A method is proposed to make for the loss of the orthogonal converting matrix ' s performance on constant beam - width , that is giving different frequency components different weighing values during orthogonal process , which is called weighted orthogonal converting matrix 对于转换矩阵(恒定束宽波束形成矩阵)正交化过程对恒定束宽性能的损失提出了一种补偿措施，即在正交化过程中对不同频率对应的波束进行加权，称之为加权正交化恒定束宽波束形成矩阵。
Lake - experiment for an un - baffled practical circular array verified the effectiveness and error tolerance of this new method . 5 . the intrinsic mechanism of optimal array gains is studied for the scenario when the element spacing is less than one half - wavelength , with emphasis on un - baffled circular arrays 针对一个24元均匀分布圆阵的湖上实验结果表明，这种新的恒定束宽波束形成方法是有效的，且在一般条件下，对基阵阵元幅度和相位响应误差具有良好的宽容性。
The beam width is stretched . the algorithm performance has the very big weaken . but the convention beamforming algorithm performance is stabler , time delay unbalance , time domain sampling , plane wave supposition and array element the influence which creates to it is not big 通过比较,高分辨率算法在考虑上述情况后,波束方向出现偏差,束宽被展宽,幅度有很大的衰减,性能明显下降;而常规波束形成算法的性能较稳定,延时失配、时域抽样、平面波假设和基阵的幅相不一致对其造成的影响不大。
The work presented in this paper is carrying out to the theory research of dbf . the work includes : research of dbf algorithms , dbf antenna system composition and realization . the application of dbf algorithms used in high frequency ground wave radar for near ocean inspection and ocean situation remote sensor is also presented . at last , we give a effective scheme to implement broad - band constant beamwidth digital beam - former 本文的主要工作是围绕数字波束形成技术的理论研究，内容包括：数字波束形成算法的研究，数字波束形成天线的系统构成和实现，以及将数字波束形成算法应用于高频地波雷达近海监测和海态遥感，最后给出了一种宽带恒定束宽数字波束形成器的设计方案。
2 . the two thoughts of designing constant beam - width beam - former are studied , and the least square method and spatial resample method to calculate the weighting coefficients of the array elements are analyzed and compared , and the constant beam - width beam - former is designed , both in frequency and time domains 研究了宽带恒定束宽波束形成器的两种设计思想，并重点分析了计算阵元权系数的最小二乘法和空间重采样法，比较了二者的性能，分析了恒定束宽波束形成器的频域和时域实现原理。
Chapter 2 : using a so - called variance matrix , we studied the propagation and the focusing characteristics of the paraxial light beams . the quantities characterizing the gross features for a paraxial optical beam , such as the beam width , the divergence , the curvature radius of the wavefront , the complex beam parameter q . and the beam quality factor , are related by using variance matrix 第二章：阐述了常数折射率介质中光束的传输和聚焦，建立了表征傍轴光束总的特征的量，如：束宽、衍射发散角、波前曲率半径、复光束参数q与变换矩阵的关系，得到了光束质量因子和变换矩阵行列式的定量关系。
On one hand , is the product of beam waist radius and half divergence angle , wavelength is not involved . so there is possibility to compare the acutal focusing ability among laser beams with different wavelength . on the other hand , is a calculated result by measuring experiment , and it is more brief and persuadable than m 2factor , since the latter one is a ratio with basic mode gauss beam 论文研究论证了用值评价激光光束质量的实际意义在于两个方面,一方面它仅仅包含了光束束宽和发散角,不涉及波长的因素,使不同波长激光束的可加工能力具有可比性;另一方面,值是根据对光束传输路径上不同位置处束宽实际测量结果的计算值,比其在与基模高斯光束进行比值计算得到的m2因子更简洁、更有说服力。
This method is easy to implement and has no restriction on array geometry and sensor patterns ; three methods for the design of broadband frequency invariant beamformer are proposed , which are the method of resampling signals received by the array , the dft ( discrete fourier transform ) interpolation method and adaptive synthesis method , respectively . examples and performance analyses are given for each method ; a simplified linear constrained minimum variance broadband adaptive algorithm that based on dft interpolation method is presented . compared with conventional broadband adaptive algorithms , the presented method can reduce computation work greatly 提出了一种简单、易于实现的恒定束宽波束形成器设计方法，该方法对阵形和阵元指向性没有任何限制；分别提出了基于阵列接收数据重采样、基于dft插值和自适应综合的三种具有频率不变波束图的宽带波束形成器设计方法，对于每一种设计方法都给出了一个设计实例并做了性能分析；提出一种基于dft插值的简化线性约束最小方差宽带自适应阵列算法，该方法可以大大降低自适应阵列的运算量。
Chapter 3 : in this chapter , the propagation characteristic and focusing properties of elegant hermite - cosh - gaussian ( ehchg ) beam through a finite aperture are investigated . the variance of the beam width , the generalized analytical expression of mg2 - factor and the power fraction of the truncated beam are derived theoretically and illustrated numerically 第三章：讨论了eleganthermite - cosh - gaussian ( ehchc )光束通过有限孔径的传播特性和聚焦性质，得到了其光束束宽， m ~ 2因子及能量分数的解析表达式，并分析了影响光束参数的因素及其变化规律。
We discuss the effect on the focusing of the probe beams for the five initial parameters : the amplitude of the pump beam , the separation between the pump and the probe beam centers , the wavelength ratio of the pump and the probe beams and the ratio of the initial beam widths at the directions of x and y . our numerical results show that , more the amplitude of the pump beam , the wavelength ratio of the pump and the probe beams and the ratio of the initial beam widths at the direction of y , more the probe focus ; the separation between the pump and the probe beam centers and the ratio of the initial beam widths at the direction of x have optimum values , respectively 研究了泵浦光束输入振幅、泵浦光束-信号光束初始偏移、泵浦光束-信号光束波长比和泵浦光束-信号光束x 、 y方向的初始束宽比五个参量对信号光束聚焦程度的影响。数值模拟结果表明，泵浦光束输入振幅越大、泵浦光束-信号光束波长比越大、 y方向束宽比越大，信号光束聚焦程度越大；泵浦光束-信号光束初始偏移和x方向初始束宽比都存在一个最佳值，使得光束聚焦达到最佳效果，有趣的是这两个最佳值的比值基本保持不变约为0 . 4 0 . 6 。
