the propagation of electromagnetic waves within a certain band of frequencies. This cheracteristic of EBG has wide application. The structures to be studied here are mainly planar EBG materials of two dimensions, which are periodic arrays of holes etched in the ground plane of a conventional microstrip line. EBG structures are calculated with finite-difference time-domain (FDTD) method in this paper. Technique of the perfectly matched layer is used for the absorption of electromagnetic waves in FDTD. The FDTD method is programmed with the blend of C + +and Matlab languages, which makes the program beth simple and fast computing. A kind of new EBG structure is brought out through a lot of experiments and analyses. A filter with wide stop-band and another filter with two stop-bands are designed.     

A Design of RFID Antenna based on Left-hand Material

Square-shaped Split-ring resonator(SRR) lefthand Material(LHM) is proposed in Radio frequency band and S parameter extraction method was used to extract the effective permittivity and permittivity are all negative, hence verifying the nature of its left-hand properties. LHM is put on to dielectric layer of the center frequency of 920 MHZ microstrip patch antenna with 50 Ω coaxial feed. Then the left-hand microstrip patch antenna and conventional antenna are compared, finding that return loss S11 down from- 30 dB to-60 dB.     

用于RFID读卡器的低旁瓣圆极化微带天线阵的设计

A low-sidelobe circularly-polarized （CP） microstrip patch array for 2.4 GHz radio frequency identification （RFID） readers is presented. The antenna array with a Chebyshev current distribution is composed of 6 microstrip elements. The CP operation is obtained by the quasi-square patch with difference in lengths of the two sides. The antenna has been investigated numerically and experimentally. Measured results show that the array has a Chebyshev pattern with the sidelobe level of -23 dB, the half-power beamwidth of 16° and an impedance bandwidth （S11 ≥-10 dB） of 130 MHz, which is suitable for RFID reader applications.     

紧缩结构双频天线的设计

为了实现双频天线的小型化,对平面倒F形天线给出一种改进,在辐射贴片上开一个T形槽．再将它的尾部向内折叠。通过与L形开槽的倒F形天线相比表明：改进后天线的结构更加紧凑,尺寸减小30％以上,且在给定的工作频段具有良好的辐射特性。     

A four spiral slots microstrip patch antenna for radiotelemetry capsules based on FDTD

Antenna is very crucial to radiotelemetry capsules which can measure the physiological parameters of the gastroin- testinal (GI) tract. The objective of this paper is to design a novel spiral slots microstrip patch antenna for the radiotelemetry capsules communicating with external recorder at 915 MHz located in ISM (Industry, Science, and Medical) bands. The microstrip patch antenna is designed and evaluated using the finite-difference time-domain (FDTD) method. Return loss characteristics and the effect of the human body on resonant frequency are analyzed, and the performances of radiation patterns at different positions of the human alimentary tract are also estimated. Finally, specific absorption rate (SAR) computations are performed, and the peak 1-g and 10-g SAR values are calculated. According to the peak SAR values, the maximum delivered power for the designed antenna was found so that the SAR values of the antenna satisfy the ANSI (American National Standards Institute) limitations.     

平面天线阵列馈电网络应用教学探讨

在综合分析了微带平面天线阵列馈电网络的两种传统馈电方式的基础上,提出了一种在微波工程应用中实际使用的一种新型馈电网络,提高学生理论知识与实践相结合的能力,更好的掌握最新技术发展。其新型馈电网络由一种左-右手混合微带传输线构成,可以获得高于传统并联馈电网络的天线阵列增益;同时,可以修正传统串联馈电网络的天线阵列辐射方向图的波束偏移,给出了一个工作频率为35GHz的2×2微带面阵的馈电网络设计案例,验证了其理论的正确性。     

Corner-fed microstrip antenna analysis for dual polarization

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