Numerical Modeling and Computer Simulation of a Meander Line Antenna for Alzheimer’s Disease Treatment, a Feasibility Study

Alzheimer’s disease (AD) is a brain disorder that eventually causes memory loss and the ability to perform simple cognitive functions;research efforts within pharmaceuticals and other medical treatments have minimal impact on the disease. Our preliminary biological studies showed that Repeated Electromagnetic Field Stimulation (REFMS) applying an EM frequency of 64 MHz and a specific absorption rate (SAR) of 0.4 - 0.9 W/kg decrease the level of amyloid-β peptides (Aβ), which is the most likely etiology of AD. This study emphasizes uniform E/H field and SAR distribution with adequate penetration depth penetration through multiple human head layers driven with low input power for safety treatments. In this work, we performed numerical modeling and computer simulations of a portable Meander Line antenna (MLA) to achieve the required EMF parameters to treat AD. The MLA device features a low cost, small size, wide bandwidth, and the ability to integrate into a portable system. This study utilized a High-Frequency Simulation System (HFSS) in the design of the MLA with the desired characteristics suited for AD treatment in humans. The team designed a 24-turn antenna with a 60 cm length and 25 cm width and achieved the required resonant frequency of 64 MHz. Here we used two numerical human head phantoms to test the antenna, the MIDA and spherical head phantom with six and seven tissue layers, respectively. The antenna was fed from a 50-Watt input source to obtain the SAR of 0.6 W/kg requirement in the center of the simulated brain tissue layer. We found that the E/H field and SAR distribution produced was not homogeneous;there were areas of high SAR values close to the antenna transmitter, also areas of low SAR value far away from the antenna. This paper details the antenna parameters, the scattering parameters response, the efficiency response, and the E and H field distribution;we presented the computer simulation results and discussed future work for a practical model.

An Inductor Model for Analyzing the Performance of Printed Meander Line Antennas in Smart Structures

Meander line antenna has been considered desirable on flight vehicles to reduce drag and minimize aerodynamic disturbance;however, the antenna design and performance analysis have made mostly by trial-and-error. An inductor model by simulating the meander line sections as electrical inductors and the interconnecting radiation elements as a quasi-monopole antenna is developed to analyze the antenna performance. Experimental verifications of the printed meander line antennas embedded in composite laminated substrates show that the inductor model is effective to design and analyze. Of the 4 antennas tested, the discrepancy of resonant frequency in simulation and experiment is within 4.6%.

Antenna-in-package system integrated with meander line antenna based on LTCC technology

We present an antenna-in-package system integrated with a meander line antenna based on low temperature co-fired ceramic(LTCC) technology. The proposed system employs a meander line patch antenna, a packaging layer, and a laminated multi-chip module(MCM) for integration of integrated circuit(IC) bare chips.A microstrip feed line is used to reduce the interaction between patch and package. To decrease electromagnetic coupling, a via hole structure is designed and analyzed. The meander line antenna achieved a bandwidth of 220 MHz with the center frequency at 2.4 GHz, a maximum gain of 2.2 d B, and a radiation efficiency about 90% over its operational frequency. The whole system, with a small size of 20.2 mm×6.1 mm×2.6 mm, can be easily realized by a standard LTCC process. This antenna-in-package system integrated with a meander line antenna was fabricated and the experimental results agreed with simulations well.

LOW PROFILE MEANDER LINE PRINTED QUADRIFILAR HELIX ANTENNA

In this paper,a new approach of meander line technique for Printed Quadrifilar Helix Antenna(PQHA) is studied.Compared with other meander line techniques,this approach has lowered the axial height of antenna greatly and improved the efficiency of model-building in simulation processing.We have focused on the analysis of radiation pattern,axial ratio,and design graph for the Meander line Printed Quadrifilar Helix Antenna(MPQHA).Finally,we have reduced successfully 67% size in geometry compared with traditional PQHA method,and obtained rather reasonable results.

Compensating the effects of DC bias lines on terahertz photomixer antennas using resistively loaded lines

This paper proposed a method,namely resistively loaded lines(RLL),to compensate the effects of the DC bias lines after investigating its effects on several types of antennas for terahertz photomixers.The RLL is formed by placing lumped resistances periodically on the DC bias line in order to cease the leakage current virtually,w hich cause a significant amount of distortion on the antenna performance.The simulation results of the dipole,folded dipole,log-periodic,and spiral antennas show that RLL almost removes the effects of the bias lines and improves the antenna radiation resistance and radiation pattern notably compared w ith that of the commonly used bias line types,such as coplanar stripline and photonic bandgap type bias lines.

Analysis and Deskgn of Radiated Element and Array for a Radial Line Slot Antenna

The double layered Radial Line Slot Antenna (RLSA) is a new type of antenna for Ku band Direct Broadcasting Satellite (DBS) reception. This paper presents the structure, aperture field distribution, gain and efficiency of the antenna, discusses parameters of slot pair structure and influences of aperture field distribution and suggests calculation of parameters of the slot pairs and the array structure and CAD design procedures.

Design of Rectangular Dielectric Resonator Antenna Fed by Dielectric Image Line with a Finite Ground Plane

A Rectangular Dielectric Resonator Antenna (RDRA) fed by Dielectric Image Line (DIL) through a narrow slot placed on a finite ground plane is numerically investigated. The effects of ground plane size on the radiation performance of the antenna are carried out. To increase the antenna gain, four sidewalls are placed around the corners of the ground. Also, a reflector is placed at the back side of the structures to reduce backward radiation. Results show that 7.7 dB gain is obtained at 10 GHz with a broadside radiation pattern. For the DRA with four sidewalls maximum gain of 10.4 dB at 10.4 GHz is achieved which is 2.7 dB higher than the gain of the structure without them. The effect of air gap between dielectric resonator and ground plane is also investigated. The results show that with increasing the distance between the DR and ground, antenna gain is decreased.

Design and Construction of Axial Mode Mono-Filar Helical Antenna for Hydrogen Line Emission Studies with 4NEC2 Tool

Antennas have come to play a significant role in the reception and transmission of electromagnetic radiation or signals which in turn have improved scientific research in the various areas where they have been used. Astronomy is not left out;as a study of everything beyond earth’s atmosphere, useful signals have to travel great distances to reach us. Hence the need for equipment to detect such signals. The Helical Antenna is known to possess high gain (directivity) and can process signals with any type of orientation/polarization which implies high sensitivity hence the desire to use it. Simulation was done using the legacy 4NEC2 software. The purpose of this paper is to design a circularly polarized helical antenna operating in axial mode that is suitable for detection of neutral hydrogen line emission at the frequency of 1420 MHz and to show how it can be used as a feed for an off-set parabolic dish.

Design and Development of a 2 ×1 Array of Slotted Microstrip Line Fed Shorted Patch Antenna for DCS Mobile Communication System

Compact microstrip antennas have recently received much attention due to the increasing demand of small antennas for personal communication equipment. The problem of achieving a wide impedance bandwidth for compact microstrip antennas is becoming an important topic in microstrip antenna design. In this paper the design and development of a 2 × 1 array of a low cost slotted microstrip line fed shorted patch antenna (MFSPA) has been presented. Both the shorted patch and microstrip line feed network have air substrate. The material cost is thus reduced to a minimum. The array consists of two adjacent patches fed, using a simple microstrip T network. The impedance bandwidth of nearly 40%, covering the bandwidth requirement of 1750 MHz band is obtained. Also the antenna exhibits dual band operation. The cross polarization radiation in H-Plane observed with a single element antenna has been reduced considerably with 2 × 1 array. A peak antenna gain of 9.2 dBi is obtained with a small variation of 0.8 dBi. From the results obtained it is clear that the antenna array studied has a low cost fabrication and is suitable for applications in DCS mobile communication base station.

IMPROVED PERTURBATION ANALYSIS OF MILLIMETER-WAVE DIELEC TRIC GRATING LEAKY WAVE ANTENNA

An improved perturbation procedure is used for analyzing the radiation character-istics of the millimeter wave dielectric grating leaky wave antenna. The electromagnetic fields aredescribed in terms of an active transverse transmission line network, which brings considerablephysical insight into the overall behavior of the antenna. The analysis is simple and practical. Itsaccuracy is as high as the rigorous method.

Aperture Coupled Microstrip Antenna for Dual-Band

This paper presents air gap aperture coupled microstrip antenna for dual-band operation over the frequency range of (2.9 to 6.0 GHz). This antenna differs from any other microstrip antenna with their feeding structure of the radiating patch element. Input signal couples to the radiating patch trough the aperture that exists on the ground plane of microstrip feed line. The dual-band achieved by variation of air gap [2 mm to 6 mm] between single patch antenna and aper-ture coupled microstrip antenna. The main advantage of this type antenna is increased the bandwidth of the antenna as compared to a single layered patch antenna. The two resonant frequencies can vary over a wide frequency range and the input impedance is easily matched for both frequencies. The obtain ratios of resonance frequencies are variable from 2.1 GHz to 1.1 GHz with increasing the air gap between single patch and aperture coupled microstrip antenna. The measured return loss [–14 dB] exhibits an impedance bandwidth of 35%. The input impedance and VSWR return loss have been measured with the help of Network analyzer.

Broadband Feed for Low Cross-Polarization Uniplanar Tapered Slot Antennas on Low-Permittivity Substrate

A broadband feeding technique for the uniplanar tapered slot antenna (TSA) is presented. The TSA operates at a center frequency of 6.5 GHz with a 7 GHz bandwidth (107 percent). The antenna and feed are realized with a broadband microstrip-to-slotline transition on a low permittivity high frequency substrate, Rogers RT/Duroid 5880. The input impedance of the system is designed for 50 Ω compatibility with other system components, and the cross polarization is kept below –30 dB. The developed TSA system was simulated with commercially available electromagnetic software and manufactured. Measured results validate the design process and the antenna’s performance.

一种低驻波宽角波束超宽带双锥线阵列天线研制

设计和制作了一种实现宽角波束扫描的1×3超宽带双锥线极化阵列天线,可以应用于无人机上实现空地宽带通信。由于无人机平台安装尺寸受限,通过用椭球形阵子代替传统锥形阵子,并切割椭球振子外部轮廓使其安装在250 mm×130 mm×90 mm的空间内,实现了低剖面、小型化等特点。仿真结果表明,该阵列天线在0.8~2.4 GHz的频带范围内电压驻波比均小于2.5,在±45°波束扫描范围内的4个波束的最低增益均超过了2 dBi,满足实际的应用需求。

5G天线端口和线序检测方法研究

天线是收发无线信号的物理载体,天线的正确连接对5G系统非常重要。文中介绍了5G系统中常见的天线端口和线序检测类型,分析了天线线序接错的网络影响,给出了小区内天线极化检测和小区间天线线序检测的自动化算法设计和关键步骤,并对外场和实验室验证效果进行了详细分析,为5G系统天线端口和线序检测提供了重要指导。

利用并矢Green函数模拟地井电磁远探测响应

采用水平层状各向异性介质中的并矢Green函数模拟地井电磁远探测同线、旁线和回线3种发射源的响应,分析频率、收发水平间距、背景地层各向异性、目的层电导率对电磁场各分量的影响特性。结果表明,不同的发射方式、电磁场的不同分量对目的层的识别能力不同。3种发射方式中同线发射方式的综合识别能力最强,其中又以E_(zx)分量最佳。频率越高,各种发射方式的探测深度越浅,但对目的层的综合识别能力越高。收发水平间距的变化对不同分量探测深度的影响特性存在差异,但总体而言影响程度相对较低。背景地层各向异性和目的层电导率的变化对不同分量的影响程度不同,同线发射方式的E_(zx)分量所受影响最大。相关结论可为地井电磁远探测方案的设计和参数的选择提供理论指导。

介质透镜天线在西北交通干线4G组网方案研究及应用

受制于站址建设难度大和投资效益差等客观因素,交通干线4G无线网络覆盖“弱、盲”问题普遍存在。在地广人稀的西北地区,该问题尤为突出,急需一种新技术手段帮助运营商实现交通干线场景的低成本、高质量4G无线网络覆盖。本文通过理论分析及实际组网测试验证了介质透镜天线提升单站覆盖范围的有效性。采用介质透镜天线替换交通干线沿线站点的传统板状天线,可有效提升交通干线的4G无线网络覆盖。特定场景下,通过“隔站闭站”技术还可以在保证网络质量的同时减少站址密度,达到降本增效的目的。

一种风力发电机组叶片扭转变形监测方法的研究

分别在风电机组三支叶片内安装3支GPS定位天线,风电机组叶片叶尖前后缘分别对称安装1个,叶片叶根桨0°标定位置安装1个。经过叶片叶根GPS定位天线位置,并根据风电机组当前提供的桨距角,实时绘制出1条动态直线。叶尖对称安装的2个GPS定位天线,通过两点成为一条直线,实时绘制出1条动态直线。实时判断当前两条动态直线是否处于同一平面、两条动态直线投影到同一平面内的夹角,并实时传送给风电机组控制系统。一旦两条动态直线不处于同一平面,集合风电机组状态数据,判断当前是否处于扭转形变情况,并将判断结果实时传送至风电机组控制系统。风电机组控制系统一旦收到叶片扭转状态,启动安全保护控制策略,并根据两条动态直线的夹角变化,判断控制情况,保证及时减弱机组叶片扭转情况,从而保证叶片安全。

微带线耦合馈电的低RCS微带天线设计

设计一种微带线耦合馈电的低雷达散射截面(RCS)微带天线,天线工作频带为BD2 B3。通过提高介质基板的介电常数使天线小型化,并采用微带线耦合馈电技术,经仿真和实测结果表明,天线结构简单,调频容易,辐射性能优于同轴探针馈电微带天线,并有效地缩减了天线频带内的RCS,最大缩减量达到了30dB。

GIS局部放电检测用小型化平面螺旋天线研究

随着变电站中气体绝缘金属封闭开关设备(GIS)的广泛应用,局部放电检测逐渐成为发现故障隐患的重要手段。基于超高频(UHF)局部放电的检测原理,设计了一种工作于UHF频段的小型化天线。该天线基于传统阿基米德平面螺旋天线,利用一种振幅随着幅角线性增加的新型正弦波加载方式对天线进行进一步的小型化处理。通过HFSS软件进行仿真和试验验证,结果表明该天线在端口性能、方向性能以及增益等方面均满足局部放电检测的要求;同时天线尺寸较小,使用时易于安装,后续在GIS设备局部放电现场检测中有较大应用前景。

特高压输电线舞动监测技术研究

针对现有输电线舞动测量精度不高、数据传输量过大等局限性,在现有微位移测量的微波比相测距技术工作的基础上,提出了1种基于智能天线、扩频技术的特高压输电线舞动监测方案,并对系统的工作原理进行了详细阐述。方案中智能天线对安装在特高压输电线上的多个无线电信标的空间角、距离信息进行监测,利用角度和距离信息计算获得特高压输电线舞动量。针对多信标的空间角估计需求,提出了1种基于平面阵的酉-旋转不变参数估计的改进算法,并对算法进行了仿真分析。仿真结果表明,提出的算法可以精确估计信标的角度信息,结合微波比相测距技术得到的距离信息,可对特高压输电线舞动进行高精度实时监测。