本文選題：四維天線陣 + 時(shí)間調(diào)制�。� 參考：《電子科技大學(xué)》2014年碩士論文

【摘要】：隨著無(wú)線電子系統(tǒng)的快速發(fā)展,陣列天線對(duì)于無(wú)線系統(tǒng)整體性能的提升起著越來(lái)越重要的作用。廣泛應(yīng)用于各種電磁環(huán)境中的陣列天線往往要求其具有低副瓣、多波束、波束掃描以及波束賦形等特性,這些性能要求極大的增加了陣列天線的設(shè)計(jì)難度和饋電網(wǎng)絡(luò)的復(fù)雜程度,并且要求器件具有較高精度。引入時(shí)間設(shè)計(jì)自由度的四維天線陣能夠有效地降低天線陣列設(shè)計(jì)的難度和對(duì)饋電幅度、相位等的依賴。此外,其優(yōu)越于常規(guī)陣列天線的輻射特性也越來(lái)越多地得以發(fā)掘并受到廣泛關(guān)注。本文基于四維天線陣的頻域特性,對(duì)四維天線陣的高效設(shè)計(jì)和系統(tǒng)應(yīng)用基礎(chǔ)兩方面展開深入研究。針對(duì)這兩方面的研究主要涵蓋了以下內(nèi)容:在四維天線陣的高效設(shè)計(jì)方面,針對(duì)四維天線陣開關(guān)時(shí)序優(yōu)化設(shè)計(jì)中的效率問(wèn)題,提出了逐位進(jìn)化遺傳算法�？紤]周期性時(shí)間調(diào)制的特點(diǎn),將開關(guān)時(shí)序的數(shù)學(xué)表達(dá)與物理含義進(jìn)行有機(jī)結(jié)合。算法將染色體中的每一個(gè)基因作為獨(dú)立進(jìn)化單元,并引入基因保留概率的概念,通過(guò)保留優(yōu)質(zhì)基因,反轉(zhuǎn)劣質(zhì)基因的方法實(shí)現(xiàn)了利用種群中的所有個(gè)體共同推進(jìn)基因進(jìn)化。通過(guò)與物理含義的結(jié)合,算法顯著提高了迭代的方向性,且針對(duì)含有大量參數(shù)的大陣列設(shè)計(jì),較現(xiàn)有算法具有更好的優(yōu)化能力。大量的仿真實(shí)驗(yàn)表明,將逐位進(jìn)化遺傳算法用于四維天線陣的優(yōu)化設(shè)計(jì),不僅能獲得更好輻射性能,而且能顯著提高設(shè)計(jì)效率。在四維天線陣的系統(tǒng)應(yīng)用基礎(chǔ)方面,充分利用四維天線陣具有邊帶輻射的特性,將中心頻率和多個(gè)邊帶頻率信號(hào)應(yīng)用于空間譜估計(jì)中。首先,考慮四維天線陣列形式隨時(shí)間變化的特點(diǎn),改進(jìn)MUSIC算法以利用邊帶信號(hào)而不是各單元接收的信號(hào)構(gòu)成信號(hào)空間。其次,將DE/BEGA算法與MUSIC算法相結(jié)合,在多種時(shí)間調(diào)制方式下提高可分辨概率、降低均方根誤差并抑制偽峰,實(shí)現(xiàn)了對(duì)空間譜估計(jì)性能的優(yōu)化,較常規(guī)陣列具有顯著優(yōu)勢(shì)。最后,構(gòu)建了一個(gè)基于四維天線陣的空間譜估計(jì)實(shí)驗(yàn)平臺(tái),完成了在實(shí)際環(huán)境中對(duì)信號(hào)的發(fā)射、接收以及離散信號(hào)處理,通過(guò)原理性實(shí)驗(yàn)驗(yàn)證了四維天線陣在空間譜估計(jì)應(yīng)用領(lǐng)域的可行性。
[Abstract]:With the rapid development of wireless electronic systems, array antennas play an increasingly important role in improving the overall performance of wireless systems. Array antennas, which are widely used in various electromagnetic environments, often require low sidelobe, multi-beam, beam scanning and beamforming, etc. These performance requirements greatly increase the design difficulty of array antenna and the complexity of feed network, and require the device to have high precision. The four dimensional antenna array with time design degree of freedom can effectively reduce the difficulty of antenna array design and its dependence on the feed amplitude and phase. In addition, the radiation characteristics which are superior to conventional array antennas are more and more explored and paid more attention to. Based on the frequency-domain characteristics of four-dimensional antenna array, this paper studies the efficient design of four-dimensional antenna array and the basis of system application. The main contents of this paper are as follows: in the aspect of high efficiency design of four dimensional antenna array, a bit by bit evolutionary genetic algorithm is proposed to solve the efficiency problem in the switching sequence optimization design of four dimensional antenna array. Considering the characteristic of periodic time modulation, the mathematical expression of switch timing is combined with the physical meaning. The algorithm takes each gene in the chromosome as an independent evolutionary unit, and introduces the concept of gene retention probability. By preserving high-quality genes and reversing inferior genes, all individuals in the population can be used to promote gene evolution together. By combining with the physical meaning, the algorithm improves the direction of iteration significantly, and has better optimization ability than the existing algorithms for the design of large array with a large number of parameters. A large number of simulation experiments show that applying bit by bit evolutionary genetic algorithm to the optimization design of four-dimensional antenna array can not only obtain better radiation performance, but also improve the design efficiency significantly. On the basis of the system application of four-dimensional antenna array, the center frequency and multiple sideband frequency signals are applied to the spatial spectrum estimation by making full use of the sideband radiation characteristics of the four-dimensional antenna array. Firstly, considering the variation of the antenna array form with time, the MUSIC algorithm is improved to make use of the sideband signal instead of the signal received by each unit to form the signal space. Secondly, the DE/BEGA algorithm and MUSIC algorithm are combined to improve the resolution probability, reduce the root mean square error and suppress the pseudo peak under various time modulation modes. The performance of spatial spectrum estimation is optimized and has a significant advantage over the conventional array. Finally, an experimental platform of spatial spectrum estimation based on four-dimensional antenna array is constructed, and the signal transmitting, receiving and discrete signal processing are completed in the actual environment. The feasibility of four dimensional antenna array in the application of spatial spectrum estimation is verified by theoretical experiments.
【學(xué)位授予單位】：電子科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：TN820.15

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本文編號(hào)：1907539