On Thursday 18 October 2001 10:19 am, Muranyi, Arpad wrote: > Mike, Ramesh, > > I found that we have to be very careful about removing points from > the IV curves. Reason: Reflection coefficients are determined by > the slope of the IV curve (AC impedance), not the actual R=V/I at > a given point. Depending on how the simulator handles the > discontinuity that arises at each of these points when using > simple linear interpolation, one could get interesting results. > Assuming that this is done properly with good interpolation > techniques, the accuracy of the slope at a given point may still > be more sensitive to the spacing between points than R calculated > from V/I. So we can't just say that we got a good correlation > between the reduced points curve and the original curve by looking > at how close the two curves overlap. We would need to make a > judgment using the overlay of their derivatives. But the point removal is not to reduce the point count. One reason for it is to clean up the derivative. Too often, the tables provided are contaminated by noise. Removing some points reduces the noise. This noise sometimes causes wild excursions of the derivative, when the measurement precision does not justify it. This noise in the derivative also causes problems in waveform generation. Why is it that no ibis-view tools or simulators show the derivative? ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu