RADIO FREQUENCY INTERFACE CIRCUIT FOR A RADIO FREQUENCY IDENTIFICATION TAG

摘要

A radio frequency interface circuit (11) for a radio frequency identification tag comprising - at least two input terminals (RF+, RF-) for connecting the circuit (10) with an antenna structure of the radio frequency identification tag, - one or more variable resistive loads (14) coupled across pairs of the input terminals (RF+, RF-) - one or more rectifiers (15) each connected on its input side to a pair of input terminals (RF+, RF-) and on its output side to a parallel connection of voltage control means (16) and modulation control means (17), wherein combiner means (18) are provided which are adapted to receive an output signal (19, 20) from the voltage control means (16) and the modulation control means (17), respectively, and to generate a control signal (21) for controlling each variable resistive load (14) depending on the received signals (19, 20) in such a way that each variable resistive load (14) serves as a modulation and voltage regulation circuit, and wherein each variable resistive load is adapted to serve as an electro static discharge protection circuit.