SIW Broadband Circularly Polarized High-Gain Low-Profile Magneto-Electric Dipole Antenna Array

This study presents a substrate integrated waveguide (SIW) broadband circularly polarized (CP) high-gain low-profile magneto-electric dipole antenna array. The antenna array is characterized by wide impedance bandwidth (IBW), novel CP operating principle, small form factor, and good radiation performance. First, the antenna element consists of a two-layer dielectric substrate, two pairs of magneto-electric dipoles, and a SIW cavity coupled and fed through a cross-shaped rectangular slit. To achieve a wide CP bandwidth (BW), a pair of magneto-electric dipoles is rectangularly chamfered and then an “L” type parasitic patch is introduced. The simulation results show that the antenna element has an axial ratio (AR) BW of 14.2% in the 31.48–36.16 GHz range, the IBW in the 29.08–35.98 GHz range is 21.2%, and the gain is greater than 8 dBic in all bands. The antenna exhibits stable patterns and wide overlap IBW (31.48–35.98 GHz). Then, a planar 2 × 2 antenna array fed by a one-part-four SIW power divider was designed, fabricated, and measured. The measured results show that the array has an ARBW of 14% in the range of 31.29−35.83 GHz, an IBW of 21.8% in the range of 29.28–35.83 GHz, and a peak gain of 14.1 dBic.