Precoded waveshaping transmitter for a twisted pair which eliminates the need for a filter

摘要

A precoded waveshaping transmitter comprises a synchronous delay line circuit, a transmitter state machine and a differential current digital to analog converter. Through the provision of a plurality of precoded staggered time delayed data from the combination of the delay line circuit and transmitter state machine the DAC can provide a predetermined output. In a preferred implementation, a subharmonic frequency can be maintained at least 27dB below the fundamental frequency when the PWT is driven by an all ones Manchester encoded signal.