Design and Characterization of Circularly Polarized Discrete Lens Antennas in 60-GHz Band

Three 400-element circularly polarized discrete lens antennas with different F/D ratios and main beam directions are studied in the 60-GHz band. They are fabricated with a standard printed circuit board technology and demonstrate excellent performance with a radiation efficiency of 53%-61%, an aperture efficiency of 15%-28%, 20-23 dBi gain, and a very good axial ratio. The typical 1-dB gain- bandwidths are above 12%, and the F/D = 0.5 prototype demonstrated a 1-dB axial-ratio bandwidth larger than 16.3%. To our knowledge, this work is the first demonstration of low-cost discrete lens antennas compatible with high-data-rate communications in V-band.