【摘要】：數(shù)字波束形成是陣列天線波束形成原理和數(shù)字信號處理相結(jié)合的產(chǎn)物。與傳統(tǒng)波束形成方法相比,數(shù)字波束形成具有精度高、控制靈活等優(yōu)點,可顯著提高波束形成效率。隨著數(shù)字信號處理技術(shù)的不斷提高,數(shù)字波束形成技術(shù)的應(yīng)用越來越廣泛。本文設(shè)計并實現(xiàn)了收發(fā)數(shù)字波束形成系統(tǒng),從原理分析到具體實現(xiàn),本文的研究工作主要集中于以下幾點:1.從相控陣天線基本原理出發(fā),仿真分析了均勻線陣和面陣天線方向圖,分別討論了陣元數(shù)、陣元間距以及工作波長對線陣天線方向圖性能的影響。同時針對接收數(shù)字波束形成系統(tǒng)討論了漢寧窗加權(quán)、三角形窗加權(quán)、泰勒窗加權(quán)等幾種不同幅度加權(quán)方式在降低副瓣電平提升天線方向圖性能方面的效果,并根據(jù)系統(tǒng)要求最終選取泰勒窗加權(quán)作為本次接收數(shù)字波束形成系統(tǒng)的加權(quán)方案。2.以直接數(shù)字合成(DDS)技術(shù)為核心設(shè)計了發(fā)射數(shù)字波束形成系統(tǒng)。針對陣列天線多通道波束形成特點,分析了發(fā)射通道間幅相誤差對波束形成性能的影響,同時結(jié)合系統(tǒng)需求設(shè)計了開環(huán)法和閉環(huán)法幅相誤差校正方案,并根據(jù)實際校正過程和校正效果分析對比了這兩種方法。3.分析了接收數(shù)字波束形成算法并以FPGA為硬件基礎(chǔ)完成了接收數(shù)字波束形成的系統(tǒng)設(shè)計。針對接收通道的幅相誤差,設(shè)計了有效的誤差校正方案,其通過采用同一路T/R組件作為發(fā)射端、不同被測通道的T/R組件作為接收端、發(fā)射信號通過衰減器直接耦合回被測通道的方式,在保證回波信號相同的情況下準(zhǔn)確測試出了通道間的幅相差。4.設(shè)計了天線方向圖測試方案,分別對本次發(fā)射、接收數(shù)字波束形成的效果進行了現(xiàn)場測試。測試結(jié)果表明,本次收發(fā)數(shù)字波束形成系統(tǒng)設(shè)計方案是可行的。
[Abstract]:Digital beamforming is the product of the combination of array antenna beamforming principle and digital signal processing. Compared with the traditional beamforming method, digital beamforming has the advantages of high precision and flexible control, and can significantly improve the beamforming efficiency. With the continuous improvement of digital signal processing technology, digital beamforming technology is more and more widely used. In this paper, the transceiver digital beamforming system is designed and implemented. From the principle analysis to the concrete implementation, the research work of this paper mainly focuses on the following points: 1. Based on the basic principle of phased array antenna, the pattern of uniform linear array and area array antenna is simulated and analyzed, and the effects of array element number, array element spacing and working wavelength on the performance of linear array antenna are discussed respectively. At the same time, the effects of several different amplitude weighting methods, such as Hanning window weighting, triangular window weighting and Taylor window weighting, on reducing the sidelobe level to improve the antenna pattern performance are discussed for the received digital beamforming system. According to the requirements of the system, Taylor window weighting is finally selected as the weighting scheme of the received digital beamforming system. 2. A transmit digital beamforming system is designed based on direct digital synthesis (DDS) technology. According to the characteristics of multi-channel beamforming of array antenna, the influence of amplitude and phase error between transmit channels on beamforming performance is analyzed. At the same time, the amplitude and phase error correction schemes of open loop method and closed loop method are designed according to the requirements of the system, and the two methods are analyzed and compared according to the actual correction process and correction effect. The receiving digital beamforming algorithm is analyzed and the system design of received digital beamforming is completed based on FPGA. Aiming at the amplitude and phase error of the receiving channel, an effective error correction scheme is designed. The amplitude difference between the channels is accurately measured by using the same T 鈮，

本文編號：2503558