AnsweredAssumed Answered

50 ohm lines

Question asked by AGLATFELTER on Feb 17, 2005
Latest reply on Mar 2, 2005 by ALEPEREZ
A 50 ohm microstrip line (0.7 mils thick) on a 20 mil substrate (Er=3.7, Tand=0.008) calculates to be 42.5 mils at 1 GHz in Linecalc. A similar line constructed in momentum shows that 44 mils wide has much better return loss.

Similarly, a 50 ohm line on a 10 mil substrate calculates to be 21 mils wide in Linecalc, while a 24.5 mil line has much better return loss in momentum.

Both lines were 1 inch long, terminated in 50 ohms.

My momentum simulations for 50 ohm lines are not matching up with my linecalc calculations.

Which one should I believe?