宽频及双频介质谐振天线的研究与设计

发布时间：2019-03-22 12:17

【摘要】：为了提高和改善无线通讯系统中信号传输的速度和质量,移动通信标准不断更替。这就促使无线系统中的主要部件—天线要更具兼容性。宽频以及双频带技术能够覆盖多个工作频带,因而能够同时兼容多个通信标准。因此,对于双频以及宽频带天线的理论知识和设计方法的研究具有非常重要的实际意义。介质谐振天线因其小体积、低损耗、高辐射效率等特点受到广泛关注。对于传统平面天线来说,当工作频率升高时,天线本身的欧姆损耗也会随之恶化,这对天线性能会产生严重的影响。然而,介质谐振天线具有独特且简单的结构,因而几乎不存在表面波损耗和欧姆损耗。因此,无论是在无线通讯领域还是毫米波雷达领域,介质谐振天线都显示出巨大的发展潜力。本文主要设计了一种双频介质谐振天线和两种宽频带介质谐振天线,可概括为:1.设计了一种新型双频介质谐振天线。基于微扰的Sierpinski分形结构,经过两次迭代,该修饰过的三角形介质谐振天线可同时覆盖两个工作频带,并且具有宽带特性。天线的整体尺寸为0.32λ×0.27λ×0.17λ(工作频率为2.4GHz)或者0.47λ×0.43λ×0.24λ(工作频率为3.5GHz),λ为天线在工作频率处自由空间中的波长。实测结果表明,该天线-10dB相对阻抗带宽分别为14.46%(2.25—2.60GHz)和27.78%(3.10—4.10GHz),可以完全覆盖无线局域网(wireless local area network,WLAN)2.4—2.484GHz和全球微波互联(worldwide interoperability for microwave access,WiMAX)3.4—3.69GHz。同时,天线在这两个频带内的最大增益分别为5.58dB和5.51dB。2.设计了一种宽频带矩形介质谐振天线。该设计引入U型缝隙实现两种功能:一是作为该矩形介质谐振天线的馈电结构;二是同时作为有效的辐射单元。同时,增加寄生H型缝隙来改善阻抗匹配。介质板和介质谐振器之间增加了一层空气间隙可以进一步展宽带宽。实测结果表明,该天线-10dB相对阻抗带宽可达73.72%,最大增益为7.0dB。同时,天线的整体尺寸(包括地板)仅为0.71λ×0.71λ×0.17λ(λ为天线工作在中心频率时的波长)。3.设计了一种低剖面宽带介质谐振天线。该设计采用多层结构,即上层为两块高介电常数(介电常数约为93)的介质谐振器,中间层为低介电常数的介质板,最下面一层为地板,从而实现低剖面和宽带宽的特性。实测结果表明,天线的-10dB相对阻抗带宽可达10.49%,并且在整个工作频带内增益均大于6dB,交叉极化均小于-35dB。同时,该天线的整体高度仅为1.57mm或者0.039λ(λ是天线工作在中心频率时的波长)。
[Abstract]:In order to improve the speed and quality of signal transmission in wireless communication system, mobile communication standards are constantly changing. This makes antenna, the main component of wireless systems, more compatible. Broadband and dual-band technologies can cover multiple operating bands, so they can be compatible with multiple communication standards at the same time. Therefore, it is of great practical significance to study the theoretical knowledge and design method of dual-band and broadband antennas. Dielectric resonant antenna is widely concerned because of its small size, low loss and high radiation efficiency. For the conventional planar antenna, the ohmic loss of the antenna itself will worsen when the operating frequency is increased, which will have a serious impact on the performance of the antenna. However, dielectric resonant antenna has a unique and simple structure, so there is almost no surface wave loss and ohmic loss. Therefore, dielectric resonant antennas show great potential in the field of wireless communication and millimeter wave radar. In this paper, a dual frequency dielectric resonant antenna and two kinds of broadband dielectric resonant antenna are designed, which can be summarized as follows: 1. A novel dual frequency dielectric resonant antenna is designed. Based on the perturbed Sierpinski fractal structure, after two iterations, the modified triangular dielectric resonant antenna can cover two working bands at the same time, and has broadband characteristics. The whole size of the antenna is 0.32 位脳 0.27 位脳 0.17 位 (working frequency is 2.4GHz) or 0.47 位脳 0.43 位脳 0.24 位 (working frequency is 3.5GHz), 位 is the wavelength of the antenna in the free space at the working frequency. The measured results show that the relative impedance bandwidth of the antenna-10dB is 14.46% (2.25-2.60GHz) and 27.78% (3.10-4.10GHz) respectively, which can completely cover the WLAN (wireless local area network,. (WLAN) 2.4-2.484GHz and Global Microwave Interconnection (worldwide interoperability for microwave access,WiMAX (3.4? 3.69 GHz). At the same time, the maximum gain of the antenna in these two bands is 5.58dB and 5.51dB.2, respectively. A broadband rectangular dielectric resonant antenna is designed. The design introduces U-shaped slot to realize two functions: one is the feed structure of the rectangular dielectric resonant antenna; the other is the effective radiation unit at the same time. At the same time, the parasitic H-gap is added to improve impedance matching. The addition of a layer of air gap between the dielectric plate and the dielectric resonator can further widen the bandwidth. The measured results show that the relative impedance bandwidth of the antenna-10dB is 73.72%, and the maximum gain is 7.0 dB. At the same time, the overall size (including the floor) of the antenna is only 0.71 位脳 0.71 位脳 0.17 位 (位 is the wavelength of the antenna at the central frequency). A low profile broadband dielectric resonant antenna is designed. The design adopts a multi-layer structure, that is, two dielectric resonators with high dielectric constant (about 93 dielectric constant) in the upper layer, a dielectric plate with low dielectric constant in the middle layer and a floor in the bottom layer, thus realizing the characteristics of low profile and wide bandwidth. The measured results show that the-10dB relative impedance bandwidth of the antenna can reach 10.49%, and the gain is more than 6 dB and the cross polarization is less than-35 dB in the whole operating band. At the same time, the overall height of the antenna is only 1.57mm or 0.039 位 (位 is the wavelength of the antenna operating at the center frequency).
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN822

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