Apparatus for transmitting an output with predetermined frequency response to an unshielded twisted-pair media and waveform shaping circuit and method employed therein

摘要

A waveform shaping circuit includes an input terminal, an output terminal, and a plurality of cascaded circuit stages. Each of the cascaded circuit stages includes a delay circuit having an output and an input, a current source, and a switch circuit, connected electrically to the output of the delay circuit and controlled by the delay circuit, for connecting electrically the current source to the output terminal. The input of the delay circuit of a first one of the circuit stages is connected electrically to the input terminal. The input of the delay circuit of remaining ones of the circuit stages is connected electrically to the output of the delay circuit of an immediately preceding one of the circuit stages. The delay circuits have equal delay times. The total delay time provided by the delay circuits of the circuit stages is equal to or is a multiple of half a bit time of the fundamental data rate. The current sources have current values derived from time samples of a finite impulse response of a filter transfer function of the waveform shaping circuit.