You shouldn't really trust the files you find at distributors like Digikey. They are managing data for 100's of 1000's of parts, and sometimes they make mistakes. It's much better to go directly to the manufacturer website if you're looking for simulation models (or datasheets, footprint recommendations, etc.).
If you go to the page for this product at infineon.com and scroll down to the "Simulation" section, you will see they offer models for several different simulators:
It looks like Digikey offered only the second one of these files, probably meant for use with the Microwave Office simulator by AWR Software.
But if you download the file from Infineon with "SPICE" in its name, you will get a .LIB file that appears to be very basic SPICE (i.e. not using any of the commands that typically give compatibility issues between different SPICEs), and is very likely to work with LTSpice.