Inverse class-F power amplifier using the metamaterial structure on the harmonic control circuit

In this study, the inverse class-F power amplifier at 1.8 GHz using the harmonic control circuit based on a metamaterial structure is proposed and experimentally tested. The harmonic control circuit has been used with transmission line and metamaterial structure to open the 2nd harmonics, to short the 3rd harmonics, and to match the fundamental frequency to 50 Ω. The interesting properties of the metamaterial structure allow a size reduction of the harmonic control circuit as well simplification of the design. A detailed analysis of the metamaterial structures based on the equivalent circuit model is provided. The proposed harmonic control circuit has been used to design the inverse class-F power amplifier with maximum PAE of 70.4%. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2881–2884, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23836