Design and development of novel helical antennas for navigational applications

Abstract

Navigational devices have become integral part of the systems used in applications such as marine military security surveillance weather prediction and broadcast and field mapping The navigational devices are expected to be compact and provide the seamless navigational data irrespective of location and environmental conditions The performance of navigational devices largely depend on the radiation characteristics of antenna which captures the signals transmitted from the GNSS satellites Hence the development of antennas covering multiple GNSS bands is required for different applications In this dissertation the design and development of novel navigational antennas have been successfully carried out based on the following two strategies I Miniaturizing navigational antenna without compromising the radiation performance for handheld and portable device application and ii wideband interoperable navigational antenna by improving the matching feed network so that the antenna covers all GNSS bands for vehicle mount and geodetic device applications For effective reception of the GNSS satellite signals three major circularly polarised antenna topologies are commonly used and they are spiral antenna quadrifilar helix antenna and microstrip patch antenna Among the existing topologies quadrifilar helix antenna QHA is an optimal choice because of its radiation characteristics newline