| 摘要 |
A radio communication apparatus is provided, which realizes a desired impedance matching state between a retractable antenna and a circuit connected thereto in both a situation where the antenna environment is similar to a free space and a situation where the antenna environment is dissimilar from a free space. The apparatus comprises (a) a casing; (b) a retractable antenna having first and second elements joined together; the second element being connected to an internal circuit provided in the casing; (c) a terminal matching circuit for matching an impedance of the antenna to that of the internal circuit in a first situation where an environment of the antenna is similar to a free space and a second situation where an environment of the antenna is dissimilar from a free space; the terminal matching circuit being configured to provide at least two terminal impedance values for the antenna; and (d) a control circuit for controlling an operation of the terminal matching circuit corresponding to whether the apparatus is placed in the first situation or the second situation; the control circuit controlling the terminal matching circuit in such a way that a first one of the at least two terminal impedance values is selected when the apparatus is placed in the first situation and a second one of the at least two terminal impedance values is selected when the apparatus is placed in the second situation. <IMAGE> |
