The model below corresponds most closely to a lossy transmission line
driven by a voltage source and open circuited at the output end.
R L
0/\/\/\() () ()+0
Vin () ()  Vout
 C


V
Being an opencircuited tline, you fully expect a reflection
coefficient of 1 at the open end, (and 1 at the source end) and hence
big oscillations with a period determined by the sqrt(LC) time
constant. The effect of adding the series R is to damp these
oscillationsessentially changing from a lossless (crude) tline
model to a lossy (crude) one. But the oscillations will still be
thereat least until you make the resistance larger than 2*sqrt(L/C),
at which point the circuit becomes more like a distributed RC
transmission line (familiar to people who deal with onchip
interconnects) than the LC ones that PCB designers know and love.
Eric
 J. Eric Bracken, Ph.D. Tel: 1.412.261.3200 x135 Group Leader, Signal Integrity R&D Fax: 1.412.471.9427 Ansoft Corp., Four Station Square, Suite 660 bracken@ansoft.com Pittsburgh, PA USA 152191119 http://www.ansoft.com**** To unsubscribe from silist: send email to majordomo@silab.eng.sun.com. In the BODY of message put: UNSUBSCRIBE silist, for more help, put HELP. silist archives are accessible at http://www.qsl.net/wb6tpu/silist ****