Electronic – How does a wire dipole antenna work when not straight

antenna

I recently bought an FM antenna for a receiver like this.

enter image description here

I've flattened it out a good bit on my windowsill but it's far from straight and is fairly wavy/curled from being bundled like this for who knows how long after manufacturing.

How does this still work as an antenna? I was under the impression antennas were (when practical) designed to be straight and some nice fraction of a wavelength.

Best Answer

I think this could be compared to meandered dipole antenna, a technique commonly found in UHF RFID tag antennas. But here is one article for research of VHF dipole antenna. So, if you keep the length l (dipole length) the same and add meanders, the frequency goes down because the electrical length of the antenna is longer:

Meander dipole1

In your situation the dipole length is reduced, but the electrical length of the dipole is the same:

Meander dipole 2

Even though the "meanders" are a bit different, I suspect it could be working quite close to the intended frequency.