【摘要】：天線一般工作在其輻射遠場區(qū)域。對于某些特定場合,要求天線輻射的能量聚集在其近場區(qū)域的某一特定點上,這就需要近場聚焦天線。針對近場聚焦天線的研究已經(jīng)持續(xù)了很長時間。在特定區(qū)域具有高能量密度的近場聚焦天線不僅可以用于提高醫(yī)學(xué)與工業(yè)檢測系統(tǒng)的探測和成像能力,還能用于門禁系統(tǒng)、微波無線輸能系統(tǒng)、射頻識別系統(tǒng)以及微波無線電系統(tǒng)等方面,具有廣泛的應(yīng)用前景和研究價值。不同應(yīng)用場合對近場聚焦天線的需求也不相同。在微波熱療應(yīng)用中希望利用最大功率加熱癌組織,而不希望其對鄰近健康組織產(chǎn)生危害;在非接觸式微波感應(yīng)中并不希望在焦點旁邊有較高副瓣影響其準(zhǔn)確性。因此,對近場聚焦天線實現(xiàn)低副瓣設(shè)計是降低副焦瓣影響的有效方法。當(dāng)近場聚焦天線用于大面積檢測時,可以通過需要焦斑掃描來擴大覆蓋或提高位置定位精度。本文針對近場聚焦陣列天線相關(guān)問題展開研究,具體體現(xiàn)在:首先,在分析平面天線近場聚焦原理基礎(chǔ)上,結(jié)合基片集成波導(dǎo)與金屬圓波導(dǎo)實現(xiàn)了電磁波的近場聚焦。通過對基片集成波導(dǎo)近場聚焦天線的子部件進行分析,并對天線焦距與焦斑特性進行了討論,最終對Ka頻段基片集成波導(dǎo)近場聚焦天線進行設(shè)計、加工與實測。在此基礎(chǔ)上,進一步研究近場聚焦天線的副瓣抑制問題。通過闡述近場區(qū)域低副焦瓣與圓極化的生成原理,即利用基片集成縫隙天線通過多元法實現(xiàn)圓極化,基于基片集成波導(dǎo)功分網(wǎng)絡(luò)通過泰勒分布賦形實現(xiàn)所需近場副瓣電平,最終對K波段低副焦瓣雙圓極化近場聚焦天線進行設(shè)計、加工與測試。最后,結(jié)合改進的基片集成波導(dǎo)羅特曼透鏡與基片集成縫隙天線縫隙陣列天線,實現(xiàn)了Ka波段多焦斑天線。為了將基片集成羅特曼透鏡作為聚焦波束形成網(wǎng)絡(luò),對傳統(tǒng)羅特曼透鏡的相移網(wǎng)絡(luò)進行修改以滿足波束聚焦和掃描的要求。當(dāng)從不同的輸入端口激發(fā)時,焦點可實現(xiàn)橫向掃描。最終對Ka波段基片集成改進羅特曼透鏡多焦斑近場聚焦天線進行設(shè)計、加工與測試。
[Abstract]:Antennas generally work in the far-field region of their radiation. For some special occasions, the energy of antenna radiation is required to gather at a certain point in its near-field region, which requires the near-field focusing antenna. The research on the near-field focusing antenna has been going on for a long time. Near-field focusing antennas with high energy density in specific areas can be used not only to improve the detection and imaging capabilities of medical and industrial detection systems, but also to use in access control systems and microwave wireless energy transmission systems. Radio frequency identification system and microwave radio system have a wide application prospect and research value. The requirements of near-field focusing antenna are different in different applications. In the application of microwave hyperthermia, it is desirable to use the maximum power to heat the cancer tissue without harming the adjacent healthy tissue, and in the non-contact microwave induction, it is not desired to have a higher sidelobe next to the focus to affect the accuracy of the cancer tissue. Therefore, the design of low sidelobe for near-field focusing antenna is an effective method to reduce the influence of the sidelobe. When the near field focusing antenna is used for large area detection, the focal spot scanning can be used to expand the coverage or improve the positioning accuracy. In this paper, the related problems of near-field focusing array antenna are studied. Firstly, based on the analysis of the near-field focusing principle of planar antenna, the near-field focusing of electromagnetic wave is realized by combining the substrate integrated waveguide with the metal circular waveguide. Based on the analysis of the sub-components of the near-field focusing antenna of the substrate integrated waveguide, the focal length and focal spot characteristics of the antenna are discussed. Finally, the near-field focusing antenna of the substrate integrated waveguide in the Ka band is designed, machined and measured. On this basis, the sidelobe suppression problem of near-field focusing antenna is further studied. The generation principle of low focus lobe and circular polarization in near field region is described, that is, the circular polarization is realized by using substrate integrated slot antenna through multivariate method, and the required near field sidelobe level is realized by Taylor distribution based on substrates integrated waveguide power division network. At last, the design, fabrication and test of K band low-petal dual-circular polarized near-field focusing antenna are carried out. Finally, the Ka band multi-focal spot antenna is realized by combining the improved integrated waveguide Rottmann lens with the slot array antenna of the substrate integrated slot antenna. In order to integrate the substrate into the Rottmann lens as a focusing beamforming network, the phase shift network of the traditional Rottmann lens was modified to meet the requirements of beam focusing and scanning. When fired from different input ports, the focus can be scanned horizontally. Finally, the design, fabrication and test of the Ka band substrate integrated and improved Rottmann lens near field focusing antenna with multiple focal spots are carried out.
【學(xué)位授予單位】：電子科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TN820

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本文編號：2334857