Adaptive-Adaptive Sidelobe Cancellation Strategy for Two-dimensional Phased Arrays

传统旁瓣对消方法采用单元天线作为辅助通道,系统对消输出的信噪比较低,且合成阵列存在较高的副瓣抬升隐患。针对二维稀疏阵列的应用特点,提出一种新的自适应—自适应旁瓣对消策略。该方法取代了传统方法中使用的单元天线以及数字加权方法,使用小型阵列作为辅助通道和射频加权,并借助辅助通道对干扰方向进行估计,根据估计得到的干扰方向信息对辅助子阵列内部的射频加权系数进行调整,使得辅助通道的波束最大可能地对准干扰方向。最后利用恒增益对消技术,实现主阵列中的旁瓣对消。仿真实验结果表明了该方法的有效性和优势。The traditional adaptive sidelobe cancellation method uses single antenna as assistant channel,so the signal to noise ratio( SNR) of system output is small,and it is possible to uplift the sidelobe in synthetic array. In view of application feature of two-dimensional sparse array,a new method named adaptive-adaptive sidelobe cancellation is proposed in this paper. The new method replaces the single antenna with small synthetic arrays as assistant channel and replaces digital weighting method with RF weighting method,and it estimates the direction of the jamming with assistant channel. According to the information about the direction,the new method adjusts the RF weight of assistant channel,and makes the beam of assistant channel align the jamming directions. The sidelobe cancellation method with constant gain is used to perform the sidelobe cancellation. The simulation results prove the effectiveness and advantages of the proposed method.国家自然科学基金资助项目(61301009);; 福建省自然科学基金计划资助项目(2013J01252);; 高等学校博士学科点专项科研基金资助项目(20120121120027

A Sidelobe Cancellation Method with Constant Gain

在旁瓣对消系统中,当辅助天线数目大于干扰源数目时,期望信号也被当成一个干扰源而被系统对消掉。一般采用在辅助通道添加阻塞矩阵的方法来解决此问题。然而当期望信号方向与干扰信号方向接近时,采用阻塞矩阵方法会导致合成方向图有较大旁瓣抬升。提出一种新方法,对辅助天线的输出进行线性约束,使辅助天线在期望信号方向形成零陷,从而有效消除辅助通道的期望信号成分,并且具有较好的旁瓣保形能力。通过仿真可以看出,该方法能在保持期望信号方向最大增益的同时,在干扰方向形成非常理想的零陷。In a sidelobe cancellation system,the desired signal can also be eliminated when the number ofauxiliary antennas is larger than the number of interference sources.Generally,this problem can be solvedby adding a blocking matrix on the auxiliary channel.However,the sidelobe shows great uplift when the di-rection of the desired signal is closing on the that of the interference signal.To address the issue,a novelmethod is proposed in this paper,which eliminates the desired signal from the auxiliary antenna by addinga linear constraint on its output.It is observed through simulation that the new method maintains the maxgain in the direction of the desired signal while forming an optimal null in the direction of interference.国家自然科学基金资助项目(61301009); 中央高校基本科研业务费专项资助项目(2012121036); 高等学校博士学科点专项科研基金资助项目(20120121120027); 福建省自然科学基金计划资助项目(2013J01252

Light Distribution Design and Simulation of LED for High Uniformity Illumination of Desk Lamp

针对台灯照明的高均匀性要求,设计一个自由曲面透镜对lEd光源进行二次光学配光。根据非成像光学理论,在已知入射光强分布与所需配光效果的前提下,建立关于透镜自由曲面面型的偏微分方程,并采用相应的数值解法,得到自由曲面面型数据。通过在建模软件rHInOCErOS中建立光学透镜的模型,并在TrACEPrO中进行光学仿真,得出仿真结果,验证此设计方法的可行性。According to high uniformity requirements of desk lamp lighting, a free curved surface lens is de-signed to perform the secondary light distribution of light emitting diode(LED) light source.Based on the theory ofnon-imaging optics, at the condition of known incident light intensity distribution and required light distribution effect,partial differential equations related to the shape of free curved surface are established.And corresponding numericalvalue algorithm is adopted to obtain the data of the shape of free curved surface.The models of optical lens are builtthrough simulation software Rhinoceros.And optical simulation is performed in Tracepro.The simulation results areobtained to verify the feasibility of the design method.福建省重大科技项目资助(2006H0092

LED Lighting Design of Underground Parking Lots Based on DILAUX

目前由于汽车的广泛普及,对城市的地下车库照明提出了更多的要求,但随着新一代照明光源lEd照明技术进一步的发展与完善,使得地下车库照明有了更节能、更环保、更经济的可能。在dIlAuX中建模57x33.3M2的中型地下车库,并利用dIlAuX计算软件对地下车库的lEd照明进行模拟、计算、优化,不断的调整灯具位置以及灯具间隔来到达最佳的照明效果,通过实景分析来探讨lEd在地下车库照明领域应用的可行性及其应用前景,并为地下车库照明提供一种设计上的借鉴。More requirements for the light system of civil underground parking lot lighting are concerned since cars are wildly-used nowadays.And it becomes possible to make the light system of underground parking lot more energy-saving,more environmental friendly and more economic as the new generation of LED technology gets more and more developed and improved.DILAUX is a kind of lighting calculation software,and it is used to model an underground parking lot with a medium 57 × 33.3m2and some simulations,calculations,and optimization on the LED light of the parking lot are also done by DILAUX.Therefore,constantly adjust locations and intervals of the lighting fixtures to achieve the optimal results.Furthermore,the feasibilities and application prospects of LED lighting applications in the underground parking lot field can also be explored through the real analysis.Overall,it shows an example to design the light system for civil underground parking lots.国家自然科学基金(61301009); 福建省重大科技项目资助(2006H0092); 福建省自然科学基金计划资助项目(2013J01252

Novel Antenna Array Synthesis Methods and Adaptive Sidelobe Cancellation Algorithms

在雷达或电子对抗系统中，由于主波束比较窄，干扰信号一般从天线旁瓣进入系统。尽管天线旁瓣增益比主瓣增益低得多，但是当干扰很强时，从天线旁瓣进入的有源干扰功率可能远远大于从主瓣进入的目标信号的功率。系统接收到的目标信号将有可能被干扰信号湮没，从而导致系统无法有效的工作。针对这种从副瓣进入的有源强干扰，超低副瓣技术、旁瓣消隐技术以及旁瓣对消技术是目前工程上采用的主要的三种方法。 超低副瓣技术的实现有赖于阵列综合方法的创新。阵元数目、阵元位置、阵元权系数决定了天线阵列的辐射特性，控制这三个因素可以改变辐射场的特征。阵列方向图综合是指按规定的方向图要求，用特定方法优化阵元数目、阵元位置、阵元权系数，使...In radar or electronic warfare systems, the interference signal enter into the systems generally from the sidelobe because the main beam is narrow.Under normal circumstances, the sidelobe gain is much lower than the main lobe gain. But the power of active interference signal come from sidelobe will be far greater than the power of target signal come from main lobe when the interference is strong. ...学位：工学硕士院系专业：物理与机电工程学院_电磁场与微波技术学号：1982011115283

Prediction of Energy Resolution in the JUNO Experiment

International audienceThis paper presents the energy resolution study in the JUNO experiment, incorporating the latest knowledge acquired during the detector construction phase. The determination of neutrino mass ordering in JUNO requires an exceptional energy resolution better than 3% at 1 MeV. To achieve this ambitious goal, significant efforts have been undertaken in the design and production of the key components of the JUNO detector. Various factors affecting the detection of inverse beta decay signals have an impact on the energy resolution, extending beyond the statistical fluctuations of the detected number of photons, such as the properties of liquid scintillator, performance of photomultiplier tubes, and the energy reconstruction algorithm. To account for these effects, a full JUNO simulation and reconstruction approach is employed. This enables the modeling of all relevant effects and the evaluation of associated inputs to accurately estimate the energy resolution. The study reveals an energy resolution of 2.95% at 1 MeV. Furthermore, the study assesses the contribution of major effects to the overall energy resolution budget. This analysis serves as a reference for interpreting future measurements of energy resolution during JUNO data taking. Moreover, it provides a guideline in comprehending the energy resolution characteristics of liquid scintillator-based detectors

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel

JUNO sensitivity on proton decay p → ν K + searches*

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this study, the potential of searching for proton decay in the $p\to \bar{\nu} K^+$ mode with JUNO is investigated. The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar{\nu} K^+$ is 36.9% ± 4.9% with a background level of $0.2\pm 0.05({\rm syst})\pm$$0.2({\rm stat})$ events after 10 years of data collection. The estimated sensitivity based on 200 kton-years of exposure is $9.6 \times 10^{33}$ years, which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies