Hi Peter,

Thank you so much for the reply. I will try the HFSS circuit model you mentioned. 

I am still curious to know why there is a difference in the results between the case with lumped RLCs and lumped ports. I set up the lumped ports by using rectangular sheets. I used Assign Excitation > Lumped port and then drew the integration line along the path of current. I did a similar procedure for lumped RLCs by using Assign Boundary > Lumped RLC and then provided a value to the resistor/capacitor. The figure below shows the rectangular sheets (green) used for the boundary conditions/excitation. The long one is a resistor and the short one is a capacitor. I am curious about this because I do not think it is the problem with ADS. I suspect that this difference in the results come from the HFSS simulations itself. The main problem is that lumped ports simulation on HFSS will not generate any meaningful results that we can analyse. The results can only be verified after importing the snp files to a circuit simulator. 

Is there something wrong with my setup? Anything to be modified and tried?

Lumped ports