Electronic label reading and writing device antenna and a RFID system

Abstract

The invention discloses an electronic tag reader antenna and an RFID system, wherein, the antenna is used to be connected with a reader, and the reader transmits ultra high frequency radio frequency signals through the antenna for activating an electronic tag to communicate with the reader; the antenna can be composed of an antenna radiating element or a plurality of antenna radiating elements connected in series, the front face of each antenna radiating element is provided with a micro-strip line, and the back face thereof is equipped with a ground plane. The antenna is less influenced by installation environment, and facilitates the flexible making and installation, and is simple and practical, and the antenna can be placed in an extreme narrow space, and the reader can communicate with a plurality of passive UHF frequency band RFID electronic tags placed in the extreme narrow space via the antenna stably and correctly. The antenna and the system particularly solve the problem that the plurality of passive UHF frequency band RFID electronic tags in the narrow space can not be read stably and correctly under the condition that the extreme narrow space is enclosed by large area of metal.

Description

technical field [0001] The invention relates to the technical field of radio frequency identification, in particular to an antenna of an electronic tag reader-writer and an RFID system. Background technique [0002] RFID (Radio Frequency Identification, radio frequency identification) technology, also known as electronic tag technology, is a non-contact automatic identification technology. Its basic working principle is to use radio frequency signals and inductance or electromagnetic space coupling transmission characteristics to realize identification automatic identification. RFID system generally includes three parts: RFID electronic tag (Tag), reader (Reader) and computer application system. [0003] The basic workflow of the RFID system is as follows: the reader sends a radio frequency signal of a specific working frequency through the radio frequency antenna. When the electronic tag enters the working coverage area of ​​the reader's transmitting antenna, its radio fre...

AI Technical Summary

Problems solved by technology

[0006] If in a very narrow space, and at least three sides of the space are surrounded by large areas of metal (such as metal cabinets), when reading multiple passive UHF frequency band RFID electronic tags in a small space , the metal has a strong reflection effect on the electromagnetic waves emitted by the reader. Usually, the indicators of the supporting antenna of the reader will change greatly, especially the VSWR (Voltage Standing Wave Ratio, voltage standing wave ratio) of the antenna port. Rapid deterioration, resulting in a mismatch between the antenna port of the reader and the antenna, and the failure to communicate with the electronic tag normally

And because the electromagnetic waves emitted by the reader are reflected multiple times in a small range in an environment covered by multiple metals, the radiation field of the antenna becomes unpredictable

Through some tests, it is found that there will be some dead zones in this environment, that is, the electronic tag cannot receive the electromagnetic wave energy emitted by the reader at all.

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