Internal antenna diversity for mobile phones at 850MHz

Antenna diversity and mobile phones seem to be two opposed concepts as diversity requires decoupling between the sensors and mobile phones are getting smaller and smaller. But in order to cope with high data throughput and network saturation, it is necessary to develop antennas which allow to be placed in close proximity with a reduced coupling. This article presents a solution where three 850MHz antennas have been implemented inside a flip phone with a maximum coupling of -15dB.