You may use any of the following adapters for a desktop system:
- Intel® Dual Band Wireless-AC 7260 for Desktop
- Intel® Centrino® Advanced-N 6205 for Desktop
- Intel® Centrino® Wireless-N 2200 for Desktop
All of them support Intel® WiDi, you can check the other supported features here:
Intel® Wireless Product Selection Guide
Just as a side note: At this moment, Samsung* TVs sold in the US have not passed Intel® WiDi certification. For that reason functionality could be limited; if you have question about this certification we would recommend contacting Samsung for details.