The Jacob Shekel circuit analysis method - Need help from The Electrician!

Thread Starter

bitrex

Joined Dec 13, 2009
79
I was reviewing the method of circuit analysis that The Electrician sent me some files about a while back, using admittance matricies. Unfortunately, I'm somewhat confused about how the admittance matricies for the transistors in a circuit were developed - if The Electrician is around, could you walk me through how the matricies for the transistors were derived in the following: http://forum.allaboutcircuits.com/attachment.php?attachmentid=11648&d=1250840496

I have a PDF specifically on the topic that you sent me, but unfortunately some of the figures in it are hard to read from the scan and I'm having a difficult time translating the matricies given in the document into the ones you derived, regardless.

Thanks in advance.
 

Jony130

Joined Feb 17, 2009
5,186
Well, here you have matrix for CE amplifier

\(Y = \left[ \begin{array}{2}\frac{1}{h11} & \frac{-h12}{h11}\\ \frac{h21}{h11} & \frac{h11*h22-h12*h21}{h11}\end{array}\right]\)

And
H11 = (β+1)*re
H21 = β
H22 = ro
H12 = ?? I don't know

And if emitter in not grounded the re need to be add.

So
1/H11 = 1/(β+1)*re

H21/H11 = β/(β+1)*re
And so on.
 

Thread Starter

bitrex

Joined Dec 13, 2009
79
Thank you! To use this method it looks like I need to know the h parameters of a transistor in its various configurations - common emitter, common base, etc. Is there somewhere I can find such a list?
 

The Electrician

Joined Oct 9, 2007
2,803
Thank you! To use this method it looks like I need to know the h parameters of a transistor in its various configurations - common emitter, common base, etc. Is there somewhere I can find such a list?
You can just do what I mentioned in the first image above, where I say:

"Now that we have an indefinite matrix, we can get the definite matrix for the circuit with a different node grounded. Just delete the row and column corresponding to the node to be grounded"

So, you can start with, for example, the definite matrix of a common emitter configuration, convert it to an indefinite matrix and then delete the node corresponding to the base and you will have a 2x2 definite matrix for a common base configuration.
 
Top