A close-packed dielectric-loaded horn array for 60 GHz

The design of an 8-element vertically polarised array for a 60 GHz radar application is described. The array consists of 10 E-plane step horns that are dielectric loaded to allow an element spacing of half wavelength. These horns are connected to 8 inputs (the end elements of the array are parasitic) by waveguide runs that include transitions from a dielectric-filled square waveguide to a standard air-filled WR-15 rectangular waveguide. This array has been fabricated and results obtained from measuring the radiation patterns, return loss and horn cross coupling are outlined.