查询词典 antenna array

Secondly, in this paper, the four typical UWB antennas of TEM horn antenna, log-periodic antenna, biconical antenna and helical antenna are theoretically analyzed and the UWB antenna design methods are generalized and discussed.

其次，本文对TEM喇叭天线、对数周期天线、双锥形天线和螺旋天线四种典型的超宽带天线进行了理论分析，总结并讨论超宽带天线的设计方法和手段。

According to requirements of engineering design, antenna efficiency and broadband impedance match network, conical antenna is defined as unit antenna after comparing the electric apparatus and element forms of cage antenna and conical antenna.

从工程设计角度出发，根据天线效率和宽带阻抗匹配网络要求，在比较笼形和锥形两种天线的电气和结构性能之后，确定锥形天线为单元天线。

In modern specification of handset, there is one about SAR. However, current mobile phone antenna is dipole antenna with omni-directional radiation pattern in azimuth plane. So much better performance of antenna means higher SAR value. Therefore, in order to improve SAR performance, designer may be forced to detune antenna or use resistor. The two methods will reduce efficiency of antenna.

在移动电话的技术规范中往往有SAR值的要求，这给手机天线的设计带来了严峻的挑战，因为现代的手机天线基本上是在水平面具有全向辐射特点的偶极子天线，因此天线的性能越好往往SAR值越高，所以有时为了降低SAR值甚至故意劣化天线的性能。

The antenna system includes a mechanism for electrically connecting the displaceable antenna to internal RF circuitry of the portable WCD when the displaceable antenna is in an extended position and for electrically isolating the displaceable antenna from the internal RF circuit when the displaceable antenna is in a retracted position within the casing.

该天线系统包括一个机构，用来在可移动天线处于拉伸位置时把可移动天线电连接至便携式WCD的内部RF电路，并在可移动天线处于外壳内的收缩位置时把可移动天线和便携式WCD的内部RF电路电隔离。

To solve the problem, a concept of dynamic antenna is introduced, which comprises the antenna with wireless sensor, wheels, and vehicle body. A 3D electromagnetic simulation model for the dynamic antenna is built and a simulation is performed. The parameters of dynamic antenna obtained by the simulation are then used in the design of matching circuit of base antenna.

针对该问题提出将无线传感器天线、轮毂、车身看作一个动态天线，建立动态天线的三维电磁场仿真模型，并将仿真得到的动态天线参数用于无线传感器天线的匹配电路设计。

a novel miniaturization bow tie rfid tag antenna is proposed based on the triangular sierpinski fractal microstrip.the port characteristics of the proposed antenna are presented by simulation.at the same time,the resonance frequency,the radiation pattern and the efficiency of the sierpinski tag antenna is given.the results of the simulation show that multiple frequency band can be obtained by varying the dimensions of the fractal structure.hence this kind of antenna can be used into the rfid tag antenna very conveniently.

摘 要：基于三角形sierpinski微带分形贴片，提出了一种新型的小尺寸领带结rfid标签天线设计。通过仿真，给出了该分形天线的端口特性，同时给出了该领带结型sierpinski标签天线的谐振频率、方向图以及天线效率。结果表明，采用不同维数的分形结构，可以实现多频段的工作特性，因而该天线可以很方便地应用于rfid电子标签中。

Feeding patterns of antenna array are researched and feeding network is designed. Three-unit and four-unit models for the cylindrically conformal microstrip antenna array are set up and their directivities are simulated respectively. Through the comparison of the simulation results, the four-unit array is proved to be feasible.

对天线阵列的馈电方式进行了研究，设计了天线阵列的馈电网络，建立了三单元和四单元柱面共形微带天线阵列模型，对方向性分别进行了仿真分析，比较仿真结果，选用了满足工程需要的四单元阵列。

After antenna array is meliorated, the channel capacity of multi-beam array is much better than that of the adaptive array antenna.

合理设计单元天线和阵列结构，其提高系统信道容量的能力远大于自适应智能天线。

By time-varying filtering, we realize the signal selectivity and interference suppression, especially for the signals with time-varying power spectrum. It is shown herein that conventional eigenstructure based methods are lower dimensional special case of the time-frequency subspace fitting method. The closed-form array response estimation algorithms for blind source separation in wireless communication is also developed in the dissertation by exploiting the data structure of second-order statistics of the array output in the presence of multipath. The proposed method achieves array response estimation with little constraint on signal property and propagation environment such as scatters or angular spread. Moreover, the array utilized here can be of arbitrary geometry and even uncalibrated. Since the closed-form solution is obtained, no misconvergency may occur and large amount of computation can be saved. The equivalent feed model and corresponding optimization designation are proposed to realize the downlink multi-user selective transmission. By coherent and non-coherent superposition of the electromagnetical field, multiple beams can be formed using a single array, so that each co-channel user signal is transmitted in each beam and will not interfered with each other. The proposed system scheme implements the digital beamforming and the channel allocation in the base band, therefore is suitable for the utilization of the radio software technology. The feasibility and effectiveness of the proposed model are proved by the RF experiment.

在窄带条件下，GSC－SSF方法还可以提高阵列的虚拟孔径，从而提高估计的性能；可以证明，Cyclic DOA 和SC-SSF方法可看作该方法的特例或近似； 3、提出了二维GSC－SSF方法和宽带谱相关DOA矩阵方法，利用信号的循环平稳特性解决了宽带条件下二维 DOA 估计问题，并具有阵元数少、计算量较小的特点； 4、提出了时频子空间拟合和宽带时频DOA估计算法，将联合时频分析的理论和方法引入到阵列信号的空间谱估计研究中，利用时变滤波实现信号选择性测向和干扰抑制，特别适合于谱时变信号；可以证明传统特征结构法可看作是时频子空间拟合方法的特例； 5、提出了多用户环境下阵列响应的估计方法——CARE方法，该方法对信号结构和传播参数（主要是散射源分布与角度散布）的约束较少，适用于各种几何结构的阵列甚至未校准的阵列，能够直接得到阵列响应的闭式解，因此计算量小、稳健性好，不存在收敛问题； 6、提出了针对多用户下行选择性发送的阵列等效激励模型、优化设计方法及其系统实现方案，通过空间场的相干叠加与非相干叠加使得单一阵列能够形成多个波束，并保证各波束内的用户信号各不相同且相互干扰最小；其系统方案具有在基带实现数字波束成形、信道分配并便于软件无线电实现的特点，其有效性已得到外场实测数据的证实。

The relationships among perfect punctured binary array pair, quasi-perfect and double quasi-perfect punctured binary array pair is presented. Specially, when first and second dimension period of the punctured binary array pair are odd, the perfect punctured binary array pair, quasi-perfect and double quasi-perfect punctured binary array are able to change each other.

定义了准最佳屏蔽二进阵列偶和双准最佳屏蔽二进阵列偶，研究了它们的变换性质和频谱特性，给出了它们存在的组合允许条件，利用这些组合允许条件，有效地搜索出若干准最佳屏蔽二进阵列偶和双准最佳屏蔽二进阵列偶。

Fostering the concept of multi-culture firmly and mastering the development of advanced culture correctly are conductive to resisting terrorism, separatism of nationalities and ultraism of religion, which is of great academic theoretical, immediate and profound historical si...

牢固树立多元文化的理念和正确把握先进文化的发展方向，有助于在世界范围内自觉地抵制恐怖主义，民族分裂主义和宗教极端主义。不仅具有重大的学术理论意义，而且也具有重大的现实意义和深远的历史意义。

But if anyone walks in the night, he stumbles, because the light is not in him.

11：10 若在黑夜行走，就必碰跌，因为那光不在他里面。