本文選題：數(shù)字波束形成 + 旁瓣對消�。� 參考：《西安電子科技大學》2014年碩士論文

【摘要】：未來復雜、多變的海戰(zhàn)環(huán)境要求艦載相控陣雷達在各種條件下自適應工作,使雷達與使用環(huán)境始終處于最佳的匹配狀態(tài)。近幾年來,數(shù)字波束形成的應用和實時自適應處理技術的發(fā)展使艦載相控陣雷達的自適應能力提高到一個新水平。數(shù)字波束形成是采用數(shù)字技術實現(xiàn)瞬時多波束,能夠對干擾源自適應瞄零,有很強的自適應處理能力,并可獲得超分辨率和超低旁瓣性能。雷達系統(tǒng)中,如何使得陣列方向圖的旁瓣得以有效地改善已經(jīng)成為一個基本且十分關鍵的問題,對于規(guī)則數(shù)字子陣,可以利用在陣元上采用兩種不同形式的加權方法來達到對和差波束的旁瓣進行同時抑制的效果,分別是用于降低和波束旁瓣的Taylor加權和用于降低差波束旁瓣的Bayliss加權。而針對共形面陣,也要整體考慮幅度加權的方法,但是由于共形陣列不再是均勻陣列,幅度加權時需要優(yōu)化設計來達到低的副瓣,采用加權與目標方位和俯仰無關的權矢量來降低復雜度,且要盡量減少信噪比(SNR)的損失。隨著雷達技術的發(fā)展以及現(xiàn)代海事戰(zhàn)場需求的持續(xù)增加,自適應旁瓣對消技術已成為雷達系統(tǒng)至關重要的部分,它是信號處理技術與天線技術相結合的產(chǎn)物,已成為抑制陣列天線旁瓣干擾的有效方法,在雷達中的應用也變得越來越廣泛。在有源干擾存在的情況下,通常人們采用能夠使得對消剩余輸出最小的準則即最小均方準則(LMS),自適應地改變輔助天線的加權系數(shù),使得干擾信號的輸入功率達到最小,在方向圖上具體表現(xiàn)為:在干擾信號的接收方向上形成空間零點,從而實現(xiàn)對旁瓣干擾的抑制。自適應陣列系統(tǒng)中,存在若干影響旁瓣對消系統(tǒng)性能的重要因素,諸如量化噪聲、通道噪聲、通道不一致性、目標回波信號、干擾帶寬、天線之間的距離、不同的數(shù)字波束形成方法等。而對于輔助通道的選取,包括輔助天線的數(shù)目選擇,輔助天線的位置選擇等,更是影響旁瓣對消性能的關鍵因素。本文基于數(shù)字波束形成的理論研究,采用一種新的權值優(yōu)化方法來實現(xiàn)低副瓣的和差波束形成,并考慮單元方向圖因素的影響,分析有向陣元對形成折面陣的和差波束方向圖所造成的影響。另外基于自適應旁瓣對消的理論基礎,對影響旁瓣干擾對消性能的幾個重要因素進行仿真,包括干擾信號的帶寬、天線之間的距離、不同輔助天線個數(shù)以及天線機械掃描對旁瓣對消性能造成的影響,給出仿真結果,并進行相應的分析。針對項目需求,對旁瓣對消系統(tǒng)的輔助通道的選取提出不同的方案設計及對應的性能分析,建立仿真模型,根據(jù)性能分析結果優(yōu)化輔助通道的選取。最后結合方案設計,對旁瓣對消系統(tǒng)的各個功能模塊進行了詳細介紹并結合其程序設計給出相應的實現(xiàn)流程。
[Abstract]:In the future, the complex and changeable naval battle environment requires shipborne phased array radar to work adaptively under various conditions, so that the radar and the operational environment are always in the best matching state. In recent years, the application of digital beamforming and the development of real-time adaptive processing technology have improved the adaptive capability of shipborne phased array radar to a new level. Digital beamforming uses digital technology to realize instantaneous multi-beam, which can self-adaptively aim at zero to interference source, has strong adaptive processing ability, and can obtain super-resolution and ultra-low sidelobe performance. In radar system, how to improve the sidelobe of array pattern effectively has become a basic and critical problem. Two different weighting methods can be used to simultaneously suppress the sidelobe of the sum beam, I. E. Taylor weighting for reducing the sidelobe and Bayliss weighting for reducing the sidelobe of the differential beam. For conformal array, the amplitude weighting method should be considered as a whole, but because conformal array is no longer uniform array, it is necessary to optimize design to achieve low sidelobe when amplitude weighting. Weighted weight vectors independent of target azimuth and pitch are used to reduce complexity and SNR loss is minimized. With the development of radar technology and the increasing demand of modern maritime battlefield, adaptive sidelobe cancellation technology has become the most important part of radar system. It is the result of combining signal processing technology with antenna technology. It has become an effective method to suppress array antenna sidelobe interference, and has become more and more widely used in radar. In the presence of active jamming, the least mean square criterion, which can minimize the residual output of cancellation, is usually adopted to adaptively change the weighting coefficient of the auxiliary antenna, so that the input power of the interference signal is minimized. In the pattern, the spatial zero is formed in the direction of receiving the interference signal, which can suppress the sidelobe interference. In adaptive array systems, there are several important factors that affect the performance of sidelobe cancellation systems, such as quantization noise, channel inconsistency, target echo signals, interference bandwidth and the distance between antennas. Different digital beamforming methods and so on. The selection of auxiliary channels, including the number of auxiliary antennas and the position of auxiliary antennas, is a key factor affecting the performance of sidelobe cancellation. Based on the theoretical research of digital beamforming, a new weight optimization method is used to realize low sidelobe sum difference beamforming. The effect of directed array elements on the sum difference beam pattern of a folded plane array is analyzed. In addition, based on the theoretical basis of adaptive sidelobe cancellation, several important factors affecting the performance of sidelobe interference cancellation are simulated, including the bandwidth of interference signal, the distance between antennas, The effects of different number of auxiliary antennas and antenna mechanical scanning on the sidelobe cancellation performance are presented. The simulation results are given and the corresponding analysis is carried out. According to the requirements of the project, different scheme design and corresponding performance analysis are put forward for the selection of auxiliary channel of sidelobe cancellation system. The simulation model is established, and the selection of auxiliary channel is optimized according to the result of performance analysis. Finally, each function module of the sidelobe cancellation system is introduced in detail with the scheme design, and the corresponding realization flow is given in combination with the program design.
【學位授予單位】：西安電子科技大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：TN958.92

【參考文獻】

相關期刊論文 前2條

1 郭健;沈泉;;一種用于共形相控陣的寬頻帶寬波束雙圓極化微帶貼片天線[J];現(xiàn)代電子技術;2007年08期

2 劉潮;李政杰;童寧寧;;自適應旁瓣對消分析與仿真[J];現(xiàn)代防御技術;2011年02期

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本文編號：2011307