My last name is roughly pronounced as /Qobaadi/.
The earlier forms of Ghobad was "Kuaz", then it turned to "Kuad", then "Kobad" and then "Ghobad".
Some languistics beleive that, this word come from a language in the north of IRAN. Maybe Siberian language. The word (Koaz) means "The King".

Historically, Ghobad was the name of nineteenth Sassanid king of Persia, reigning from 488 to 531.