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:
Jun. 06, 1995
Filed:
Mar. 18, 1993
Darrell Epperson, Wake Forest, NC (US);
Paul W Dent, Cary, NC (US);
Ericsson GE Mobile Communications Inc., Research Triangle Park, NC (US);
Abstract
The present invention relates generally to RF power amplifiers for portable cellular radiotelephones, and more particularly, to dual-mode cellular radiotelephones. A power supply network enables the RF power amplifier in a dual-mode radiotelephone to operate with two separate modes: saturated and unsaturated. Switches in the power supply network, e.g. complementary transistors, are driven to a first set of logic states by a square wave which is synchronized with transmit time slots present in a TDMA frame structure to charge a capacitor from a battery. When the switches are then driven to a second set of logic states, the capacitor is placed in series with the battery to essentially double the supply voltage. When the radiotelephone operates in a digital mode, the increased supply voltage coincides with the transmit time slot and temporarily increases the saturation point of the RF power amplifier to permit linear amplification. When the radiotelephone operates in an analog mode, the switches are fixed at the first set of logic states. The resulting lower supply voltage lowers the saturation point of the RF power amplifier, causing it to operate in a nonlinear but more efficient mode.