A Novel Dielectrically-Loaded Helical Antenna Topology for Multi-band GNSS

As GNSS services develop in depth, with multiple interoperable systems, and in sophistication, with many channels, there is a developing need for small, high-quality, multi-band GNSS antennas. We present a novel class of dielectric-loaded multi-filar helix antennas which is exemplified by the particular example of the hexafilar-turnstile antenna. The design and measured performance of this particular topology is described for the case of a GPS dual-band L1 and L2 antenna in which a hexafilar loop antenna resonates at L1 and surrounds a turnstile antenna resonating at L2. The measured data verifies that the antenna provides excellent gain performance at L1. At present there is lower gain at L2 but this is expected to improve with further development. An extension to triple-band L1, L2 and L5 frequency bands is proposed.