The geometry is presented below. It is a wire HF monopole antenna over a ground screen. In the monopole is a cone to improve the bandwidth of the device. The cone and its ground plane are simulated with 12 wires.
This calculation involves the computation of the Sommerfeld integrals.
First create a line :
(30,0,0) => (0,0,0) => (0,0,1) => (8,0,20) => (0,0,20)
Use the GiD copy tool to duplicate this line and create the body the monopole and the disk of its ground screen :
Assign a radius of 1 cm to all the created wires :
Divide into two parts the small wire at the junction between the monopole and its ground screen :
Assign a voltage source to the created point :
Define a lossy gound :
Set a radiation pattern output for the upper half space :
Check the settings :
Set a frequency range from 3 to 20 MHz :
Mesh, save and run
Computed far field pattern at 3 MHz :
Computed far field pattern at 8 MHz (the scale of the 3D pattern is the same over the whole frequency range, in order to easily compare all the frequencies) :
The computed surface wave pattern (mainly located in a plane parallel to the ground plane) :
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