【摘要】：寬帶通信由于通信容量大、保密性好等諸多優(yōu)點(diǎn),成為通信系統(tǒng)研究的重要部分。而圓極化天線由于抗干擾能力強(qiáng)、能夠接受任意線極化及相同旋向圓極化來波等優(yōu)點(diǎn)而廣泛應(yīng)用于雷達(dá)、導(dǎo)航、衛(wèi)星等電子系統(tǒng)中。同時(shí)波導(dǎo)縫隙天線具有高增益、高效率、結(jié)構(gòu)緊湊等優(yōu)點(diǎn)。因此本文對寬帶圓極化波導(dǎo)縫隙天線進(jìn)行深入研究,設(shè)計(jì)出兩種寬帶圓極化天線單元和陣列。研究內(nèi)容主要包括：第一,提出一種加載背腔式H型寬縫的新型圓極化波導(dǎo)縫隙天線。天線在饋電波導(dǎo)寬邊開縱縫的基礎(chǔ)上,加載旋轉(zhuǎn)45°放置的方形金屬腔,金屬腔的上口面加矩形微擾形成H型寬縫。饋電波導(dǎo)將能量從寬邊縱縫耦合至上方的腔體,激勵(lì)出兩種空間正交的電場模式。H型寬縫引入微擾實(shí)現(xiàn)90°相差,從而輻射圓極化波。背腔式寬縫的引入實(shí)現(xiàn)了寬帶圓極化輻射。本文設(shè)計(jì)了中心頻率為12.5GHz的1×8線陣,仿真得到線陣的阻抗帶寬為4%,軸比帶寬為6.4%,增益為17dB,副瓣電平為-17dB。第二,為降低天線剖面,將第一種設(shè)計(jì)中傾斜的腔體優(yōu)化為正常放置,H型寬縫改為對角有一對方片微擾的方形寬縫。優(yōu)化后天線高度降低了25%。研制出中心頻率為12.5GHz的1×8線陣。測得的阻抗帶寬為6.9%,軸比帶寬為8.8%,增益15.4dB,口徑效率53.7%。第三,設(shè)計(jì)了一種新型的加載雙層貼片的圓極化波導(dǎo)縫隙天線陣。天線單元由三部分組成,分別是饋電波導(dǎo)、一對分裂的切角貼片和完整的切角貼片。整體天線剖面較低,高度為半個(gè)空間波長。圓極化性能由兩層切角貼片實(shí)現(xiàn),層疊的貼片結(jié)構(gòu)可以產(chǎn)生兩個(gè)相互靠近的諧振點(diǎn),從而展寬軸比帶寬。本文設(shè)計(jì)了中心頻率為10.5GHz的1×10線陣,仿真得到的阻抗帶寬為5.4%,軸比帶寬為15.2%,增益為17dB。本文設(shè)計(jì)了兩種寬帶圓極化波導(dǎo)縫隙天線陣列,將傳統(tǒng)波導(dǎo)縫隙天線與寬帶圓極化單元相結(jié)合,使新的天線結(jié)構(gòu)不僅具有波導(dǎo)縫隙天線增益高、效率高的優(yōu)點(diǎn),而且擁有加載的圓極化單元寬軸比帶寬的性能。天線整體結(jié)構(gòu)緊湊、剖面低、易加工,具有很好的應(yīng)用前景。
[Abstract]:Broadband communication has become an important part of communication system because of its large capacity and good confidentiality. The circular polarization antenna is widely used in radar, navigation, satellite and other electronic systems because of its strong anti-jamming ability and can accept the advantages of arbitrary line polarization and the same rotating circular polarization wave. At the same time, waveguide slot antenna has the advantages of high gain, high efficiency and compact structure. In this paper, two kinds of broadband circularly polarized antenna elements and arrays are designed. The main contents are as follows: first, a novel circularly polarized waveguide slot antenna loaded with H-shaped wide slit is proposed. On the basis of the longitudinal slot on the wide edge of the feed waveguide, the square metal cavity with 45 擄rotation is loaded and the upper surface of the metal cavity is perturbed by rectangular perturbation to form H-shaped wide slit. The feed waveguide couples the energy from the longitudinal slit of the wide edge to the upper cavity, and excites two spatially orthogonal electric field modes. The H-shaped wide slit is introduced into the perturbation to realize the 90 擄phase difference, thus the circular polarization wave is radiated. The broadband circular polarization radiation is realized by the introduction of the back cavity wide slit. A 1 脳 8 linear array with center frequency of 12.5GHz is designed in this paper. The simulation results show that the impedance bandwidth of the linear array is 4, the axial ratio bandwidth is 6.4, the gain is 17 dB, and the sidelobe level is -17 dB. Secondly, in order to reduce the antenna profile, the sloping cavity in the first design is optimized for normal placement, and the H type wide slit is changed to a square wide slot with a diagonal perturbation of each other. The optimized antenna height is reduced by 25%. A 1 脳 8 linear array with center frequency of 12.5GHz has been developed. The measured impedance bandwidth is 6.9, axial ratio bandwidth is 8.8, gain is 15.4 dB, aperture efficiency is 53.7. Thirdly, a new circular polarization waveguide slot antenna array loaded with double layer patch is designed. The antenna element consists of three parts: feed waveguide, split tangent patch and complete tangent patch. The whole antenna profile is low and the height is half space wavelength. The circular polarization is realized by two layers of tangential patch. The stacked patch structure can produce two resonant points close to each other and widen the bandwidth of axial ratio. A 1 脳 10 linear array with center frequency of 10.5GHz is designed in this paper. The simulation results show that the impedance bandwidth is 5.4, the axial ratio bandwidth is 15.2 and the gain is 17 dB. In this paper, two kinds of wide-band circularly polarized waveguide slot antenna arrays are designed. By combining the traditional waveguide slot antennas with broadband circular polarization elements, the new antenna structure not only has the advantages of high gain and high efficiency of waveguide slot antennas. Moreover, it has the performance of wide axis ratio bandwidth of loaded circular polarization cell. The antenna has a compact structure, low profile, easy processing, and has a good application prospect.
【學(xué)位授予單位】：南京理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2016
【分類號(hào)】：TN823.24
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本文編號(hào)：2417943