Passive sensing circuit and control method thereof

Abstract

The embodiment of the invention discloses a passive sensing circuit and a control method thereof. The passive sensing circuit comprises a sensor used for sensing data; a first capacitor used for providing a first working voltage for the sensor; a rectifier used for converting the received induced voltage into a second working voltage so as to charge the first capacitor; a demodulator used for analyzing a first instruction included in the induced voltage; and a controller used for controlling the sensor to start to work according to the first instruction. According to the embodiment of the invention, the sensing precision and the sensing distance of a passive RFID label with the sensor are improved.

Description

technical field [0001] Embodiments of the present invention relate to sensing technology, in particular to a passive sensing circuit and a control method thereof. Background technique [0002] Radio Frequency Identification (RFID) is a kind of automatic identification technology. It uses radio frequency to perform non-contact two-way data communication, and uses radio frequency to read recording media (electronic tags or radio frequency cards). Writing, so as to achieve the purpose of identifying targets and data exchange, it is considered to be one of the most potential information technologies in the 21st century. [0003] However, for the existing passive RFID tag circuit with sensors, the reader always emits continuous waves to provide power to the tags and the sensors on them during the working process of the sensors. This does two things against the sensor. The first point is that the continuous wave emitted by the reader will bring strong radio frequency interferenc...

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Problems solved by technology

This does two things against the sensor

The first point is that the continuous wave emitted by the reader will bring strong radio frequency interference. If the power consumption of the sensor is large, the power supply suppression of the sensor is poor, or the sensor is external, the radio frequency interference will be very large, which may make the entire sensor The accuracy varies greatly in different application scenarios; the second point is that the continuous wave received by the tag itself cannot guarantee stability, resulting in unstable power supply to the sensor. In some application scenarios, the tag, reader or other objects may be moving , the RF energy received by the tag will change, or the tag is affected by the RF signal of other readers, or the transmitting power of the reader is unstable after long-term operation, resulting in unstable power supply. Sensing accuracy and sensing distance of passive RFID tags with sensors

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