How do I connect a 1-port network as termination?

Hello,

I would like to attach a 1-port network as a termination to the second port of a 2-port network, i.e. cascading the two and then look at S11 at port 1 of the 2-port network.

I am unable to do so as all the cascading functions work with 2-port networks only and I cannot figure out how to solve this issue.

Thank you for your help.

Answer 1

[Joe Wargo]

Hello Alessandro,

You can use the cascadesparams() function. By default, cascadesparams cascades two port networks (or 2N-port networks), but can also be used to generically connect networks together. For the whole documentation, see:

    doc cascadesparams

Here's a few examples to get you started:

(1) If your data is in files, let's assume the two-port data is in 'foo.s2p' and the one-port data is in 'bar.s1p'. Do the following:

    S2 = sparameters('foo.s2p');
    S1 = sparameters('bar.s1p');
    Sfinal = cascadesparams(S2,S1,1);

It is important to note that, for this to work, the frequencies and impedances in the s2p file must match those in the s1p file. If you would like to visualize the resulting S11 data:

    rfplot(Sfinal,1,1)

If you would like to access the numeric values of the S11 data:

    s11 = rfparam(Sfinal,1,1);

(2) If your data is in variables, let's assume your two-port data is stored in a 2x2xK variable named data2, and your one-port data is stored in a 1x1xK variable named data1. Then:

    datafinal = cascadesparams(data2,data1,1);

I hope this helps!

Joe

Answer 2

[Alessandro Aimone]

Thank you very very much! I somehow missed it as in the help it states all networks should have same number of ports.

Thank you again