Title :
Transmission-line load-network topology for class-E power amplifiers
Author :
Wilkinson, Andrew J. ; Everard, Jeremy K A
Author_Institution :
Dept. of Electr. Eng., Cape Town Univ., Rondebosch, South Africa
fDate :
6/1/2001 12:00:00 AM
Abstract :
Class-E amplifiers are a type of switching amplifier offering very high efficiency approaching 100%. In this paper, a topology and design methodology, which could be used for a transmission-line implementation of a class-E power amplifier, is presented. A simple transmission-line class-E load network is proposed that offers combined transformation of the load resistance down to a suitable level, as well as simultaneous suppression of harmonics in the load. The load network was developed and tested with the aid of a time-domain simulator (i.e., SPICE). A microstrip layout was designed and a first prototype was built operating at 1 GHz utilizing a field-effect transistor as the switching device. A drain efficiency of 72% was measured for our prototype after tuning, although better performance can be expected with an improved switching transistor and careful tuning of the load network
Keywords :
UHF power amplifiers; distributed amplifiers; equivalent circuits; harmonics suppression; microstrip circuits; network synthesis; network topology; switching circuits; 1 GHz; 72 percent; FET switching device; SPICE; class-E power amplifiers; design methodology; field-effect transistor; harmonics; load resistance transformation; microstrip layout design; switching amplifier; time-domain simulator; transmission-line implementation; transmission-line load-network topology; Design methodology; FETs; Microstrip; Network topology; Power amplifiers; Prototypes; SPICE; Testing; Time domain analysis; Transmission lines;
Journal_Title :
Microwave Theory and Techniques, IEEE Transactions on
