Influence of antenna configuration on achievable throughput in real indoor propagation environment for 2-by-2 single-user MIMO in LTE-advanced uplink

This paper clarifies the influence of the antenna configuration on the achievable throughput in a real indoor propagation environment for 2-by-2 single-user (SU) multiple-input multiple-output (MIMO) in the Long Term Evolution (LTE)-Advanced uplink using single carrier-based radio access. In indoor experiments conducted in an office at walking speed, we consider four antenna configurations: co-polarized antennas with a long or small separation, cross-polarized antenna, and a distributed antenna arrangement. The experimental results show that when rank-2 MIMO spatial multiplexing is applied, the cross-polarized antenna configuration achieves a higher user throughput than the other antenna configurations. Furthermore, we show that when closed-loop rank-1 precoding is applied, the cross-polarized antenna configuration is effective in stably achieving a relatively high throughput regardless of the tilt angle of the mobile station transmitter antenna, although the other antenna configurations indicate better throughput under ideal antenna-tilt angle conditions.     

机载MIMO-SAR线性阵列天线配置研究

等效相位中心原理的应用为多发多收合成孔径雷达(MIMO-SAR)的天线设计提供了更大的自由度。文中阐述了等效相位中心原理,分析了传统ARTINO天线配置,指出由于其发射阵元布设于机翼处而剧烈抖动造成图像模糊的问题。然后,对传统ARTINO天线结构进行了改进,并提出了发射居中紧凑和接收居中紧凑2种天线构形。最后,对4种天线构形的方向图进行了仿真。结果表明,MIMO-SAR采用等效相位中心原理进行天线结构配置,可以在保证天线方向图具有良好指向性的同时,提高天线配置的灵活性并降低成本。     

Dual frequency wire antennas

A new type of dual frequency antenna is introduced by combining a helical and a monopole antenna. The antenna configuration is shown to operate at two discrete frequencies. i.e. ~900 and 1800 MHz. The size of the antenna configuration can be decreased at the cost of the bandwidth. The bandwidth is shown to increase by adding a reactive matching network to the antenna     

用于星载SAR的双频双极化天线

该文设计了共用一个物理孔径的双频双极化的微带天线。天线采用了可折叠的充气式聚酯薄膜介质结构，有较小的介电常数，较大的相对带宽。天线采用孔径耦合馈电方式，对L波段和S波段的馈电线路可各自优化。讨论了此天线的交叉极化特性和阻抗区配，计算了天线的各个参数和天线用于星载SAR时的系统性能指标。     

双弯曲赋形反射面天线的外形选择

对双弯曲赋形反射面外形特征进行了理论分析，研究了不同外形反射面对天线电性能的影响，给出了选择反射面外形的方法，对双弯曲赋形反射面天线的设计有一定的帮助。     

Analysis and optimization of an electrically small receivingantenna

A theoretical and experimental study of an optimum receiving antenna configuration that fits within certain allocated space requirements is presented. This optimum monopole antenna configuration is applicable for Loran-C reception. The antenna analysis is based on a quasi-static numerical study of a conducting body of revolution above a perfectly conducting ground plane. A general numerical algorithm is developed to determine the input impedance and the effective height of the antenna. In addition, the amplifier noise and its role in the choice of the optimum antenna are examined. Results are presented for cylindrical and truncated conical structures both with and without a top load     

Circular-polarised dielectric resonator antenna excited by dualconformal strips

A circular-polarised cylindrical dielectric resonator antenna excited by dual conformal strips is investigated experimentally. The configuration offers a wide axial-ratio bandwidth of 20%. We measured axial ratio, radiation patterns and antenna gain of the configuration are presented and discussed     

Dual frequency multilayered circular patch antenna withself-diplexing function

A novel type of dual frequency and double-layered patch antenna with self-diplexing function is presented. Experimental results of the proposed antenna which consists of a circular patch antenna and a ring patch antenna with partially shorting planes are shown to verify the practicality of the new antenna configuration     

Broadband two-layer shorted patch antenna with lowcross-polarisation

The design and experimental results of a new configuration two-layer shorted square microstrip antenna with low cross-polarisation are described. The antenna has a bandwidth of 11% centred around 1.975GHz with a gain of 8.6 dB, and exhibits better than 13 dB cross-polarisation levels in the H-plane. The computed and measured results of the co-planar configuration of the structure are compared with its new two-layer stacked configuration     

一种新型的层叠式介质埋藏贴片八木天线

为了解决平面式微带贴片八木天线的主波束不能与微带天线基片平面垂直的问题,运用微带天线耦合理论、八木天线原理和微带天线理论,借鉴八木天线设计经验和微带天线制作技术,研制出了一种新型的层叠式介质埋藏贴片八木天线,并提出在八木天线振子两旁增加“栅栏”的改进结构形式。经仿真计算和实物天线测试证明：这种天线性能优于平面式的微带贴片八木天线。     

Offset dual-disk dielectric resonator antenna of very highpermittivity

An aperture-coupled offset dual-disk dielectric resonator antenna of very high permittivity is investigated experimentally. It is found that the new configuration offers an impedance bandwidth 4.6 times wider than that of the single element. The voltage standing wave ratio, radiation patterns, and antenna gain of the configuration are studied     

Compact stripline-fed meander slot antenna

A meander-type slot antenna fed by a stripline is proposed for use in miniaturised personal communication systems. By varying the slot configuration of the antenna, a 56% smaller antenna to substitute the conventional slot antenna is achieved. Simulated and measured results are presented     

Development of a Cavity-Backed Broadband Circularly Polarized Slot/Strip Loop Antenna With a Simple Feeding Structure

A cavity-backed loop antenna is developed for producing broadband circularly polarized (CP) radiation. The antenna configuration consists of a slot loop and a strip loop. The slot loop radiates a CP wave at a lower frequency while the strip loop produces CP radiation at a higher frequency. A combination of the two frequencies leads to a bandwidth enhancement. The slot/strip loop antenna is fed by a single straight microstrip line. It is demonstrated that the cavity-backed slot/strip loop antenna can achieve an axial ratio (les 3 dB) bandwidth of 19% with good impedance matching. The antenna configuration is described and the operating principles for broadband circular polarization and impedance matching are analyzed. The antenna performance is confirmed by experimental results.     

Dual frequency miniature microstrip antenna

A single-feed dual frequency compact microstrip antenna with a shorting pin is described. This new antenna configuration gives a large variation in frequency ratio of the two operating frequencies, without increasing the overall size of the antenna     

一种新型超宽带平面单极子天线

设计了一种结构简单的H形双面印刷超宽带单极子天线.通过采用FDTD建模和HFSS软件仿真分析发现,适当调整天线凹槽的长宽和改变馈电结构可以调整天线的中心频率与带宽.由此设计制作了这种天线,并进行实验测试.结果表明:在厚度为0.15 cm的介质基片上,双面印刷的H型单极子天线, 实测带宽可达53 %(VSWR＜2.0), 中心频率处增益达2.88 dB.     

A new log-periodic dipole antenna

A log-periodic antenna having triangular dipoles as its constituent elements is presented. The design criterion and its electrical properties are discussed. The proposed configuration is compared with the conventional log-periodic dipole antenna. It is shown that this configuration offers a better frequency transition, bettor gain and a reduction in the axial length over the conventional log-periodic dipole array.     

Low-profile circular disk DR antenna of very high permittivityexcited by a microstripline

A microstripline-fed dielectric resonator (DR) antenna disk of very high permittivity is investigated experimentally. The configuration has the advantage of being low-profile and allows the ground plane to be arbitrarily thick for mechanical support and/or heatsink purposes. The return loss, radiation patterns, and antenna gain of the configuration are studied and compared with those of the aperture-coupled version     

一种新型的介质反射面天线

提出了一种新型的多层介质结构的反射面天线，反射平面上所需要的相位补偿通过选择合适的介质厚度来实现，使用几个多层圆形介质即可满足条件。与传统的高增益天线相比，该结构设计简单，加工方便。验证了几种不同层数的结构和一个等口径的抛物面反射面天线。加工并测试了一个采用Vivaldi做馈源的4层结构的反射面天线。仿真和测试结果均表明该天线具有良好性能。     

Adaptive Counting Rule for Cooperative Spectrum Sensing Under Correlated Environments

We propose in this paper a dual-antenna-array (with transmitter antenna array and receiver antenna array) architecture, where the antenna elements are divided into several antenna element sets and each traffic channel is transmitted over an antenna element set, to realize the multiple traffic channels set up by a user. A SINR feedback based algorithm, which can regulate the transmission rate by iteratively adjusting the power on each traffic channel, is proposed to execute the rate control for the proposed dual-antenna-array architecture under cochannel interference. It is shown that the proposed algorithm can make the throughput meet the throughput requirement or achieve the weighted bandwidth sharing for certain fairness. In addition, we further propose a traffic channel configuration algorithm to help the SINR feedback based algorithm find the optimal traffic channel configuration that can meet the throughput requirement for each traffic channel or results in the maximal total throughput for each user.     

基于FEKO的超短波通信对抗系统电磁兼容性仿真分析

对超短波通信对抗系统的电磁兼容性问题进行了分析,建立了系统间电磁兼容性的最小配置距离数学模型,采用FEKO软件对干扰天线(对数周期偶极子天线)方向特性进行了建模与仿真,计算了侦察站通信接收机输入端的干扰功率与配置距离间的关系,给出了通信干扰站与侦察站之间的最小电磁兼容性配置距离。