【作者】 郑泽华； 史汝川； 陈景； 吉小军； 韩韬； 王骥；

【Author】 ZHENG Ze-hua;SHI Ru-chuan;CHEN Jing;JI Xiao-jun;HAN Tao;WANG Ji;School of Electronic Information and Electrical Engineering,Shanghai Jiaotong University;

【机构】 上海交通大学电子信息与电气工程学院； 宁波大学工学院；

【摘要】 当前声表面波射频识别(SAW-RFID)标签系统是基于发送单脉冲查询信号,采集标签中的反射栅反射的回波信号,回波中的每个脉冲对应一个反射栅。但由于查询信号功率有限,返回的脉冲峰值也有限,并且随着反射栅个数的增加峰值不断减小,限制了标签的识别范围。本文采用二次查询,第一次发送单脉冲查询信号后得到标签的单位冲激响应,经过IQ解调、时域反转和共轭处理后作为查询信号再次发送。由于时间反转法的自适应聚焦特性,多个脉冲在提前可知的固定时刻同相叠加而形成明显主峰,增强了现有SAW标签的识别范围,通过判断固定时刻尖峰的有无可识别不同标签,为标签的防碰撞提供了另一种途径。更多还原

【Abstract】 Currently,SAW-RFID tag system is based on sending a single pulse signal,collecting response signal reflected by reflectors of tag,every pulse of response signal corresponding to a reflector.However,due to the power of interrogation signal is limited,the peak value of returned pulse is also limited,and with the increase of the number of reflectors,the peak value decreases continuously,which limits the identification scope of SAW tag.In this paper,we adopt double interrogation,getting the unit impulse response of the tag after sending a single pulse signal,and do IQ demodulation,inversion and conjugation on its time domain,then sent it as interrogation signal again.Due to the adaptive focusing properties of time reverse method,multiple pulses with the same phase superimpose at the center position of the response signal,which enhances the identification scope of SAW tags,it can also discern different SAW tags by judging whether existing peak pulse at the certain position of the response signal,providing a new way for anti-collision of SAW tags.更多还原