Miniature antennas with low proximity effects and filter response characteristics for Bluetooth and 3G applications

This paper describes an antenna topology (Sarantel) which maintains a high cross-polar gain, is very small and is power efficient. The antenna exhibits an alignment of electric and magnetic minima as well as a far field minimum directed towards the user´s head together with balanced electric-field loading across a dielectric core. These attributes minimise the near-field electromagnetic energy that is offered to and dissipated in the user. The high dielectric core stores much of the near field including the potentially frequency changing reactive near field. Together with a balanced feed system that isolates the antenna from the handset, the proposed topology maintains its far field pattern even when the handset is held by energy absorbing human tissue. As the user absorbs little energy, the antenna is power efficient, lowering power consumption of the handset and therefore extending battery life.