What type of antenna is used in mobile phones?

Answer: The modern mobile phone uses a fractal antenna.

History: Previous generations of mobile phones used the dipole antenna. (Some protruded, others were retractable.)

Details: A mobile phone must work in any orientation, so the antenna must be omnidirectional. Today's various cellular networks have multiple frequency bands. Smart phones have a variety of protocols (GPRS, PCS, Bluetooth, near-field, Ant, WiFi) requiring several transmitters and receivers working at a wide range of frequencies. Fitting two of more antenna in the same case increases complexity and costs. The only single antenna that can handle all these demands is fractal, thus, the entire industry now uses one or another style of fractal antenna.