Scattering transfer parameters
The t-matrix  is a 3-dimensional
numpy.ndarraywhich has shape fx2x2, where f is frequency axis. Note that indexing starts at 0, so t11 can be accessed by taking the slice t[:,0,0].
The t-matrix, also known as the wave cascading matrix, is only defined for a 2-port Network.
Returns: t – t-parameters, aka scattering transfer parameters Return type: complex numpy.ndarry of shape fx2x2