antenna fabrication issues

hi ,if any antenna designer helped me in understanding one thing , i have simualted antenna on substrate of dimensions 26*26 mm while for impedance transfer i have take a balun of dimension 10*40mm now i am not sure either my structure will remained balanced when i will attach my balun with my antenna, bkz i saw some one has add an extra portion to balun to making it equal to substrate dimension? i have attached a pics of both sitaution, anyone who has used balun and antenna plz do guide me, thanks