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.

Input Arguments

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

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

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

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

Port order, specified as 1, 2, 3 determines how the function orders the ports:

  • 1smm2s 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.

  • 2smm2s 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.

  • 3smm2s 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

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

Examples

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Convert between mixed-mode and single-ended S-parameters. Create mixed-mode S-parameters:

ckt = read(rfckt.passive,'default.s4p'); 
s4p = ckt.NetworkData.Data; 
[sdd,scd,sdc,scc] = s2smm(s4p);

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

s4p_converted_back = smm2s(sdd,scd,sdc,scc);
s4p_converted_back_new = s4p_converted_back(1:5)
s4p_converted_back_new = 1×5 complex

   0.0857 - 0.1168i  -0.5366 - 0.6860i   0.0957 - 0.0700i   0.0055 + 0.0051i  -0.5372 - 0.6804i

References

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

See Also

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Introduced in R2009a