The authors designed a set of four ICs to provide encoding, multiplexing, clock extraction/demultiplexing, and decoding for gigabit-rate serial data transmission. These chips form a high bandwidth data link for point-to-point communication. A new line code is implemented that provides DC balance, efficient encoding, framing, and simple clock extraction. Embedded in the code is a fixed transition used by the phase/frequency locked loop (PLL) for simple clock extraction and frame synchronization. Unlike other links, this PLL requires no trimming for data retiming, either in production or later. An on-chip voltage-controlled oscillator (VCO) with a tuning range of 1.1-1.6 GHz is available for use with the PLL. With this chip set the authors demonstrated a transmission rate of 16 bits in parallel at 75 MHz or, with encoding overhead, a serial rate of 1.5 Gb/s.>

A time-domain skin-effect model is used to analyze the tapped coaxial cable. The paper first presents the step response of a coaxial cable with a single tap in the middle. Very good agreement has been obtained between the calculated and the measured results. The model is then applied to the study of a 500 m coaxial cable used in the 10 Mbit/s baseband local area networks. In order to compensate for the skin-effect loss, a simple equalization circuit is designed which can be used in the receivers located anywhere on the cable. Four different cases of tap distribution with up to 100 taps are studied in detail. For each case, two parameters are extracted from the receiver output signal. They are plotted as a function of the cable length to provide a quantitative description of the signal quality.