Patent ID: 8131226

Claim:
A high-frequency circuit disposed between an antenna which transmits and receives in at least two different first and second communications systems and transmitting/receiving circuits for the at least two different communications systems, comprising: a high-frequency switch circuit comprising a first terminal, a second terminal, a third terminal, and a fourth terminal for switching a three-way connection of said antenna to a transmitting circuit of the first communications system via the third terminal, a receiving circuit of the first communications system via the second terminal, and a transmitting/receiving circuit of the second communications system via the first terminal; a first bandpass filter that is coupled to the antenna and the fourth terminal and suppresses signal components with frequencies higher and lower than frequency bands of said first and second communications systems, wherein the first bandpass filter is an only bandpass filter disposed in a first path between said antenna and said receiving circuit of the first communications system, and in a second path between said antenna and said transmitting/receiving circuit of the second communications system, and other bandpass filters are not disposed in the first and second paths; and a first balanced-unbalanced conversion circuit which is coupled to the receiving circuit of said first communications system and the second terminal of said high-frequency switch circuit.