The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 18, 2004
Filed:
Jun. 09, 2000
Tetsuya Saito, Saitama, JP;
NEC Corporation, Tokyo, JP;
Abstract
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.