A Zero-Voltage-Switching Contour-Based Power Amplifier With Minimal Efficiency Degradation Under Back-Off

Author

Singhal, Nitesh ; Nidhi, Nitin ; Patel, Rishi ; Pamarti, Sudhakar

Author_Institution

Dept. of Electr. Eng., Univ. of Cal ifornia at Los Angeles (UCLA), Los Angeles, CA, USA

Volume

59

Issue

6

fYear

2011

fDate

6/1/2011 12:00:00 AM

Firstpage

1589

Lastpage

1598

Abstract

A switching power amplifier (PA) architecture that offers up to 13 dB of output power back-off without any drain efficiency degradation is presented. The proposed zero-voltage-switching (ZVS) contour-based PA employs a series class-E PA in conjunction with duty cycle modulation and a proposed tunable impedance transformation network. So-called ZVS conditions that ensure ideally 100% drain efficiency are satisfied not just at peak output power, but over the 13-dB back-off range. Theoretical analyses of losses in the PA and the impedance transformation network are also presented to prove that drain efficiency actually improves with back-off. Measurement results of a 100-MHz PA built using discrete components on an FR4 printed circuit board showing drain efficiency greater than or equal to the peak efficiency (40%) at all output power levels are also presented.

Keywords

power amplifiers; drain efficiency degradation; duty cycle modulation; minimal efficiency degradation; output power back-off; series class-E PA; switching power amplifier architecture; tunable impedance transformation network; zero-voltage-switching contour-based PA; zero-voltage-switching contour-based power amplifier; Capacitance; Impedance; Modulation; Power generation; Resistance; Switches; Zero voltage switching; Peak-to-average power ratio (PAR); peak-to-minimum power ratio (PMR); power amplifier (PA); zero voltage switching (ZVS);

fLanguage

English

Journal_Title

Microwave Theory and Techniques, IEEE Transactions on

Publisher

ieee

ISSN

0018-9480

Type

jour

DOI

10.1109/TMTT.2011.2131677

Filename

5749288