Patent ID: 8610312

Claim:
An inductive electric power transfer circuit, comprising: a transmitter antenna connected with a series power supply circuit that supply electric power at angular frequency (ω); a receiver antenna connected with a series load circuit that consumes the electric power; capacitance (C 1 ) which is connected between both ends of the transmitter antenna; and capacitance (C 2 ) which is connected between both ends of the receiver antenna; wherein distance between the transmitter antenna and the receiver antenna is not greater than ½π wavelengths of electromagnetic field at the angular frequency (ω) the transmitter antenna has effective self-inductance (L 1 ), and the receiver antenna has effective self-inductance (L 2 ), the magnetic coefficient of coupling of electromagnetic induction between the transmitter antenna and the receiver antenna is represented by the symbol k, and wherein with a phase angle (β) that is not less than zero and not greater than pi, the angular frequency (ω) is reciprocal of square root of L 2 ×C 2 ×(1+k×cos(β)), the power supply circuit has output impedance of kωL 1 ×sin(β)≡r 1 , and the load circuit has input impedance of kωL 2 ×sin(β)≡r 2 , power is transferred from the power supply circuit to the load circuit through space.