Design and Performance Evaluation of a Compact Beam-Tilted Circularly Polarized Slotted Waveguide Antenna

This paper presents design configuration and performance analysis of a compact and thin beam-tilted circularly polarised (CP) radial line slot array (RLSA) waveguide antenna. In conventional CP RLSA beam-tilting method, the aperture efficiency degrades significantly due to sparsely distributed slots throughout the aperture. In this paper, we have presented a new design configuration by utilizing the most effective aperture of the antenna, and eliminating the least effective area. Using this method, an antenna was designed at 18 GHz with a beam tilt angle of 30° and a total aperture of 10λ 0 . The antenna has demonstrated a directivity of 25.9 dBic and a realized gain of 25.6 dBic at 18 GHz with a tilt angle of 30°. The far-field radiation pattern has shown a side lobe level of less than -21 dB.