A class-J power amplifier with varactor-based dynamic load modulation across a large bandwidth

• A novel class-J operated power amplifier (PA) utilizing varactor-based dynamic load modulation is presented. It is theoretically shown that the proposed PA can maintain high average efficiency across more than 35% RF bandwidth by means of a purely reactive load modulation after the transistor output capacitance. The theory is experimentally verified by a 15 W GaN HEMT PA operating from 1.80 to 2.20 GHz, using SiC varactors as dynamically tunable load elements. In the band, the PA presents a power added efficiency (PAE) higher than 39% at 6 dB output power back-off. For a 3.84 MHz W-CDMA signal with 6.7 dB peak to average power ratio, an average PAE higher than 39% and an adjacent channel leakage ratio below -45.8 dBc are obtained across the entire band after linearization.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Elektroteknik och elektronik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Electrical Engineering, Electronic Engineering, Information Engineering (hsv//eng)

Keyword

power amplifiers

wideband

Energy efficiency

silicon carbide (SiC)

varactors

gallium nitride (GaN)

Publication and Content Type

kon (subject category)

ref (subject category)