How to model the PAD's effect and bonding wire effect?

I am using chartered0.25um process to design a PA.
How to model the pad's effect and bonding wire effect?
How large attenuation should be considered when designing matching circuit? Thanks for ur help!

Turn to the foundry for the parasitic values of PADs
Even more, you can simulatie the PAD with some EM Sim tools...such as HFSS or Momentum etc.