Dual-Polarized Patch Array Antennas with Wide Beamwidth for Automotive Radar Applications

This work presents $24-\mathrm{GHz}$ dual-polarized wide-beamwidth patch array antennas for automotive radar applications. The dual-polarized $1 \times 8$ array antenna in Design 1 is realized by two orthogonally stacked substrate-integrated waveguide (SIW) feed networks. Its beamwidth can reach 80° and 141° under two orthogonal polarizations, respectively. In Design 2, cross-shaped parasitic elements are added on the side of the main radiating patches, and the reverse current generated by the parasitic element can increase the beamwidth. Its beamwidth in two orthogonal polarizations can be increased by up to 120° and 172°.