多阵面拼接雷达方向图优化研究

增大雷达天线的孔径是提升雷达探测距离、测角分辨率和测角精度最直接的方法。但是增大雷达的天线孔径除了需要考虑载体平台的物理结构限制之外,还必须要考虑对雷达机动性的影响。为兼顾雷达的机动性、雷达的威力和测角分辨力,考虑将多个可便携的阵面拼接合成一个大阵面,为避免拼接后的方向图产生高副瓣,首先对阵面间距与合成方向图栅瓣产生关系进行研究,接着在阵面间距保证阵面不会出现栅瓣条件下,使用凸优化算法对拼接后方向图的高副瓣进行抑制,并通过仿真试验验证了本文方法的正确性。

基于MADDPG的多阵面相控阵雷达引导搜索资源优化算法

针对传统单阵面雷达搜索资源优化算法在复杂多阵面场景下的参数求解困难问题,提出一种基于多智能体深度确定性策略梯度(MADDPG)的多阵面雷达搜索资源优化算法。考虑多阵面相控阵雷达场景约束,结合机载雷达实际搜索任务需求,建立基于最大目标平均积累期望发现概率的多阵面雷达搜索资源优化模型。分别设计多智能体局部及全局观测空间和带折扣因子的复合奖励函数,基于执行者-评论者(Actor-Critic)算法结构,通过各智能体策略网络在线更新各雷达阵面搜索资源分配系数实现上述模型参数的优化求解。仿真结果表明,该算法能够根据空域-目标覆盖情况及各目标威胁权系数迅速作出精确的自主决策,在多阵面相控阵雷达搜索资源优化场景下的表现显著优于传统算法。

舰载多阵面机械零位动态对准方法研究

针对舰船摇摆情况下多阵面机械零位动态对准的需求,提出了一种基于GPS双天线的组合惯导测量系统,通过定义主惯导和子惯导,实现两位置姿态信息的实时输出,最终利用转换矩阵将主惯导的姿态信息传输到多个阵面设备上,从而实现多阵面机械零位的动态对准。

一种多平面组合相控阵天线波束控制实现方法

针对类似网格化球顶相控阵体制雷达波束控制系统,本文提出了一种对于多阵面雷达波束控制的实现方法。该方法采用集中运算、区域管理、总线传输等方案,实现雷达阵面的波束指向控制。本文阐述了多平面阵组合相控阵雷达波束控制系统的工作特点,提出了利用不同工作模式码组合的一种区域管理、集中运算的优化方案,介绍了该波束控制系统设计原理、功能组成和时序关系内容。该方案具有控制灵活、响应快、硬件简单、成本低廉和易于工程实现等特点,能够满足多平面相控阵体制雷达对波束控制的要求。

Design and Characteristics of InGaAs/GaAs MQW SEED Arrays Structure

The influence of DBR in resonant cavity on the characteristics of the reflectivity of InGaAs/GaAs MQW SEED arrays has been discussed. InGaAs/GaAs acting as the active region of MQW SEED to gain 980nm work wavelergth has been introduced. A new resonant cavity structure of the InGaAs/GaAs MQW SEED arrays has been designed and analyzed. The MQW materials grown by MOCVD system have also been measured and analyzed with micro optical spot reflection spectra, PL measurement and X ray measurement. The results of measurement prove the good quality of the wafer and the accuracy of our design and analysis of the structure of the device.

PARETO FRONT CAPTURE USING DETERMINISTIC OPTIMIZATION METHODS IN MULTI-CRITERION AERODYNAMIC DESIGN

Deterministic optimization methods are combined with the Pareto front concept to solve multi-criterion design problems. The algorithm and the numerical implementation are applied to aerodynamic designs. Evolutionary algorithms （EAs） and the Pareto front concept are used to solve practical design problems in industry for its robustness in capturing convex, concave, discrete or discontinuous Pareto fronts of multi-objective optimization problems. However, the process is time-consuming. Therefore, deterministic optimization methods are introduced to capture the Pareto front, and the types of the captured Pareto front are explained. Numerical experiments show that the deterministic optimization method is a good alternative to EAs for capturing any convex and some concave Pareto fronts in multi-criterion aerodynamic optimization problems due to its efficiency.

Notes on Quantitative Structure-Properties Relationships （QSPR） Part Four： Quantum Multimolecular Polyhedra, Collective Vectors, Quantum Similarity, and Quantum QSPR Fundamental Equation

The nature and origin of a fundamental quantum QSPR （QQSPR） equation are discussed. In principle, as any molecular structure can be associated to quantum mechanical density functions （DF）, a molecular set can be reconstructed as a quantum multimolecular polyhedron （QMP）, whose vertices are formed by each molecular DF. According to QQSPR theory, complicated kinds of molecular properties, like biological activity or toxicity, of molecular sets can be calculated via the quantum expectation value of an approximate Hermitian operator, which can be evaluated with the geometrical information contained in the attached QMP via quantum similarity matrices. Practical ways of solving the QQSPR problem from the point of view of QMP geometrical structure are provided. Such a development results into a powerful algorithm, which can be implemented within molecular design as an alternative to the current classical QSPR procedures.

The Assodated Matrices of Ap, n, 4p-5 Polyhedra and their Admissible Onerations

In this paper we describe the decomposition problem of a special kind of Ap,n,4p-5 polyhedra by using the associated matrices and their admissible operations.

Stable homotopy classification of A_n^4-polyhedra with 2-torsion free homology

We study the stable homotopy types of F_n^4(2)-polyhedra, i.e.,(n- 1)-connected, at most(n+ 4)-dimensional polyhedra with 2-torsion free homologies. We are able to classify the indecomposable F_n^4(2)-polyhedra. The proof relies on the matrix problem technique which was developed in the classification of representations of algebras and applied to homotopy theory by Baues and Drozd(1999, 2001, 2004).

Mutual coupling reduction of multiple antenna systems

A multi-band multi-antenna system has become an important trend in the development of mobile communication systems.However,strong mutual coupling tends to occur between antenna elements with a small space,distorting array antennas’performance.Therefore,in the multiple-input multiple-output(MIMO)antenna system,high isolation based on miniaturization of the antenna array has been pursued.We study in depth the methods of decoupling between antenna elements.Reasons for the existence of mutual coupling and advantages of mutual coupling reduction are analyzed.Then the decoupling methods proposed in recent works are compared and analyzed.Finally,we propose a metasurface consisting of double-layer short wires,which can be applied to improve the port isolation of antennas arranged along the H-plane and E-plane.Results show that the proposed metasurface has good decoupling effect on a closely placed antenna array.

On the Buchstaber Invariant of Simple Convex 3-Polytopes

and uses it imply that application In this paper the author gives a method of constructing characteristic matrices, to determine the Buchstaber invariants of all simple convex 3-polytopes, which each simple convex 3-polytope admits a characteristic function. As a further of the method, the author also gives a simple new proof of five-color theorem.