For an education on the subject Bing search for HD antenna videos
There are several videos showing how to make such an antenna.
I have one I carry in my RV. In a campground near Ft worth it received 58 channels.
The problem is if you are distant, 25 miles or so) they must be high and may be directional
The dirty little secret is your grandpa’s old TV antenna works too. HD Antennas are nothing new but the manufacturers want you to think so.
“HD antenna” is a marketing term. The signals are still broadcast over VHF or UHF, so any good antenna that picks up those bands will work.