How to reference a patent with BibTeX?

The 'traditional' BibTeX styles do not include an entry type for patents. As such, any entry of the form

@patent{...

will be treated as a misc entry. The formatting that results, may well not be what you want, so I would recommend doing things 'by hand' using the misc type and howpublished field.

[Some styles do recognise patents. The exact details of the fields supported vary a bit, so it's best to consult the appropriate documentation.)

I would also recommend creating your own misc entry on BibTeX and populating the howpublished field with your patent's pre-print URL if possible. The website bibtex.online can convert online your BibTeX entry/ies to formatted text in other formats: APA, MLA, Chicago, etc.

For instance: