How to bend a plane I modified? I've used a plane to model this:





I want it to bend but when I add a "Simple Deform" modifier and I select "bend", here's what I get: 



As you can see only some of the faces are going to be bend. 

Q: What can I do to bend the geometry as a whole?
I just needed to put it on the Z axis, apply then rotate it. Found the answer on this video (at 3:45) while searching for a solution.