We revisit the radiation characteristics of a dielectric-filled edge-slot (DFES) antenna, which is made by circumferentially removing the outer conductor of a coaxial line. The Fourier transform and the mode-matching technique are utilized to obtain a new solution in a fast converging series. A dominant-mode solution for the reflected power and the radiation field is given in a simple form. The numerical investigation is performed to show the behavior of the antenna input impedance and the radiation pattern.¿ 1997 American Geophysical Union