A novel low-noise high-linearity CMOS transmitter for mobile UHF RFID reader

A novel CMOS transmitter with low TX noise and high linearity is implemented in a 0.18μm 1P6M standard CMOS process for Mobile UHF RFID reader.Adopting double-sideband amplitude-shift-keying(DSBASK)as the only modulation is supported,this transmitter has very low power consumption.A novel analog baseband circuit is proposed to reduce the transmitter noise.With a G′′m–cancellation technology,a highly linear up-conversion active mixer and a power amplifier driver are designed.The transmitter has a measured output1 dB compression point of 13.4 dBm.Occupying a silicon area of about 1 mm2and consuming 144 mW from a1.8 V voltage supply,the transmitter makes the Mobile UHF RFID reader communicate with a transponder in a distance of 1 m conveniently.     

一种小型化便携式UHF RFID读写器的实现

设计实现了一款小型化便携式UHF RFID读写器.采用Impinj公司的射频收发芯片R1000作为核心芯片,并结合电源管理模块、ARM7及其外围电路的设计,实现工作频率为860 MHz～960 MHz软件可调,可兼容EPC global Gen2和IS018000-6C两种标准.在8 dBi天线下,该读写器实现3 m以上的读写距离,并且可多标签读写.     

超高频RFID标签芯片基带处理器的低功耗设计

设计了一种符合ISO18000-6B协议的超高频无源电子标签的数字基带处理器,芯片采用TSMC 0.18μm 1P5M嵌入式EEPROM的混合CMOS工艺实现,己成功通过流片,并对其进行了验证和测试.从测试结果看,本芯片完成了符合ISO18000-6B协议的所有强制命令以及部分建议命令,达到完成标签盘存操作、读写操作以...     

一款新型太阳能无线超高频阅读器的设计

射频识别是物联网的关键技术之一,其中超高频段(860 MHz⁹60 MHz)射频识别系统是目前比较成熟的射频识别系统。设计出一款太阳能无线超高频阅读器。LPC2138片内PLL可达60 MHz,具有很好的数据处理能力。μCOS-Ⅱ操作系统是一款嵌入式强实时操作系统,使用它能够满足阅读器的多任务要求。CN3722是一款太阳能采集芯片,能够实现最大功率点跟踪。本设计采用CN3722配合锂电池充电芯片TP4056,设计出一款多功能充电电路。无线数据传输方案采用蓝牙转串口模块实现。     

A low profile aperture coupled antenna with broadband circular polarization characteristics for UHF RFID applications

An aperture coupled microstrip‐line fed antenna (circular patch) with CP radiation is initially investigated. To achieve good CP radiation at 925 MHz UHF RFID frequency, the technique of loading an inverted C‐shaped slit into the circular patch is initially proposed. By further loading an open eccentric‐ring shaped parasitic element around the circular patch, an additional CP frequency can be excited at 910 MHz, and by combining these two CP frequencies, broad CP bandwidth that can cover the entire 902‐928 MHz UHF RFID band is achieved. Because of the parasitic element, the total dimension of proposed antenna is modified to 170 × 170 × 11.4 mm³. From the measured results, the impedance and CP bandwidths of the proposed antenna were 9.4% (859‐944 MHz) and 3.1% (902‐930 MHz). Furthermore, its corresponding peak gain and efficiency are 5.9 dBic and 84.3%, respectively. Further analyses have shown that the proposed antenna can also achieve good CP frequency agility across the desired UHF RFID operating band (902‐928 MHz).     

一种应用于UHF读写器的数字跳频技术

针对超高频(UHF)读卡器在实际应用中容易出现盲区而无法顺利读取标签的情况,提出了应用于UHF读写器的数字跳频技术方案。通过上位机软件发送数字跳频参数给FPGA,FPGA根据得到的参数对集成锁相环芯片Si4133、功率放大器RF2173及外设进行配置,得到数字跳频的载波信号。测试结果证明,该方案应用于UHF读卡器项目中,能顺利读到标签。     

基于MSP430F149的手持式RFID读写器低功耗设计

基于 MSP430F149单片机的手持式 RFID 读写器低功耗设计策略及器件选择方案,结合RFID 读写器的工作情况提出了一种采用调节 MSP430F149工作时钟频率和对系统工作模式进行智能管理来降低读写器系统功耗的方法。     

Experimental platform for waveform optimization in passive UHF RFID systems

The article presents an experimental platform, so called “RFID Waveformer,” dedicated to the study of waveform optimization in the radio frequency identification (RFID) context. It is a flexible solution that enables waveform design and their energetic performance evaluation in a ultra high frequency (UHF) RFID link following the ISO‐18000 GEN2 standard protocol. It consists of a reader emulated by a LabVIEW interface controlling radiofrequency laboratory instruments, which perform real time tag response detection. Its interconnection with MATLAB routines enables the design and the evaluation of arbitrarily shaped RFID waveforms. In this article, for illustration, three waveforms are tested with RFID Waveformer in a complex propagation environment: pulsed wave (PW) and time reversal (TR) modes compared to the traditional continuous wave (CW) mode. Experimental results show that both PW and TR modes improve the energetic efficiency of the forward link and so the RFID read range compared to CW mode. Furthermore, TR presents the optimal efficiency in complex propagation medium. The RFID Waveformer enables tag response detection in the three modes offering ease of use and repeatability of measurements. The RFID Waveformer being not limited to the scenario considered in this article, it is a versatile solution extendable to other contexts.     

A dual band dual antenna with read range enhancement for UHF RFID tags

This article presents a novel dual antenna structure for dual ultra high frequency bands (f₁ = 866 MHz and f₂ = 915 MHz) for radio frequency identification tags. The proposed structure consists of two dual band antennas, one acting as a receiving antenna and the other as a backscattering antenna at both the frequency bands. The receiving antenna is designed to have input impedance complex conjugate to the impedance of tag IC in order to maximize power transfer between the antenna and the microchip. The backscattered antenna is designed to have real‐valued input impedance at both the operating frequency bands to obtain maximum differential radar cross section leading to read range enhancement. The dual band receiving antenna is designed by embedding a pair of thin slits at a radiating edge of inset fed microstrip antenna. The backscattering antenna is comprised of two elements, one is a comb‐shaped open ring element, and the other is a meander line structure which is within the open ring element. Compared to conventional antennas, the proposed dual antenna structure provides a read range enhancement due to improved maximum differential RCS. The proposed dual antenna produced 4.3 m and 6.8 m read range at 866 MHz and 915 MHz, respectively.     

超高频RFID读写器数字接收机设计

针对超高频无源标签返回信号能量差异显著、数据率偏差大的特点,提出一种超高频无线射频识别(RFID)读写器数字接收机的实现方案。采用包含功率估计、数字锁相环同步和差分解码等模块的接收机方案,实现快速准确的接收。该数字接收机经过Matlab仿真验证,在Xilinx Spartan3E平台上实现并测试通过。与常用的多组相关器接收机方案相比,该数字接收机能以更少的硬件资源消耗实现更高性能的接收效果。     

A single sided dual‐antenna structure for UHF RFID tag applications

In this article, a dual‐antenna structure is presented for UHF RFID tag. The proposed structure is made of two L‐shaped strip antennas along with a cross‐shaped slot loaded patch. One antenna is exclusively used for receiving and harvesting full energy with complex conjugate of tag chip, whereas another used as backscatter to enhance maximum differential radar cross section with purely real input impedance, which results in the enhancement of read range. Further, electromagnetic band gap structure is used around the dual‐antenna structure to increase the gain which results in improved read range. The proposed antennas are fabricated and the S‐parameters are measured with the help of differential probe technique. Simulation and measurement results are found in good agreement. The performance of the proposed antenna is also investigated when it placed on different materials such as metal, wood, glass, and plastic. The study shows that the read range of antenna increases considerably when it is mounted on a metallic surface, while the maximum performance is observed when the antenna is attached on a glass surface with highest relative permittivity. © 2015 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:619–628, 2015.