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A calculation method and calculation results that show that a new kind of shaped paraboloid antennas can produce a ringy radiation pattern is presented.

通过数值计算发现将抛物线绕通过焦点的非抛物线对称轴旋转而形成的赋形抛物面天线可产生环状的方向图主瓣(此主瓣指的是主瓣最大值处)。

All above laid a foundation for the research of polarimetric information processing and application. Then, target optimum polarization and polarimetric synthesis technique were studied. By constraining polarimetric states of transmitting and receiving antennas, co-polarized and cross-polarized signatures were obtained. Because the received wave was partially polarized, completely polarized, completely unpolarized, and total available power signatures were defined based on the power of the return wave.

接着，论文深入研究了目标最佳极化和极化合成技术，通过约束收发天线的极化状态可以得到共极化特征图和交叉极化特征图，由于雷达接收的电磁波通常是部分极化的，根据接收波的平均功率密度可以得到未极化特征图、完全极化特征图和匹配极化特征图，在极化特征图空间中搜索可以很容易地获得目标的最佳极化，这些目标最佳极化可以作为极化目标识别和分类的极化特征。

A very fast and efficient array pattern synthesis algorithm-SFFT is described in this paper. This algorithm is well suited for many synthesis problems of planar array antennas with periodic element spacing, particularly the large arrays.

介绍了连续快速傅里叶变换，该算法适用于辐射单元周期排列阵列的各种综合问题，尤其对大型阵列综合表述更简捷、性能更优良、计算速度更快。

Photoconductor antennas irradiated by ultrashort laser pulses can emit electromagnetic waves at the terahertz bandgap, which has been studied extensively and used widely as a terahertz source.

利用超短激光脉冲触发光电导天线产生太赫兹波是目前研究比较深入，同时得到广泛采用的一种太赫兹波源。

The physical optics method is used to analysis the electromagnetic scattering fromelectric-large size radome-enclosed antennas.

应用物理光学法对电大尺寸带罩天线的散射特性进行分析。

The microstrip antennas has the volume small, the weight light, the structure stable, the section plane low, the feed way nimble, the cost low, is easy and the flight vehicle line, is altogether easy to produce the plan polarized wave and and so on the merit.

微带天线具有体积小、重量轻、结构稳定、剖面低、馈电方式灵活、成本低、易与飞行器共行、易产生线极化波和圆极化波等优点。

Secondly, by establishing a discrete time Markov model with spatial reuse for a MANET, we analyze the performance of the network under the AODV routing protocol. The average route length and the probability to communicate within a limited hop distance are obtained. Several performance parameters of the route discovery and route maintain process are analytically studied, such as the probability generating function and the expectation of the flooding distabce. the probability that a route is discovered by a query packet with a "hop limit", the probability that a request packet finds a valid route, the average time needed to discover a valid route and the cost to successfully route a data packet to its destination. Furthermore, we present a concrete example based on the transmitter characteristic of directional antennas and obtain the corresponding results.

建立了移动自组网络空间可重用的离散时间马氏链模型，得到了AODV路由协议下网络任意两节点间的平均路由长度、在指定"跳限"要求下通信的概率；对随选型路由协议下路由发现和路由维护过程中若干网络性能参数进行了解析分析，如网络中任意两节点问的泛洪距离的概率母函数及其期望、限定泛洪步数时成功寻路的概率、发现一条有效路由的平均时间、成功路由的代价等；并基于定向天线的发射特征给出了一个具体实例，分析计算了相应的网络性能参数。

The dissertation includes the work as follows: Firstly, we present a random graph model with spatial reuse for a dense MANET which using directional antennas. The analytic formula of several important performance parameters for the MANET are obtained under the DSR routing protocol, such as the average flooding distance, the probability generating function of the flooding distance, the probability of a flooding route to be symmetrically valid, the average time to find a symmetrically valid route and the cost to successfully route a data packet to its destination. We compare the two models with spatial reuse and without spatial reuse by evaluating these parameters. It is shown that the spatial reuse model is much more effcctive in terms of the performance of the dense network with directional antenna, because the bigger is the degree of spatial reuse, the smaller is the average flooding distance.

在定向天线技术的支持下，建立了移动自组网络空间可重用的贝努利随机图模型，获得了DSR路由协议下平均泛洪距离的解析公式和泛洪距离的概率母函数：给出了有效对称路由概率、发现有效路由平均时间、成功路由代价等关键性能参数的解析分析；在网络性能参数定量分析的基础上，对空间可重用和无重用的网络进行了比较分析，结果显示空间重用度增大，则平均泛洪距离、路由发现时延、网络代价减少。

The data arrived on a radio signal so weak -- a ten quadrillionth of a watt -- that 38 giant radio antennas on four continents were used to catch Voyager's whispered message.

无线电信号送达的数据很弱——一瓦的百兆分之一。在四大洲用了三十八根巨型无线电天线才捕捉到"旅行者"耳语般的信息。

With rapid development of space technology and continual updating of communication device, the requisition for antennas becomes higher and higher. General method of Far-Field measurement of antenna has much difficulty in its implementing, even powerless sometimes. So people aspire after a way to calculate radicalization field of antenna by measuring its near field.

随着空间技术的迅速发展以及通信设备的不断更新，对天线的要求越来越高，常规的远场测量天线的方法由于实施过程中存在许多困难，有时甚至无能为力，于是人们就渴望通过测量天线的近场而计算出其辐射场的方法。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。