Re: microstrip Patch antenna radiation pattern

[Kevin Thomas <kjt@cray.com>]

Ahmed,

I don't have an example using far field sweeps, but I can
give you some general directions.

First, read the "Far field conventions and tips" web page:
http://lc.cray.com/doc/far.html

Be sure that your model geometry is sufficiently distant from
the edge of the grid.  Usually you'll want free space all
around it, but in the case of a patch antenna with a ground
plane beneath it, a half space will do.

Sufficiently distant means about one wavelength, 10 to 20 cells.
The absolute minimum distance required is 5 cells, due to the
way that the far field is calculated.

You'll probably want to use the PML absorbing boundary conditions
(not the default Mur) to reduce the amount of non-physical reflection
from the grid boundary.

I don't know exactly what kind of pattern you're most interested
in, but the most basic would be a 360 degree sweep around the
antenna in the plane of the antenna, and a 180 degree sweep going
over the antenna, orthogonal to the plane (perhaps two 180 degree
sweeps orthogonal to each other).  For example, if your patch
lies in the Z-plane, with a ground plane below it, the first sweep
would be with Theta=90 and varying Phi from 0 to 360.  The second
sweep would be Phi=0 and Theta varying from 90 to -90, and the
third Phi=90 and Theta varying from 90 to -90.

Enabling sweeps takes both more memory and more computation, so
this is likely to be a large simulation.

-- 
Kevin Thomas    kjt@cray.com   tel 1-651-605-9072
http://lc.cray.com/~kjt/        or 1-800-284-2729 x6059072

Ahmed Taha wrote:
> 
> I'm a beginner with LC, so, Is there anybody experienced using far field
> sweeps?
> I need to get the radiation pattern of simple microstrip patch antenna, if
> you please give me one complete example .
> 
> Thanks