Patent ID: 6441789
Filing Date: 2002-08-27
Classification: H01Q

Abstract:
An antenna, comprising:a &lgr;/4 antenna element retractably coupled to a case of a portable device; a conductive structure having a cylindrical shape and a length of &lgr;/4 for coaxially housing said antenna element when the antenna element is retracted in the device; a first insulator having a cylindrical shape with a first central hole for slidably supporting said antenna element in said first central hole, said first insulator being provided on an upper end of said conductive structure; a second insulator having a cylindrical shape with a second central hole for connection with a lower end of said antenna element, said second insulator being provided on a lower end of said conductive structure; and a radio frequency power feed conductor of cylindrical shape with a third central hole, said radio frequency power feed conductor being connected to an inner side of said first cylindrical insulator in sliding contact with said antenna element through said first central hole, and being insulated from said conductive structure, whereby: one pole of a radio frequency power is connected to said radio frequency power feed conductor; and another pole of the radio frequency power is connected to an upper end of said conductive structure.