mm-Wave Polarization Insensitive Spiral Antenna for 5G Energy Harvesting Applications

This paper presents the development of a dual-band antenna for novel RF Energy Harvesting and Wireless Power Transfer systems operating on the fifth-generation (5G) cellular networks frequencies. A logarithmic spiral is selected to provide circular polarization in 5G bands. A conformal balun is designed to ensure a symmetric excitation of the spirals’ arms. A ring reflector is proposed to ascertain the stable gain (>5dBic) and axial ratio (<3db) in the 20 and 40 GHz frequency bands after the spiral and the balun were integrated. A ring reflector for realised gain improvement is implemented. The internal radius, external radius and thickness of the ring were optimised to provide additional gain over the desired frequencies without noticeable deterioration of the axial ratio.