A method of operating a communication circuit comprises the steps of receiving a plurality of signals from a plurality of remote transmitters and determining which of the plurality of remote transmitters use transmit diversity. An array of differential MOS switches are all biased by a common tail current source. A digital processor processes a series over time of digital color images of the body part and represents the digital images as a signal over time that is converted to a learning vector using mathematical functions. Each tail may also be positioned to overlap the other. The annular rotor board rotates to cause changes in a gap between each of the magnetic cores and the board inner surface of the gap forming board. The fillers can be fibers or particles.