摘要 |
A wireless power transmission unit includes oscillators that convert DC energy into RF energy with a frequency f0, power transmitting antennas, and power receiving antennas. Each power transmitting antenna is a series resonant circuit in which a power transmitting inductor and a first capacitor are connected in series. Each power receiving antenna is a parallel resonant circuit in which a power receiving inductor and a second capacitor are connected in parallel. If the oscillator has a voltage step-up ratio Voc, the power transmitting inductor has an inductance L1, the power receiving inductor has an inductance L2, and the power transmitting and power receiving antennas and have a coupling coefficient k, (L2/L1)≧4(k/Voc)2 is satisfied. The absolute value of the phase differenceθres between the respective resonant magnetic fields of first and second pairs of resonant antennas is set to fall within the range of 90 to 180 degrees. |