Is there any design equation for conical horn antenna?

Is there any mathematical equation relating conical horn height,thickness of the cone, top and bottom radius of the cone with the frequency, if so could anyone suggest me where can i get it.

hi aswin,
link below might help you.

http://www.antenna-theory.com/antenn...rture/horn.php

hi pragash,
thanks for the response , i am looking for a conical horn type antenna, for which the parameters i have is the thickness, top and bottom diameter, height of the cone, operating frequency. hence with these parameters is there any equation .