A quadrature mixer with a shared transconductor stage is analyzed,including voltage conversion gain, linearity, noise figure, and image rejection. The analysis indicates it has better performance than a conventional G...A quadrature mixer with a shared transconductor stage is analyzed,including voltage conversion gain, linearity, noise figure, and image rejection. The analysis indicates it has better performance than a conventional Gilbert mixer pair in commutating mode. A quadrature down-conversion mixer based on this topology is designed and optimized for an ultra high frequency RFID reader. Operating in the 915MHz ISM band, the presented quadrature mixer measures a conversion gain of 12.5dB,an IIP3 of 10dBm, an IIP2 of 58dBm, and an SSB noise figure of 17.6riB. The chip was fabricated in a 0. 18μm 1P6M RF CMOS process and consumes only 3mA of current from a 1.8V power supply.展开更多
A low-sidelobe circularly-polarized(CP) microstrip patch array for 2.4 GHz radio frequency identification(RFID) readers is presented.The antenna array with a Chebyshev current distribution is composed of 6 microstrip ...A low-sidelobe circularly-polarized(CP) microstrip patch array for 2.4 GHz radio frequency identification(RFID) readers is presented.The antenna array with a Chebyshev current distribution is composed of 6 microstrip elements.The CP operation is obtained by the quasi-square patch with difference in lengths of the two sides.The antenna has been investigated numerically and experimentally.Measured results show that the array has a Chebyshev pattern with the sidelobe level of-23 dB, the half-power beamwidth of 16° and an impedance bandwidth(S11≤-10 dB) of 130 MHz, which is suitable for RFID reader applications.展开更多
One of the most important goals followed in most systems is to increase efficiency, reduce errors and enhance ease of data entry tasks such as better services in organizations. Therefore, the use of intelligent tools ...One of the most important goals followed in most systems is to increase efficiency, reduce errors and enhance ease of data entry tasks such as better services in organizations. Therefore, the use of intelligent tools is of the most important requirements for a management system in order to collect complete and accurate data and create complete information. In management, use of new technologies is recommended to have smart systems and reduce human errors. This study aimed to investigate “professors and students attendance system using RFID” and research population consists of professors and students. Findings show that, as attendance checking system in universities and schools is done through the class list and checking attendance of students needs to spend time and energy so it leads to a waste of valuable time and energy of professors to teach. Therefore, it is essential to use efficient and modern systems, because with the design and implementation of RFID attendance system and replacing the traditional system, time and energy waste could be avoided and attendance system could be promoted to an intelligent and integrated one. The designed system includes a number of hours of presence and absence, delays and rush to pay the salaries of professors at the University with its automatic identification through radio frequency. This system aims to create changes in this area and it is economic in whole.展开更多
无线射频识别技术(Radio Frequency Identification,RFID)具有无需直接接触即可读取数据的特性,已广泛应用于自动识别和数据捕获系统,特别是地铁票卡系统中。通过使用RFID技术,地铁票卡读写器系统不仅能提高票卡处理速度,还能增强数据...无线射频识别技术(Radio Frequency Identification,RFID)具有无需直接接触即可读取数据的特性,已广泛应用于自动识别和数据捕获系统,特别是地铁票卡系统中。通过使用RFID技术,地铁票卡读写器系统不仅能提高票卡处理速度,还能增强数据的安全性和处理能力。本文深入探讨了基于RFID技术的地铁票卡读写器系统的设计与优化,包括系统需求分析、数据处理、读写识别技术的优化以及整体系统功能的实现,并通过系列系统测试验证了所提出优化措施的有效性。展开更多
设计基于轮询机制,分别从4台RFID读卡器获取主动式RFID标签的数据。采用Visual Studio C++6.0开发语言和MS SQL Server 2005数据库,通过WINDOWS API和CSerialPort类库实现COM端口与RFID读卡器、RFID卡配置器和身份证阅读器之间的通信,...设计基于轮询机制,分别从4台RFID读卡器获取主动式RFID标签的数据。采用Visual Studio C++6.0开发语言和MS SQL Server 2005数据库,通过WINDOWS API和CSerialPort类库实现COM端口与RFID读卡器、RFID卡配置器和身份证阅读器之间的通信,并通过RFID读卡器数据记录与RFID卡配置模块的数据记录进行匹配,实时获取人员所在位置,实现人员的定位和管理。应用效果表明,RFID读卡系统能快速稳定地完成数据采集与更新,解决景区景点相隔较远的人员定位和管理问题。展开更多
利用RFID(Radio Frequency Identification)技术辅以车牌识别技术、电感线圈车辆检测技术,建立驾训车辆诱导系统。明确系统工作流程、涉及到的对象以及各类用户,划分相应功能模块,确定阅读器及显示屏的设置地点及诱导内容,为实际应用提...利用RFID(Radio Frequency Identification)技术辅以车牌识别技术、电感线圈车辆检测技术,建立驾训车辆诱导系统。明确系统工作流程、涉及到的对象以及各类用户,划分相应功能模块,确定阅读器及显示屏的设置地点及诱导内容,为实际应用提供参考。展开更多
射频收发信机是射频识别系统中的一个重要组成部分。为了加深对EPC Class 1 Generation 2协议的理解、完成链路预算及一些指标测试,该文利用ADS(Advanced Design System)仿真软件、89601 VSA(Vector Signal Analyzer)软件以及Agilent公...射频收发信机是射频识别系统中的一个重要组成部分。为了加深对EPC Class 1 Generation 2协议的理解、完成链路预算及一些指标测试,该文利用ADS(Advanced Design System)仿真软件、89601 VSA(Vector Signal Analyzer)软件以及Agilent公司的各种仪器,外加一个真实的UHF频段的射频标签,来构成一个链路信号测试环境,这种新颖且相当具有实用价值的方案是对RFID(Radio Frequency Identification)阅读器及标签研发的一个强有力补充。通过仿真,深刻理解EPC Class1 Generation 2协议,完成了RFID链路的各种性能测试,为将来实际阅读器研发提供指导。展开更多
文摘A quadrature mixer with a shared transconductor stage is analyzed,including voltage conversion gain, linearity, noise figure, and image rejection. The analysis indicates it has better performance than a conventional Gilbert mixer pair in commutating mode. A quadrature down-conversion mixer based on this topology is designed and optimized for an ultra high frequency RFID reader. Operating in the 915MHz ISM band, the presented quadrature mixer measures a conversion gain of 12.5dB,an IIP3 of 10dBm, an IIP2 of 58dBm, and an SSB noise figure of 17.6riB. The chip was fabricated in a 0. 18μm 1P6M RF CMOS process and consumes only 3mA of current from a 1.8V power supply.
基金supported by the Shanghai Leading Academic Discipline Project (Grant No.T0102)
文摘A low-sidelobe circularly-polarized(CP) microstrip patch array for 2.4 GHz radio frequency identification(RFID) readers is presented.The antenna array with a Chebyshev current distribution is composed of 6 microstrip elements.The CP operation is obtained by the quasi-square patch with difference in lengths of the two sides.The antenna has been investigated numerically and experimentally.Measured results show that the array has a Chebyshev pattern with the sidelobe level of-23 dB, the half-power beamwidth of 16° and an impedance bandwidth(S11≤-10 dB) of 130 MHz, which is suitable for RFID reader applications.
文摘One of the most important goals followed in most systems is to increase efficiency, reduce errors and enhance ease of data entry tasks such as better services in organizations. Therefore, the use of intelligent tools is of the most important requirements for a management system in order to collect complete and accurate data and create complete information. In management, use of new technologies is recommended to have smart systems and reduce human errors. This study aimed to investigate “professors and students attendance system using RFID” and research population consists of professors and students. Findings show that, as attendance checking system in universities and schools is done through the class list and checking attendance of students needs to spend time and energy so it leads to a waste of valuable time and energy of professors to teach. Therefore, it is essential to use efficient and modern systems, because with the design and implementation of RFID attendance system and replacing the traditional system, time and energy waste could be avoided and attendance system could be promoted to an intelligent and integrated one. The designed system includes a number of hours of presence and absence, delays and rush to pay the salaries of professors at the University with its automatic identification through radio frequency. This system aims to create changes in this area and it is economic in whole.
文摘无线射频识别技术(Radio Frequency Identification,RFID)具有无需直接接触即可读取数据的特性,已广泛应用于自动识别和数据捕获系统,特别是地铁票卡系统中。通过使用RFID技术,地铁票卡读写器系统不仅能提高票卡处理速度,还能增强数据的安全性和处理能力。本文深入探讨了基于RFID技术的地铁票卡读写器系统的设计与优化,包括系统需求分析、数据处理、读写识别技术的优化以及整体系统功能的实现,并通过系列系统测试验证了所提出优化措施的有效性。
文摘设计基于轮询机制,分别从4台RFID读卡器获取主动式RFID标签的数据。采用Visual Studio C++6.0开发语言和MS SQL Server 2005数据库,通过WINDOWS API和CSerialPort类库实现COM端口与RFID读卡器、RFID卡配置器和身份证阅读器之间的通信,并通过RFID读卡器数据记录与RFID卡配置模块的数据记录进行匹配,实时获取人员所在位置,实现人员的定位和管理。应用效果表明,RFID读卡系统能快速稳定地完成数据采集与更新,解决景区景点相隔较远的人员定位和管理问题。
文摘射频收发信机是射频识别系统中的一个重要组成部分。为了加深对EPC Class 1 Generation 2协议的理解、完成链路预算及一些指标测试,该文利用ADS(Advanced Design System)仿真软件、89601 VSA(Vector Signal Analyzer)软件以及Agilent公司的各种仪器,外加一个真实的UHF频段的射频标签,来构成一个链路信号测试环境,这种新颖且相当具有实用价值的方案是对RFID(Radio Frequency Identification)阅读器及标签研发的一个强有力补充。通过仿真,深刻理解EPC Class1 Generation 2协议,完成了RFID链路的各种性能测试,为将来实际阅读器研发提供指导。
