查询词典 antenna

Ds Explained the technology of tolerance design;Aimed at Antenna Structure based on modularized assembly, by referring to the random numbers based on Uncertainty Theory that accord with tolerance distribution rule and using Monte Carlo simulation, a simulated analysis and mathematical statistics of the Antenna-Structured Precision Information Model terminal error have been done.

对产品精度信息模型的公差分析和公差综合技术进行说明；针对模块化装配的天线结构产品精度信息模型，基于不确定性理论的随机公差分布，利用蒙特卡洛模拟法来对天线结构的装配产品精度信息模型的终端误差进行仿真分析和综合。

A lot of transmogrification designs are implemented on the structure of the antenna, from meander slot antenna, feedback line to parasitic unit.

在对天线进行综合选型的基础上，重点阐述了蛇形槽天线的研究。

Multiple antenna arrays are often used to overcome the effect of channel fading which is caused by multipath interference. In chapters 4 and 5 ,we derive spatial correlation equations of ULA ,UCA and CRA for two types of angular spread distributions (uniform distribution and truncated Gaussian distribution).We also compare the difference between these antenna arrays by showing the bit error rate simulation results and discuss the relationship between BER and spatial correlation. In a multi-user mobile radio environment , we present simulation results to show that adaptive MBER algorithms have better performance than the traditional MMSE algorithm.

多天线阵列常被用来克服多重路径干扰导致通道衰减的影响，我们对各种天线阵列架构进行比较，在第四、五章中推导出ULA、UCA与CRA个别对两种角度扩散机率密度分布的空间相关性函数，由实际实验模拟的位元错误率图形比较天线阵列间的差异，并讨论位元错误率与空间相关性之关连，在多用户端行动通讯环境下，我们也由模拟验证可适性MBER演算法，会比传统MMSE准则有更好的效果。

With the miniature intelligent antenna array adopted by the invention, the ultrahigh frequency portable reader can improve reading and writing distance, reading and writing range and reading and writing accuracy, leading a system to sense labels in different antenna covering areas, enlarge the covering range of the system and effectively improve the ratio of the distance and power consumption.

本发明采用小型智能天线阵列，能够提高读写距离、范围和准确性，使系统能够感知不同天线覆盖区域的标签，增大系统覆盖范围，有效提高了距离和功耗的比值。

The invention discloses an ultrahigh frequency portable reader which is based on a self-adaptive antenna array and comprises a da vinci chip. The da Vinci chip is externally connected with a USB interface, a Bluetooth interface, a liquid crystal display and at least an AD circuit which is connected with an RF circuit. The RF circuit is connected with the antenna array.

本发明公开了一种基于自适应天线阵列的超高频便携式读写器，包括达芬奇芯片，达芬奇芯片外接USB接口、蓝牙接口、液晶显示器和至少一个AD电路，AD电路上连接有RF电路，RF电路上连接有天线阵列。

In reference [1] , Waterhouse proposed the method of reducing resonance frequency and dimension of antenna by putting a shorting post in the microstrip patch antenna, and experimented on this kind of antennas.

但是，这种天线在较低频率应用时尺寸太大，不能满足实际要求，从而影响了微带贴片天线在低频频段的应用。

The position of microstrip antennas feeding spot determines the wave pattern of antenna radiation and whether antenna can match feeding line.

微带天线馈点的位置决定天线辐射波的模式和天线与馈线的匹配情况。

The input impedance of the antenna, the wideness of the frequency working range and purity of the diagram of the antenna remained practically unchanged.

天线的输入阻抗，工作频率的带宽和纯正的方向图几乎保持不变。

Based on variational principle and split-based interpolation finite element method for fast and accurate analysis of normal mode helical antenna,Combination of genetic algorithm and then load the normal mode helical antenna loaded on the value of lumped elements,Load location,and matching network integrated optimal design parameters,And using Sherman-morrisorr Woodbury formula to quickly solce the load component values and load the changed position of the impedance matrix equation to improve the efficiency of optimized design.

采用基于变分原理和剖分插值为基础的有限元法来快速精确分析法向模螺旋天线，然后结合遗传算法对加载法向模螺旋天线上的加载集总元件的值、加载位置以及匹配网络参数进行一体化优化设计，并采用Sherman-Morrisorr Woodbury公式来快速求解加载元件值和加载位置改变后的阻抗矩阵方程，提高优化设计的效率。

This paper analyzes the Yagi antenna structure and principle and the use of HFSS software Yagi antenna performance analysis and structural design, made to further improve and optimize the performance of the methods.

本文主要分析了八木天线的结构及原理，并利用HFSS 软件对八木天线的性能结构进行分析和设计，提出了进一步改进和优化性能指标的方法。

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％。