Build a circuit according to a Zero-Pole plot.

Thread Starter

omar-rodriguez

Joined Jun 24, 2015
67
Hello, I have to find a circuit that meets the following Zero-Pole diagram of a imput impedance:


The impedance evaluated at s= 0 is:

Z(0)=1.8k Ohm

Poles at:
P1=2.58*10^6j
P2=-2.58*10^6j
Zeros at:
C1=-2.78*10^5+2.57*10^6j
C2=-2.78*10^5-2.57*10^6j

The only clue I have is that the circuit has a resistor, a capacitor and a coil, but I don't know the topology.

I think that if the poles are imaginary conjugates then the answer has to be without loss or oscillatory, but I'm not sure, the input impedance could be this way

 

shteii01

Joined Feb 19, 2010
4,644
Your Zin(s) has s factored out. That is a problem because:
- Z capacitor is \(\frac{1}{sC}\)
- Z of inductor is sL
As you can see s is not factored out, so you have to rewrite your Zin(s) in such a way that you would have sL and \(\frac{1}{sC}\) in it. Once you rewrite it, you will see where you have capacitor and where you have inductor.
 

Thread Starter

omar-rodriguez

Joined Jun 24, 2015
67
Using MATLAB, I found that I can rewrite the equation as follows:

but it doesn't help much, I was seeing if there is any similarity with the input impedance of this circuit
 
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