Antenna Scatterers Analysis Program

Source Code Description: Subroutine GFF


PURPOSE: to calculate the far-zone field of a sinusoidal electric monopole.

METHOD: If an electric line source has length d and endpoints at (x1, y1, z1) and (x2, y2, z2), then the coordinates of any point on the source are

x = x1 + l cos(x)

y = y1 + l cos(y)

z = z1 + l cos(z)

where cos(x), cos(y), cos(z) are the direction cosines of the l axis, and l is the distance along the source measured from the endpoint (x1, y1, z1). Let the current distribution on the monopole be:

gff1.gif 1.45 K

Where I1 and I2 are the endpoint currents. The far-zone field of this source is:

gff2.gif 2.07 K


gff3.gif 2.33 K

gff4.gif 2.50 K

and gff5.gif 0.95 K are the spherical coordinates of the observation point.

In this subroutine the range dependence has been suppressed. The far field vanishes in the endfire direction where GK=0. If a ground plane is present (IGRD > 0) the E1 equation above is decomposed into the x, y, and z components and the reflection coefficients are applied before Eq and Ef field components are returned to the calling program.



Return to System Manual

Goto User's Manual

See also the quick reference for the user's guide.

Goto Examples page

Goto Download Page

Return to ASAP Homepage

Last modified on: 3 Nov 2007