#### Hawaslsh

##### Full Member level 3

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Hello all,

I made some 2-port measurements using a a VNA and needed to deembed a length of transmission line. So i converted the S-parameters to ABCD, did the matrix math to remove the t-line then converted back to S-parameters.

I need to know know the input and output impedance so i converted the deembedded S-parameters to Z-parameters. For the longest time I thought Z11 and Z22 would represent my input and output impedance but I ran across:

Have I been interpreting Z11 and Z22 wrong all these years? Should I be using the equations above to solve for the input and output impedance?

Side question: If i had a one port network would Z11 be in the input impedance?

Bonus question: I just realized the method I am doing only deembedds a length of transmission line from port 1. I want to remove an identical length of line from port 2 but my matrix math is a bit rusty. Using ABCD matrices, the initial condition is [tline]~~[tline]=[measurement]. I can perform ~~~~[tline]=[tline]^-1*[measurement] to remove the tline from port 1, but how do I go about getting rid of the second tline?~~

Thanks in advance!

I made some 2-port measurements using a a VNA and needed to deembed a length of transmission line. So i converted the S-parameters to ABCD, did the matrix math to remove the t-line then converted back to S-parameters.

I need to know know the input and output impedance so i converted the deembedded S-parameters to Z-parameters. For the longest time I thought Z11 and Z22 would represent my input and output impedance but I ran across:

Have I been interpreting Z11 and Z22 wrong all these years? Should I be using the equations above to solve for the input and output impedance?

Side question: If i had a one port network would Z11 be in the input impedance?

Bonus question: I just realized the method I am doing only deembedds a length of transmission line from port 1. I want to remove an identical length of line from port 2 but my matrix math is a bit rusty. Using ABCD matrices, the initial condition is [tline]

Thanks in advance!

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