蝶形微带天线的双频工作

Characteristics of a single-feed dual-frequency bow-tie microstrip antenna are studied. By using the variation method, simple formulas for resonant frequencies of the bow-tie microstrip antenna are derived. It is shown that the dual-frequency ratio can be controlled easily by choosing the parameters of the antenna. This design gives compact antenna size and simple antenna structure. Experimental results are presented, verifying the validity of the design.     

基于FM1702SL的USB接口的RFID读卡器的设计

本文设计了基于FM1702SL芯片的USB接口的RFID读卡器,分析了C8051F320和FM1702SL芯片的结构和应用特点,给出了读卡器具体硬件的设计方案.该读卡器的使用将大大降低读卡器的成本.     

用ADS仿真设计制作一种高性能的微带低通滤波器

介绍一种借助ADS(Advanced Design System)仿真设计软件,设计制作一种高性能微带低通滤波器的方法,并总结出用ADS软件仿真设计微带电路时应注意的问题。     

四阶RC有源带通滤波器的设计

在电子电路中滤波器的应用越来越广泛,带通滤波器是滤波器中应用最多的一种.文章设计的四阶RC有源带通滤波器元件少,制作方便,并对设计的带通滤波器的传递函数及中心频率等特性参数进行了详细的推导,由幅频特性测试得到实测的中心频率误差较小,在通带内具有均匀而稳定的增益.     

采用U型谐振器的小型化带阻滤波器设计

采用三维电磁软件HFSS对U型谐振器进行仿真分析,设计一款中心频率为2.44 GHz的带阻滤波器。这是一款小型化的微带带阻滤波器,该滤波器由1/4波长传输线以及两个相互耦合的U型微带谐振器组合而成。其内共有2个传输零点和4个传输极点,具有较好的工作性能,且尺寸仅为0.156λ_g×0.098λ_g。对所设计的滤波器进行实物加工与测试,实物测试结果与仿真结果具有较好的一致性。     

交指形哑铃带隙结构的小型化带通滤波器设计

设计了一种交指形哑铃带隙结构的带通滤波器,在传统哑铃结构的基础上,把直线臂改进为交指形结构,增加了开路枝节,从而增加等效并联电容,实现了滤波器的小型化。与传统结构相比,新设计的结构尺寸减小了16%,并在阻带增加了2个传输零点,抑制了寄生通带。     

音频频率电平指示器的设计

在音频频率电平指示器中,采用OP07构成输入放大电路,对输入或采样的音频信号进行放大,放大后的音频信号经10频段音频带通滤波器在50Hz～10kHz内进行分频,各频段所得信号经放大后独立控制一组10LED灯,以每频段灯亮的数目来表示该频段信号的强弱。经测试,该系统10频段分频准确,所控制的LED灯亮数目和亮度符合设计要求。     

中心频率可调的FIR数字带通滤波器设计

本文设计制作的中心频率可调的FIR数字带通滤波器,其中心频率为5kHz~150kHz多点可调,通带的3dB带宽为4kHz.这是一个通用的滤波器,可广泛应用与通信、实验测量和控制等诸多场合.     

用于低中频GPS接收机的高性能CMOS差分低噪声放大器设计(英文)

设计了一个可用于低中频GPS接收机系统的1.575 GHz的低噪声放大器.首先考虑了ESD保护二极管和焊盘的寄生效应,对输入匹配和噪声性能的优化做了分析,并将窄带电感模型用于电路设计优化.其次基于Vol-terra级数,对放大器的非线性做了分析,推导了电路各参数与,IIp3的关系表达式,据此在功耗和线性度之间做了折衷考虑.采用TSMC 0.18μm射频工艺对低噪声放大器进行设计和仿真.仿真结果表明:在1.8 V工作电压下,噪声系数仅为1.1 dB,IIP3为-8.3 dBm,电流消耗3 mA,电路的输入匹配良好.     

Design of S-band circularly polarized double-layer microstrip antenna

This paper proposes a compact polarization microstrip antenna based on double-layer structure.The bandwidth of the whole antenna is widened by expanding the top and bottom layers respectively.After the design of antenna structure and adjustment of size,the proposed antenna can achieve both the left-and right-hand circular polarizations in 2.33 GHz-2.97 GHz.Measurement results indicate that the effective bandwidth is 640 MHz in S-band and the relative bandwidth can achieve 24% with 11 S less than 15 dB.     

综合口径雷达的宽频带双极化口径耦合微带阵

An 8×1-element wideband dual-polarized slot-coupled microstrip antenna array with high isolation and low cross-polarization in X-band is presented. The array antenna offers an impedance bandwidth (VSWR≤2) of 23% and 21% for dual polarization ports, respectively. The measured isolation between two polarization ports is better than 35 dB and the measured cross-polarization level below -25 dB in the main beam over the operation frequency band of 9.35 GHz to 9.75 GHz. This array is well suitable for X-band SAR (synthetic aperture radar) antenna application.     

基于射频识别技术(RFID)的航空物流模型

随着RFID硬件技术的不断发展和成本的不断降低,扩展了RFID的应用领域,本文主要讨论如何运用RFID技术构建新的航空物流系统,从软件设计的流程、技术基础、仓储系统等方面研究了这一基于RFID技术的零售业系统架构。     

一种圆柱形介质谐振器天线阵列设计

在圆柱形介质谐振器天线单元分析的基础上,设计了一种4单元介质谐振器天线阵列。天线阵采用微带线馈电网络,保证单元之间满足相位匹配关系,使该天线阵列具有良好的定向辐射特性,而且在带宽方面满足要求。     

基于RFID的智能仓储管理系统的研发

介绍了RFID技术的基本概念、特点及应用，讨论了基于RFID的智能仓储管理系统的典型框架结构、主要特点及功能模块，与传统的识别方式相比，具有无需直接接触、无需光学可视、无需人工干预即可完成信号输入和处理、操作快捷方便等优点，初步实验表明了本设计方案的合理性和实用性。     

RFID认证协议的研究及仿真

针对RFID应用中存在的安全问题,讨论了现有基于哈希函数的RFID认证协议的特点,并给出一种基于哈希函数的RFID同步认证协议在Linux 2.4内核操作系统下的仿真模拟。仿真结果表明,该RFID认证协议在不失信息保密性及反克隆等安全性的前提下,执行效率也有所提高。     

Security and privacy threats in RFID traceability network

To address security and privacy issues in radio frequency identification (RFID) traceability networks, a multi-layer privacy and security framework is proposed, which includes four facets: a security model, a communication protocol, access permission and privacy preservation. According to the security requirements that are needed in an RFID system, a security model that incorporates security requirements that include privacy of tag data, privacy of ownership, and availability of tag identity is introduced. Using this model, a secure communication protocol that can be used for anti-counterfeiting, automatic identification and privacy preservation is then developed. In order to manage the number of parties, data records of items, and complicated transitions of access permissions in an item-level traceability context, a well-designed access control protocol is proposed to parties that can prove the physical possession of an item;meanwhile, to address the privacy issues during data sharing in an RFID network, a vision of database systems that take responsibility for the privacy of the data they manage is also presented.     

基于RFID的仪器设备管理系统的设计与实现

随着高校实验仪器设备的增加和不断更新,如何科学有效的管理这些实验仪器和设备,就成了摆在我们面前的重要课题。通过整合管理系统和运用现代化网络技术、射频识别技术,设计了一个基于B/S结构的仪器管理系统。系统能实现仪器设备入库、识别、清查、跟踪、定位等功能,既可以实现实验仪器、设备的高效管理,也可以保证实验教学和科研工作更加科学、有效的开展。     

A New Dual Polarized Aperture—Coupled Printed Array for SAR Applications

This paper presents a new design of dual polarized aperture-coupled printed antenna array,The finite-difference time-do-main(FDTD) analysis of an aperture-coupled microstrip element is performed,and the effects of antenna parameters on ist characteristics are obtained to guide the design of the printed array,Then an 8^2 dual polarized array design in X-band is introduced with configuration plots,In order to improve its isolation and cross polarization.an outphase-displacement feeding technique is adopted in the feed network.Also,the round bends are used instead of conventional right-angle bends so as to acieve better VSWR performance,Experimental results are presented.indicating the validity of the design.This dual polarized array can be applied as a sub-array of paceborne SAR systems.     

基于MFRC500芯片的RFID读写器的设计与实现

介绍了一种基于MFRCS00芯片的RFID读写器系统的设计原理,给出该系统的软硬件设计方法。该读写器能够快速、准确读写MIFARF1电子标签,并把所写数据上传到数据库,为用户二次开发提供便利。