Patent ID: 7259677

Claim:
A radio data communication apparatus, comprising; a circuit unit configured to perform data read and write operations relative to an IC tag; and at least one antenna unit each configured to have an antenna and to conduct a predetermined signal modulation to a first signal to be transmitted through the antenna by radio transmission to a specific IC tag in the data write operation and a predetermined signal demodulation to a second signal received through the antenna from the specific IC tag in accordance with the data read operation, each one of the at least one antenna unit being arranged at a position separated from the circuit unit, wherein the circuit unit comprises an oscillating circuit configured to generate a carrier wave having a specific frequency, and a control circuit configured to synchronize the carrier wave and a data signal and output the carrier wave and the data signal in synchronism with each other, wherein the antenna unit comprises a signal modulation circuit configured to modulate the carrier wave and the data signal with the predetermined signal modulation to generate the first signal to be transmitted through the antenna in the data write operation and to demodulate the second signal received through the antenna in the data read operation.