smm2s

Convert mixed-mode 2N-port S-parameters to single-ended 4N-port S-parameters

Syntax

s_params = smm2s(s_dd,s_dc,s_cd,s_cc)

s_params = smm2s(s_dd,s_dc,s_cd,s_cc,option)

Description

s_params = smm2s(s_dd,s_dc,s_cd,s_cc) converts mixed-mode, N-port S-parameters into single-ended, 2N-port S-parameters, s_params. smm2s maps the first half of the mixed-mode ports to the odd-numbered pairs of single-ended ports and maps the second half to the even-numbered pairs.

s_params = smm2s(s_dd,s_dc,s_cd,s_cc,option) converts the S-parameter data using the optional argument option. You can also reorder the ports in s_params using the snp2smp function.

Examples

Mixed-Mode S-Parameters to Single-Ended S-Parameters

Convert between mixed-mode and single-ended S-Parameters.

Create mixed-mode S-Parameters:

S = sparameters('default.s4p'); 
s4p = S.Parameters;  
[sdd,scd,sdc,scc] = s2smm(s4p);

Convert them back to 4-port, single-ended S-Parameters.

s4p_converted_back = smm2s(sdd,scd,sdc,scc);

Display the single-ended S-Parameters at the first frequency.

s4p_converted_back_new = s4p_converted_back(:,:,1)

s4p_converted_back_new = 4×4 complex

   0.0857 - 0.1168i  -0.5372 - 0.6804i   0.0966 - 0.0706i   0.0067 + 0.0053i
  -0.5366 - 0.6860i   0.0803 - 0.1234i   0.0059 + 0.0048i   0.0977 - 0.0703i
   0.0957 - 0.0700i   0.0067 + 0.0048i   0.0818 - 0.1104i  -0.5362 - 0.6838i
   0.0055 + 0.0051i   0.0972 - 0.0703i  -0.5376 - 0.6840i   0.0761 - 0.1180i

Input Arguments

s_cc — S-parameters

array

S-parameters, specified as a complex N-by-N-by-K array containing K matrices of common-mode, N-port S-parameters (S_cc).

s_cd — S-parameters

array

S-parameters, specified as a complex N-by-N-by-K array containing K matrices of cross-mode, N-port S-parameters (S_cd).

s_dc — S-parameters

array

S-parameters, specified as a complex N-by-N-by-K array containing K matrices of cross-mode, N-port S-parameters (S_dc).

s_dd — S-parameters

array

S-parameters, specified as a complex N-by-N-by-K array containing K matrices of differential-mode, N-port S-parameters (S_dd).

option — Port order

1 (default) | 2 | 3 | scalar

Port order, a scalar, specified as 1, 2,or 3. Port order determines how the function orders the ports:

• 1 — smm2s maps the first half of the mixed-mode pairs to odd-numbered pairs of single-ended ports and maps the second half to even-numbered pairs. For example, in a mixed-mode, 4-port network:

  • Port 1 becomes single-ended ports 1 and 3.

  • Port 2 becomes single-ended ports 5 and 7.

  • Port 3 becomes single-ended ports 2 and 4.

  • Port 4 becomes single-ended ports 6 and 8.

  

• 2 — smm2s maps the first half of the mixed-mode pairs to single-ended ports in ascending numerical order, followed by the second half, also in ascending order. For example, in a mixed-mode, 4-port network:

  • Port 1 becomes single-ended ports 1 and 2.

  • Port 2 becomes single-ended ports 3 and 4.

  • Port 3 becomes single-ended ports 5 and 6.

  • Port 4 becomes single-ended ports 7 and 8.

  

• 3 — smm2s maps the first half of the mixed-mode pairs to single-ended ports in ascending numerical order. The function maps the second half to pairs of ports in descending order. For example, in a mixed-mode, 4-port network:

  • Port 1 becomes single-ended ports 1 and 2.

  • Port 2 becomes single-ended ports 3 and 4.

  • Port 3 becomes single-ended ports 8 and 7.

  • Port 4 becomes single-ended ports 6 and 5.

  

Output Arguments

s_params — S-parameters

array of complex numbers

S-parameters, returned as a 2N-by-2N-by-K array of complex numbers representing K single-ended, 2N-port S-parameters.

References

[1] Granberg, T.,.Handbook of Digital Techniques for High-Speed Design.Upper Saddle River, NJ: Prentice Hall, 2004.