A full-wave analysis of small aperture radial line slot antennas with circular short wall

Extremely small aperture radial line slot antennas (RLSAs) are analysed by the moment method technique using a rectangular cavity model with annularly arrayed pins in it; the full structure such as the curvature of slot arrangement and the circular short wall at the aperture periphery is modeled with high fidelity. Two kinds of non-symmetrical slot arrangement are considered. The reflection and the radiation patterns are predicted and compared with measured data. This analysis model is effective and indispensable in the design of extremely small aperture RLSAs. The effects of real slot arrangement and the waveguide short wall can be assessed in the future design of small aperture RLSAs.