Fully-integrated ultra-wide band LNA in 0.18μm CMOS technology for 3-10 GHz applications

The paper presents a fully integrated ultra-wide band(UWB)low noise amplifier(LNA)for 3-10 GHz applications.It employs self-biased resistive-feedback and current-reused technique to achieve wide input matching and low power characteristics.An improved biased architecture is adopted in the second stage to attain a better gain-compensation performance.The design is verified with TSMC standard 1 P6 M 0.18μm RF CMOS process.The measurement results show that the parasitic problem of the transistors at high frequencies is solved.A high and flat S21 of 9.7±1.5 dB and the lowest NF 3.5 dB are achieved in the desired frequency band.The power consumption is only 7.5 mA under 1.6 V supply.The proposed LNA achieves broadband flat gain,low noise,and high linearity performance simultaneously,allowing it to be used in 3-10 GHz UWB applications.

Compact Coplanar Epsilon-Negative Antenna with Ultra-Wide Band Character

In this paper, a compact coplanar epsilon.negative(ENG) antenna is proposed with ultra.wide operation band and small size of 18×11.5 mm2. The proposed antenna is designed based on a coplanar.waveguide(CPW) feeding antenna, and thus the via.free structure is employed to realize the ENG unit cell, which is convenient to tune the frequency of zeroth.order resonance(ZOR) and extends the ZOR bandwidth. The high.order resonant frequencies are achieved and mainly determined by the separate slots that are located between the radiating patch and the ground plane. Adding the left.handed inductance between the radiating patch and ground has slight impact on the high.order resonant frequencies, and then the ultra.wide band is achieved by merging the ZOR bandwidth with the high.order resonant bandwidths. The ground plane primarily works as a matching network for the proposed antenna. Although it generates a low.frequency resonance, the performance is undesirable due to the impedance mismatching. The measured results show that the reflection coefficient, |S11| <.10 d B, is in a wide frequency range from 5.25 to 13 GHz, which covers the upper operation band of UWB communication. Also, the antenna contains relatively stable gains and omni.directional radiation patterns.

Isolation Enhancement in a Compact Four-Element MIMO Antenna for Ultra-Wideband Applications

Mutual coupling reduction or isolation enhancement in antenna arrays is an important area of research as it severely affects the performance of an antenna.In this paper,a new type of compact and highly isolated Multiple-Input-Multiple-Output(MIMO)antenna for ultra-wideband(UWB)applications is presented.The design consists of four radiators that are orthogonally positioned and confined to a compact 40×40×0.8 mm3 space.The final antenna design uses an inverted L shape partial ground to produce an acceptable reflection coefficient(S11<−10 dB)in an entire UWB band(3.1–10.6)giga hertz(GHz).Moreover,the inter-element isolation has also been enhanced to>20 db for majority of the UWB band.The antenna was fabricated and tested with the vector network analyzer(VNA)and in an anechoic chamber for scattering parameters and radiation patterns.Furthermore,different MIMO diversity performance metrics are also measured to validate the proposed model.The simulation results and the experimental results from the constructed model agree quite well.The proposed antenna is compared with similar designs in recently published literature for various performance metrics.Because of its low envelope correlation coefficient(ECC<0.1),high diversity gain(DG>9.99 dB),peak gain of 4.6 dB,reduced channel capacity loss(CCL<0.4 b/s/Hz),and average radiation efficiency of over 85%,the proposed MIMO antenna is ideally suited for practical UWB applications.

Numerical simulation of the coupling of ultra-wide band electromagnetic pulse into landmine by aperture

The modern landmine＇s electronic fuse is susceptible to strong interference or can even be damaged by the ultra-wide band electromagnetic pulse（UWB-EMP）. The finite-difference time-domain（FDTD） method in lossy media with cylindrical coordinates is used to study the interactions of the UWB-EMP with the landmine. First, the coupling of UWB-EMP into the landmine shielding shell through an aperture is numerically simulated. Second, the coupled electromagnetic field of mine shells made of different shielding materials and with apertures of different sizes is plotted. Third, the aperture coupling laws of UWB-EMP into shells are analyzed and categorized. Such an algorithm is capable of effectively preventing ladder similar errors, and consequently improving the calculation precision, and in addition to adopting the message passing interface（MPI） parallel method to divide the total calculating range into more sub-ranges, the overall calculating efficiency is greatly increased. These calculations are surely a constructive reference for modern landmine design against electromagnetic damage.

Design of Integrated Triple Band Notched for Ultra-Wide Band Microstrip Antenna

Ultra-wideband (UWB) is one of the recent topics that received a great concern from academia and industry. However, UWB found many difficulties to be standardized due to the overlay working that made UWB an important potential interference source to many licensed and unlicensed spectrum throughout the band 3.1 to 10.6 GHz. This paper demonstrates the design of integrated triple band notched for UWB Microstrip antenna. We simulated UWB short range systems which require low power and these are built using inexpensive digital components. We proposed a compact triple band notched CPW (Co-planar Waveguide) fed Micro strip Antenna (MSA) for UWB. This band-notched antenna has rejection characteristics at 3.2 GHz (for Wi-MAX band 3.16 to 3.32 GHz), at 5.5 GHz (for WLAN 2 band—5.3 to 5.72 GHz) and at 7.9 GHz (for ITU band 7.72 GHz to 8.13 GHz). The simulation was done using IE3D simulator.

Designing a Carbon Nanotube Field-Effect Transistor with High Transition Frequency for Ultra-Wideband Application

Theoretical calculations predict transition frequencies in the terahertz range for the field-effect transistors based on carbon nanotubes, and this shows their suitability for being used in high frequency applications. In this paper, we have designed a field-effect transistor based on carbon nanotube with high transition frequency suitable for ultra-wide band applications. We did this by optimizing nanotube diameter, gate insulator thickness and dielectric constant. As a result, we achieved the transition frequency about 7.45 THz. The environment of open source software FETToy is used to simulate the device. Also a suitable model for calculating the transition frequency is presented.

Evaluation of System Performance of Ultra-Wide Band Jointing in MC Signaling in Correlated Environments

The evaluation of System Performance of UWB (ultra-wide band) jointing in MC (multi-carrier) signaling in correlated environments is presented in the report. The correlated Nakagami-m statistical distribution for the multipath fading model is assumed in this scenario. In fact to establish the model for analyzing in this article is using MC-CDMA (multi-carrier code-division multiple-access) system characterization combined with a UWB scheme. The average BER (bit error rate) is calculated and compared to a special case of previously published results. Studied results from this paper can be implied to approve the system performance for a UWB system combined with a MC-CDMA wireless communication system. It is worth noting that the Nakagami-m distributed fading parameter significantly dominates UWB system performance when it cooperates with MC signaling under a fading environment. Finally, it is worthy of noting that when the SNR (signal-to-noise ratio) at system’s receiver reaches a preset high threshold value, the parameter of power decay ratio effect could be not included.

Novel Compact UWB Band Notch Antenna Design for Body-Centric Communications

This research analyzes and implements an innovative and tiny ultrawideband(UWB)antenna with band-notched features for body-centric communication.The shape of the designed antenna looks like a‘swan’with a slotted patch.Computer Simulation Technology(CST)is used to assess and investigate the performance of this antenna.With a band notch,this antenna can prevent interference from Wireless Local Area Network(WLAN)(5.15–5.825 GHz)and Worldwide Interoperability for Microwave Access(WiMAX)(5.25–5.85 GHz)systems.At first,the performance parameters like return loss response,gain,radiation patterns,and radiation efficiency of this UWB antenna are evaluated.After that,the human body effects on the antenna performance of the antenna are also examined to place the antenna at various distances away from 3-layers of phantom body model at different frequencies.All the on-body performance parameter results are compared and analyzed with free space performance parameter results.Lastly,by changing patch slot length and ground plane length,parametric studies were done for performance comparison.According to this research,it is noticed that the antenna is tiny and new.It shows good performance in body case as well.Hence,the antenna is very suitable for healthcare applications.

Optimization of band-notched UWB antenna using micro-genetic algorithm combined with FDTD

The micro-genetic algorithm (MGA) optimization combined with the finite-difference time-domain (FDTD) method is applied to design a band-notched ultra wide-band (UWB) antenna. A U-type slot on a stepped U-type UWB monopole is used to obtain the band-notched characteristic for 5 GHz wireless local area network (WLAN) band. The measured results show that voltage standing wave ration (VSWR) less than 2 covers 3.1-10.6 GHz operating band and VSWR more than 2 is within 5.150-5.825 GHz notched one with the highest value of 5.6. Agreement among the calculated, HFSS simulated and measured results validates the effiectiveness of this MGA-FDTD method, which is efficient for UWB antennas design.

Compact Bluetooth/UWB Antenna with Multi-Band Notched Characteristics

A small-sized, low-profile, and planar dual band antenna for Bluetooth (2.4 - 2.484 GHz) and ultra-wideband (UWB) (3.1 - 10.6 GHz) with multi-band notched antennas is presented. Two antennas A and B with different types of slots are used to obtain tri-band notched characteristic. In antenna A notched bands, 5 - 6 GHz for WLAN, and 3.3 - 4 GHz for WiMAX, are achieved using a U-slot in ground structure and in the radiating patch. In antenna B two notched bands at 3.3 - 4 GHz, for WiMAX and 7.2 GHz for C-band satellite communication systems are achieved by using a U-slot in ground structure and a H-shaped slot in the radiating patch. The radiation characteristics of the two antennas are calculated using a commercial EM simulator based on Finite Element Method (FEM) and the Finite Integration Technique (FIT). The two antennas show acceptable gain flatness with stable omnidirectional radiation patterns across the integrated Bluetooth and UWB bands.

Design and Analysis of a Compact Band Notch UWB Antenna for Body Area Network

This paper presents the design of a small printed ultra wideband antenna with Band Notched characteristics. Both the free space and on-body performances of this antenna were investigated through simulation. The newly designed UWB antenna is more revised small form factor sized, with the ability to avoid interference caused by WLAN (5.15 - 5.825 GHz) and WiMAX (5.25 - 5.85 GHz) systems with a band notch. The return loss response, gain, radiation pattern on free space of the antenna were investigated. After that, the on-body performances were tested on 3-layer human body model with radiation pattern, gain, return loss, and efficiency at 3.5, 5.7, 8, 10 GHz and all the results were compared with free space results. As the on-body performance was very good, the proposed antenna will be suitable to be used for multi-purpose medical applications and sports performance monitoring.

A Novel Bow-Tie Antenna with Triple Band-Notched Characteristics for UWB Applications

This paper presents the design of a compact bow-tie antenna with triple band notched characteristics for UWB applications. The proposed antenna can operate from 3.1 to 10.6 GHz with VSWR - 8.4 GHz) centered at 8.1 GHz, the CSRR2 rejects the WLAN band (5.15 - 5.85 GHz) centered at 5.6 GHz, and the CSRR3 rejects the band (4.10 - 4.47 GHz) centered at 4.32 GHz. Compared with recent design, this antenna is more compact, and presents better simulation results of its characteristics. Our newly designed antenna is a potential candidate for application in UWB communication systems.

面向复杂环境的UWB/LiDAR/IMU组合定位方法

针对室外全球卫星导航系统(GNSS)拒止并且超宽带(UWB)和LiDAR在非视距和点云特征稀疏环境下定位效果较差的问题,提出了一种面向复杂环境的UWB/LiDAR/惯性测量单元(IMU)组合定位方法。首先,利用LiDAR和UWB的互补特性设计了时变因子,用于对车辆进行重定位;然后,引入三种运动模型描述车辆的运动状态,各模型采用无迹卡尔曼滤波方法设计滤波器;最后,将重定位后的车辆定位和IMU的测量数据作为交互式多模型-无迹卡尔曼滤波算法的状态输入,解算出最终的车辆位置。实验结果表明,所提组合定位方法具有较高的定位精度,相对于UWB和LiDAR单一传感器,视距环境下的定位精度分别提升了35.1%和22.8%,非视距环境下分别提升了53.1%和27.2%;所提重定位方法相对于UWB和LiDAR单一传感器,视距环境下的定位精度分别提升了23.2%和8.7%,非视距环境下分别提升了42.9%和11.4%,体现出了较高的定位精度和对复杂环境的适应能力。

类星型手性超材料超宽带隙特性研究

振动和噪声的抑制一直是工程中的重要问题,而超材料在实现减振降噪方面具有良好的应用价值。基于传统空心星型超材料,添加手性结构特性,设计一种新型的空心类星型手性超材料,并在其基础上进一步演化出实心类星型手性超材料。通过振动模态分析带隙产生机理和不同结构参数对带隙的影响,通过频散曲面、波传播方向、群速度和相速度等研究弹性波在结构中的传播特性,并研究有限周期结构的传输特性。结果表明:实心类星型手性超材料可以产生宽度为5116 Hz的超宽带隙,带隙形成主要是由于凹角星和韧带的旋转振动耗散了弹性波能量,内凹角α的减小以及韧带与水平方向的夹角θ的增大使得最宽带隙的宽度增大;有限周期结构在其带隙范围内可以产生明显的位移幅值衰减,该新型超材料具有良好的隔振性能。

基于MOEA/D算法的三陷波超宽带天线设计

为实现超宽带通信中对WIMAX(3.3~3.7 GHz)、WLAN(5.150~5.825 GHz)和ITU(8.01~8.50 GHz)频段干扰的抑制,提出了一种基于MOEA/D算法优化设计的具有三陷波特性的超宽带天线。天线采用T形结构作为辐射贴片,通过改变贴片形状等方法实现在3~12 GHz的超宽带。在辐射贴片上刻蚀两个U形缝隙和在传输线两侧加载C形开口环,对天线进行陷波设计。利用MOEA/D算法对陷波结构的结构参数和加载位置进行优化,实现了在3.31~3.69 GHz、5.25~6.13 GHz和8.01~8.51 GHz频段的陷波效果,成功抑制了频段干扰。与传统扫频优化的设计方法相比,采用MOEA/D算法设计的天线在陷波频带内增益低至-19 dB,各陷波频带准确度误差均在3.6%以下,提高了天线的设计效率,具有一定的工程应用价值。

一种基于超宽带基站设置虚拟围栏的手术室移动医疗设备定位方法

针对医院手术室各手术间存在大量移动医疗设备交叉使用难以实时定位管控的难题,该研究提出一种时效性高、易于部署且定位准确度相对较高的基于UWB技术的实时定位方法。该方法包括对超宽带(UWB)基站的拓扑布局,在手术室走廊、设备间内应用改进的飞行时间(TOF)双边双向测距定位法定位,在手术间入口设置虚拟围栏判断设备是否进入。经试验,该方法可大幅度降低UWB基站布置数量,具备厘米级定位精度和较高识别率,可替代传统的手术室移动医疗设备人工定位管控方式。

一种复杂环境下UWB测距误差预测方法

针对复杂室内环境中,多径干扰和视距遮挡影响室内定位精度的问题,提出一种复杂环境下UWB测距误差的预测方法:根据超宽带(UWB)室内定位方法抗干扰能力强、定位精度高的特点,从理论上分析影响超宽带信号测距精度的因素;然后通过模型量化分析每种影响因素对测距误差的影响程度,改进以往通过信道脉冲响应特征分析单一的视距遮挡参数来提高定位精度的补偿算法;最后从数据挖掘和机器学习的角度出发,将多径效应、视距遮挡、标签与基站的距离、标签移动速度、标签与基站天线俯仰角以及气象因素(温度、湿度、压强)等对测距精度造成影响的重要因素作为特征进行分类和归类,并使用梯度提升决策树模型对数据集进行训练和预测。实验结果表明,该模型可以根据当前状态下的组合特征值估计出测距误差值,将当前预测的误差值补偿到测量值上,可以有效提高超宽带室内定位的精度。

信号干扰下的超宽带精确定位问题研究

针对在室内应用超宽带UWB(Ultra Wide Band)定位技术时,需要建立高效精确的三维坐标定位系统以克服信号干扰问题,应用机器学习方法对其进行了研究。首先使用多种统计分析模型清理无效或误差测量值;然后将TOF(Time Of Flight)算法的先验知识与神经网络、XGBoost(eXterme Gradient Boosting)算法相结合,提出了神经XGB(Exterme Gradient Boosting)三维定位系统,该系统可通过“正常数据”和“异常数据”(受干扰)以及4个锚点的坐标精准预测靶点的坐标值,能使误差在二维平面降至5.08 cm,在三维空间降至8.03 cm;同时建立了判断数据是否受干扰的神经网络分类模型,精确率为0.88;最后通过结合上述系统,得到了连续且规律的运动轨迹,证明了系统的有效性与鲁棒性。

基于碳化硅等离子体器件的功率脉冲锐化技术

利用Sentaurus搭建了碳化硅漂移阶跃恢复二极管(DSRD)与雪崩整形二极管(DAS)全电路仿真模型,研究了碳化硅等离子体器件在脉冲锐化方面的能力,并且通过器件内部等离子浓度分布解释了这两种器件实现脉冲锐化的机制。借助碳化硅DSRD可以将峰值超过千伏的电压脉冲的前沿缩短到300 ps;碳化硅DSRD与DAS的组合可以输出脉冲前沿在35 ps、峰值超过2 kV的电压脉冲。仿真与实验发现当触发脉冲与碳化硅DAS匹配时,可以实现快速开启后快速关断,得益于碳化硅DAS这种神奇现象,可以将峰值在两千伏以上脉冲的半高宽缩小到百皮秒量级;通过频谱分析发现脉冲经过DAS整形后,其最高幅值−30 dB对应的频谱带宽扩大了37倍,达到7.4 GHz。

基于带宽交织采样架构的80 GSps超宽带实时采集系统

利用8片10 GSps的模数转换器(ADC)芯片,基于带宽交织采样架构设计并且实现了具有80 GSps,20 GHz带宽的超宽带实时数据采集系统。对带宽交织采集系统中的子带分解、多子带间采集同步、交叠带以及全频带拼合等一系列问题展开了研究,并基于分治法的思想提出了相应的校准以及补偿方法,补偿前后的时域以及频域分析对比证明了提出补偿方法的有效性。实验结果表明,系统实现了具有80 GSps采样率、20 GHz带宽指标,其中有效位数(ENOB)以及无杂散动态范围(SFDR)在20 GHz处可以达到6 bit以及40 dB,并给出了系统ENOB随频率变化的曲线,采集系统上升时间为22 ps,实验数据表明系统各项指标处于国内领先水平。