How to import CST or HFSS result into Cadence Spectre?

Hi!
I am new to RFIC design. I wanna do a simulation for a whole RF transceiver including the antenna and the wave propagation.
If I design an antenna in CST or HFSS. How can I import their result inot Cadence spectre?
If without the sepecific character data of antenna, I think I cannot make sure that my transceiver can work well.

Use S-parameter of Touchstone format.
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