基于GPS的警犬状态监测系统设计

针对目前警犬出勤及日常训练管理过程中不能及时掌握警犬状态的问题,本文提出了基于GPS的警犬状态远程监测系统设计。该系统具有小型化、可穿戴、可内嵌的特性,能有效解决警犬状态实时监测的难题,经试验验证设计可行、系统可靠有效,对警犬状态监测的研究具有一定意义。     

阵列天线方向图仿真系统设计与研究

针对阵列天线的布阵问题,设计了一种阵列天线仿真系统,实现了阵列天线设计的可视化操作.通过设置阵元数、波长、阵元间距等天线相关参数,系统能够实现直线、平面、圆形和圆柱四类阵列天线的仿真分析.针对四类阵列天线稀疏布阵问题,系统采用遗传算法,对稀疏阵列天线的方向图特性进行研究.通过系统的仿真,用户可以直观地观察阵列天线方向图...     

一种相控阵天线强迫风冷热设计方法

阵面温度控制是相控阵天线结构设计的关键技术之一。文中针对某相控阵天线的热设计要求,设计了一种用于相控阵天线散热的强迫风冷系统,并采用数值分析方法,对该系统作用下的相控阵天线阵面热性能进行了分析。对不同流道参数、散热器参数和冷却气体流速下的阵面温度和流体压力进行了仿真。仿真结果表明：冷却气体温度和速度对散热效果影响显著,增加散热片的肋片数量和高度能够提高散热性能。以仿真结果为依据,对相控阵天线的结构参数进行了优选。进行了对比实验,验证了仿真计算的有效性。     

相控阵天线方向图的建模与实时仿真方法

在雷达系统的优化设计的研究中,根据天线波束在扫描过程中增益、波束形状和副瓣电平等参量的特性及其变化规律,研究了相控阵雷达天线方向图的建模与实时仿真问题.为了提高相阵天线的性能,提出了一种相控阵天线方向图的实时仿真方法.并以矩形/圆形平面相控阵天线为例,采用辛格函数的变形组合给出了一种实用的相控阵天线方向图实时仿真模型....     

基于AISG2.0协议的电调天线远程控制单元的设计实现

电调天线远程控制单元(RCU)是进行天线下倾角调节和天线状态远程实时监控的核心部件。本文从实际应用出发,阐述了RCU的硬件设计和相关软件模块的实现,并对RCU与基站对接过程中容易被忽视的问题进行了简要概述。     

雷达天线控制系统频域辨识与仿真方法研究

雷达天线控制系统仿真是雷达系统目标跟踪动态仿真中一个重要环节;为解决雷达天线控制系统仿真中滞后误差大、动态效果差等问题,依据某雷达天线控制系统性能实际测试结果,以典型系统模型作为研究对象,利用频域最小二乘法完成模型参数辨识,建立系统模型,并对辨识模型进行验证;在此基础上,采用基于时域的增广矩阵法对系统进行了数字快速仿真分析;结果表明,辨识模型满足精度,且增广矩阵法能够有效快速地完成系统数字仿真,对天线控制系统建模以及快速动态仿真研究具有一定的参考价值.     

TPMS倒F螺旋天线的设计与实现

在TPMS系统中,天线性能的好坏直接影响无线通信的效果.倒F螺旋天线具有全向性、增益高的特点.针对倒F螺旋全向天线进行研究与设计,用电磁仿真软件CST对天线模型进行了设计与仿真,并根据优化结果制作了实物模型.测试结果表明:谐振频率为433 MHz,回波损耗为-19.49 dB,测试结果与仿真结果吻合良好.     

均匀圆阵列天线仿真系统设计

均匀圆阵列天线以其优越的系统性能在通信、雷达探测、导航制导等许多领域得到了广泛的应用。该文建立了均匀圆阵列天线的系统模型,在此模型基础上对天线的系统性能和各种误差的影响进行了仿真分析,并针对接收信号的不同类型选择了合适的算法,进而完成了波达角估计（DOA）和输出特性的仿真分析。文章中还介绍了用MATLAB实现均匀圆阵列天线（UCA）仿真系统的思路、方法及实现方案,并建立了对均匀圆阵列天线进行全面分析的模拟仿真平台,为实验室研究提供了方便的工具。     

低旁瓣反射面天线设计

反射面天线设计在追求高增益的同时,往往也要求天线具有较低的旁瓣水平,以防止对其他系统产生干扰。通过分析不同天线形式反射面天线旁瓣的影响因素,研究了低旁瓣反射面天线设计时参数选取原则和方法,总结了低旁瓣反射面天线的设计方法。给出了一个实际工程应用的超低旁瓣双偏置反射面天线的设计实例和性能仿真计算,天线仿真的口径效率优于59%,旁瓣优于-40dB,验证了分析与设计方法的正确性,该方法可用于指导低旁瓣反射面天线的工程设计。     

SAW温度传感器测温系统中的天线设计

为实现对电力设备接点的测温,设计了基于声表面波的无源无线温度传感器的测温方案,具体研究其天线设计以及天线和传感器的匹配方法。方案中读写器天线采用平面倒F天线,传感器天线采用法向模螺旋天线。通过仿真分析和优化设计使得两款天线的谐振频率均为915 MHz,驻波比均小于1.5,达到了系统要求。通过改变馈点位置实现了平面倒F天线的匹配,法向模螺旋天线的匹配采用了Smith v2.0软件,最终两款天线的阻抗均为50Ω。     

多应用环境下新型微带偶极子天线设计与优化

传统偶极子天线结构存在偶极子臂细、安全性低、天线走线占用空间大、增益特性差等问题,提出多应用环境下螺旋形印刷微带偶极子天线设计与优化方法。初始化微带偶极子天线工作结构,设计加粗偶极子臂的螺旋形印刷天线,减小天线走线占用空间。设计振子方向、振子阻抗特性,推导出最优结构参数。实验证明可知,在330MHZ-332MHZ的有效范围内,驻波比小于1.30dB ,在331.5MHZ-334.9MHZ有效范围内,回波损耗小于-10dB,其方向对称性较好,天线输入端驻波比与回波损耗较为理想,该天线具有较好特性。     

Remote monitoring of cardiac activity using a flexible loop antenna

In this paper, a meandered loop antenna, useful for medical cardiac monitoring application, more specifically, for heart beating close scrutiny is designed and experimentally tested. The proposed antenna is operating at the MICS band displays a high flexibility which allowing it to be curved easily around the heart's wall. In both, Simulation and measured results the antenna shows a sensitive nature any change introduced in heart's model size and would certainly bring about a noticeable shift in the antenna's resonant frequency. Linking the frequency variations taking place in concord with the heart movement turns out to stand as an effective key that provides extremely valuable information about the heart's activities. A correspondence between the obtained frequency variation linking with the change in size of the heart. In addition to the frequency response evaluation, the antenna characteristically displays an omni‐directional radiation pattern, which necessarily fits it for in‐body operation.     

Bit error rate reduction for circular ultrawideband antenna by dynamic differential evolution

The dynamic differential evolution (DDE) is used to synthesize the radiation pattern of the directional circular arc array to minimize the bit error rate (BER) performance in indoor ultrawideband (UWB) communication system. Using the impulse response of multipath channel, the BER performance of the synthesized antenna pattern on binary pulse amplitude modulation system can be calculated. Based on the topography of the circular antenna array and the BER formula, the array pattern synthesis problem can be reformulated into an optimization problem and solved by the DDE algorithm. The novelties of our approach are not only choosing BER as the object function instead of sidelobe level of the antenna pattern but also considering the antenna feed length effect of each array element. The strong point of the DDE algorithm is that it can find out the solution even if the performance index cannot be formulated by simple equations. Simulation results show that the synthesized antenna array pattern is effective to focus maximum gain to the line of site path which scales as the number of array elements. In other words, the receiver can increase the received signal energy to noise ratio. The synthesized array pattern also can mitigate severe multipath fading in complex propagation environment. As a result, the BER can be reduced substantially in indoor UWB communication system. © 2011 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2012.     

一种天馈线监测系统远程通信方法

天馈线监测系统与远端监控终端的通信在移动基站的维护保障工作中具有重要的意义,通过对该通信需求的研究,使用基于公共电话网采用调制解调器的数据传输方法,能够更好的实现通信功能。     

基于机载平台的吸波材料对U/V波段天线性能影响分析

隐形战机在现代军事中的重要性不断提升,为了降低机载天线的雷达散射面积,会在天线外的天线罩上涂敷吸波材料,而吸波材料会对自身天线性能有一定影响。文章基于此问题展开研究并分析,通过CATIA建立天线罩模型以及机载平台模型并结合HFSS进行天线系统整体仿真分析,探究在天线罩外涂敷吸波材料对U/V波段天线性能影响。     

Design of a 16‐beam pattern‐reconfigurable antenna for vehicular environment

This article presents the design of a multipattern antenna with pattern switching for vehicular communications. The proposed antenna has four triangular patches integrated onto a split square ring (SR) resonator to operate at two distinct frequencies, viz. 2.4 and 3.5 GHz. The proposed antenna is designed with a view to enhancing the link reliability of Wireless Local Area Network (WLAN), WiMax, and vehicle to vehicle communication frequencies. Each triangular patch is separately excited using a microstrip line feed to enable beam steering. The ground plane of the antenna is embedded with two SR slots to improve the bandwidth and radiation performance. Further gain enhancement is achieved by loading the antenna with a plane reflector located at a distance of 20 mm from the antenna's ground surface. In reality, this reflector is realized using the vehicle's roof which provides gain enhancement up to 5.2 dBi at 2.4 GHz and 4 dBi at 3.5 GHz. By exciting single to multiple ports sequentially 16 different radiation patterns are obtained, which provides high‐gain omnidirectional coverage. The prototype antenna is fabricated and the simulation results are verified using experimental measurements. From the results, it is evident that the proposed antenna is suitable for vehicular communication applications.     

动态电轴跟踪系统中扭极化问题的解决方案

动态电轴跟踪系统是常用的雷达罩电性能测试系统,该系统在使用过程中存在着被测天线扭极化的问题。对造成扭极化的原因进行了分析,确认该问题是由雷达罩转台和天线转台方位轴不同轴造成的。利用几何光学三维射线跟踪法对扭极化的危害进行了分析。提出了扭极化问题的解决方案,即将天线转台安装到随动于雷达罩方位轴的天线支杆上。同时归纳出了动态电轴跟踪系统中被测天线的安装要求。     

天馈系统监控方式研究

天馈监控系统可以通过严格的新站入网流程、日常天馈数据管理及网络技术手段等几方面结合有效实现故障排查,达到天馈系统健康、稳定运行.     

A polarization reconfigurable CPW fed monopole antenna with L‐shaped parasitic element

A coplanar waveguide fed polarization reconfigurable monopole antenna is proposed in this letter. The proposed antenna consists of L‐shaped stubs placed on either side of a monopole, two p‐i‐n diodes and a slot in the ground plane. In the proposed antenna structure, the switching element is not directly connected to the feed line. Depending on the switching state of the p‐i‐n diodes, the antenna either radiates left/right circular polarization or linear polarization. To validate the proposed design, the antenna was fabricated and its performance was measured. Since the ground plane is electrically small, the effect of the cable and SMA connector on the performance of the antenna is also investigated. The measured impedance bandwidth is 66.78% (3.67 GHz to 7.35 GHz) and the axial ratio bandwidth is 13.62% (4.24‐4.86 GHz) for circular polarization and 23.61% (3.81‐4.83 GHz) impedance bandwidth for linear polarization.     

基于混合天线的火车头车位监控系统

利用定向天线高增益、抗干扰能力强、通信距离远、方向性好和全向天线的覆盖范围广的优点,设计了结合两种天线的火车头车位监控系统.传感器节点以MSP430G2533单片机作为主控芯片,无线通信采用nRF905射频模块,GPS定位模块用于采集火车头的地理信息,并使用VB 6.0编写了监控软件,实现了对火车头车位的监控.测试结果表明,系统数据传输延迟小、丢包率低、运行稳定、测量准确,能够满足火车头车位监控的应用需求.