Scott Alan Yoder

US Patent:

20120299647, Nov 29, 2012

Filed:

Nov 28, 2011

Appl. No.:

13/304943

Inventors:

Hirofumi Honjo - Palo Alto CA, US
Brian Baxter - Greensboro NC, US
Stuart Williams - Horsham, GB
Roman Zbigniew Arkiszewski - Oak Ridge NC, US
David E. Jones - Cedar Rapids IA, US
Chris Levesque - Fountain Valley CA, US
William David Southcombe - San Diego CA, US
Scott Yoder - Fuquay Varina NC, US
Terry J. Stockert - Cedar Rapids IA, US

Assignee:

RF MICRO DEVICES, INC. - Greensboro NC

International Classification:

H03F 3/189

US Classification:

330127

Abstract:

A power amplifier (PA) envelope power supply, which provides an envelope power supply signal to radio frequency (RF) PA circuitry, and a process to prevent undershoot of the PA envelope power supply is disclosed. The process includes determining if an envelope control signal to the PA envelope power supply has a step change from a high magnitude to a low magnitude that exceeds a step change limit. Such a step change may cause undershoot of the PA envelope power supply. As such, if the step change exceeds the step change limit, the envelope control signal is modified to use an intermediate magnitude for period of time. Otherwise, if the step change does not exceed the step change limit, the envelope control signal is not modified.