Non-lumped resistor in CST Microwave Studio.

[deadsoulf]

Hi everyone!

Could you help me with the following question: how can I make a non-lumped resistor in CST MWS? I have to simulate a thin-film resistors in my microstrip design, but when I use standart option of setting a material options (electric conductivity & mue for Lossy Metal type) - I cannot get a valid simulation results according to a real desing measurement. I tried to set that thin-film resistor as a 'Ohmic sheet' also.

I start with a most simple thing - a microstrip (Z=50 Ohms), powered within a waveguide port and finished with a 50 Ohm thin-film resistor. So, VSWR must be little more than 1 in a wide frequency range. But still I can't get an adequate simulation results.

I attach my projects downwards.

P.S.: I simulate within both a Time Domain and a Frequency Domain solvers.
View attachment Planes_for_forum.rar

 

[prafuldeo]

Hello,

Have you tried to put a waveguide port at other end too, instead of lump resistance? If your microstrip is 50 ohms then second waveguide port should behave as a 50 ohm termination. You may assign souce as port 1 in TD / FD solver.

Regards

Praful

 

[deadsoulf]

Thank's, Praful!

Yes, of course I tried such a way of solving my problem and got a near-real results. But I also have a 100 Ohm serial thin-film resistors in my design and I still don't know how I should define them.