| 摘要 |
PROBLEM TO BE SOLVED: To provide an antenna device capable of appropriately switching the antenna even when a matching circuit which causes a capacitive coupling is used.SOLUTION: An antenna device 1 includes: an inverted L-type antenna 2; a helical antenna 3; a radio circuit 4; high frequency switches 5, 11 and 12; and matching circuits 6 and 7. When the high frequency switch 5 connects the radio circuit 4 to the inverted L-type antenna 2, the high frequency switch 12 is opened, and a channel between the radio circuit 4 and the helical antenna 3 is shut off. When the high frequency switch 5 connects the radio circuit 4 to the helical antenna 3, the high frequency switch 11 is opened, and a channel between the radio circuit 4 and the inverted L-type antenna 2 is shut off. With this, a power supply channel to an antenna which is not connected by the high frequency switch 5 is shut off. |
