Broadband power efficient Class E amplifiers with a non-linear CAD model of the active MOS device

Abstract

This paper describes how broadband power efficient Class E amplifiers can be designed which are capable of efficiencies approaching 100% over 35%fractional bandwidths. The paper contains a brief review of switching ClassE amplifiers, which are normally narrow band, and describes how these can be made broadband. As an example, a broadband 130 to 180 MHz r.f. amplifier has been designed, built and tested and the results are reported here. To enable an accurate computer simulation of the r.f. power amplifier to be made, a non-linear CAD model of the active device (an r.f. power MOSFET) is developed. CAD techniques for matching the non-linear input impedance of the MOSFET are also presented. Experiment and theory are compared and show close correlation.