Christopher D Stephens

US Patent:

7177370, Feb 13, 2007

Filed:

Dec 17, 2003

Appl. No.:

10/740238

Inventors:

Andrew Zhang - Portland OR, US
Thomas R. Apel - Portland OR, US
Christopher R. Stephens - Portland OR, US

Assignee:

TriQuint Semiconductor, Inc. - Hillsboro OR

International Classification:

H04K 1/02
H04L 25/03
H04L 25/49

US Classification:

375297, 375308, 330297, 332100

Abstract:

An RF transmitter provides both GSM and EDGE capability by implementing collector voltage control over the power transistor(s) in a power amplifier. During EDGE mode, linear base-biasing a power amplifier (PA) allows collector control to provide either saturated mode PA operation (during ramp up/ramp down) or linear mode PA operation (during data burst). Collector control can therefore be used to provide the accurate ramp up and ramp down profiles required for both GSM and EDGE burst output signals, and can also be used to set the level of the constant envelope data burst of a GSM burst output signal, while linear mode PA operation can provide the non-constant envelope EDGE data burst. A variable gain amplifier is used to adjust the input signal to the power amplifier such that the desired transmission level is achieved.