矩形微带天线的一种快速优化设计方法研究

针对矩形微带天线优化设计主要依赖经验和反复试验的现状,研究提出了一种矩形微带天线的快速优化设计方法。分析了传输线理论对矩形微带天线分析时的准确性,并将传输线理论成功地与改进的量子遗传算法(IQGA)相结合,应用于矩形微带天线的优化设计之中。利用该方法优化设计了一款矩形微带天线,通过将设计分析的结果与有限元软件HFSS计算结果比较,说明该算法的高效性及准确性。为方便该方法的应用,开发了一款矩形微带天线的快速优化设计软件包。     

基于T型谐振器的抗干扰矩形波导缝隙阵列天线设计

介绍了一种抗干扰矩形波导缝隙阵列天线的设计方法,仿真、设计并加工了一款基于T型谐振器的四缝隙矩形波导缝隙阵列天线. 通过在矩形波导下壁引入周期性的T型谐振器,有效提升了天线的抗干扰能力. 测试结果表明,该天线的?10 dB阻抗带宽为10.3%（5.5～6.1 GHz）,增益为11.5～12.8 dBi,天线效率为72.1%～87.3%。与传统矩形波导缝隙阵列天线相比较,本文设计天线在抑制频段 7.9～9.6 GHz的抗干扰能力提升了32.2～69.3 dB,适用于多频段、多任务的无线通信、雷达系统等.     

A Compact Rectangular Dual Patch Antenna for Multiple Satellite Communication Applications

At present, with the advances in satellite communication systems and their increasing importance, wideband antennas are in great demand for both military and commercial applications. Most of the communication systems need a wideband antenna that operates on multi-octave frequencies. In patch antenna, diverse techniques played a vital role in enhancing the antenna parameters such as gain or bandwidth. A new design concept of a compact rectangular dual patch antenna has been developed for both high gain and wider bandwidth. In this work, a compact rectangular dual patch antenna is proposed as a wideband antenna for multiple satellite communication applications such as Global Positioning System, Global Navigation Satellite System, Indian Regional Navigation Satellite System, and S-Band Satellite Communication. The designed rectangular dual patch antenna is simulated and fabricated. Based on the performance, the fabricated antenna is compared with the simulated results in terms of VSWR, gain, axial ratio, and 3 dB beam width. Increased gain and wider bandwidth have been achieved with the developed rectangular patches and their energy distributed on the surface of the dual patches simultaneously. Finally, the proposed rectangular dual patch antenna shows improved performance for the multiple satellite communication applications.

     

Measurement and analysis of miniature multilayer patch antenna

Although the microstrip patch antenna has a number of advantages such as low-cost and light weight, its physical size is quite large at low microwave frequencies. The designs of multilayer miniature patch antennas with coaxial feed are presented. The first design is a rectangular two-layer patch antenna. Measured results and the results of a preliminary analysis are presented. The projection area of the two-layer patch antenna is kept the same as the single-layer rectangular patch antenna. The resonant frequency of the two-layer antenna is reduced by 50% and has bandwidth of 5%, which is wider than the single-layer rectangular patch antenna. In the second design, the upper patch is cut into a bow-tie shape. This results in a 60% reduction in resonant frequency and a 12% bandwidth. Both the two-layer rectangular and the two-layer bow-tie antennas have good radiation patterns, with cross-polarization level lower than the copolarization level by more than 20 dB     

A circularly polarized rectangular microstrip antenna usingsingle-fed proximity-coupled method

A new circularly polarized rectangular microstrip antenna using a proximity-coupled feed method is proposed in this paper. This antenna is fed by a microstrip line offset from the center of a rectangular microstrip antenna. The proposed antenna has no 90-degree hybrid coupler for circular polarization and allows easy connection between a microstrip line and an antenna element. The measured results verify the circular polarization and show that good return loss and axial ratio characteristics have been obtained     

Small broadband rectangular microstrip antenna with chip-resistorloading

Designs of a chip-resistor-loaded rectangular microstrip antenna fed using a probe feed or an inset microstrip-line feed are presented. These antenna designs have the advantages of small antenna size and wide antenna bandwidth, compared to a conventional rectangular microstrip antenna. Details of the experimental results are given     

Ultra-wideband antipodal slot antenna with improved radiation performance

A novel antipodal wide-slot antenna for ultra-wideband (UWB) applications is proposed and studied in detail. The antenna is fed by a microstrip line terminated with a rectangular tuning patch. An antipodal structure is employed to improve the radiation performances. The return losses, surface E-field, current distribution, radiation patterns and gains of the antenna are numerically and experimentally investigated. Results show that the proposed antipodal antenna has an impedance bandwidth from 0.79 to 4.0?GHz, which is about 5:1. Compared with conventional rectangular wide-slot antenna, more stable radiation pattern with lower cross-polarisation level and flatter gain variation over a 3:1 bandwidth can be obtained. Thus, the proposed antenna should be more suitable for future UWB-multiple-input multiple-output applications using polarisation diversity than conventional UWB rectangular slot antennas.     

一种新型介质加载的矩形喇叭天线

传统的卫星地面通信系统多采用抛物面天线,但抛物面天线却存在体积大、灵活性差等缺点,而喇叭天线则可以较明显地克服上述不足,但其增益较小、损耗较大。文中设计了一种新型介质加载的矩形喇叭天线,该天线有两层结构:上层为辐射结构,下层为微带-槽耦合馈电结构。辐射结构是中心为矩形喇叭孔的长方体铜板。这种结构的喇叭天线体积适中、活动方便,而且天线增益、反射系数和半功率波瓣宽度相比于传统形式的喇叭天线都有明显改善。     

Ultra Wideband Co-planer Microstrip Patch Antenna for Wireless Applications

In this paper, a comparative study of co-planar gap coupled rectangular and elliptical microstrip patch antenna is presented. It is analyzed by using circuit theory concept. The proposed antennas show ultra wideband operations which depend on dimensions of the patches, gap between them as well as air gap thickness. It is observed that the performance of gap coupled elliptical patch antenna is better than that of rectangular patch antenna while the area of rectangular and elliptical patches is same. The bandwidth of proposed rectangular patch antenna is found to be 50.7 % with average gain of 6.5 dBi while for elliptical patch antenna the bandwidth and gain further improves up to 57.6 % and 9.5 dBi respectively. The theoretical results are in good agreement with the simulated results obtained from IE3D simulation software.     

Compact active integrated antenna with transistor oscillator andline impedance transformer

A novel oscillating antenna is realised by integrating a transistor oscillator and a line impedance transformer inside a rectangular opening in a rectangular patch antenna. This active antenna exhibits stable operation and a clean spectrum. The measured copolarisation radiation patterns are not affected by the modification of the patch while the cross-polarisation levels are low     

60 GHz band radial line slot array antenna fed by rectangularwaveguide

A single-layered radial line slot array (SL-RLSA) antenna etched on a substrate and fed by a rectangular waveguide is presented in the 60 GHz band. The design curves are obtained by an efficient electromagnetic coupling analysis using Ewald sum technique and Shanks' transformation. The antenna has rectangular waveguide feed structure using a rectangular waveguide-to-radial line transition. The prototype antenna of 10 cm diameter was tested and the gain of 30 dBi was measured at 60 GHz     

适用于物联网多频段通信的矩形微带天线设计

为满足主流物联网通信技术的应用需求,提出一种新型的矩形微带单极天线,适用于多频段通信,如射频识别、全球定位系统和无线局域网等。该矩形微带天线由一个带两个U形槽的矩形贴片和一个带两个长方形槽的接地面组成,具有四个工作频段,当谐振频率分别为1.22GHz, 2.47GHz, 3.61GHz和5.60 GHz时,相对带宽为25.7%（1.12~1.45 GHz）、25.3%（2.24~2.89 GHz）、15.7%（3.40~3.98 GHz）以及13.6%（5.21~5.97GHz）。仿真与实测结果显示,该天线的工作频段数量更多且相对带宽更高,在各工作频段内具有良好的全向辐射特性。     

基于左手材料的矩形环分形微带天线研究

通过将矩形环分形天线嵌入到左手材料中,形成一种基于左手材料的矩形环分形微带天线。采用有限元法对该复合天线进行分析和仿真,发现基于左手材料的矩形环分形微带天线在各频段增益明显增大,同时具有较低的回波损耗和电压驻波比,实现了较好的匹配性,且有效地改善了天线的性能。由此可以看出基于左手材料的矩形环分形微带天线在移动通信、卫星通信以及航空航天等领域具有潜在的应用价值。     

A New Method for Measuring Dielectric Constant Using the Resonant Frequency of a Patch Antenna

An analytical expression is given for the resonant frequency of a rectangular patch antenna. It shows explicitly the dependence of the resonant frequency on the characteristic parameters of a patch antenna. Based on this result, a new method is developed for the measurement of the dielectric constant of a thin slab substrate. Basically, the test equipment consists of a rectangular microstrip antenna the patch of which is fed either by a microstrip line or coaxial line. From the measured resonance parameters of the rectangular patch antenna, the dielectric constant can be easily obtained. The measured values of the present method are in agreement with the precision standard cavity resonator method. Accuracy of the dielectric constant so obtained is satisfactory.     

Compact CPW-fed dual-band antenna

A novel coplanar waveguide (CPW) antenna is proposed for dual-band WLAN applications. It comprises a rectangular patch, a rectangular notch cut at the lower edge of the patch and a CPW transmission line. The rectangular patch together with the ground plane of the coplanar waveguide radiates at the lower frequency band, 2.4 GHz for IEEE 802.11b/g, while the rectangular notch resonates in the upper band, 5.2/5.8 GHz for IEEE 802.11a. The designed antenna is only 32 × 5 mm, which can provide stable omnidirectional radiation patterns with an average gain of 2 dBi in both the bands. The antenna is very compact and suitable for 2.4 and 5.2/5.8 GHz WLAN operations.     

Rectangular backfire antenna with dielectric surface-wave structure

A rectangular backfire antenna with a dielectric surface-wave structure is studied experimentally and theoretically. It consists basically of two plane rectangular reflectors and a dielectric structure as a rectangular-waveguide prolongation. The antenna construction is compared with those of ordinary dielectric and horn antennas, which are more than twice the length of the backfire antenna. Simple expressions for the far-field radiation pattern are derived in terms of the near-field amplitude distribution.     

矩形贴片天线基模和高次模的研究和利用

对矩形贴片天线的基模和高次模进行了研究。研究表明,矩形贴片天线的基模和高次模都具有良好的辐射性能。据此提出了同时利用天线的基模和高次模来实现高性能的大频差双频段天线的思路。本文研究为实现性能优良的双频段大频差天线提供了一种新的思路。     

可调频矩形帖片天线的研究

本文首次采用有限元法对有调谐销钉的可调频薄基片矩形贴片微带天线的谐振频率和输入阻抗进行了计算,谐振频率的计算结果与实验结果符合很好.该方法原则上适合于任意数目调谐销钉置于任意位置的情形.可能会是处理带调谐销钉的最有效的方法.     

微带天线的设计和阻抗匹配

讨论了矩形微带天线工作原理、结构及其应用.介绍了设计中心频率为800 MHz矩形微带天线的整个流程,首先根据矩形微带天线设计公式计算出天线参数,然后在Ansoft公司的仿真软件HFSS中建立天线模型并对其仿真,通过调整天线模型得到最佳的天线参数使天线特性符合设计要求,最后利用Agilent公司的微波电路仿真软件先进设计系统ADS设计了微带天线的匹配网络.     

Superstrate loading effects on the circular polarization andcrosspolarization characteristics of a rectangular microstrip patchantenna

The authors present the superstrate loading effect on a circularly polarized rectangular microstrip antenna. The design parameters of the superstrate-loading microstrip antenna for achieving circular polarization at the main-beam direction are discussed. The circular polarization property in the entire main-beam region is also analyzed. Next, the crosspolarization characteristics of a rectangular patch antenna due to the superstrate loading are studied. A great dependence of the copolarized and crosspolarized radiations on the superstrate permittivity and thickness is observed