Anyone know how to translate "Planarspule Sensor" into Eng.

Hi, all

I'm now starting to do a project, it is about Planarspule Sensor, 
however as my broken German language I really want to find some English 
description about it, Could anyone translate "Planarspule Sensor" into 
English for me? Or if there is not a exact English word to describe it, 
could anyone explain a little bit for me?

Thanks a lot.

Cherry