Millimeter wave antenna array based on dielectric-filled waveguides

This paper presents components based on metallic dielectric-filled waveguides (DFWG) for antenna arrays. Air-filled waveguide feeding networks have low losses but the spacing between the elements of the array cannot be half-a-wavelength which is required for the grating lobe free radiation patterns. By filling the waveguides with dielectric material, the physical dimensions can be decreased. Three prototypes are developed for the lower E-band (71–76 GHz): a transition from DFWG to the standard WR-12 waveguide, a single antenna element based on the DFWG, and a 1×4 linear antenna array. The prototypes are manufactured and measured. The measured insertion loss of the structure with two transitions is 1.3–2 dB at the desired frequency range. The measured realised gain for the single element is 7–9 dBi at the desired band.