Laser-assisted Simulation of Dose Rate Effects of Wide Band Gap Semiconductor Devices

Laser-assisted simulation technique has played a crucial role in the investigation of dose rate effects of silicon-based devices and integrated circuits,due to its exceptional advantages in terms of flexibility,safety,convenience,and precision.In recent years,wide band gap materials,known for their strong bonding and high ionization energy,have gained increasing attention from researchers and hold significant promise for extensive applications in specialized environments.Consequently,there is a growing need for comprehensive research on the dose rate effects of wide band gap materials.In response to this need,the use of laser-assisted simulation technology has emerged as a promising approach,offering an effective means to assess the efficacy of investigating these materials and devices.This paper focused on investigating the feasibility of laser-assisted simulation to study the dose rate effects of wide band gap semiconductor devices.Theoretical conversion factors for laser-assisted simulation of dose rate effects of GaN-based and SiC-based devices were been provided.Moreover,to validate the accuracy of the conversion factors,pulsed laser and dose rate experiments were conducted on GaN-based and SiC-based PIN diodes.The results demonstrate that pulsed laser radiation andγ-ray radiation can produce highly similar photocurrent responses in GaN-based and SiC-based PIN diodes,with correlation coefficients of 0.98 and 0.974,respectively.This finding reaffirms the effectiveness of laser-assisted simulation technology,making it a valuable complement in studying the dose rate effects of wide band gap semiconductor devices.

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.

A Wide-Band High-Linearity Down-Conversion Mixer for Cable Receptions

We analyze a wide-band,high-linearity down-conversion mixer for cable receptions that is implemented in 0. 35μm SiGe BiCMOS technology. The bandwidth of the RF （radio frequency） input covers the range from 1 to 1.8GHz. The measured input power at the - 1dB compression point of the mixer reaches ＋ 14.23dBm. The highest voltage conversion gain is 8. 31dB, while the lowest noise figure is 19.4dB. The power consumed is 54mW with a 5V supply. The test result of the down-conversion mixer is outlined.

A Wide-Band Low Noise Amplifier for Terrestrial and Cable Receptions

We present the design of a wide-band low-noise amplifier （LNA） implemented in 0.35μm SiGe BiCMOS technology for cable and terrestrial tuner applications. The LNA utilizes current injection to achieve high linearity. Without using inductors, the LNA achieves 0.1 ～ 1GHz wide bandwidth and 18. 8dB gain with less than 1.4dB of gain variation. The noise figure of the wideband LNA is 5dB, and its 1dB compression point is - 2dBm and IIP3 is 8dBm. The LNA dissipates 120mW of power with a 5V supply.

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.

A WIDE BAND UP-CONVERSION MIXER FOR CABLE TELEVISION TUNER

An up-conversion mixer implemented in a 0.35μm SiGe BiCMOS technology for a double conversion cable TV tuner is described, The mixer converts the 100MHz to 1000MHz band to the Intermediate Frequency of 1GHz above. The mixer meets the linearity and noise figure requirements for a TV tuner. The noise figure （IF） of 19.2-17.5dB, ldB compression of 12.1dBm, and gain of-1-0.7dB in the 900MHz band are achieved at a supply voltage of 5V. The power consumption is 47mW.

Advanced Aircraft Power Electronics Systems- the impact of simulation, standards and wide band-gap devices

The rapid pace of change in the wide band gap(WBG)power semiconductor area has led to an explosion in potential uses for WBG devices in a huge variety of applications.The applications include automotive,aerospace and traction applications,as well as grid related or charging systems,with the potential to provide paradigm shifts in performance and efficiency over Silicon devices in current use today.Despite these exciting developments,however,there are still many outstanding challenges for both researchers and industry to solve before WBG technology becomes pervasive.In this paper we will explore some of these challenges and highlight the strengths of WBG devices,some of the specific issues for machine drives and develop some potential solutions for future developments in power electronics.

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.

UWB Positioning System Based on Genetic Algorithm

In order to enhance the positioning accuracy, a UWB positioning system based on genetic algorithm is proposed. Firstly, it uses the DW1000 module to measure the distance, and preprocesses the measured data to remove noise. Then, a positioning equation is established according to the processed distance information, and the genetic algorithm is used to solve the equation to obtain the coordinates of the unknown node. The experimental results show that the measured positioning accuracy is within 30 cm, which means that the system can obtain a good positioning effect and meet the need for precise positioning.

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.

Improved Adaptive Iterated Extended Kalman Filter for GNSS/INS/UWB-Integrated Fixed-Point Positioning

To provide stable and accurate position information of control points in a complex coastal environment,an adaptive iterated extended Kalman filter(AIEKF)for fixed-point positioning integrating global navigation satellite system,inertial navigation system,and ultra wide band(UWB)is proposed.In thismethod,the switched global navigation satellite system(GNSS)and UWB measurement are used as the measurement of the proposed filter.For the data fusion filter,the expectation-maximization(EM)based IEKF is used as the forward filter,then,the Rauch-Tung-Striebel smoother for IEKF filter’s result smoothing.Tests illustrate that the proposed AIEKF is able to provide an accurate estimation.

Multifunctional polarization converter based on multilayer reconfigurable metasurface

In the modern wireless communication system,the manipulation for polarization of electromagnetic wave plays a important role in improving the capacity and reliability of communication.In this paper,a multifunctional polarization converter(MFPC)based on the multilayer reconfigurable metasurface is proposed,which can assist the source antenna to transmit and receive multiple polarization signals.The MFPC consists of a grating which can filter out the undesired polarization and four layers of metasurfaces incorporated with PIN diodes.The functions of the MFPC include LTC and LTL polarization conversions,co-polarization transmission and reflection for arbitrary polarization.By changing the states of PIN diodes,the functions of MFPC can be dynamically switched.Loaded on the aperture of source antenna,the proposed MFPC can serve as a transmissive array with multiple polarization channels,and can also provide EM protection for source antenna by reflecting the incoming interference waves.Cascading of the metasurfaces produces Fabry-Perot resonance in the MFPC,and it contributes to the realization of LTC and LTL polarization conversions.To verify the performance of the proposed MFPC,the prototype is fabricated and tested.The measured results show that the fractional bandwidths of four functions are all higher than 31.9% with transmission or reflection coefficients higher than-2 d B.The frequency band of each function is mainly concentrated in S-band.The measured data are in agreement with the simulated results.

Relationship between office workers’staying and workstation attributes in a non-territorial office using ultra wide band sensor network

This paper investigates the staying and moving characteristics of office workers in a non-territorial office using an ultra wide band(UWB)impulse radio sensor network.The differences between office workers’staying and moving are clarified according to the individual workstation type that they select.The study determines the characteristics of each type of workstation.By clarifying office workers’preference for staying and moving with regard to individual workstation types and office worker post,the reasons why office workers in different posts tended to select different types of workstations were revealed.Specifically,leaders tended to select workstations at the“inner meeting corner side”most frequently,as they had a greater need to stay in other areas.In contrast,ordinary staff needed to visit office workers in other areas less often,and as such,they tended to select individual workstations at the“middle meeting corner side.”Barring this,they tended to select individual workstations at the“middle corridor side”or“outer-meeting corner side.”Temporary staff members had little need to visit or stay at other places so they tended to select individual workstations at the“window side,”which is seldom visited or stayed at by other office workers and they could be disturbed less often from their solo work.

Method of Jamming C/A Code GPS Receiver

The schemes and effects of electronically jamming GPS’s C/A code receivers are studied by using CW as the narrow band jamming signal and BPSK signal modulated by Gold code which is incoherent to that adopted by GPS as the wide band one. By simulating with Monte Carlo method and programming in Matlab language, the various jamming results in terms of bit error rate under several jamming scenarios are obtained. Through analyzing the simulation results and quantitative dependences of jamming effects on the distance from jammer to GPS receiver and the jammer’s height over ground, it is concluded that jamming with wide band jammer is much more effective than that with narrow band one.

宽带网络信息安全实时保护管理系统的研究

本文介绍了统一控制平台下的具有智能检测功能的宽带网络信息安全实时保护管理系统,该系统包括统一的控制中心、网络入侵检测(NIDS)、主机入侵检测(HIDS)、漏洞扫描和网络密罐等子系统,可通过动态探查网络内的异常情况,及时向防火墙、路由器等设备发出警报,有效弥补了其它静态防御工具的不足。

基于宽带网的视频监控在实验教学管理中的应用

采用视频处理技术、宽带网传输技术、计算机多媒体技术,组建一种基于宽带网的实时视频监控系统,将其运用到实验工作的管理及实验室的多媒体教学中。

Temperature Dependence of Performance of 6H-SiC Unipolar Power Devices

The temperature dependence of some performance of 6H SiC unipolar power devices is analyzed theoretically.By employing the temperature dependent ionization coefficient and mobility of a silicon carbide,the analytical expressions of the temperature dependent performance,such as breakdown characteristics and on resistance of 6H SiC unipolar power devices are derived in a closed form.The analytical results are compared with the experimental results,with good accordance found in the breakdown characteristics.

微型嵌入式GIS软件平台的重要意义及发展动态

近年来 ,嵌入式应用技术蓬勃发展 ,市场迅猛扩大 ,产品已经深入到工业生产和人们生活的各个角落 .制造工业、过程控制、通讯、汽车、船舶、航空、航天、军事装备、消费类产品等都已成为嵌入式计算机的应用领域 ,给微型嵌入式 GIS软件的研究与发展提供了良好的机遇 .本文从技术发展背景、含义及特点、应用发展前景、国内外发展动态、我国微型嵌入式 GIS软件平台发展的重要意义以及发展微型嵌入式 GIS软件平台的技术探讨与建议等几方面对微型嵌入式 GIS软件平台进行了详细的论述 .

浅论ADSL宽带网接入技术

本文就ADSL(Asymmetric Digital Subscriber Line)宽带网接入技术的特点和应用情况作了深入地分析,指出它是一种较为实用的宽带网接入技术方案。

宽带网发展及建议

介绍了我国宽带网的发展状况和面临的问题,提出了几点建议以推动我国的宽带网发展。