Annular slot antenna.

摘要

A microstrip annular antenna structure is formed by four quarter-wavelength microstrip radiator patches arranged in a quadrant formation and having outwardly directed adjacent radiating apertures which together provide a composite annular radiating slot extending about 360° of azimuth. All such radiators are fed in-phase by a single centrally located: feedpoint (22) and equal length microstrip transmission lines (26) extending diagonally therefrom to a respective matched impedance feedpoint (24) associated with each radiator patch structure. An extremely low profile rf antenna system results with a monopole or annular slot vertically polarized radiation pattern.