Multi-phase Class D resonant inverters for wireless power transfer applications are introduced in this work.A three-phase resonant inverter with a common resonant circuit topology is presented in Fig.1.Its multi-level version is also proposed and applied in a WPT system as shown in Fig.2.Symmetrical and asymmetrical phase control concepts are introduced.A phase-frequency hybrid control strategy is invented as an alternative for the traditional frequency and phase control methods.A frequency-domain analysis of the inverters is performed.