RFID tag chip antenna impedance automatic tuning system and method

Abstract

The invention discloses an RFID tag chip antenna impedance automatic tuning system and method, and the system comprises a rectifier which converts the radio frequency energy collected by an antenna connected between radio frequency ports RF + and RF-into a direct-current voltage, and supplies the direct-current voltage to each power utilization unit of a tag chip; a first oscillator module which outputs a first oscillation signal with different oscillation frequencies along with different DC voltages after the tag chip is powered on; a second oscillator module which outputs a stable second oscillation signal according to the direct current voltage; a digital processing module which counts the first oscillation signals by using the second oscillation signal as a clock when the tag chip is powered on, and outputs a first control signal and a second control signal according to a counting result to respectively control the states of the first oscillator module and the impedance tuning array; and an impedance tuning array which is used for changing the antenna impedance by connecting different capacitors between the radio frequency ports RF + and RF-under the control of the second control signal so as to realize the automatic tuning of the antenna impedance.

Description

technical field [0001] The invention relates to the technical field of radio frequency identification, in particular to an RFID tag chip antenna impedance automatic tuning system and method. Background technique [0002] As a key technology of the Internet of Things, RFID technology is widely used in the field of wireless identification. Since the identification process of RFID tags is affected by distance and complex environmental factors, too long distances, dry and wet environments, bending degrees, and environmental changes will cause tag impedance matching detuning, which will affect the identification and communication functions of RFID tags. Therefore, it is necessary to carry out Impedance Tuning of RFID Tag Chip Antenna. [0003] The impedance tuning method of the existing RFID tag chip antenna is usually done by manually changing the tuning device or using the pruning method at the initial stage of RFID tag design or installation. The tuning flexibility is poor an...

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Problems solved by technology

[0004] In order to overcome the deficiencies in the above-mentioned prior art, the object of the present invention is to provide an RFID tag chip antenna impedance automatic tuning system and method, to solve the problem that the existing RFID tag chip antenna impedance tuning method has poor tuning flexibility, and there are Technical issues with low precision limitations

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