Quadrifilar helical antennas for a handheld terminal in satellite personal communication networks (SPCN)

The global personal communication network (PCN) will provide telecommunication functionality regardless of user´s location. The vision of PCN focuses on the provision of a high quality two-way communication service to both business users and consumers on the move, outdoor and indoors. The goal is to create a a global PCN which will be complementary to the public switched telecommunication network EM-/wired-and to any other wireless system. Satellite networks, by their ubiquitous presence in low Earth orbits (LEO), medium Earth orbits (MEO) or any other combination of orbits, are well suited to fill the gaps in the land coverage left by the terrestrial networks, offering, in co-operation with the existing terrestrial systems, personal communication services virtually everywhere on the globe. A critical point in the user´s terminal design, size and performance is the antenna. The antenna design has to be tightly related to the propagation, system and environment conditions. The prime factors which the designer should take into account are examined