MOBILE WIRELESS APPLICATION DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a mobile wireless application device provided with a function of suppressing electromagnetic coupling between a wireless circuit and a digital circuit placed on one printed circuit board. SOLUTION: A current control mechanism is placed between the wireless circuit and the digital circuit in order to control both or one only of intrusion of a harmonic current generated in the digital circuit to the wireless circuit section and intrusion of a wireless frequency current generated in the wireless circuit section to the digital circuit. The current control mechanism is characterized in that it comprises metallic plates placed to upper and lower parts of a printed circuit board enclosing a current of a control object and an end edge of which acts like a short-circuiting plate and one equivalent metallic square prism tube or two comprising a narrow pitch via-hole array. Selecting the length from the aperture of the equivalent metallic square prism to the short- circuiting plate to be 1/4 of the wavelength of the current of the control object can enhance the input impedance at the aperture thereby suppressing the electromagnetic coupling. Or a plurality of the narrow pitch via-hole arrays may be configured.