As Steve said, follow the energy (power). Pout=Vout*Vout/Rload, so smaller P => smaller V. So - The short answer is energy loss ALWAYS reduces both voltage and current at the load compared to the output voltage (the two exceptions are no reduced voltage for Zout=short, and no reduced current for Zout=open). * Your analysis with an ideal voltage source would be improved by adding a non-ideal connection between the voltage source and the load, to model transmission line loss. * For a DC representation of interconnect loss, try a series-shunt-series- (TEE section) using 3 resistors of 1 ohm each. To get a feel for the effect of dielectric loss (represented by shunt resistor), do the basic circuit analysis with the shunt resistor at 1 ohm and then at 100-ohm (larger resistance = smaller dielectric loss). Even without a load, the voltage is reduced at the output. To get a feeling for trends in output voltages, one could repeat the analysis with Zout=50 and Zout=100 and check the output voltages and currents. Hope this helps to clarify effects of lossy interconnects. Lynne PS: before anyone nags me, my circuit example values were selected to make it easier to see trends. They are not intended to represent any actual T-line. "IBIS training when you need it, where you need it." Dr. Lynne Green Green Streak Programs http://www.greenstreakprograms.com 425-788-0412 lgreen22@xxxxxxxxxxxxxx On 1/6/2012 3:14 AM, rajneesh shukla wrote: > Thanks Steve but question remains unanswered !! > > > I agree there will be a loss in energy due to dielectric loss but I was > talking about loss in amplitude of signal (voltage) not loss in total > energy, Energy loss does not always translates into voltage loss, right ? > Receiver senses voltage( Potential Energy per unit charge) not total energy. > > > > As per basic circuit theory, If I have a driver that has zero o/p impedance > is driving a 50 Ohm load and now if I connect 100 Ohm resistance across > this load, Though there is energy loss due to 100 ohm resistance but still > my load will see the same voltage, agree ? > > > > In transmission line, If series loss i.e. conductor loss is zero then I > don't find the reason of any voltage drop in transmission line coz > dielectric loss which is shunt loss can only dissipate total energy but > can't change amplitude(voltage) of signal. > > > > Do you find any discrepancy in this analogy ? > > > On Fri, Jan 6, 2012 at 2:40 PM, steve weir<weirsi@xxxxxxxxxx> wrote: > >> Follow the energy. Achieve enlightenment. Of the energy that a shunt >> draws, how much of that energy remains available to the signal? >> >> Steve. >> On 1/6/2012 12:54 AM, rajneesh shukla wrote: >>> Experts, >>> As we know for perfectly matched line insertion loss is due to ohmic& >>> dielctric losses and due to these losses we see loss in rise/fall time as >>> well as loss in amplitude of signal. >>> >>> My question is what actually affects amplitude loss, is it ohmic loss or >>> dielectric loss ? My understanding says, it should be ohmic loss as >>> it comes in series coz dielectric one is shunt loss. If this analogy is >>> correct then a channel having very low ohmic loss but significant >>> dielectric loss will have only changes in rise time but minimal amplitude >>> loss, right ?? >>> >>> Rajneesh >>> >>> >>> >>> -- >>> Steve Weir >>> IPBLOX, LLC >>> 150 N. Center St. #211 >>> Reno, NV 89501 >>> www.ipblox.com >>> >>> (775) 299-4236 Business >>> (866) 675-4630 Toll-free >>> (707) 780-1951 Fax >>> >>> All contents Copyright (c)2012 IPBLOX, LLC. All Rights Reserved. >>> This e-mail may contain confidential material. >>> If you are not the intended recipient, please destroy all records >>> and notify the sender. >>> >>> ------------------------------------------------------------------ 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 technical documents are available at: http://www.si-list.net List archives are viewable at: //www.freelists.org/archives/si-list Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu