A large scale integrated (LSI) circuit includes a first terminal, a second terminal, a transmitting circuit coupled to the first terminal and the second terminal, and a receiving circuit coupled to the first terminal and the second terminal. The first and second terminals are coupled to an external portion of the large scale integrated circuit. The external portion includes a first branching circuit, a second branching circuit coupled to the first branching circuit, and first and second antennas coupled to the second branching circuit.