Patent ID: 7391328

Claim:
A radio frequency identification system, comprising: a reader arranged to generate a control signal; a first antenna electrically connected to the reader, wherein the reader is arranged to transmit the control signal through the first antenna; a second antenna arranged to receive the control signal; and a transponder integrated into an electronic element of a portable electronic device and electrically connected to the second antenna, the transponder arranged to select a data signal according to the control signal and transmit the data signal to the reader through the second antenna and the first antenna, wherein the transponder comprises: a codec arranged to convert the control signal into a control code; a memory unit storing a plurality of predetermined codes; and a control unit electrically connected to the codec and the memory unit, wherein the control unit is arranged to select a data code from the predetermined codes according to the control code, and the codec is arranged to convert the data code into the data signal.