PURPOSE: A USB connection device for a wireless communication device is provided to equip a noise cancelation circuit inside the device, thereby efficiently reduce noise generated in a USB transmission system. CONSTITUTION: A PCB(220) includes a circuit which transceives data with other communication devices according to a USB communication standard. A connecting unit is connected to a USB terminal of the other communication devices. A noise reduction circuit(210) is connected between an output end of the PCB and the connecting unit to cancel the noise of data signal. The noise reduction circuit includes a common mode filter(212), and a bypass capacitor(214) to block the high frequency noise.
