Switch Simulation in CST

[Akbar Ali]

I am working on frequency reconfigurable antennas and simulating design in cst. I am facing problems in simulation of pin diode like dimension of pin diode, width of connecting strips...etc.
Plz see this attachment and help me to simulate switch.

 

[johnjoe]

Hi,

pictures are quite small, did you placed a port between the lead pins of your diode? If yes, you can include a model in the cst schematic editor and simulate or structure.

 

[Akbar Ali]

Thank you johnjoe for your reply. But I coudn't get your point. Actually I am using BAP64-02 silicon PIN diode & its size is nearly 2mm. So I just left 2mm space between two ends of antenna and directly put lumped network element over it and assign it RLC values.
I want to know is it right way to do?
**broken link removed**

 

[johnjoe]

Could not get your attachment. Lumped network element is not correct, because your diode is nonlinear. Place your ports on both sides and add in the schematic window a model between both ports and run your simulation.

 

[Akbar Ali]

If you have any design simulating switch then plz send me. Because I don't have any idea of schematic window.

 

[johnjoe]

At the moment I don't have any templates, but have a look in the manual and search for microwave studio co-simulation.

 

[Akbar Ali]

Thank you for this suggestion, it nearly resolve my problem. One thing more, I want to use spice model of diode but I couldn't get that file which is imported in spice model block.

 

[johnjoe]

You have a spice model file for your diode?

 

[Akbar Ali]

In CST DS help I found that " commercial SPICE simulators such as HSPICE, PSPICE, LTSPICE, etc. are not supported.This type of block imports a circuit from a file in Berkeley SPICE syntax.

I don't know how to draw spice model in berkeley syntax and where to draw.

 

[johnjoe]

I attached you a site of howto WRITE spice models, you save it as text file and attach the file into the schematic.

https://www.seas.upenn.edu/~jan/spice/spice.overview.html

 

[volker@muehlhaus]

Lumped network element is not correct, because your diode is nonlinear.

For PIN diodes used as a switch, it would be reasonable to simply use R for the "closed" state and C for the "open" state, instead of a non-linear model.