We used to get a bow-tie antenna with tv's. For receiving broadcasts on uhf channels.
About nine inches across. Two leads coming out. Rough shape was a loop but the wires were bent to be close together in the center. At the center was a plastic notch which would attach to the rabbit ears (the larger antenna for vhf channels).
I don't know that the bow-tie is necessarily a better shape for an antenna than the loop. The bowtie could ride on the rabbit ears, thus it was easy to move it around and raise it higher for better reception. The loop antenna on the other hand generally stayed in a fixed position.