skrf.network.Network.extrapolate_to_dc¶

Network.
extrapolate_to_dc
(points=None, dc_sparam=None, kind='rational', coords='cart', **kwargs)[source]¶ Extrapolate Sparameters down to 0 Hz and interpolate to uniform spacing.
If frequency vector needs to be interpolated aliasing will occur in timedomain. For the best results first frequency point should be a multiple of the frequency step so that points from DC to the first measured point can be added without interpolating rest of the frequency points.
Parameters:  points (int or None) – Number of frequency points to be used in interpolation. If None number of points is calculated based on the frequency step size and spacing between 0 Hz and first measured frequency point.
 dc_sparam (class:numpy.ndarray or None) – NxN Sparameters matrix at 0 Hz. If None Sparameters at 0 Hz are determined by linear extrapolation.
 kind (str or int) –
Specifies the kind of interpolation as a string (‘linear’, ‘nearest’, ‘zero’, ‘slinear’, ‘quadratic, ‘cubic’) or as an integer specifying the order of the spline interpolator to use for scipy.interp1d.
kind = ‘rational’ uses interpolation by rational polynomials.
d kwarg controls the degree of rational polynomials when kind is ‘rational’. Defaults to 4.
 coords (['cart','polar']) –
 coordinate system to use for interpolation.
 ’cart’ is cartesian is Re/Im
 ’polar’ is unwrapped phase/mag
Passed to
Network.interpolate()
Returns: result – Extrapolated Network
Return type: See also