RF功放设计

RF功放设计RF Power Amplifier Design

Markus Mayer & Holger Arthaber
Department of Electrical Measurements and Circuit Design Vienna University of Technology June 11, 2001

Contents
¤ Basic Amplifier Concepts l Class A, B, C, F, hHCA l Linearity Aspects l Amplifier Example ¤ Enhanced Amplifier Concepts l Feedback, Feedforward, ... l Predistortion l LINC, Doherty, EER, ...
2

Efficiency Definitions
POUT PDC

¤ Drain Efficiency:

ηD =

1 ¤ Power Added Efficiency: η PA = POUT PIN = η D 1 PDC G

3

Ideal FET Input and Output Characteristics
IDS Im VGS=0

gm VGS VGS=VP VK VDD Saturation VDS

2VP

VP

0

0

VDSmax

Ohmic

Breakdown

κ=

VDD V K VDD
4

Maximum Output Power Match
I DS Im VGS=0

gm VGS VGS=VP VK VDD Saturation VDS

2VP

VP

0

0

VDSmax

Ohmic

Breakdown

ROPT =

VDS max VK Im
5

Cl