A wireless energy transfer system for transferring energy between a power supply and a load, comprising: a source resonator coil; a device resonator coil inductively coupled to the source resonator coil; a tunable switching amplifier configured to be driven by the power supply and configured to drive the source resonator coil through a source impedance matching network, the switching amplifier having electronically controllable switching elements; a tunable switching rectifier configured to drive the load and receiving energy from the device resonator coil through a device impedance matching network, the switching rectifier having electronically controllable switching elements; a source amplifier control configured to control a switching characteristic of the switching elements of the amplifier to regulate power extracted from the power supply; and a rectifier control configured to control a switching characteristic of the switching elements of the rectifier to regulate a characteristic of an output presented to the load, the rectifier control communicatively coupled to the source amplifier control; characterized in that: the amplifier control is configured to provide a fixed switching frequency to the switching elements of the amplifier, wherein the amplifier control is configured to control at least one dead time of the switching characteristics of the switching elements of the amplifier to maintain zero voltage switching, wherein the system is designed at a maximum load power level, so that impedance matching is achieved throughout the wireless energy transfer system, so that the tunable switching amplifier maintains zero current switching, and so that a predetermined output DC voltage is seen at the load, and wherein the tunable switching amplifier is configured to reduce, as the power demanded by the load is decreasing, the output power of the tunable switching amplifier by the same amount via reducing its duty cycle and losing zero current switching while an impedance matching level and a DC load voltage or an impedance matching level and a DC load current remain the same. a source resonator coil; a device resonator coil inductively coupled to the source resonator coil; a tunable switching amplifier configured to be driven by the power supply and configured to drive the source resonator coil through a source impedance matching network, the switching amplifier having electronically controllable switching elements; a tunable switching rectifier configured to drive the load and receiving energy from the device resonator coil through a device impedance matching network, the switching rectifier having electronically controllable switching elements; a source amplifier control configured to control a switching characteristic of the switching elements of the amplifier to regulate power extracted from the power supply; and a rectifier control configured to control a switching characteristic of the switching elements of the rectifier to regulate a characteristic of an output presented to the load, the rectifier control communicatively coupled to the source amplifier control; characterized in that: the amplifier control is configured to provide a fixed switching frequency to the switching elements of the amplifier, wherein the amplifier control is configured to control at least one dead time of the switching characteristics of the switching elements of the amplifier to maintain zero voltage switching, wherein the system is designed at a maximum load power level, so that impedance matching is achieved throughout the wireless energy transfer system, so that the tunable switching amplifier maintains zero current switching, and so that a predetermined output DC voltage is seen at the load, and wherein the tunable switching amplifier is configured to reduce, as the power demanded by the load is decreasing, the output power of the tunable switching amplifier by the same amount via reducing its duty cycle and losing zero current switching while an impedance matching level and a DC load voltage or an impedance matching level and a DC load current remain the same. the amplifier control is configured to provide a fixed switching frequency to the switching elements of the amplifier, wherein the amplifier control is configured to control at least one dead time of the switching characteristics of the switching elements of the amplifier to maintain zero voltage switching, wherein the system is designed at a maximum load power level, so that impedance matching is achieved throughout the wireless energy transfer system, so that the tunable switching amplifier maintains zero current switching, and so that a predetermined output DC voltage is seen at the load, and wherein the tunable switching amplifier is configured to reduce, as the power demanded by the load is decreasing, the output power of the tunable switching amplifier by the same amount via reducing its duty cycle and losing zero current switching while an impedance matching level and a DC load voltage or an impedance matching level and a DC load current remain the same.