bugfix timedomain,use  abs() [instead of nothing or real]
@@ -625,7 +625,7 @@ def ifft(x):
"""
Transforms S-parameters to time-domain bandpass.
"""
- return npy.fft.fftshift(npy.fft.ifft(x, axis=0), axes=0)
+ return npy.abs(npy.fft.fftshift(npy.fft.ifft(x, axis=0), axes=0))
def irfft(x, n=None):
"""
