RF ID TAG DEVICE

摘要

To overcome the drawback of the conventional RF ID tag devices having a short possible communication distance and magnify the communication distance of the conventional system by several times. The conventional system employs a balanced feeding/balanced modulation (two terminal circuits for antenna operation), while the present invention employs an unbalanced feeding/balanced modulation (three terminal circuits for antenna operation). The conventional system employs a simple rectification of received RF signals, while the present invention employs a circuit configured by combining an impedance-conversion boosting system based on the stub resonance with a ladder boosting system. The conventional system employs an ASK or BPSK modulation, while the present invention can employ a QPSK modulation circuit in addition to a passive modulation.