An ultrahigh-frequency (UHF) band passive radio-frequency identification (RFID) tag integrated circuit (IC) supporting both generation-2 (Gen-2) and visible RFID modes is proposed in this paper. Two sources can be used to provide modulated data for the dual-mode tag IC: a radio frequency (RF) or visible light (VL) source. When a modulated RF signal is used, the tag IC operates in electronic product code Gen-2 mode. In the visible RFID mode, modulated VL delivers data and continuous-wave RF provides power for the tag IC. In both modes, power is provided by RF. For the tag IC, a self-calibrating clock generator (CLKG) robust to process variation is proposed. Without a battery, the CLKG has an accuracy of ±4% by continuously calibrating its frequency using downlink pulse-interval encoding (PIE) symbols from a reader. In the core of the CLKG, there is a new PIE decoder that reliably distinguishes between data-0 and data-1 under process, voltage, and temperature variations. The tag IC has been fabricated using a 0.18 μm CMOS process with a chip area of 1.4 × 1.7 mm2. The power consumption of the tag IC is 64 μW. Experiments are conducted using a photodiode in the visible RFID mode. With 0.34 mW power from a VL source, the tag IC shows successful detection of VL signal at distances up to 15 m.

中文翻译：

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使用过程补偿自校准时钟发生器支持 Gen-2 和可见 RFID 模式的双模 RFID 标签 IC

本文提出了一种支持第 2 代 (Gen-2) 和可见 RFID 模式的超高频 (UHF) 波段无源射频识别 (RFID) 标签集成电路 (IC)。可以使用两个源为双模标签 IC 提供调制数据：射频 (RF) 或可见光 (VL) 源。当使用调制射频信号时，标签 IC 以电子产品代码 Gen-2 模式运行。在可见 RFID 模式下，调制 VL 提供数据，连续波 RF 为标签 IC 提供电源。在这两种模式中，功率都由 RF 提供。对于标签 IC，提出了一种对工艺变化具有鲁棒性的自校准时钟发生器 (CLKG)。在没有电池的情况下，通过使用来自阅读器的下行链路脉冲间隔编码 (PIE) 符号连续校准其频率，CLKG 的精度为 ±4%。在 CLKG 的核心中，有一个新的 PIE 解码器，可以在工艺、电压和温度变化下可靠地区分数据 0 和数据 1。标签 IC 采用 0.18 μm CMOS 工艺制造，芯片面积为 1.4 × 1.7 mm2。标签 IC 的功耗为 64 μW。实验是在可见 RFID 模式下使用光电二极管进行的。使用来自 VL 源的 0.34 mW 功率，标签 IC 显示在最远 15 m 的距离内成功检测到 VL 信号。