GNSS Antenna Technologies: A Critical Review of Design, Performance, and Emerging Directions for Resilient Positioning, Navigation, and Timing

Global Navigation Satellite Systems (GNSS) now underpin a wide range of positioning, navigation, and timing (PNT) applications, from autonomous vehicles and precision agriculture to critical infrastructure timing and geodetic monitoring. The antenna remains a performance-limiting component in these systems: it determines how effectively satellite signals are captured, how well multipath and interference are suppressed, and how stable the phase reference is for high-precision measurements. This review provides a critical assessment of GNSS antenna technologies, covering established designs (patch, helical, choke ring, chip, stacked, dipole, and array antennas) alongside their operating principles, performance trade-offs, and application suitability. Key performance parameters, including gain, bandwidth, axial ratio, polarization purity, impedance matching, phase centre stability, and group delay, are examined with attention to their practical influence on positioning accuracy. The review also addresses frequency band support across GPS, GLONASS, Galileo, BeiDou, QZSS, and NavIC constellations, and maps antenna requirements against current and forthcoming signal modernisation efforts. Importantly, the paper situates GNSS antenna design within the broader context of emerging challenges and opportunities: the growing threat of intentional jamming and spoofing, the development of controlled reception pattern antennas (CRPAs) for interference mitigation, the integration of GNSS with low Earth orbit (LEO) PNT augmentation layers, the convergence of satellite navigation with 5G/6G non-terrestrial networks, and the demand for compact, wearable, and reconfigurable antenna solutions. The review identifies specific gaps in current research and outlines directions for antenna designs capable of meeting the requirements of next-generation resilient PNT architectures.