Hello All

Page 14 of Agilent Application Note -

parameters' from S-parameters.

Cascading of the two 2-port networks are is achieved by

multiplying the two 'Transfer parameters' matrices.

I need to cascade two 2-port networks -

measurement, that is for each network I have the following information

[ S11dd S12dd S11dc S12dc

S21dd S22dd S21dc S22dc

S11cd S12cd S11cc S12cc

S21cd S22cd S21cc S22cc ].

The following method is what I plan to use - Please ascertain this

From the given 4x4 matrix, create four 2x2 matrices, each one

having information about 'dd', 'dc' , 'cd' and 'cc' respectively. That

is, the following four 2x2 matrices results

(1) [ S11dd S12dd

S21dd S22dd]

(2) [ S11dc S12dc

S21dc S22dc]

and so on...

Now for each of these 2x2 matrices, compute the 'Scattering Transfer

parameters' . Let us call these M1,M2, M3 and M4

Similarly, compute the 'Scattering Transfer parameters' for the

second network. Let us call these N1,N2, N3 and N4.

Multiply the corresponding matrices to get the cascaded network.:

P1 = M1 * N1;

P2 = M2 * N2; and so on...

Thanks in advance

Partha

Page 14 of Agilent Application Note -

**AN154**- 'S-Parameter Design', Clearly specifies the equations to compute 'Scattering Transferparameters' from S-parameters.

Cascading of the two 2-port networks are is achieved by

multiplying the two 'Transfer parameters' matrices.

I need to cascade two 2-port networks -

**Differential**measurement, that is for each network I have the following information

[ S11dd S12dd S11dc S12dc

S21dd S22dd S21dc S22dc

S11cd S12cd S11cc S12cc

S21cd S22cd S21cc S22cc ].

**How do we cascade two such networks??**The following method is what I plan to use - Please ascertain this

From the given 4x4 matrix, create four 2x2 matrices, each one

having information about 'dd', 'dc' , 'cd' and 'cc' respectively. That

is, the following four 2x2 matrices results

(1) [ S11dd S12dd

S21dd S22dd]

(2) [ S11dc S12dc

S21dc S22dc]

and so on...

Now for each of these 2x2 matrices, compute the 'Scattering Transfer

parameters' . Let us call these M1,M2, M3 and M4

Similarly, compute the 'Scattering Transfer parameters' for the

second network. Let us call these N1,N2, N3 and N4.

Multiply the corresponding matrices to get the cascaded network.:

P1 = M1 * N1;

P2 = M2 * N2; and so on...

**Can I hope to get a meaningful result with this method?**Thanks in advance

Partha

If I may ask, are your a researcher, designer or student? Is your device active or passive. What are the relative sizes of the differential, common and cross mode gains. Why not just compute the single-ended S-parameters in two 4-port networks, dump it into ADS, then cascade the networks in ADS, and look at the results?