Design of Varactor-Based Tunable Matching Networks for Dynamic Load Modulation of High Power Amplifiers

Author

Nemati, Hossein Mashad ; Fager, Christian ; Gustavsson, Ulf ; Jos, Rik ; Zirath, Herbert

Author_Institution

Dept. of Microtechnol. & Nanosci., Chalmers Univ. of Technol., Goteborg

Volume

57

Issue

5

fYear

2009

fDate

5/1/2009 12:00:00 AM

Firstpage

1110

Lastpage

1118

Abstract

In this paper, the design of varactor-based tunable matching networks for dynamic load modulation of high power amplifiers (PAs) is presented. Design guidelines to overcome the common breakdown, and tunability problems of the varactors for high power applications are proposed. Based on the guidelines, using commercially available abrupt junction silicon varactors, a tunable matching network is built and measured. The matching network is then used for load modulation of a 1-GHz 7-W class-E LDMOS PA. Static measurements of the load modulated PA show that the power-added efficiency of the PA is improved by an absolute value of 10% at 10-dB backoff. This promising result proves, for the first time, the feasibility of load modulation techniques for high-power applications in the gigahertz frequency range.

Keywords

MIS devices; circuit tuning; elemental semiconductors; microwave power amplifiers; semiconductor junctions; silicon; varactors; Si; abrupt junction silicon varactor; backoff; class-E LDMOS PA; dynamic load modulation; frequency 1 GHz; high power amplifier; power 7 W; static measurements; varactor-based tunable matching network design; Load modulation; power amplifier (PA); tunable-matching network;

fLanguage

English

Journal_Title

Microwave Theory and Techniques, IEEE Transactions on

Publisher

ieee

ISSN

0018-9480

Type

jour

DOI

10.1109/TMTT.2009.2017257

Filename

4814544