Patent ID: 6738603
Filing Date: 2004-05-18
Classification: H01Q

Abstract:
A radio communication apparatus comprising:(a) a casing; (b) an antenna retractable into said casing; said antenna having a first element and a second element joined together; said first element being placed outside even when said antenna is retracted; said second element being retracted into said casing when said antenna is retracted; said second element being connected to an internal circuit provided in said casing; (c) a terminal matching circuit for matching an impedance of said antenna to that of said internal circuit in a first situation where an environment of said antenna is similar to a free space and in a second situation where an environment of said antenna is dissimilar from a free space; said terminal matching circuit being configured to provide at least two terminal impedance values for said antenna both in the extended state and in the retracted state; and (d) a control circuit for controlling an operation off said terminal matching circuit corresponding to whether said apparatus is placed in said first situation or said second situation; said control circuit controlling said terminal matching circuit in such a way that a first one of the at least two terminal impedance values is selected when said apparatus is placed in said first situation and a second one of the at least two terminal impedance values is selected when said apparatus is placed in said second situation.