i could use some help?!?!

[pzizi]

hello everybody,
i need to build a microstrip patch array antenna, build with 4 by 4 elements, it supposed to be for television reception at home , working between 478MHZ and 538MHZ. i'm using the IE3D simulation to try and find the proper sizes of each element and the measurments of the array and i'm pretty unsuccessful in finding the element measurments.
can anyone help me, please???[/b]

 

[mr_ghz]

Hi pzizi,

what exactly is the problem: Do you get dimensions, and if you try them
out (you build an antenna) they don't match or do you have problems
with the IE3D?

Bye

 

[pzizi]

thanks for answering so quickly,
my problem is that i don't know exactly which measurments to use (length, width and thickness), and the one that i use don't match at all.

hope you can help me.

 

[mr_ghz]

Hi pzizi,

First of all, I think you will get a problem with your patch-antenna to cover
the whole frequency-band from 478MHz .. 538MHz, because patches are
resonant antennas and have a small bandwith of a few percent.
To design such an antenna you have to choose first your base material.
This depends on the working frequency and the dimensions you will reach.
The higher the frequency, the better (and more expensive) the material
has to be. For 500MHz it's possible to use simple FR-4.
The thickness of the material gives the loss of the antenna and the band-
width. A would choose between 1 and 1.6mm.
Next you have to estimate the dimensions of the antenna. This can be
done with the simulation program (e.g. Ansoft Ensemble (student-version
is free)). The you have to optimize the size of your antenna for best
matching (S11). The feedpoint is not at an edge, so you can feed it
through a hole or make a transformer.
After you have designed one antenna, you can build your array. The
position of your single antennas will give you the directivity / sidelobes.
You have to place your single antennas and to combine them with feeding
network. They give the correct phase and impedance for each single
antenna.
After all you can etch the design, test it with a network-analyzer for
correct matching (dimensions) and in an antenna measurement box for
correct directivity....
I hope this will help a bit.

Bye

 

[pzizi]

thank you so much mr_ghz,
i've been very helpful to me and i will try to do that as soon as possible and hopefully, do it successfully.

thanks again,
pzizi