A broadband low frequency passive receiving antenna system is disclosed which is an omnidirectional receiving antenna configured to provide broadband reception of the low frequency (LF) portion of the radio frequency (RF) spectrum. The broadband low frequency passive receiving antenna system floats in the radiated noise field. The broadband low frequency passive receiving antenna system has a differential input so it cancels the common mode noise which surrounds it.

A foldable electronic device includes an antenna, where the antenna uses a first side frame and a second side frame that are disposed in the foldable electronic device as radiators. A part of the first side frame is used as a feed stub, and a part of the second side frame is used as a parasitic stub. A gap is provided on the parasitic stub, so that a radiation aperture of the parasitic stub is increased.

A foldable electronic device includes an antenna, where the antenna uses a first side frame and a second side frame that are disposed in the foldable electronic device as radiators. A part of the first side frame is used as a feed stub, and a part of the second side frame is used as a parasitic stub. A gap is provided on the parasitic stub, so that a radiation aperture of the parasitic stub is increased.