In this paper, a broadband class-F-1 power amplifier (PA) that can be integrated into compact-sized micro-radio units is introduced. This PA utilizes a multi-harmonic impedance merging technique at harmonic frequencies so that the circuit areas of matching networks can be minimized. As well, in order to maximize the bandwidth of high efficiency, circuit configuration was optimized by the first order differentiation of the fundamental-frequency impedance. For the sake of verification, a 10 W inverse class-F PA operating at 1.9 GHz was designed with a commercial GaN transistor. It exhibited a 39.2% size reduction as compared to conventional PAs of the similar power. In addition, it exhibited a bandwidth of 600 MHz (1.6 ~ 2.2 GHz) at an efficiency greater than 60%, a peak efficiency of 83.9%, and an output power of 42.2 dBm.
2. Cripps, S. C., RF Power Amplifiers for Wireless Communications, 2nd Ed., Artech, Boston, MA, 2006.
3. Lin, S. and A. E. Fathy, "Development of a wideband highly efficient GaN VMCD VHF/UHF power amplifier," Progress In Electromagnetics Research C, Vol. 19, 135-147, 2011.
4. Jimenez-Martin, J. L., V. Gonzalez-Posadas, J. E. Gonzalez-Garcia, F. J. Arques-Orobon, L. E. Garcia-Munoz, and D. Segovia-Vargas, "Dual band high efficiency class ce power amplifier based on CRLH diplexer," Progress In Electromagnetics Research, Vol. 97, 217-240, 2009.
doi:10.2528/PIER09071609
5. Yang, J.-R., H.-C. Son, and Y.-J. Park, "A class-E power amplifier with coupling coils for a wireless power transfer system," Progress In Electromagnetics Research C, Vol. 35, 13-22, 2013.
6. Gustavsson, U., "Design of an inverse class D amplifier using GaN HEMT technology," Department of Technology, Orebro University, 2006.
7. Tanany, A. A., A. Sayed, and G. Boeck, "Analysis of broadband GaN switch mode class-E power amplifier ," Progress In Electromagnetics Research Letters, Vol. 38, 151-160, 2013.
8. Lee, C.-M. and Y.-C. Park, "Design of dualband class-F PAs for cellular and WLAN applications," Journal of Electromagnetic Engineering and Science, Vol. 10, No. 1, 6-12, 2010.
9. Juntunen, E., D. Dawn, S. Pinel, and J. Laskar, "A high-efficiency, high-power millimeter-wave oscillator using a feedback Class-E power amplifier in 45nm CMOS," IEEE Microw. Wireless Compon. Lett., Vol. 21, No. 8, 430-432, 2011.
doi:10.1109/LMWC.2011.2157334
10. Park, Y. C. and J. K. Kim, "A small-sized class-J power amplifier from combined multi-harmonic voltage reflection functions," IEICE Electronics Express, Vol. 10, 17, 2013.
doi:10.1587/elex.10.20130171
11. Pozar, D. M., Microwave Engineering Wiley, Hoboken, 1997.