An active rfid system with wireless charging

Abstract

The invention discloses an active RFID system with wireless charging, which includes a reader and an active tag; the active tag includes two modes: a sleeping mode and a working mode. When the active tag is in the sleep mode, the switch is switched to the receiving path. At this time, the wake-up receiver circuit and the energy harvesting circuit work at the same time. The wake-up receiver circuit detects the wake-up signal energy in free space, and the energy harvesting circuit detects the free electromagnetic waves in the air. The energy is rectified and converted to DC and stored in a button battery. When the wake-up circuit side monitors the wake-up signal volume of the modulated information, the active tag changes its working state, and the switch switches to the working mode. At this time, the radio frequency IC of the active tag sends radio frequency data information to the reader side for data information transmission. The invention effectively prolongs the service life of the active tag through wireless charging and low power consumption design, the overall system structure is simple, the volume is small, the cost is low, and the adaptability is good in complex electromagnetic environments.

Description

technical field [0001] The invention belongs to the technical field of radio frequency communication and short-range detection, in particular to an active RFID system with wireless charging. Background technique [0002] Radio frequency identification technology, also known as RFID, uses radio frequency signals to radiate and couple in free space to realize medium and long-distance non-contact transmission of data information. As a means of information transmission, it is convenient for electronic data storage and data transmission. Features, as well as security during transmission, are widely used in public transportation systems such as subways and buses, retail enterprises, personal identification, logistics management, etc. in every corner of life, and are considered to be the ten most promising technologies in the 21st century one. It has better practicability and adaptability to use active RFID tags in daily life. In some complex electromagnetic wave environments and...

AI Technical Summary

Problems solved by technology

In the article "A low power-long range active RFID-system consisting of active RFIDbackscatter transponders", scholar Emil Nilsson combined the binary tree algorithm to allocate the amount of identified identity information, and represented the corresponding digital information by dividing different channel frequencies. Because a large number of tags exchange information with the reader at the same time, the overall power consumption of multiple tags is reduced, and the delay is low at the same time. However, the system itself still uses the method of receiving the RF signal of the reader to trigger the tag to oscillate and feedback the amount of data information, which has low sensitivity and Not easy to transmit over long distances

Dr. Che Wenyi of Fudan University wrote the article "Research and Design of Semi-Active Ultra-high Frequency Identification Tag Chip", which designed a low-power semi-active UHF electronic tag under the SMIC 0.18um EEPROMCOMS process. This kind of tag takes into account high-sensitivity communication, has the function of timing reading temperature, quasi-constant current and constant voltage charging and battery voltage detection function, the sleep current is only 150nA, and the technology can greatly reduce the sleep working current of RFID to reduce the power consumption in the sleep state Loss, this kind of radio frequency identification electronic tag is highly integrated, but the design is relatively difficult, and it is greatly affected by the voltage and temperature characteristics, which is easy to trigger the system to wake up by mistake, resulting in frequent waste of electric energy

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