Printed-circuit board, electronic part having shield structure, and radio communication apparatus

摘要

In a fitting region for a SAW filter which includes langasite as its piezoelectric element, there are included an input side terminal electrode and an output side terminal electrode which are connected to an input terminal and to an output terminal of the SAW filter. To each of the terminal electrodes, at a position which is separated by just a predetermined distance from the fitting region of the SAW filter, there is connected a micro strip line which extends in mutually opposite directions along a direction which is parallel to the transmission direction of a frequency signal within the SAW filter. A slit is provided in the fitting region of the SAW filter and extends in a direction which intersects the transmission direction of the frequency signal within the SAW filter. A plurality of through holes are provided in the printed substrate and electrically connect together its surface and its rear surface which is grounded. Furthermore, there is provided a protective member which has a conductive surface and which is in contact with the surface of said filter, and said conductive surface of said protective member which is in contact with the surface of said filter is set so as to be of the same size as the surface of said filter, or so as to be smaller than it.