The problem of radiation from narrow axial slots on a conducting circular cylinder with transverse electric (TE11, where the first 1 refers to the number of circumferential variation ad the second 1 refers to the number of radial variation) mode excitation was solved. The Fourier transform and mode matching were used to obtain a set of simultaneous equations. Fast convergent series solutions for radiation, transmission, and reflection coefficients were presented in terms of discrete modal coefficients. A 20-slot antenna was fabricated, and its radiation patterns were measured. Our numerical results agree favorably with measured data.