Intelligent quadrifilar helix antenna

The concept of the intelligent quadrifilar helix antenna (I-QHA) as an antenna for handheld mobile terminals is detailed. The potential advantages of using the I-QHA in both terrestrial and satellite mobile communications are presented. The I-QHA may be used as a multiband or multimode antenna, allowing a handset to operate in different frequency bands and in both terrestrial and satellite communications environments. The adaptive matching component of the I-QHA not only matches the antenna for different frequency bands, but counters the detuning effects caused by the user. Finally, diversity gain improvements of up to 14 dB in heavily shadowed environments, achieved by implementing diversity techniques on the elements of the I-QHA, are demonstrated.