improving directivitiy

[anemmalu]

hiii

i have designed a bulky coil antenna ...and i got it cased in a box recently... i would like to know how i can improve the directivity of the antenna?

would something like an aluminium foiling (in the shape of an inverted funnel or a horn) over the case deliver better directivity? is there a way by which we can improve the directivity with just one antenna? would changing excitation point improve it?

regards
anem

 

[N_Jay]

hiii

i have designed a bulky coil antenna ...and i got it cased in a box recently... i would like to know how i can improve the directivity of the antenna?

would something like an aluminium foiling (in the shape of an inverted funnel or a horn) over the case deliver better directivity? is there a way by which we can improve the directivity with just one antenna? would changing excitation point improve it?

regards
anem

Does your antenna follow any of the classic designs?

 

[k9rzz]

What frequencies are we talking about?

Any pics online you can direct us to as to just what kind of 'coil' antenna this is? I can think of several different kinds.

John k9rzz

 

[anemmalu]

@N Jay & k9rzz

http://buyrfid.com/catalog/product_...d/176?osCsid=ebc9e99e4cb37d1a4f79ab488a6db735

I ve tried to arrive at the best match with this antenna operating at 915 MHz in terms of VSWR ....So, now my antenna would appear like the one above (but for the company label :- ) While this product employs a bistatic antenna which would mean it does both tx nd rception.....but whatever it be..i could observe that my antenna lobe patterns had a very broad principal beam and i would like to narrow it down...what should i do?