Re: SPICE - Frequency dependent resistor model

On 26 Feb 2006 17:38:22 -0800, aravindalwan@xxxxxxxxx wrote:

Hi,

I would like to know if there is any way to include a resistor with
frequency dependence in SPICE. Specifically, I am looking for some
spice element that has a voltage current relationship given by

V / I = k * (w ^ 2) where k is a constant and w is the angular
frequency

I'm working on an electroacoustical model of a microphone. For those
who are not familiar with this, electroacoustic circuits are equivalent
analog electical models of acoustic devices. Different acoustic
elements are transformed into equivalent resistances, capacitances,
etc. So please note that the resistance that I refer to is NOT a real
electrical resistance. It is just an equivalent model.

I tried looking into all the user manuals that I could lay my hands on,
but am unable to find anything that I can use. I am an absolute newbie
when it comes to SPICE, so I'm not even sure if this can be done in
SPICE at all. I would be grateful if you could either tell me how to do
this or tell me where I may find this information. Any help would be
greatly appreciated.

Thanks,

Aravind

You can use Laplace transforms to make frequency dependent resistors
for AC simulations. See
http://www.ecircuitcenter.com/Circuits/vc_resistor1/vc_resistor1.htm
for ideas on making resistors out of voltage and current sources. I
like using current sources to make variable resistors. Some flavors of
Spice (LTspice and PSpice come to mind) allow you to use Laplace
transforms in the E and G devices.

---
Mark
.