MMWave Pad Design and Simulation

Hello,

I want to make PADS for my MMWave Layouts that are not included in my PDK - I want to use a GSG set up.

For DC Signal and GND pads, should I use many metal layers down to the substrate attached with many vias to lower contact resistance ?

For the RF Signal PAD, I am confused. Some papers say only use top metal for this RF Signal Pad while others say you need more than top metal (say three metals) to get the proper mechanical integrity for the pads.

For the RF GND Pads, are they similar to the DC GND Pads, or are they different with different considerations ?

Finally is there a good reference on Microwave to MMWave DC/RF Pad Design for CMOS or SiGe ?

Finally, I should EM Simulate all of these to verify their parasitics and lumped models, correct ?

Thank you.