无芯片RFID标签散射场后时响应研究

Late-Time Response of Scattered Field from Chipless RFID Tag

无芯片射频识别(Radio Frequency Identification,RFID)标签散射场信号包含两部分:早时响应和后时响应。早时响应与激励源有关,后时响应是一系列衰减信号与标签复杂自然谐振(Complex Natural Resonances,CNRs)相关,也是识别无芯片RFID标签的关键部分。提出一种改进型矩阵束算法(Matrix Pencil Method,MPM)在信号极点提取的同时准确区分了散射场早时响应和后时响应,找出了散射场信号后时响应开启时间。为了研究散射场信号并验证改进算法有效性,利用开槽圆型无芯片标签来建模。仿真结果表明,从后时响应开启时间提取信号的极点有较高精确度。

The scattered field from chipless RFID （ Radio Frequency Identification） tag includes two parts ： the early-time response and the late-time response. The early-time response is related to the excitation source, and the late-time response correlated with a series of damped exponential signals and the tag＇ s CNRs （Complex Natural Resonances） , and the latter is also the key component for identifying chipless RFID tags. A modified algorithm of MPM （ Matrix Pencil Method） is proposed, which could extract signal- pole accurately distinguish the early-time and late-time response from the scattered field, and finally find the turn-on time of the scattered field. In order to research the scattered field and verify the effectiveness of the modified algorithm, a model based on slotted circular chipless RFID tag is constructed. Simulation results show that this algorithm enjoys a fairly high accuracy in extracting signal-pole after the turn-on time of late-time response.