Design and Fabrication of a Dual-Polarization Waveguide Slot Array Antenna With High Isolation and High Antenna Efficiency for the 60 GHz Band

We propose a slot array antenna for dual-polarization operation in the 60 GHz band. To realize the dual-polarization, cross-shaped radiating slots and a multilayer feeding structure are employed. A 16 × 16-element array is fabricated by diffusion bonding of laminated thin copper plates, which has the advantages of high precision and low loss characteristics. To suppress the grating lobes, we employ several design techniques, such as a thick cavity structure and dense element spacing. The high antenna gain higher than 32.0 dBi and the antenna efficiency near 80.0% are obtained over 60.0-64.0 GHz for two different polarizations. The 1-dB-down gain bandwidths reach 10.4% and 10.9%. High isolation above 50 dB is achieved between the two input ports.