50 ohm matched microstrip TL

hello
what permittivity should i use to calculate the 50 matched line ?

permittivity (dk) max = 4.7 FR4 material

and permittivity @ 1.3 GHZ = 4.33 as n datasheet...

im workin in 1.3ghz band.....

FR4 1OZ copper 1/32 in thinckness

so using ultracad or any microstip calculator whats the permittivity should i use to measure the line width ? first or second ?


thanks n advance

I think you can use the second one just as in the datasheeet!