Resonant inductive coupling

Resonant inductive coupling or Magnetic phase synchronous coupling is the phenomenon that the coupling is enhanced when the secondary side of the loosely coupled coil resonates.　The most basic resonant inductive coupling consists of one drive coil on the primary side and one resonance circuit on the secondary side. In this case, when the resonant state on the secondary side is observed from the primary side, two resonances as a pair are observed. One of them is called the antiresonant frequency (parallel resonant frequency), and the other is called the resonant frequency (series resonant frequency). The short-circuit inductance and resonant capacitor of the secondary coil are combined into a resonant circuit. When the primary coil is driven with a resonance frequency (serial resonance frequency), the phases of the magnetic fields of the primary coil and the secondary coil are synchronized. As a result, the maximum voltage is generated in the secondary coil. The resonant inductive coupling is the near field wireless transmission of electrical energy between magnetically coupled coils, which is part of a resonant circuit tuned to resonate at the same frequency as the driving frequency. This process occurs in a resonant transformer, an electrical component which consists of high Q coil wound on the same core with capacitors connected across the coils to make coupled LC circuit. Resonant transformers are widely used in radio circuits as bandpass filters, and in switching power supplies. Resonant inductive coupling is also being used in wireless power systems. Here the LC circuit is in different devices; a transmitter coil in one device transmits electric power across an intervening space to a resonant receiver coil in another device. This technology is being developed for powering and charging portable devices such as cellphones and tablet computers at a distance, without being tethered to an outlet. The WiTricity type magnetic resonance is that the primary side resonant is added to the basic resonant inductive coupling system in order to increase the power transmission intensity of the resonance. Thus, the WiTricity type magnetic resonance is characterized in that the resonant coils on the primary side and the resonant coils on the secondary side are paired.

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