A system for wireless energy transfer, the system comprises: a circuit for wireless transmission of energy, the circuit comprises: a first resonator circuit comprising: a transmitter coil having a large number of windings N2; a variable capacitance device connected in shunt across the transmitter coil with the transmitter coil and the variable capacitor and intrinsic capacitance of the transmitter coil forming the resonator circuit; and an input coil configured to be connected to an input RF source, with the input coil having a low number of windings N1 compared to the number of windings N2 of the transmitter coil, and the input coil being inductively coupled to the transmitter coil to provide power output from the resonator circuit at a resonant frequency in a range of about 100 kHz to 30 MHz; and a circuit for wireless reception of energy, the circuit comprises: a second resonator circuit comprising: a receiver coil inductively coupled to the transmitter coil, the receiver coil having a large number of windings N2; a variable capacitance device connected in shunt across the receiver coil with the receiver coil and the variable capacitor and intrinsic capacitance of the receiver coil forming the second resonator circuit; and an output coil with a low number of windings N1 compared to the number of windings N2 of the receiver coil, the output coil being inductively coupled to the receiver coil to provide power output from the circuit, with the resonator circuit having a resonant frequency in a range of about 100 kHz to 30 MHz; characterized in that the system further comprises a resonator disposed between the circuit for wireless transmission of energy and the circuit for wireless reception of energy to inductively couple with the first and second resonator circuits to effectively produce a rectified voltage having a DC component at the circuit for wireless reception of energy; wherein the circuit to inductively couple includes a magnetic field transmitter operating at the first harmonic or higher harmonic of the base transmitter frequency; wherein the resonator is a LC tank circuit with resonant frequency f, driven by rectangular pulse oscillator and a power switch or amplifier. a circuit for wireless transmission of energy, the circuit comprises: a first resonator circuit comprising: a transmitter coil having a large number of windings N2; a variable capacitance device connected in shunt across the transmitter coil with the transmitter coil and the variable capacitor and intrinsic capacitance of the transmitter coil forming the resonator circuit; and an input coil configured to be connected to an input RF source, with the input coil having a low number of windings N1 compared to the number of windings N2 of the transmitter coil, and the input coil being inductively coupled to the transmitter coil to provide power output from the resonator circuit at a resonant frequency in a range of about 100 kHz to 30 MHz; and a transmitter coil having a large number of windings N2; a variable capacitance device connected in shunt across the transmitter coil with the transmitter coil and the variable capacitor and intrinsic capacitance of the transmitter coil forming the resonator circuit; and an input coil configured to be connected to an input RF source, with the input coil having a low number of windings N1 compared to the number of windings N2 of the transmitter coil, and the input coil being inductively coupled to the transmitter coil to provide power output from the resonator circuit at a resonant frequency in a range of about 100 kHz to 30 MHz; and a circuit for wireless reception of energy, the circuit comprises: a second resonator circuit comprising: a receiver coil inductively coupled to the transmitter coil, the receiver coil having a large number of windings N2; a variable capacitance device connected in shunt across the receiver coil with the receiver coil and the variable capacitor and intrinsic capacitance of the receiver coil forming the second resonator circuit; and an output coil with a low number of windings N1 compared to the number of windings N2 of the receiver coil, the output coil being inductively coupled to the receiver coil to provide power output from the circuit, with the resonator circuit having a resonant frequency in a range of about 100 kHz to 30 MHz; a receiver coil inductively coupled to the transmitter coil, the receiver coil having a large number of windings N2; a variable capacitance device connected in shunt across the receiver coil with the receiver coil and the variable capacitor and intrinsic capacitance of the receiver coil forming the second resonator circuit; and an output coil with a low number of windings N1 compared to the number of windings N2 of the receiver coil, the output coil being inductively coupled to the receiver coil to provide power output from the circuit, with the resonator circuit having a resonant frequency in a range of about 100 kHz to 30 MHz; characterized in that the system further comprises a resonator disposed between the circuit for wireless transmission of energy and the circuit for wireless reception of energy to inductively couple with the first and second resonator circuits to effectively produce a rectified voltage having a DC component at the circuit for wireless reception of energy; wherein the circuit to inductively couple includes a magnetic field transmitter operating at the first harmonic or higher harmonic of the base transmitter frequency; wherein the resonator is a LC tank circuit with resonant frequency f, driven by rectangular pulse oscillator and a power switch or amplifier.