Patent ID: 8036148
Filing Date: 2011-10-11
Classification: H01L,H04B

Abstract:
1. A high-frequency circuit for wireless communications selectively using at least a first frequency band and a second frequency band lower than said first frequency band, comprising an antenna terminal; a first transmission terminal to which a transmitting signal in said first frequency band is input; a second transmission 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, comprising a switch transmission terminal and a switch receiving terminal, for switching the connection of said antenna terminal to said first and second transmission terminals and the connection of said antenna terminal to said first and second receiving terminals; a first diplexer circuit disposed between said switch circuit and said first and second transmission terminals; a second diplexer circuit disposed between said switch circuit and said first and second receiving terminals; a first power amplifier circuit disposed between said first diplexer circuit and said first transmission terminal; a second power amplifier circuit disposed between said first diplexer circuit and said second transmission terminal; a low-noise amplifier circuit coupled to an antenna side of the second diplexer circuit and disposed between said switch circuit and said second receiving terminal for amplifying at least a received signal in said second frequency band; a first highpass filter circuit which is disposed in a line between said antenna terminal and said switch circuit, and is coupled to the antenna terminal and an antenna side of the switch circuit; and a second highpass filter circuit which is disposed in a line between said switch circuit and said low-noise amplifier circuit, and is coupled to the switch receiving terminal and an input of the low-noise amplifier circuit, the first highpass filter circuit and the second highpass filter circuit passing a received signal in said second frequency band while blocking a frequency band lower than said second frequency band, and a band blocked by said first highpass filter circuit being lower than a band blocked by said second highpass filter circuit.