Problem with ADS Simulation using real components

[avartta]

Hi.. I am trying to design an LNA at 2.45GHz and trying to achieve an S21 of 15dB S11 and S22 of -15dB. Initially when I performed the simulation using Agilent ADS using ideal capacitors and inductors I was able to achieve an S21 of 18dB, S11 of -14dB and S22 of 17dB. However, when I simulated them again using real murata capacitors and inductors I am only able to achieve an S21 of 4.7 dB and S11 and S22 of around -0.6dB. I am relatively new to this area and am unsure as to the why there is such a big difference in results. I have heard that this may be due to the parasitic effects. Is there any way in which I could improve the results?

 

[webdog]

Welcome to the REAL world
As you have discovered using "real" components things do differ from the ideal types.

Use good RF components, i.e. ATC or similar and run optimize to embed the stray capacitance/inductance. You shold acheive close to ideal after a few iterations.

Then, the real fun starts.... bulilding and realizing that your circuit still does not behave like within your computer

Ths is what makes analogue design such fun! True art!

Good Luck
/WD

 

[avartta]

Hihi.. Thanks a lot!! I have manage to improve my results by quite a bit!