Chances are good that you searched the Web using the expression " ham radio antenas " and you landed here!
Luckily (or should I say intentionally!;-) this page of my Web site is part of a section about ham radio antennas.
I created it to help you get the information you are looking for ... assuming, of course, that you are looking for info on amateur radio antennas.
Antenna is written with two "n"s in English.
But, you may be of a country where the native language spells antenna as "antena".
Out of curiosity, I used Google Translate to find the many languages of the world that spell antenna as "antena". Here are some of them.
Spanish
Portuguese
Polish
Catalan
Latvian
Lithuanian
Slovenian
Slovak ("anténa" with an acute accent on the "e")
Welsh
It is perfectly understandable that you could have slipped into your native language when you spelled out your search expression on Google or some other search engine.
On the other hand, you may just have simply misspelled the English word.
The important thing is that you have landed on my Web site where you will find some very useful information about amateur radio antenas ... er ... antennas! ;-)
You can start browsing around the section dedicated to antennas by clicking on this link, or by clicking on one of the links in the Table of Contents located in the upper right column of this page.