Open AccessGaN‐HEMT asymmetric three‐way Doherty power amplifier using GPD
Author(s) -
Koo Hyungmo,
Kang Hyunuk,
Lee Wooseok,
Lee Hwiseob,
Lee KangYoon,
Hwang Keum Cheol,
Yang Youngoo
Publication year - 2018
Publication title -
iet microwaves, antennas and propagation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.555
H-Index - 69
eISSN - 1751-8733
pISSN - 1751-8725
DOI - 10.1049/iet-map.2018.5464
Subject(s) - amplifier , power added efficiency , power bandwidth , linear amplifier , rf power amplifier , high electron mobility transistor , electrical engineering , direct coupled amplifier , transistor , adjacent channel , gallium nitride , power gain , power dividers and directional couplers , electronic engineering , engineering , materials science , operational amplifier , voltage , cmos , layer (electronics) , composite material
A gallium‐nitride high electron mobility transistor (GaN‐HEMT) three‐way asymmetric Doherty power amplifier using an unequal three‐way Gysel power divider (GPD) is presented in this study. Considering the output power capacity of transistors, the peaking amplifier was designed to have an output power capacity that is 1.5 times larger than that of the carrier amplifier through the use of a parallel combination of two different power amplifiers. A peaking amplifier that is 1.5 times larger can provide a back‐off level of 7.5 dB for another peak efficiency. Two different power amplifiers in the peaking amplifier can work as a single power amplifier through an optimization of the input power division ratio (PDR). To split the input power for the carrier and the two peaking amplifiers, an unequal three‐way GPD with an optimized PDR was employed. The implemented Doherty power amplifier for the 2.14 GHz band exhibited a drain efficiency (DE) of 59.5% and an adjacent channel leakage ratio (ACLR) of 27.1 dBc at an average output power of 37.2 dBm (7.2 dB for the output power back‐off) for the 2.14 GHz downlink long‐term evolution signal, which has a peak‐to‐average power ratio of 6.5 dB and a signal bandwidth of 10 MHz.