Are you asking about the bowtie antenna provided (years ago) with television sets for UHF reception? An alternate shape was a simple loop. Both types were several inches across. They needed to receive a wide range of frequencies, therefore they did not need selectivity. They could have a lot of shapes and still work, I believe.
It was convenient to make it a bowtie shape, to create a center hub for a:
* junction point for the 300-ohm twin lead
* clamp to grip the rabbit ears (VHF antenna)