Modeling Slot Antenna
 

Would someone mind explaining how I would model a Slot antenna ?
I am using EZNEC.

My initial assumption is that I create 4 planes to represent the metal
and leave the appropriate gap to represent the slot ?

I am also not sure how to make the feed point attachment.

Thanks in advance

Regards

David Huisman

Modeling Slot Antenna
 

On Mon, 11 Sep 2006 03:11:11 GMT, David
wrote:

Would someone mind explaining how I would model a Slot antenna ?
I am using EZNEC.

My initial assumption is that I create 4 planes to represent the metal
and leave the appropriate gap to represent the slot ?

I am also not sure how to make the feed point attachment.

Hi David,

Presuming you've accurately modeled both the surfaces, and the slot,
you feed across the narrow middle of the slot. The polarization is at
right angles to the slot.

73's
Richard Clark, KB7QHC

Modeling Slot Antenna
 

Richard,

I have not accurately modelled the surfaces. My question is how do I do
this.

Regards

David Huisman

Richard Clark wrote:
On Mon, 11 Sep 2006 03:11:11 GMT, David
wrote:

Would someone mind explaining how I would model a Slot antenna ?
I am using EZNEC.

My initial assumption is that I create 4 planes to represent the metal
and leave the appropriate gap to represent the slot ?

I am also not sure how to make the feed point attachment.

Hi David,

Presuming you've accurately modeled both the surfaces, and the slot,
you feed across the narrow middle of the slot. The polarization is at
right angles to the slot.

73's
Richard Clark, KB7QHC

Modeling Slot Antenna
 

On Mon, 11 Sep 2006 07:16:18 GMT, David
wrote:

I have not accurately modelled the surfaces. My question is how do I do
this.

Hi David,

Build a mesh with intersections smaller than a tenth of a wavelength
apart.

73's
Richard Clark, KB7QHC

Modeling Slot Antenna
 

Let me simplify the highly detailed explanations you have received...
1. Model the slot as a rectangle/loop antenna of fine gauge wire.
2. Model the outside edges of your antenna as another rectangle/loop
antenna.
Fill in the area between the two rectangles that is solid metal with a
criss cross of connecting wires.
3. Create a transmission line to feed the two long edges of the slot at
mid point...
4. Be aware that Mininec engines are going to be a bit iffy with this
kind of structure... But at least you get some ball park figures..

denny / k8do

Modeling Slot Antenna
 

Another thought: there were a series of antennas,
in the late '60's-early '70's , for vhf (Mainly
2 Meters), called "Skeleton Slots" (think by "J"
beams). These consisted of stacked yagi antennas,
fed by the equivalent of a slot antenna ,Driven el
portions at the narrow's top and bottom, to
each yagi. The (rectangle) fed in the middle at
the narrow center, as you would a traditional slot
antenna .
(I am NOT claiming that this was the most
effecient, just noteing it as it seemed to work
for Stacking yagi pairs ).
Might, therefore try a rectangle version of a quad
element, fed at the narrow center. Tho dont know
how much deteriation would be from the slot in an
infinenate field , possible to use as a simplified
model ?? Might give it a try ?? Jim NN7K

Denny wrote:
Let me simplify the highly detailed explanations you have received...
1. Model the slot as a rectangle/loop antenna of fine gauge wire.
2. Model the outside edges of your antenna as another rectangle/loop
antenna.
Fill in the area between the two rectangles that is solid metal with a
criss cross of connecting wires.
3. Create a transmission line to feed the two long edges of the slot at
mid point...
4. Be aware that Mininec engines are going to be a bit iffy with this
kind of structure... But at least you get some ball park figures..

denny / k8do