Radio-over-fibre (RoF) distributed antenna system (DAS) technology has been investigated for the distribution of ultra-high frequency (UHF) radio frequency identification (RFID) signals. RoF DAS allows for reduced number of readers and centralised placement of readers which facilitates easy system maintenance, but it is important to find a low-cost solution that can achieve comparable performance to a conventional RFID system. In this work, a low-cost vertical-cavity surface-emitting laser (VCSEL)-based multimode fibre (MMF) link has been developed and demonstrated for passive UHF RFID applications. The reported results show almost the same performance when compared with a conventional RFID system. In addition, simple spatial antenna diversity schemes are tested, with improved performance reported in comparison with an RFID-RoF system without diversity. Also, an investigation of RFID over fibre with RoF non-linearity is carried out showing that phase-reversal amplitude shift keying (PR-ASK) RFID modulation allows for higher levels of RF carrier and modulated signal power than the ASK RFID, for low levels of non-linearity.

中文翻译：

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低成本，基于VCSEL的MMF链接上的RFID：实验演示和失真研究

已经研究了光纤无线电（RoF）分布式天线系统（DAS）技术，用于分配超高频（UHF）射频识别（RFID）信号。RoF DAS可以减少读取器的数量，并可以集中放置读取器，从而简化系统维护，但是找到一种低成本解决方案以达到与传统RFID系统相当的性能非常重要。在这项工作中，已经开发出了低成本的基于垂直腔面发射激光器（VCSEL）的多模光纤（MMF）链路，并已针对无源UHF RFID应用进行了演示。与传统的RFID系统相比，报告的结果显示出几乎相同的性能。此外，还测试了简单的空间天线分集方案，与无多样性的RFID-RoF系统相比，具有更高的性能报告。另外，对具有RoF非线性的光纤上的RFID进行了研究，结果表明，与ASK RFID相比，相变幅度移键控（PR-ASK）RFID调制可以实现更高水平的RF载波和调制信号功率非线性。