Looking for calibrated antenna for 2.45GHz

Where can I get this calibrated antenna for 2.45GHz ?
Thank you in advance !
Ted

M I Technologies has an extensive line of standard gain horns.

do you want to build from scratch, get a kit, or buy one.

please be more specific

Azulykit,
Thank you very much for your answer.
I went to their website and seems very nice and documented.
I am going to contact them Monday morning.
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Ultrabrains,
Yes, indeed I am looking to build myself the anechoic chamber rather than looking and waiting 10 years for money spending approval for this expensive tool to buy from a professional supplier.
I have already the anechoic box ( 7' X 3' X 3' ) and I am struggling in finding a good calibrated antenna and I hope somebody at work will help me building a software in "labview" to control a "home made" positioner and the spectrum analyzer in colecting data.
The antenna I am going to test is not big ( range of 24mm square ).
I really appreciate any help regarding this "crazy" adventure called: anechoic chamber calibration. If I am going to fail, a lot of people will be "mad on me" and I don't want it to happen.
Thanks again in advance for any good idea.
I will really appreciate any help.
Have a very nice day.
Ted

Hi HS,

I saw your note. Thanks.

You might want to consider setting up an outdoor range and bypass the complexity and cost of an anechoic chamber. If you have a flat roof or open field available that might be a more practical (e.g. faster and less expensive) solution.

The chamber you have in mind might be a little small as absorber in that band is on the order of 6 to 12" thick. That does not leave much room inside. I wouldn't expect much from a 24 mm antenna at 2.4 GHz, you probably need closer to 75 mm.