【摘要】：陣列天線廣泛應(yīng)用于雷達(dá)、通信、導(dǎo)航、電子對抗等眾多領(lǐng)域。然而,隨著小型化及寬帶化需求的增加,互耦對陣列性能的影響不容忽略。由于互耦的影響,可能導(dǎo)致雷達(dá)分辨力降低、測向誤差增大、干擾零陷抬高以及波束指向偏離等不良后果。為了提高陣列天線的性能并適應(yīng)更廣泛的應(yīng)用,研究互耦校準(zhǔn)方法具有重要意義。本文針對以上研究背景開展了陣列天線互耦校準(zhǔn)方法的研究。本文詳細(xì)介紹了陣列互耦產(chǎn)生的機(jī)理及分析方法,總結(jié)了已有方法的優(yōu)缺點(diǎn),提出了新的互耦校準(zhǔn)方法,并在此基礎(chǔ)上提出了寬帶陣列互耦校準(zhǔn)方法。論文的主要工作包括以下幾個(gè)方面:1.在分析了互耦機(jī)理及已有互耦校準(zhǔn)方法的基礎(chǔ)上,從電磁分析的角度提出了新的互耦校準(zhǔn)方法——單元方向圖重建法。該方法利用單元孤立方向圖和單元陣中方向圖的差異,建立互耦矩陣的求解方程,并采用最小二乘法實(shí)現(xiàn)互耦校準(zhǔn)矩陣的求解。在此基礎(chǔ)上,進(jìn)一步推導(dǎo)出陣列單元形式一致的簡化單元方向圖重建法表達(dá)式。2.針對全向天線及定向天線陣列開展了互耦校準(zhǔn)的研究,將提出的方法應(yīng)用于陣列天線的互耦校準(zhǔn)。實(shí)現(xiàn)了對不同陣列單元、不同陣列形式的互耦校準(zhǔn)研究。具體研究了全向、定向及線極化、圓極化等天線單元形式。研究的陣列形式包括線陣、圓陣及共形陣等。并將單元方向圖重建法運(yùn)用到一維和二維DOA估計(jì)算法中,實(shí)現(xiàn)了對陣列接收信號的校準(zhǔn),仿真驗(yàn)證了所提出的互耦校準(zhǔn)方法的有效性。3.在單元方向圖重建法的基礎(chǔ)上,結(jié)合自校正方法的思想,提出了根據(jù)來波信號方向自適應(yīng)的選擇擬合區(qū)域?qū)π盘栠M(jìn)行互耦校準(zhǔn)的方法。該方法與MUSIC算法相結(jié)合,通過交替迭代實(shí)現(xiàn)了寬角度DOA估計(jì)。在此基礎(chǔ)上,將提出的方法用于一維線陣、二維L形陣列的互耦校準(zhǔn),實(shí)現(xiàn)了一維和二維DOA的精確估計(jì)。4.提出了采用插值法實(shí)現(xiàn)寬帶陣列互耦校準(zhǔn)的方法。針對寬帶信號耦合矩陣參數(shù)與頻率的關(guān)系曲線,基于單元方向圖重建法,提出采用保形分段Hermite插值法實(shí)現(xiàn)寬帶互耦校準(zhǔn)。仿真設(shè)計(jì)了寬帶對稱振子并用其構(gòu)成八元均勻圓陣,DOA效果驗(yàn)證了所提出方法的有效性。5.研究了互耦對MIMO系統(tǒng)信道容量的影響。利用加載枝節(jié)和改變地板縫隙的方法分別設(shè)計(jì)了兩款小型化多頻縫隙天線,并用其構(gòu)成MIMO陣列。利用單元方向圖重建法實(shí)現(xiàn)對MIMO陣列天線互耦矩陣的求解,針對瑞利衰落信道開展互耦對信道容量影響的研究。6.搭建了系統(tǒng)實(shí)驗(yàn)平臺,利用DOA估計(jì)實(shí)驗(yàn)完成對單元方向圖重建法的驗(yàn)證。該實(shí)驗(yàn)平臺包括天線陣列、射頻模塊和數(shù)字信號處理模塊等。針對單極子天線陣列及微帶天線陣列,進(jìn)行DOA估計(jì)實(shí)驗(yàn),分析對比了不同情況下的DOA估計(jì)結(jié)果,驗(yàn)證了單元方向圖重建法的有效性和實(shí)用性。
[Abstract]:Array antennas are widely used in radar, communication, navigation, electronic countermeasures and many other fields. However, with the increasing demand for miniaturization and broadband, the effect of mutual coupling on array performance should not be ignored. Due to the influence of mutual coupling, the radar resolution may be reduced, the direction finding error will increase, the interference will be raised and the beam-pointing will deviate. In order to improve the performance of array antennas and adapt to more extensive applications, it is of great significance to study mutual coupling calibration methods. In this paper, the mutual coupling calibration method of array antenna is studied in view of the above research background. In this paper, the mechanism and analysis method of array mutual coupling are introduced in detail, the advantages and disadvantages of existing methods are summarized, a new mutual coupling calibration method is proposed, and a wideband array mutual coupling calibration method is proposed. The main work includes the following aspects: 1. Based on the analysis of the mutual coupling mechanism and the existing mutual coupling calibration methods, a new mutual coupling calibration method, the unit pattern reconstruction method, is proposed from the point of view of electromagnetic analysis. In this method, the solution equations of the mutual coupling matrix are established by using the difference between the isolated pattern of the element and the square diagram of the element array, and the solution of the mutual coupling calibration matrix is realized by using the least square method. On this basis, the expression of simplified element pattern reconstruction method with uniform array element form is derived. 2. The mutual coupling calibration of omnidirectional antenna and directional antenna array is studied, and the proposed method is applied to the mutual coupling calibration of array antenna. The mutual coupling calibration of different array elements and different array forms is realized. The antenna elements such as omnidirectional, directional and linear polarization and circular polarization are studied in detail. The array forms are linear array, circular array and conformal array. The method of cell pattern reconstruction is applied to one and two dimensional DOA estimation algorithm to realize the calibration of array received signals. The simulation results show that the proposed method is effective. Based on the method of unit pattern reconstruction and the idea of self-tuning method, a mutual coupling calibration method is proposed based on the adaptive selection of fitting region according to the direction of incoming signal. The method is combined with the MUSIC algorithm and the wide angle DOA estimation is realized by alternating iteration. On this basis, the proposed method is applied to the mutual coupling calibration of one dimensional linear array and two dimensional L shape array, and the accurate estimation of one and two dimensional DOA is realized. A method of wideband array mutual coupling calibration using interpolation method is proposed. Aiming at the relation curve between the parameters of wideband signal coupling matrix and frequency, based on the method of cell pattern reconstruction, a new method of wideband mutual coupling calibration based on conformal piecewise Hermite interpolation is proposed. A wide-band symmetric oscillator is designed and used to form an octa-element uniform circular array. The DOA effect verifies the effectiveness of the proposed method. The influence of mutual coupling on the channel capacity of MIMO system is studied. Two miniaturized multi-frequency slot antennas are designed by means of loading branches and changing floor slits, respectively, and MIMO arrays are constructed with them. The method of cell pattern reconstruction is used to solve the mutual coupling matrix of MIMO array antenna. The influence of mutual coupling on the capacity of Rayleigh fading channel is studied. The system experiment platform is built and the DOA estimation experiment is used to verify the method of unit pattern reconstruction. The experimental platform includes antenna array, RF module and digital signal processing module. The experiment of DOA estimation for monopole antenna array and microstrip antenna array is carried out. The results of DOA estimation under different conditions are analyzed and compared. The validity and practicability of the method are verified.
【學(xué)位授予單位】：西安電子科技大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2016
【分類號】：TN820

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相關(guān)期刊論文 前1條

1 魯祖坤;高鷹;石宇;劉揚(yáng);楊佐龍;;基于MUSIC迭代法的互耦誤差校正[J];無線電通信技術(shù);2013年01期

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本文編號：2261954