Technical Notes > Radiated Fields > Antenna Parameters           

Decay Factor

When Global Environment Material is lossy, strictly speaking, the far field is zero, since the Green’s function is:

(1)

where

(2)

Against that fact, HFSS calculates the far field using the imaginary part of vector k.

You can then modify the magnitude of the field pattern by using the real part (a) of the propagation constant, which is displayed as “Decay Factor)