Comparison of the efficiencies of class D and class E rectifiers

The efficiencies of the Class D and Class E rectifiers are compared considering power losses in the parasitic resistances of capacitors, inductors and transformer windings, and conduction losses in the diodes. Equations for efficiency are plotted as functions of the output current with an output voltage V₀=5 V and a maximum output power P₀=100 W. It is shown that center-tapped rectifiers are the most suitable for low-voltage applications. Class E rectifier efficiency is higher than that of Class D circuit in the higher range of the output current. The Class E circuit is more suitable for low-current high-frequency applications. The results of this paper can be used by designers in selecting circuits with a better efficiency with respect to their specific load requirements