Patent ID: 7773956
Filing Date: 2010-08-10
Classification: H04B

Abstract:
1. A high-frequency circuit used in a dual-band wireless apparatus for wireless communications selectively using first and second frequency bands, the high-frequency circuit comprising: one or more antenna terminals each connected to an antenna capable of transmitting and receiving signals in said first and second frequency bands; a first transmitting terminal, to which a transmitting signal in said first frequency band is input; a second transmitting terminal, to which a transmitting signal in said second frequency band is input; a first receiving terminal, from which a received signal in said first frequency band is output; a second receiving terminal, from which a received signal in said second frequency band is output; a switch circuit for switching the connection between said antenna terminals and said first and second transmitting terminals or said first and second receiving terminals; and a bandpass filter circuit disposed between said antenna terminals and at least one of said first and second transmitting and receiving terminals, said switch circuit comprising: wherein said first or second diplexer circuit comprises a low-frequency filter circuit and a high-frequency filter circuit, said low frequency filter circuit being constituted by a phase line connected to a common terminal of the diplexer circuits, and a bandpass filter circuit connected to said phase line, said first and second diplexer circuits are disposed in separate regions in a laminate comprising a plurality of layers, such that said first and second diplexer circuits do not mutually overlap in a laminate direction, at least part of said first and second diplexer circuits are formed on the same layers, and a planar ground electrode is disposed between an uppermost layer among the layers on which at least part of said first and second diplexer circuits are formed and an upper surface of said laminate.