Calculated max. values of pulse transmission distance of balanced transmission by 2 lines of 45Ω PFA fine coaxial cables (when the horizontal eye pattern opening is 80 %.)
Calculated max. values of pulse transmission distance of balanced transmission by 2 lines of 45Ω PFA fine coaxial cable (when the vertical eye pattern opening is 80%.)
About the Eye Pattern Waveform of the Cable
Measuring the eye pattern is one way to evaluate the pulse transmission properties. As shown in Figure, you can measure the eye pattern by using a PPG (pulse pattern generator) to generate PRBS (pseudo random bit sequence) at a specified bit rate, entering those bit signals in the cable to be measured, then using a signal analyzer to analyze the output signals. The maximum pulse transmission range of a cable is determined by the performance of the driver and receiver employed. Junkosha determines the relationship between the bit rate (providing an eye opening degree of 80%) and transmission cable length , while defining the degrees of horizontal and vertical eye opening as shown below.