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Transfer Scattering Parameters Transmission line Question

Question asked by SOLT_guy on May 28, 2015
Latest reply on Jun 23, 2015 by SOLT_guy
Dear Sir:

     I am new to microwave fixture de-embedding and I am in the process of learning 

scattering transfer parameters T-parameters).   I have read conflicting accounts with 

regard to how transfer scattering parameters are defined.   For example, if you go to this 

link I have provided below and scroll down to the section entitled "scattering transfer parameters": 

[ http://en.wikipedia.org/wiki/Scattering_parameters ]

There one will see two equations that define the T matrix differently.   This is not the only 

example that I have read online where the T parameter matrix is defined differently.  There 

exist many definitions of T parameters. 

     Therefore, to avoid any confusion, the T parameter matrix equations that I will be 

referencing are found in Agilent Application Note 1364-1 (see Appendix for the reference 

equations).  For your convenience I have provided a link to this application note:

http://anlage.umd.edu/Microwave%20Measurements%20for%20Personal%20Web%20Site/5980-2784EN.pdf  ]

    I would like to be provided the 2x2 T matrix for two (2) lossless cables (each cable 

is a separate T matrix, cable 1 = 1/4 wavelength and cable 2 = 1/8 wavelength) connected to 

a fixture T matrix.  The two matrices are configured in this equation below:

{ Tmeasured } = { T-cable 1} * {T-fixture} * {T-cable 2 }* {T-load=Zo}

     If you see page 5 of AN 1364-1, a fixture is modelled as an ideal tline in a 2x2 S 

matrix in this form:

{ 0                      e^(-j*theta) }
{ e^(-j*theta)                 0      }

     I would like to be provided the 2x2 transmission scattering matrix (T-matrix) for each 

cable matrix, both, { T-cable 1 } and { T-cable 2 }, such that the multiplication of these 

matrices will be mathematically consistent with the { T measured } matrix found in the 

equation above. 

     Can someone please provide me with an explicit answer to this question in matrix form? 

 

      Thank you for your consideration.

Edited by: SOLT_guy on May 28, 2015 8:24 AM

Edited by: SOLT_guy on May 28, 2015 8:25 AM

Edited by: SOLT_guy on May 28, 2015 8:31 AM

Edited by: SOLT_guy on May 28, 2015 8:33 AM  

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