Square wave response calcuration of coaxial cables and twin-leads
Frequency (MHz)
Length of cable[/observation point] (m)
Output resistance of generator (Ohm)
Output capacitance of generator (pF)
Input resistance of receiver (Ohm)
Input capacitance of receiver (Ohm)
10%-90% raise/fall time (ns)
Wave form
Using cable

Type needed parameters and select wave form and type of cable, then press "compute" to get output wave form.

As for bus cables, we should consider not only end point but also mid points of cable. We can get the wave form at mid point by specifying the observation point directly followed the total length with delimited a '/' character. For example,

will calculates the wave form at the distance of 6 meter from generator with total 16 meter cable.

The computing model of this program is as follows.

  +- Rs -+-o---------------------o-+---+  ^
  |      |                         |   |  |
  G      Cs        cable           Cr  Rr Vr
  |      |                         |   |  |
  +------+-o---------------------o-+---+  -

  G = generator (2Vpp)
  Rs = output resistance of generator (Ohm)
  Cs = output capacitance of generator (pF)
  Rr = input resistance of receiver (Ohm)
  Cr = input capacitance of receiver (pF)
  cable = selected cable (m)
This program calcurates Vr as time function for specified conditions. The output wave form is either trapezoid or exponential (1 - exp(t/T)).

Caution - This program generates pretty good results. But any results of this program are disclaimed.