US Patent 7271770 Reverse F-shaped antenna

In a reverse F-shaped antenna formed on a surface of a printed board, the radiating element has a first radiating conductor, a second radiating conductor, and a chip coil. The chip coil is positioned between the first and second radiating conductors and electrically connects the first radiating conductor to the second radiating conductor. The reverse F-shaped antenna is effectively downsized. A component of current flow in the chip coil in a three-dimensional direction allows sensitivity to some extent to a wave polarized in all directions. By merely changing the inductance in the chip coil, it is possible to easily alter the resonance frequency in the reverse F-shaped antenna.