RADIO-FREQUENCY FRONT-END CIRCUIT COMBINING RECTIFICATION AND LOAD MODULATION AND PASSIVE RADIO-FREQUENCY TAG

摘要

The present invention discloses a radio-frequency (RF) front-end circuit combining functions of rectification and load modulation and a passive RF tag including thereof. The RF front-end circuit includes a first modulation unit arranged at an output of a rectifier circuit and a second modulation unit arranged between a first and a second end of an antenna coil. The first modulation unit and the second modulation unit are configured to change respectively the voltage at the output of the rectifier circuit and voltage at the two ends of the antenna coil by modulating under a strong field environment or a weak field environment, thus adjusting modulation depth of the passive RF tag. The RF front-end circuit also includes a unidirectional conducting unit to prevent loss of charges stored in a capacitor. The present invention solves existing contradiction of design specification requirements between cost and sensitivity of a passive RF tag.