L-Shaped Vertical Strip Line as a Primary Radiator for 2-Dimensional Parabolic Reflector at 60 GHz

A primary radiator for a 2-dimensional parabolic reflector was investigated for a millimeter-wave planar antenna, which was constructed by a slotted array fed by an oversized waveguide. This primary radiator consists of the vertical strip transmission line on which an L-shaped array pattern was etched. At first, the length of the L-shaped pattern was decided by calculation of the reflection characteristics. Next, the spacing between two L-shaped patterns was chosen by calculation of radiation patterns of the L-shaped array. It is obvious that a broad radiation pattern was obtained by selecting the spacing, and thus it is confirmed that this radiator is suitable for applications to the primary radiator at millimeter wavelength.