I have a modest-performance outdoor OTA antenna
Bidirectional "Swept-Wing" Antenna for Local TV Channels
Radio shack part number: 15-2181
It looks like a Frisbee with wings.

Well, the darned thing is amplified, and meant to work -with- your satellite dish, if ya have one.
To that end, it comes with two diplexers that pass power on both sides.
One side runs the LNB, and the other supplies power to the Frisbee.
I'm sure you can't buy the diplexers from R/S any more, but try SolidSignal.com
Or do a Google search. They're difficult to find and be sure you have the right animal.
Oh, and my Frisbee works with our without power, but much better with.