A new 2×2 microstrip patch sub-array for 60GHz wideband planar antenna with ridge gap waveguide distribution layer

We propose a two layer planar antenna where a ridge gap waveguide corporate distribution network feeds a subarray of 2×2 radiating microstrip patch elements. There exists a coupling slot in the ground plane of the substrate layer which allows the excitation of the microstrip patch elements from the ridge gap waveguide layer. The ground plane of the substrate also serves the purpose of top metal layer for the ridge gap waveguide section. The proposed antenna is operating over 15% relative bandwidth covering 56-66 GHz frequency range with -12 dB reflection coefficient. The simulated directivity of the 2×2 element array is 11.5dbi at the center of the band. The simulated directivity for the 16×16 element array using the infinite array approach is found to be 28.7dBi.