RFID (Radio Frequency Identification) label with air-sensitive device, RFID system and air concentration detection method

Abstract

The invention provides an RFID (Radio Frequency Identification) label with an air-sensitive device, an RFID system and an air concentration detection method. Two pins are arranged on a chip of the RFID label; a parallel structure is formed by the air-sensitive device and an antenna of the RFID label; a logical circuit for controlling switch-on / off is arranged on a line connecting the air-sensitive device with the chip of the RFID label; the connecting line and the logical circuit for controlling switch-on / off are one parts of the chip; when the logical circuit is switched off, the air-sensitive device is not in parallel connection with the antenna, and after the air-sensitive device is placed for a period of time under the condition of a certain air concentration, a first resonant frequency and the signal strength of the antenna are kept unchanged; when the logical circuit is switched on, the air-sensitive device is in parallel connection with the antenna, and after the air-sensitive device is placed for a period of time under the condition of the certain air concentration, the antenna works under a second resonant frequency; and the RFID label is used for receiving an instruction sent by an RFID reader so as to control the switch-on / off of the logical circuit, so that the change in the air concentration is detected by comparing the difference between the signal strengths under different frequencies of the antenna. The change in the air concentration can be detected with lower cost by using the RFID label with the air-sensitive device.

Description

technical field [0001] The invention relates to the technical field of RFID (Radio Frequency Identification, radio frequency identification), in particular to an RFID tag with a gas sensor, an RFID system and a gas concentration detection method. Background technique [0002] In recent years, RFID systems have become increasingly common. RFID systems are mainly used for the identification of people and objects. Generally speaking, the system includes at least one RFID reader, which can transmit and receive radio frequency signals from one or more RFID tags within a set range. The RFID tag is usually encapsulated and can be attached to an object, and it includes a microchip that communicates with the antenna. The microchip is generally an integrated circuit that stores and processes information, modulates and demodulates radio frequency signals, and performs other specialized functions. An RFID tag's antenna is used to receive and transmit radio frequency signals, and is u...

AI Technical Summary

Problems solved by technology

Generally these devices require a continuous energy source for the sensing device to detect changes in gas concentration, but this increases the cost of the device

In addition, some devices require the sensing device to be connected to a comparator circuit to detect the degree of deviation from the reference voltage, which greatly increases the cost of the device

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