Efficiency of the transformer version of class E half-wave low dv/sub D//dt rectifier

An expression for the efficiency of a transformer version of a Class E, half-wave, low dv/sub D//dt rectifier is derived in a closed form as a function of the output current. The equations giving the losses in capacitor equivalent series resistances (ESRs) in the transformer windings, and conduction losses in the diode are derived. Plots of the rectifier efficiency are given for several values of the output power, e.g., 50 W, 100 W, and 240 W, for output voltages of 5 V and 12 V, and using several values of capacitor ESRs. The Class E, half-wave rectifier is suitable for high-frequency applications that require outputs of 12 V. It is also suitable for applications with 5-V outputs only if the output power is lower than 50 W and the capacitor ESRs are low, e.g., 0.01/spl Omega/. The method can be used for the design optimization of other rectifier topologies.<>