Suppression of E-Plane Sidelobes Using a Double Slit Layer in a Corporate-Feed Waveguide Slot Array Antenna Consisting of $2\times2$ -Element Radiating Units

The E-plane sidelobe level at tilts around 30°-40° in a Taylor distribution due to tapered excitation of units of 2 × 2 radiating slots is suppressed by introducing a double slit layer in a corporate-feed waveguide slot array antenna. The double slit layer act in averaging the excitation of the adjacent radiating slots for the sidelobe suppression and suppression of reflection. A 16 × 16-element array in the 70 GHz band is fabricated. At the design frequency, the sidelobe level at tilts around 30°-40° is suppressed to -30.0 dB from -25.4 dB. Compared to the conventional antenna, the sidelobe levels of the proposed antenna are suppressed over 71.0-76.0 GHz frequencies.