Spice- Frequency Dependent Resistance in transient.

[kilio]

I would like to know if there is any way to make a frequency dependant resistor for transient simulation in OrCad ( PSpice). I have some empirical data and I would like to use it .
Any help would be greatly appreciated.

 

[NickS]

Sort of. Frequency is a bit tricky because it is usually correlated with impedance which has a resistance and reactance component. The reactance changes with frequency but resistance does not. So to to simulate a change in resistance with frequency I am not sure on that but to change the impedance with frequency could be a simple as operating in the skirt(transition band) of a low pass single pole filter. The slope would be roughly 20dB/decade for voltage. The attenuation would increase with frequency but there would not be a DC resistance change. Is that something that could be molded into a solution or does it have to be resistance change alone?

Perhaps you could give a bit more info on what the changing resistance needs to do.

 

[kilio]

"

The reactance changes with frequency but resistance does not

Resistance changes with frequency in AC -- ex. skin effect.

 

[NickS]

But again this measurement is only possible at AC. So I ask again how do you plan on using it? If you are in the realm of simulating surface resistance then you are going to need a more powerful simulation tool like ADS or Microwave Office.

 

[Militoy]

Also - unless the conductor is straight - like an uncoupled trace on a PCB - proximity effect is likely to be as much or more of an issue than skin effect.