skrf.network.Network.gmm2se

Network.gmm2se(p, z0_se=None, s_def=None)[source]

Transform network from generalized mixed mode parameters [1] to single ended parameters.

Parameters:

  • p (int) – number of differential ports

  • z0_se (Numpy array) – f x 2*p x 2*p matrix of single ended impedances, optional if input is None, extract the reference impedance from the differential network calculated as 0.5 * (0.5 * z0_diff + 2 * z0_comm) for each differential port. Single-ended ports not converted to differential mode keep their z0.

  • s_def (str -> s_def : can be: 'power', 'pseudo' or 'traveling') – Scattering parameter definition: None to use the definition set in the network s_def attribute. ‘power’ for power-waves definition [2], ‘pseudo’ for pseudo-waves definition [3]. All the definitions give the same result if z0 is real valued.

Return type:

None

Examples

In following examples, sx is single-mode port x, dy is differential-mode port y, and cz is common-mode port z. The low insertion loss path of a transmission line is symbolized by ==.

2-Port diagram:

  +-----+             +-----+
0-|s0   |           0-|d0   |
  |     | <=gmm2se=   |     |
1-|s1   |           1-|c0   |
  +-----+             +-----+

3-Port diagram:

  +-----+             +-----+
0-|s0   |           0-|d0   |
1-|s1   | <=gmm2se= 1-|c0   |
2-|s2   |           2-|s2   |
  +-----+             +-----+

Note: The port s2 remain in single-mode.

4-Port diagram:

  +------+               +------+
0-|s0==s2|-2           0-|d0==d1|-1
  |      |   <=gmm2se=   |      |
1-|s1==s3|-3           2-|c0==c1|-3
  +------+               +------+

5-Port diagram:

  +------+               +------+
0-|s0==s2|-2           0-|d0==d1|-1
1-|s1==s3|-3 <=gmm2se= 2-|c0==c1|-3
  |    s4|-4             |    s4|-4
  +------+               +------+

Note: The port s4 remain in single-mode.

8-Port diagram:

  +------+               +------+
0-|s0==s2|-2           0-|d0==d1|-1
1-|s1==s3|-3           2-|d2==d3|-3
  |      |   <=gmm2se=   |      |
4-|s4==s6|-6           4-|c0==c1|-5
5-|s5==s7|-7           6-|c2==c3|-7
  +------+               +------+

2N-Port diagram:

     A                                  B
     +------------+                     +-----------+
   0-|s0========s2|-2                 0-|d0=======d1|-1
   1-|s1========s3|-3                 2-|d2=======d3|-3
    ...          ...    <=gmm2se=     ...         ...
2N-4-|s2N-4==s2N-2|-2N-2           2N-4-|cN-4===cN-3|-2N-3
2N-3-|s2N-3==s2N-1|-2N-1           2N-2-|cN-2===cN-1|-2N-1
     +------------+                     +-----------+

Note: The network A is not cascadable with the ** operator along transmission path.

References

See also

se2gmm