Abstract: A wireless communication terminal able to change a resonance frequency of a sub antenna, able to reduce interference to a main antenna, and able to suppress deterioration performance in a dual terminal compatible with a plurality of transmission systems, wherein, in a wireless communication unit, at the time of a CDMA2000 1xEVDO mode, a first receiver circuit, a second receiver circuit, and a transmitter circuit are in an operative state, and, in the second receiver circuit, an input impedance is held at the 50 ohm input impedance of a LNA by an impedance control unit, while at the time of a CDMA2000 1x mode, the first receiver circuit and the transmitter circuit are in the operative state, the second receiver circuit is in an inoperative state, and, in the second receiver circuit, the input impedance is controlled so as to be shifted from the 50 ohm input impedance of the LNA by the impedance control unit, and an antenna switching control method for the same.

Abstract: A mobile terminal device having an antenna switch able to efficiently switch connection between reception signals from a plurality of antennas and signal processing circuits of the reception signals is provided. The device is able to communicate by a first data transmission system performing a diversity reception and a second data transmission system not performing the diversity reception. The device includes: a first antenna; a second antenna; an antenna attachable and detachable and detachable portion, to which a third antenna is attached and from which the third antenna is detached; a first wireless circuit for performing communication using the first antenna or the third antenna; a second wireless circuit for performing communication using the second antenna; a third wireless circuit for performing communication using the first antenna or the third antenna; and an antenna switch.

Abstract: A mobile terminal device having an antenna switch able to efficiently switch connection between reception signals from a first antenna, a second antenna, and a third antenna able to be plugged into an antenna socket to at least a first wireless circuit and a second wireless circuit. The antenna switch includes a first switch having a first antenna terminal, a first wireless circuit terminal and a second switch having a second antenna terminal, a second wireless circuit terminal, a third antenna terminal. The first switch switches between a state connecting the first antenna terminal and the first wireless circuit terminal and a state connecting the first input/output (I/O) terminal and the first wireless circuit terminal in accordance with plugging of the third antenna into the antenna socket.

Abstract: A wireless communication terminal able to change a resonance frequency of a sub antenna, able to reduce interference to a main antenna, and able to suppress deterioration performance in a dual terminal compatible with a plurality of transmission systems, wherein, in a wireless communication unit, at the time of a CDMA2000 1xEVDO mode, a first receiver circuit, a second receiver circuit, and a transmitter circuit are in an operative state, and, in the second receiver circuit, an input impedance is held at the 50 ohm input impedance of a LNA by an impedance control unit, while at the time of a CDMA2000 1x mode, the first receiver circuit and the transmitter circuit are in the operative state, the second receiver circuit is in an inoperative state, and, in the second receiver circuit, the input impedance is controlled so as to be shifted from the 50 ohm input impedance of the LNA by the impedance control unit, and an antenna switching control method for the same.