TY - JOUR
T1 - Adaptive Methods to Preserve Power Amplifier Linearity under Antenna Mismatch Conditions
AU - Bezooijen, van, A.
AU - Mahmoudi, R.
AU - Roermund, van, A.H.M.
PY - 2005
Y1 - 2005
N2 - Under antenna mismatch conditions at high output power, voltage clipping (due to collector voltage saturation) is the main cause of power amplifier linearity degradation. To preservelinearity under mismatch three adaptive methods are presented that make use of the detected minimum collector peak voltage.This detected signal controls either the amplifier output power,load-line, or supply voltage. These concepts are generalized analytically,and calculated results compare well to simulations. Measurements
demonstrate am error vector magnitude reduction of5% and an adjacent channel power ratio improvement of 10 d Bat a voltage standing wave ratio of 4 for an EDGE amplifier with adaptively controlled output power. These adaptive methods offer a cost and size effective alternative to the use of an isolator.
AB - Under antenna mismatch conditions at high output power, voltage clipping (due to collector voltage saturation) is the main cause of power amplifier linearity degradation. To preservelinearity under mismatch three adaptive methods are presented that make use of the detected minimum collector peak voltage.This detected signal controls either the amplifier output power,load-line, or supply voltage. These concepts are generalized analytically,and calculated results compare well to simulations. Measurements
demonstrate am error vector magnitude reduction of5% and an adjacent channel power ratio improvement of 10 d Bat a voltage standing wave ratio of 4 for an EDGE amplifier with adaptively controlled output power. These adaptive methods offer a cost and size effective alternative to the use of an isolator.
U2 - 10.1109/TCSI.2005.853254
DO - 10.1109/TCSI.2005.853254
M3 - Article
SN - 1057-7122
VL - 52
SP - 2101
EP - 2108
JO - IEEE Transactions on Circuits and Systems. I, Fundamental Theory and Applications
JF - IEEE Transactions on Circuits and Systems. I, Fundamental Theory and Applications
IS - 10
ER -