Can A Patch Ant. be modeled in EZNEC?
 

Can a Patch Antenna be modeled in EZNEC?
Do you make the flat plates with parrallel lines?
Or is there a function to give you a solid plate?
Mike

Can A Patch Ant. be modeled in EZNEC?
 

amdx wrote:
Can a Patch Antenna be modeled in EZNEC?
Do you make the flat plates with parrallel lines?

patches are tough to do a *good* job on with a MoM wire type code (such
as NEC, EZNEC, etc.).

A good start is to make a grid of wires, say, 21x21 wires, with the wire
diameter chosen so that the surface area is comparable to the gap (that
is, if the wires are d cm apart, the wire diameter would be d/pi cm.

Obviously, this breaks down horribly if your microstrip is spaced very
close to the ground plane and you use few wires.


You could also download Pozar's free microstrip patch program. PCAAD 2.1
from http://www.antennadesignassociates.com/
Old, DOS style, but works


Or is there a function to give you a solid plate?
Mike

Can A Patch Ant. be modeled in EZNEC?
 

On 14 ago, 02:11, "amdx" wrote:
Can a Patch Antenna be modeled in EZNEC?
Do you make the flat plates with parrallel lines?
Or is there a function to give you a solid plate?
Mike

Hello Mike,

As Jim wrote, Patch Antennas are tough with wire-based codes.

In NEC you are limited to Patch Antennas without a dielectric layer,
so deformation of the radiation pattern because of radiation from the
dielectric will not be shown.

I assume that you start with simulating above a perfect ground. In
that case start with grid size of about half the distance between
ground and your patch. Use a grid instead of parallel wires. Parallel
wires do behave different from a grid when you may expect current
flowing perpendicular to the wires (for example close to the feed
point).

Use a wire radius of about 20% of the grid size. This results in a
wire radius of 10% of the distance between grid and ground. Run your
simulations with varying grid size to evaluate the effect of grid size
on accuracy.

You may have a look at sonnet lite (www.sonnetusa.com) when you are
interested in input impedance and matching only. With sonnet lite you
cannot get radiation patterns as far as I know.


I hope this will help you a bit.

Best regards,

Wim
PA3DJS
www.tetech.nl

Can A Patch Ant. be modeled in EZNEC?
 

amdx wrote:
Can a Patch Antenna be modeled in EZNEC?

Only if there's no dielectric between the patch and ground plane. This
configuration is uncommon. There's no way for EZNEC or other NEC-based
program to account for the dielectric normally used.

Do you make the flat plates with parrallel lines?

Normally you would use a wire grid. The method is described in the manual.

Or is there a function to give you a solid plate?

No.

Roy Lewallen, W7EL

Can A Patch Ant. be modeled in EZNEC?
 

Roy Lewallen wrote:
amdx wrote:

Can a Patch Antenna be modeled in EZNEC?


Only if there's no dielectric between the patch and ground plane. This
configuration is uncommon. There's no way for EZNEC or other NEC-based
program to account for the dielectric normally used.

I haven't tried it, and it might have horrible other side effects, but
one might be able to use NEC4, and bury the ground plane slightly below
the surface, setting the soil properties to the dielectric properties.

Or, use insulated wires...