Input Impedance Calculation of a Multi-Stage Rectifier Circuit

We introduce an analytical method to calculate the input impedance of a multi-stage rectifier circuit. It is shown that the input impedance of a half-wave rectifier depends on the operating frequency, the input power level and the load resistance value. The introduced method uses the equivalent circuit model of a Schottky diode. The analytical method has been verified by harmonic balance analysis for different load resistances and for different input power levels as a function of frequency. Based on the input impedance of the half-wave rectifier, the analytical method is then extended to calculate the input impedance of an n-stage rectifier circuit. A voltage doubler is simulated, fabricated and its input impedance is measured. The simulation results of the analytical solution and harmonic balance are validated by measurements.