FDTD OF quasi array of two elements

hi...i would like to check with you how do you convert from using espr6.15 from your 2 elements deisgn to espr of 10.2, if all other design parameters are kept constant? to what i understand is that if i keep the espr constant, i can change my deisgn lineraly scaled with varying frequencies. Do correct me if i am wrong. thanks.

u right,if u change epsr means all design differ but nearly global one means driver length near lamda/2 and so on here is paper on yagi antenna design step ,search about it in site
regards