Patent · US Expired

Retractable antenna for a cellular telephone

US5717408A · kind A · utility

17Cited by
14References
18Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 18, 1995
Grant dateFeb 10, 1998
Priority date
Expiry dateDec 18, 2015

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH01Q1/244
  • WIPO fieldTelecommunications
  • WIPO sectorElectrical engineering

Abstract

A retractable antenna for use with a cellular telephone wherein the retractable antenna is removably mounted on the upper end of the telephone. The retractable antenna includes an antenna housing which extends upwardly from the upper end of the telephone and which has a matching circuit provided therein. A helical radiator is positioned in the antenna housing and has its lower end operatively connected to the matching circuit. An elongated radiator is selectively vertically movably positioned in the antenna housing and the telephone and is movable between extended and retracted positions with respect to the antenna housing and the telephone housing. The lower end of the elongated radiator is electrically connected to the upper end of the helical radiator when the elongated radiator is in its extended position. The elongated radiator is electrically disconnected from the helical radiator when the elongated radiator is in its retracted position. The matching circuit in the telephone housing is operatively electrically connected to the telephone circuitry so that the antenna serves as a 1/4 wave antenna when the elongated radiator is in its retracted position and so that the antenna s…

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.