| 摘要 |
<p>An object of the present invention is to provide an antenna device which corresponds to a plurality of radio communications systems and frequency bands, which can simultaneously carry out a reception and a transmission of different radio communications systems, and which is capable of using antenna diversity by a simple construction. An antenna device comprises a first antenna (1) matching with first, second, and third frequency bands, a second antenna (2) matching with the third frequency band, a diplexer (3) and the like. For signals of the first frequency band, a high-frequency switch circuit (4) connects a transmitter (8) or a receiver (7) to the diplexer (3) by switching. For signals of the second frequency band, the high-frequency switch (5) connects a receiver (9) or a transmitter (10) to the diplexer (3) by switching. For signals of the third frequency band, the high-frequency switch circuit (5) and a high-frequency switch circuit (6) connect the second antenna (2) or diplexer (3) to a transmitter/receiver (11) by switching. <IMAGE></p> |
