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Class-J2 Power Amplifiers

delete2017-08-01
delete17
PRE
AI
A
Amirreza Alizadeh *
M
Majid Yaghoobi
A
Ali Medi
DOI:10.1109/TCSI.2017.2683067delete
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Abstract

Abstract

En 中文
This paper presents the theoretical introduction and experimental validation of the Class-J(2) Mode Power Amplifier, which provides higher efficiency and output power compared with conventional class-J mode counterpart. This mode of operation is realized by injection of the second-harmonic current to drain node of a class-J power amplifier (PA) to reduce the 45 degrees phase shift between drain current and voltage signals. Similar to class-J PAs, the second-harmonic impedance of class-J(2) PAs is purely reactive to simplify the design of the output matching network. The auxiliary second-harmonic injection circuit comprises a transistor biased in class-B mode followed by a class-C biased amplifier to achieve high second-harmonic current conversion efficiency. Theoretical formulations suggest that a 5% improvement in drain efficiency (eta(D)) as well as a 1.5-dB increase in output power can be achieved for the class-J(2) mode in comparison with the typical class-J operation. To check the accuracy of theoretical predictions, a proof-of-concept 1-GHz class-J(2) PA with 12.2-dBm output power and 43% PAE is implemented in a 0.18-mu m CMOS technology. For better comparison, a 1-GHz class-J PA with the same transistor size and bias condition as the class-J(2) PA is also fabricated. The output power and PAE of the reference class-J PA are 11.4 dBm and 40.6%, respectively, which are in agreement with theoretical predictions.
Keywords:
Class-J
CMOS integrated circuits
harmonic-injection power amplifiers
high-efficiency power amplifiers
reduced conduction angle (RCA)
wideband power amplifiers
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Journal

IEEE Transactions on Circuits and Systems I-Regular Papers cover
IEEE Transactions on Circuits and Systems I-Regular Papers
IF:
5.2
Papers:
9.7K
Citations:
2.2W

Organization

S
Sharif University of Technology
Scholars:
1.1W
Papers: 1.1W
Citations: 9.5K