How to determine the frequencies in which the L&C model of an artificial transmission line works?
How to determine the frequencies in which the L&amp;C model of an artificial transmission line works?


Since you're using ADS, simulate the s-parameters of one and simulate the s-parameters of the other. 

The frequencies where the results are the same (to whatever accuracy you choose) are the ones where you can use the LC model and get the same results as using a more complete model.

As mentioned in comments, the LC model you presented doesn't look much like we'd normally expect an LC transmission line model to look.

Also, you can always extend your LC model to work at higher frequencies by splitting it up into more pi or T sections. Here are two models for the same transmission line, but the one on the right will remain accurate to a higher frequency:







simulate this circuit &ndash; Schematic created using CircuitLab