Dual-band quadrifilar square spiral antenna for satellite-mobile handsets

The design of a quadrifilar square spiral antenna (QSSA) for a handheld terminal to be used with a low-earth-orbit (LEO) personal communications network is discussed. Realisations on a finite ground and on a simulated handset are presented. The radiation performance and SAR (in the user´s head) were investigated using a hybrid computational electromagnetics technique. The most important desired characteristics, including a broad zenith-directed radiation pattern, circular polarisation and the necessary matching required at the antenna input ports were achieved. The simulated results show reasonable agreement with measurements.