this paper proposes an equivalent impedance analysis and compensation study of full-wave bridge rectifiers based on the extended impedance method (EIM). EIM provides an efficient frequency-domain numeric solution for nonlinear circuit analysis. The steady-state characteristics of a rectifier circuit can be easily and efficiently simulated with EIM, no matter it operates in CCM or DCM, under low or high frequencies. Taking the bridge rectifier in the secondary side of a 6.78-MHz wireless power transfer (WPT) system, for example, we demonstrate that EIM can model its dynamics very well. The efficient numeric method is further utilized to optimize the rectifier circuit through impedance compensation towards zero phase angle (ZPA) operation. Both the commercial simulator PSpice and experiment results validate the feasibility of this EIM based analysis and optimization.