A hybrid thin film multilayer antenna for automotive radar is presented in this work. A 2 × 8 aperture coupled stacked patch antenna array is realized on a single layer printed circuit board (PCB) using a novel thin film-based approach. Using a compact 180° phase difference power divider, inter-element spacing in a 2×2 sub-array is reduced. Measurement results show a 19% (67.9–82.5 GHz) impedance bandwidth and a wideband broadside radiation pattern, with a maximum gain of 15.4 dBi realized gain at 72 GHz. The presented antenna compares favorably with other multilayer PCB antennas in terms of performance, with the advantage of simpler manufacturing and robust design. The antenna can be employed in mid-range automotive radar applications.

In this paper, a metasurface-based aperture-coupled circularly polarized (CP) antenna with wideband and high radiation gain is proposed and analyzed. The proposed antenna is comprised of coplanar waveguide coupling with 4 × 4 corner truncated square patches, which show compact size and low profile. The mechanism of the CP antenna is analyzed theoretically based on the mode analysis and equivalent circuit analysis. The parameters of feeding structure and truncated corner are studied and optimized to achieve wide impedance bandwidth (BW) and axial ratio (AR) BW. Finally, an overall size of 38.8 mm × 38.8 mm × 3.5 mm (0.71λ0 × 0.71λ0 × 0.064λ0 at 5.5 GHz) CP antenna is proposed and fabricated. The simulated results demonstrate that over 41.7% impedance BW (S11 < −10 dB) of 4.55–6.95 GHz and 3 dB AR BW of 5.05–6.15 GHz (fractional BW is about 19.6%) are achieved. In addition, the antenna yielded a broadside CP radiation with a high gain average about 7.5 dBic. Experimental results are in good agreement with the simulated ones.