Hi guys and girls,
Ive got the following homework question ( i dont want answers just some help)

The drawing is attached but in case it doesn't work its a 2 port network with a 5 ohm resistor connected to each input and ground (in star fashion).

The question is, for the given z parameters for the 2 port network and with each resistor being 5 ohms show the whole circuit as a z parameter matrix.

My ideas on how to go about this

As a t network can be mapped as a 2 port network possibly its a configuration of 2 2port networks eg parallel parallel but im not sure how that would work as one network is literally inside the other.

Or do i just take the z parameter matrix and multiply by needed co efficients to take into account the series resistances for instance the input resistance would be as it is now + 5 ohm and v1 and v2 would be as they are now plus a voltage gained by inserting a 5 ohm resistor between the network and ground??

Please help im totally lost on this one!

 

You are aware that a tee network can be converted into a 2-port (described with Z parameters), so it must be possible to go the other way.

Let the 2-port be described as:

[ z11 z12 ]
[ z21 z22 ]

I would convert the z parameterized 2-port into a tee network. Then it's easy to add 5 ohms to each branch of the tee. Then convert back into a Z matrix.

 

Arrrrrgh i hate it when you cant see the wood for the trees and then some one comes and points out the blatently obvious Thank you very much!!