Patent · US Expired

Portable telephone

US5774797A · kind A · utility

32Cited by
4References
24Claims
0Family size

Assignee

Inventors

Key dates

Filing dateSep 22, 1995
Grant dateJun 30, 1998
Priority date
Expiry dateSep 22, 2015

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04B2001/0416
  • WIPO fieldTelecommunications
  • WIPO sectorElectrical engineering

Abstract

The present invention discloses a portable telephone which is free from overheat of power amplifier module and also capable of a stable transmission even in the condition that it is unable to amplify the power enough. The portable telephone incorporates a power amplifier module which contains power FET's for amplifying transmission signals. A supply voltage monitoring means detects a supply voltage of a power supply. A control-voltage setting table stores a plurality of commands to set a control-voltage of the power amplifier module. A control-voltage selecting means selects a relevant command out of the control-voltage setting table with reference to the detected supply voltage. A control-voltage control means controls the control-voltage of the power amplifier module according to the command selected by the control-voltage selecting means. The control-voltage will be thereby reduced when the supply voltage is high. This results in reduction of a current flow in the power amplifier module, and an overheat of the power amplifier module can be avoided.

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