designing attenuator pads
You can calculate either a PI or T network. One will have more realizable values than the other depending on if you are building from lumped components, deposited as a thin flim, or thick film. If you are using lumped components you need to know to a degree the package parasitics since this will affect the attenuation over frequency. Capacitance in paralllel with the resistive material limits the amount of attenuation you can achieve. If designing a thin film then 2.5D EM simulation is very usefull.