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101.
A compact slot antenna with an overall dimension of 30 × 30 × 1.6 mm3 is proposed for dual band applications. The radiating element is a hexagonal shape patch which protrudes from a Co‐Planar Waveguide (CPW) feed into a step shape slot. The slot is basically rectangular in shape and is extended by inserting rectangular cuts of different sizes on the ground plane around it. The ultrawide impedance bandwidth is achieved using asymmetric feed line along with extended rectangular cuts around the slot. For realizing the second band for personal communication system applications (near 1.9 GHz), a metallic stub of quarter wave length is attached at the top of the slot. The measured impedance bandwidth (for S11 < ?10 dB) is 110 MHz (1.86–1.97 GHz) for the first band and 9 GHz (3.0–12.0 GHz) for the second band. The antenna is further characterized by omnidirectional radiation patterns in the H‐plane, dumb‐bell shape radiation patterns in the E‐plane and a peak gain of 3–5 dBi over the ultrawideband. All the measured results are found to be in good agreement with the simulated results. © 2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:243–254, 2015. 相似文献
102.
103.
Michael Westrick Mohammad Almalkawi Vijay Devabhaktuni Charles Bunting 《国际射频与微波计算机辅助工程杂志》2013,23(1):111-117
A novel wire antenna for future dedicated short range communications vehicle‐to‐vehicle communications is introduced. The proposed antenna carries low‐profile and low‐cost features, and possesses an improved gain performance. This article also includes a specific feed network design for the proposed antenna to meet the mechanical and manufacturing requirements. Two different numerical techniques using CST Microwave Studio and HFSS have been applied for evaluating the performance of the proposed antenna. The whole system including the feed network and the antenna elements is integrated, and its performance is also assessed. © 2012 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2013. 相似文献
104.
Finding fault elements in linear antenna arrays using bacteria foraging optimization (BFO) is presented. One of the better options of array diagnosis is to perform it by measuring the radiated field, because in this case, removal of the array from its working site is not required and thereby not interrupting its normal operation. This task of fault finding from far‐field data is designed as an optimization problem where the difference between the far‐field power pattern obtained for a given configuration of failed element(s) and the measured one is minimized w. r. t. the excitations of the array elements. This set of excitations on comparison with the excitations of the original array gives the idea of the fault position and their type, such as either complete fault or partial fault. BFO being relatively new to microwave community when compared with other soft‐computing techniques, its performance was observed w. r. t. time of computation and convergence of the iterative process. Possibility of finding the faults from random sample points and use of minimum number of sample points for array fault finding are the novelties of the present work. © 2012 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2013. 相似文献
105.
Rotman lenses are used to obtain multiple beams from a single array. Although the beams produced by the feed antennas at focal points have no path length errors, the beams produced by feed antennas at off focal points may have large path length errors. These path length errors cause deterioration in the multiple beams. In this article, two novel methods are introduced to obtain feed curves which reduce the path length errors of off focal feed points significantly, compared with the commonly used circular and elliptical feed curves. The first method obtains feed curve points based on having zero path length error at three chosen points of the radiating array for each beam direction. The second method uses the particle swarm optimization method for obtaining optimum feed points for each beam direction. The results show that there is a very significant drop in the level of the maximum path length errors (in the order of about 1:4). © 2012 Wiley Periodicals, Inc. Int J RF and Microwave CAE 23: 634–638, 2013. 相似文献
106.
This article presents a new design of multiband planar inverted‐F antenna with slotted ground plane and S‐etched slot on the radiation patch. The proposed antenna is optimized using an efficient global hybrid optimization method combining bacterial swarm optimization and Nelder‐Mead (BSO‐NM) algorithm to cover a very important six service bands including GSM900, GPS1575, DCS1800, PCS1900, ISM2450, and 4G5000 MHz with enhanced bandwidths. The BSO‐NM algorithm in Matlab code is linked to the CST Microwave studio software to simulate the antenna. To validate the results, the antenna is analyzed using the finite difference time domain (FDTD) method. A good agreement is achieved between the results of EM simulation and that produced from the FDTD method. © 2012 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2013. 相似文献
107.
108.
介绍基于ARM和CPLD的多维天线阵控制系统的设计。系统采用串行通信方式,用ARM嵌入式系统与CPLD相连接取代传统上采用的计算机连接CPLD方式的控制,由于ARM的运用使系统控制阵列天线更具智能化、应用程序更简化,CPLD的使用大大增加了与外设相连接的引脚数,满足了项目中对多条控制线的需求。作为主控制器的ARM取代了PC机,ARM具有体积小、集成度高、运算速度快、存储器容量大、功耗低等特点,节约了项目成本,缩小了整机体积,增强了系统的稳定性和灵活性,在实际应用中取得了理想的效果。 相似文献
109.
作为一种新型无线技术,Mesh网络技术的拓扑结构、关键技术及应用领域一直以来备受关注。通过分析它的多级跳点系统拓扑结构,可以总结出它比传统无线网络具有更大的容量、速率和覆盖范围;它涉及了智能天线、MAC层多址访问等一系列关键技术,应用领域十分广泛。 相似文献
110.
多用户MIMO-CDMA是MIMO技术领域研究的最新成果,MIMO-CDMA系统可以显著地提高系统的容量和BER性能。但系统复杂度高,而天线选择技术可以大大降低MIMO-CDMA系统实现复杂度。设计了一种基于帧结构的MIMO-CDMA接收端子选择系统仿真平台,分析和比较了在MBER、MMI和MNP等不同选择准则条件下的系统性能,并对仿真结果进行了评价。 相似文献