pcb dipole antenna

hello frindzz , i am trying to analyze half wave PCB dipole antenna using Designer or HFSS , the problem that length should be lambda/2 , but what lambda should be , let say that my design frequency was 1GHz , then should i take lambda=0.3 meters ?
if yes then , what width should i take for that dipole , i mean how it will affect my design ?!

A dipole is normally half wavelength, so the longest it will be is about 0.15m, while the shortest it could be is 0.15m/sqrt(Er). It will be somewhere in between since the near fields are contained in air and PCB dielectric. That is what you use a simulator to figure out! I suggest plotting Re(Z11) and Img(Z11), then adjusting length for Img(Z11)=0. The trace width will affect Re(Z11) and Img(Z11).

do you mean that i should use the simulator to do some kind of optimization to get my 'required' resonant frequency ?