A rotor includes a rotor core and disk-shaped end plates provided to sandwich the rotor core in the direction of a rotation shaft. From about 2% to about 10% rare earth element, preferably from about 3% to about 8%, is present in the solutions. The input coupler is structured to couple approximately equal powers into the first and third arms and no more than 50% power into the second arm. Also, the controller module resets an attempt counter for the MM procedure in response to the rejection message with the MM back-off timer. from a lookup table expressed by three-dimensional X-, Y-, and Z-coordinates.