UHF RFID读写器系统设计

为了分析UHF RFID读写器系统抗干扰性能,提出了基于ISO18000-6 type B 协议下UHF RFID读写器的设计方法,并对其通信过程进行了Simulink仿真,给出了曼彻斯特编解码以及2ASK调制解调的模型。结合实际中经常遇到的高斯白噪声信道分析了系统的信道抗干扰性能,给出了系统的误码率随信噪比变化曲线。仿真表明该UHF RFID读写器系统具有较高的抗干扰性能。     

Power generation system for UHF passive RFID

A new structure to power a passive tag from an incident RF wave is presented. A test chip has been realised in a 0.18 mum standard CMOS process. Measurement results of the proposed structure and of a traditional voltage multiplier are compared in the same process. Efficiency improvement is observed from an input power of -13 dBm, leading to more available output power for a given communication range     

Noise analysis of the UHF RFID system

Noise is one of the most important parameters in designing a radio frequency (RF) system. Especially in ultra-high frequency (UHF) RF identification (RFID) systems noise plays and important role. This is because the noise performance of the receiver chain is defined not only by the intrinsic noise of the receiver, but also by the large self-jammer signal. This self-jammer signal on the one hand requires that the receiver is designed for high input dynamic range which increases the intrinsic noise of the receiver. On the other hand this self-jammer signal through the effects of reciprocal mixing and range correlation contributes significantly to the total noise of the receiver. To our knowledge this is the first work that deals in detail with the amplitude and phase noise in a UHF RFID system.     

超高频射频识别系统信号特征分析及应用

基于无源标签的超高频射频识别系统由于其上下行通信的不对称性,读写器和标签在基带分别采用PIE和FMO/Miller编码.通过分析和计算得到了其各自的功率谱特征,并依此确定了第一零点带宽与数据率的关系.同时,在读写器发射信号分别采用DSB-ASK、SSB-ASK及PR-ASK调制时,通过数值仿真得到了PIE编码数据在经过基带脉冲成形滤波器调制后的功率谱及相应的邻道功率抑制,并给出了在一定信道带宽条件下,优化的通信数据率选择方案.     

一种UHF频段RFID阅读器天线的小型化设计

采用1／4波长微带贴片以缩小天线面积,利用商业软件Ansoft HFSS10．0进行设计仿真和优化,成功研制了一款可用于UHF频段（915MHz）RFID读写器的小型化微带天线。经过实际测试,天线在工作频段内性能优良,驻波比FSWR〈2时阻抗带宽达到30MHz。贴片天线的尺寸与性能完全满足手持RFID阅读器的需求。     

A low cost integrated transceiver for mobile UHF passive RFID reader applications

2.5 mm2 including pads.     

一款便携式移动应用的低成本超高频无源射频识别读写器收发机芯片设计

A low cost integrated transceiver for mobile UHF passive RFID reader applications is implemented in a 0.18μm CMOS process. The transceiver contains an OOK modulator and a power amplifier in the transmitter chain, an IQ direct-down converter, variable-gain amplifiers, channel-select filters and a 10-bit ADC in the receiver chain. The measured output PldB power of the transmitter is 17.6 dBm and the measured receiver sensitivity is -70 dBm. The on-chip integer N synthesizer achieves a frequency resolution of 200 kHz with a phase noise of -104 dBc/Hz at 100 kHz frequency offset and -120.83 dBc/Hz at 1 MHz frequency offset. The transmitter, the receiver and the frequency synthesizer consume 201.34, 25.3 and 54 mW, respectively. The chip has a die area of 4 × 2.5 mm^2 including pads.     

超高频RFID系统CRC电路设计

介绍了超高频射频身份识别(RFID)系统中循环冗余校验(CRC)电路的原理与特点,根据ISO/IEC18000-6C标准中CRC电路的要求,对串、并行CRC电路的优、缺点进行了综合评估,且在FPGA平台上实现并进行系统性能分析.利用递归公式法设计了一种算法简单、结构紧凑、运算速度快的并行CRC电路.     

高灵敏度全集成UHF RFID标签的设计与实现

本文给出了一款基于ISO1800-6B协议的全集成的无源UHF RFID标签,这款芯片由模拟前端、基带处理器和EEPROM 存储器组成。在设计过程中,我们采用了具有高效率的差分驱动CMOS整流器使得通信范围得到扩展。我们采用新颖的高性能的电压限制器为芯片提供稳定的电压,这款限压器的在不同温度和工艺变化下的电压漂移只有172mV。在稳压器的设计中,我们采用动态带宽增强技术提高其稳压能力。对已解调器,我们采用了一款轨到轨的比较器实现在任何通信范围下对输入信号的正确解调。标签芯片采用TSMS 0.18um CMOS 工艺,芯片面积为900×800 um2。测试结果显示,芯片功耗为6.8uW,灵敏度达到-13.5dBm。     

UHF频段无源RFID系统干扰分析与抑制策略

在射频识别(RFID)领域,由于UHF频段无源RFID电子标签读写距离远、价格低、寿命长等特点,该频段RFID技术受到世界各国的广泛重视.本文首先介绍UHF频段RFID系统工作原理,然后进行该频段RFID系统的干扰分析并量化分析干扰对RFID读写距离的影响,最后给出UHF频段RFID技术的干扰抑制和部署策略,对该频段RFID技术的应用普及具有重要意义.     

可并行识别的超高频RFID系统防碰撞性能研究

对超高频射频识别(RFID)系统的防碰撞问题进行了分析.提出了基于动态帧时隙ALOHA(DFSA)协议与正交可变扩频因子码(OVSF)作为扩频码的码分多址技术相结合的超高频RFID系统,实现了在单一时隙内最多可并行识别m个RFID应答器,m为OVSF扩频码长度.对提出的RFID系统期望的系统吞吐量进行了理论分析,仿真结果表明其防碰撞性能显著超过了现有的基于动态帧时隙ALOHA(DFSA)协议的超高频RFID系统的防碰撞性能.     

基于LabVIEW的超高频RFID读写器测试系统软件设计

对于超高频RFID读写器的射频参数测试,通常采用手工的测试方法,要求测试人员熟悉读写器的各种测试指标,并能熟练操作频谱仪,这对测试人员的要求高,且工作量大。为了改善这种情况,介绍了一种基于图形化虚拟仪器编程软件LabVIEW的超高频RFID读写器测试系统。在该系统中PC/LabVIEW控制待测对象和所需仪器组成一个测试系统,把所测数据实时的显示在前面板上,并自动保存至文件中。通过现场测试,该软件运行良好,简化了测试过程,降低了对测试人员的要求,极大地提高了工作效率。     

UHF射频读写器的设计

为满足市场需求,提高读写器的读写效率,提出了一种超高频读写器的设计方案,介绍了读写器的系统硬件结构,在此基础上阐述了RFID读写器的软件设计流程以及防冲撞算法的实现。相对于采用传统随机碰撞算法的读写器,此读写器适用于超高频段,能够在多标签环境下顺利读取标签,防冲撞算法性能具有一定的提高。     

超高频RFID读写器设计

为满足市场需求,提高读写器读写效率,降低成本,提出了一种基于ISO/IEC 18000-6C的射频身份识别(RFID)读写器方案.该读写器适用于超高频段,支持跳频,发送通路来用射频发送芯片,接收回路采用相关解调,用分离元件搭建,成本较低,结构简单,易于实现.采用随机槽时隙陈计数器算法进行防碰撞设计,在多标签环境下能够识别标签,并与其成功通信.相对于采用传统随机碰撞算法的读写器,此读写器能够在多标签环境下顺利读取标签,防碰撞性能具有一定提高.     

UHF射频读写器的设计

为满足市场需求,提高读写器的读写效率,提出了一种超高频读写器的设计方案,介绍了读写器的系统硬件结构,在此基础上阐述了RFID读写器的软件设计流程以及防冲撞算法的实现。相对于采用传统随机碰撞算法的读写器,此读写器适用于超高频段,能够在多标签环境下顺利读取标签,防冲撞算法性能具有一定的提高。     

超高频射频识别天线的设计

随着射频识别技术的快速发展,提出了一款应用于RFID读写器的微带圆极化天线,该设计通过采用矩形微带贴片切角和电容耦合馈电技术实现了圆极化、宽频带特性,通过理论分析、计算、软件仿真以及加工测量等手段进行实验验证,实验结果表明该天线达到了设计要求指标,可广泛应用于超宽带无线通信领域中.     

超高频射频识别系统读写器设计

超高频射频识别系统具有读写速度快、存储容量大、识别距离远和同时读写多个标签等特点,已经在物流等领域得到越来越广泛的应用。介绍了符合ISO18000—6标准的超高频RFID电子标签主要特点、结构、工作原理及读写方法,提出了相应读写器的解决方案,重点阐述了读写器的硬件设计及软件程序流程。实际应用结果表明该读写器读写速度快（单个标签64bit／6ms）、识别率高,识别距离远（≥4m）。     

用于短距离通信的超高频射频识别系统，其标签带有片上天线

本文设计了一款基于0.18微米CMOS工艺,用于短距离通信的超高频射频识别系统。该系统包含带有片上天线的标签以及对应的读写器。整个标签的面积为0.36平方毫米,小于其他已发表的基于标准CMOS工艺的带有片上天线的标签。为了尽可能降低标签的面积与功耗,简化了传统的ISO 18000-6C协议。读写器部分包含射频收发机、数字基带、MCU和相关通信接口,其系统功耗为500mW。测试结果表明,在读写器输出功率为20dBm时,系统的通信距离为2mm。当采用磁耦合天线环绕在标签周围时,根据不同的耦合天线形状与尺寸,通信距离可以达到厘米级甚至米级。     

ESPAR array design for the UHF RFID wireless sensor communication system

In this paper, in order to improve the received signal strength (RSS) and signal quality, three arrays of electronically steerable parasitic array radiator (ESPAR) antennas are suggested for the ultra-high frequency (UHF) radio frequency identification (RFID) communication and sensing system applications. Instead of the single antenna, the array antennas have recently been widely used in many communication systems because of their peak gains, better radiation patterns, and higher radiation efficiency. Also, there are some important issues to use the antenna array like high data rates in wireless communication systems and to better understand the many targets or sensors. In this article, a wireless sensor network (WSN) is being investigated to overcome multipath fading and interference by antenna nulling technology that can be achieved through beam control ESPAR array antennas. The proposed ESPAR array antennas exhibit higher gains like 9.63, 10.2, and 12 dBi and proper radiation patterns from one array to another. Moreover, we investigate the mutual coupling effect on the performance of array antennas with different spacing (0.5λ, 0.75λ, λ) and configurations. It is found that the worst mutual coupling reduced by −28 to −34 dB for 2 × 2 array, −3 to −43 dB for 2 × 3 array, and finally −42 dB to −51 dB due to the antenna spacing from 0.5λ to λ. Thus, these suggested antennas could effectively be applied in the WSN communication systems, internet of things (IoT) networks, and massive wireless and backscatter communication systems.