LSE-NRD guide fed high efficiency folded planar antenna with uniform aperture distribution at 60GHz

A high permittivity LSE-NRD guide fed folded planar antenna with uniform aperture distribution was investigated at 59.5 GHz. The planar antenna consists of double-layered oversized waveguides, where a high permittivity LSE-NRD guide radiator is located at a focal point of a two dimensional offset parabolic reflector in the lower layer, and a slotted array etched on a dielectric substrate is exited by the oversized waveguide in the upper layer. In order to make a uniform aperture distribution, the radiation power from the slot was calculated. Two types of planar antennas, where spacings of each slot were set at I and 3/4 wavelengths, respectively, were designed and fabricated by using the theoretical results. High performance antennas with efficiencies of 57.8 % in a wavelength spaced slotted array and 59 % in 3/4 wavelength spaced one, was obtained.