Ravenhill joined the Cobblers on loan from Bradford on a month-long deal in November and has so far made six starts for the struggling League Two outfit.
Town boss Aidy Boothroyd told the club's official website: "It's very good news. I think he's the type of guy who glues a team together.
"I'm really pleased to have got him and hopefully we'll get to January and even go a little bit longer, that'll be the ideal-case scenario for us.
"It's no accident that he's part of our upturn in form."
- Sports & Recreation
- Aidy Boothroyd