一种基于PBG结构的切角微带天线

采用基片钻孔法在微带天线中加入PBG结构,设计一种工作频率为2.4Hz的PBG结构的切角微带天线。通过仿真软件建立天线模型并对其仿真,最后与采用传统结构的微带天线进行对比,证明光子晶体结构的新型天线在拓展天线带宽以及降低输入回波损耗等方面具有较大的优势,同时也指出此PBG结构微带天线的不足以及今后的改进方向。     

一种工作在S/C波段的双频微带天线的设计与仿真

设计一种同时工作在S波段和C波段的双频微带天线。天线的双频特性通过在矩形贴片上加载缝隙来实现,并采用同轴线馈电。通过基于有限元法的高频电磁场仿真软件HFSS仿真,从天线的回波损耗和方向图分析天线的性能。从仿真结果可以看出,该结构有很好的双频特性,中心频率分别为2.33GHz和4.60GHz,且在工作波段有良好的增益特性,均在3db以上。同时发现改变缝隙的长度对天线的频率影响较大,缝隙宽度的改变对天线的频率影响极小。     

一种适用于慢衰落信道OFDM系统的信道估计算法

针对慢衰落信道OFDM系统,提出了一种新的低复杂度的且能对抗定时误差的信道估计器.这种信道估计器是基于导频间隔I=2的特殊梳状导频结构设计的.基于工程实现的考虑,采用了最小平方(LS)算法进行导频信道估计,同时利用了线性内插对非导频信道进行估计.分析了定时误差对非导频子载波估计的影响,并提出了一种相当简单但十分有效的修正算法,仿真结果有力的证明了此算法能有效的抵抗定时误差对非导频信道插值估计的影响.     

小型化超宽带微带天线的设计

本文提出了一种结构简单的小型化超宽带微带天线,尺寸为28mm×30mm．天线采用渐变馈线对酒杯状贴片馈电,接地板采用缺陷地的结构．天线参数采用电磁仿真软件CST进行仿真和优化．测量结果显示该天线在S11小于-10dB时,相对带宽是170．1％（2．4GHz～30GHz）．实际制作了天线的样品并进行了测试,实测与仿真吻合良好．     

应用于WLAN的小型化差分双频微带天线设计

本文设计了一种小型化差分双频微带天线.天线辐射单元由方环形结构和1对叉形结构组成,低频由方环形结构和叉形结构共同决定,高频主要由内部叉形结构决定.天线辐射单元总尺寸为18 mm×18 mm(0.31λg×0.31λg,λg为低频导波波长),比传统半波长微带天线减小了38%.仿真和测量结果表明,天线可以工作在2.45 GHz和5.25 GHz,低频和高频段带宽分别为4.5%(2.39 GHz~2.5 GHz)和4.8%(5.1 GHz~5.35 GHz),峰值增益分别为2 d Bi和4.3 d Bi,适用于WLAN(Wireless Local Area Network)的应用.     

安全的无线通信系统——Trusted Wireless：适用于流程工业的无线通信技术

无线技术在流程工业领域的应用为企业开发了新的节能潜力，但是，在流程工业中使用的无线通信技术应该满足更高的要求。除了像WLAN802．11和蓝牙这样的主流无线通信技术以外，在流程设备现场总线技术领域中还出现了一些特殊的专用无线通信技术，例如Trusted Wireless无线通信技术。[编者按]     

应用于无线通信的小型化极化分集天线

给出一种应用于无线通信的极化分集天线.该天线结构简单紧凑,由两个方向垂直的T形天线单元实现线性极化分集.通过在接地板上开L形的槽,实现了天线的小型化,同时提高了两个端口的隔离度.仿真和测量结果表明,所实现的天线工作在2.4 GHz,在两个端口上,回波损耗小于-10 dB的带宽大于30%,两端口隔离度基本在-20 dB以下.测量结果与仿真结果基本吻合.     

一种基于STM32的3G无线通信系统的设计

本文提出了一种基于STM32的3G无线通信系统的设计方法,STM32F103作为本文使用的主芯片是以Cortex-M3为处理器的,具有更快的中断响应能力,本文采用了华为的MU509作为3G模块,用于基于TCP/IP的无线网络通信,比传统的GPRS在速度上有明显优势,可以广泛地应用于气象、水文水利、自动控制等领域的数据采集、控制和无线传输。     

基于WIFI技术无线通信系统在城郊煤矿的设计与应用

从煤矿地面、井下地形的实际特点与需求出发,分析了构建无线通信系统的必性和可行性,提出相应的建设方案和实施目标。     

一种TD-SCDMA无线通信接收平台设计

介绍一种TD-SCDMA无线通信接收平台的设计,给出系统电路设计的具体方案,并对各部分硬件电路设计进行阐述.该TD-SCDMA无线通信接收平台采用AD9640实现数据采集,利用FPGA实现预处理.采用DSP完成相应信号处理算法.由于该无线通信接收平台采用ADC+FPGA+DSP的架构,使得该平台具有较高的通用性和实用价值.     

应用于无线通信的小型化微带缝隙可重构天线

提出了一种新型的小型化频率可重构天线,通过两个开关二极管控制天线的频率,实现频率的重构.天线结构新颖简单,采用宽缝隙天线上加载开关,且开关易于操作控制.当开关闭合时,天线的实测结果谐振频率在5.34 GHz,反射系数为-23.4 dB,相对带宽为70%,实现了超宽带.当开关断开时,天线的实测结果谐振频率为2.4 GHz...     

A Compact 28 GHz Millimeter Wave Antenna for Future Wireless Communication

This article presents a novel modified chuck wagon dinner bell shaped millimeter wave (mm-wave) antenna at 28 GHz. The proposed design has ultra-thin Rogers 5880 substrate with relative permittivity of 2.2. The design consists of T shaped resonating elements and two open ended side stubs. The desired 28 GHz frequency response is achieved by careful parametric modeling of the proposed structure. The maximum achieved single element gain at the desired resonance frequency is 3.45 dBi. The efficiency of the proposed design over the operating band is more than 88%. The impedance bandwidth achieved for −10 dB reference value is nearly 2.9 GHz. The proposed antenna is transformed into four element linear array which increases the gain up to 10.5 dBi. The fabricated prototype is tested for the measured results. It is observed that measured results closely match the simulated results. By considering its simple structure and focused radiation patterns, the proposed design is well suited for IoT (Internet of Things), mmWave microwave sensing, 5G and future RF (Radio Frequency) front-ends.     

Design of a Compact Monopole Antenna for UWB Applications

In this paper, a low cost, highly efficient and low profile monopole antenna for ultra-wideband (UWB) applications is presented. A new inverted triangular-shape structure possessing meander lines is designed to achieve a wideband response and high efficiency. To design the proposed structure, three steps are utilized to achieve an UWB response. The bandwidth of the proposed antenna is improved with changing meander lines parameters, miniaturization of the ground width and optimization of the feeding line. The measured and simulated frequency band ranges from 3.2 to 12 GHz, while the radiation patterns are measured at 4, 5.3, 6 and 8 GHz frequency bands. The overall volume of the proposed antenna is 26 × 25 × 1.6 mm3 ; whereas the FR4 material is used as a substrate with a relative permittivity and loss tangent of 4.3 and 0.025, correspondingly. The peak gain of 4 dB is achieved with a radiation efficiency of 80 to 98% for the entire wideband. Design modelling of proposed antenna is performed in ANSYS HFSS 13 software. A decent consistency between the simulated and measured results is accomplished which shows that the proposed antenna is a potential candidate for the UWB applications.     

Strain-Insensitive Hierarchically Structured Stretchable Microstrip Antennas for Robust Wireless Communication

As the key component of wireless data transmission and powering, stretch-able antennas play an indispensable role in flexible/stretchable electronics. However, ...     

Reconfigurable Compact Wideband Circularly Polarised Dielectric Resonator Antenna for Wireless Applications

In this work, a novel compact wideband reconfigurable circularly polarised (CP) dielectric resonator antenna (DRA) is presented. The L-shaped Dielectric resonator antenna is excited by an inverted question mark shaped feed. This arrangement of feed-line helps to generate two orthogonal modes inside the DR, which makes the design circularly polarised. A thin micro-strip line placed on the defected ground plane not only helps to generate a wideband response but also assist in the positioning of the two diode switches. These switches located at the left and right of the micro-strip line helps in performing two switching operations. The novel compact design offers the reconfigurability between 2.9–3.8 GHz which can be used for different important wireless applications. For the switching operation I, the achieved impedance bandwidth is 24% while axial ratio bandwidth (ARBW) is 42%. For this switching state, the design has 100% CP performance. Similarly, the switching operation II achieves 60% impedance bandwidth and 58.88% ARBW with 76.36% CP performance. The proposed design has a maximum measured gain of 3.4 dBi and 93% radiation efficiency. The proposed design is novel in terms of compactness and performance parameters. The prototype is fabricated for the performance analysis which shows that the simulated and measured results are in close agreement.     

基于微带馈电的介质杆天线设计

设计了一种新型的基于微带贴片馈电的介质谐振器天线.天线的介质杆设计为锥削结构,采用具有嵌入式微带线的圆形贴片进行馈电.通过调节微带线嵌入圆形贴片的深度和宽度,获得较宽的阻抗带宽.天线样品的测试结果与设计仿真结果吻合良好.天线阻抗带宽(|S11|-10dB)为7.1%(5.73～6.14GHz),频段内的平均增益超过11.1dBi.在工作频率5.8GHz处,天线的增益达到11.2dBi,相应的口径效率为84.1%.     

Video Transmission for Third Generation Wireless Communication Systems

This paper presents a twin-class unequal protected video transmission system over wireless channels. Video partitioning based on a separation of the Variable Length Coded (VLC) Discrete Cosine Transform (DCT) coefficients within each block is considered for constant bitrate transmission (CBR). In the splitting process the fraction of bits assigned to each of the two partitions is adjusted according to the requirements of the unequal error protection scheme employed. Subsequently, partitioning is applied to the ITU-T H.263 coding standard. As a transport vehicle, we have considered one of the leading third generation cellular radio standards known as WCDMA. A dual-priority transmission system is then invoked on the WCDMA system where the video data, after being broken into two streams, is unequally protected. We use a very simple error correction coding scheme for illustration and then propose more sophisticated forms of unequal protection of the digitized video signals. We show that this strategy results in a significantly higher quality of the reconstructed video data when it is transmitted over time-varying multipath fading channels.