The antennas in the drone itself are in the front legs. I don't know if there's a way to source just the antenna, but if you're a DIY sort of person you can get replacement arms online for a reasonable price.
The controller antennas are also different. They look similar though, so if you're replacing the controller antennas, make sure you get the right ones! They're a bit harder to find, but it looks like there are some options on Ebay for parts like that.