AutoCAD 2017 has added the ability to import a PDF as vector objects and not just as a raster PDF underlay added back in AutoCAD 2007. Customers have been asking for a longtime for this feature but there has been concerns since published data can have inherent inaccurate scales and a few other issues. Autodesk chose to look at the requests from customers in order to define the needs and took a couple years in development.
So now in AutoCAD 2017 you can import a PDF as an underlay object in your AutoCAD drawing.
PDF is on the standard Import file type list to import much like importing a DGN.
Click the Insert tabImport panelImport or use the command PDFIMPORT
After selecting the PDF file to import you get the Import PDF dialog. You have the ability to specify settings on Insertion point, rotation, and scale in addition to the setting how the geometry is imported like as a block or covert solid fills to hatches.
Importing a DWG will be far more accurate with native objects, but if you need to get geometry from a PDF you can do that with AutoCAD 2017.
For more details and suggestions on importing PDF files into AutoCAD 2017 read Autodesk’s Dieter Schlaepfer’s post: AutoCAD 2017 PDF Import: Guidance for Working with PDF and AutoCAD DWG Data