The radiation from a flanged coaxial line into a dielectric slab is investi
gated in this paper. The Hankel transform and mode-matching technique are u
sed to obtain simultaneous equations for the modal coefficients, The residu
e calculus is utilized to represent the solution in rapidly convergent seri
es. Numerical computations are performed to illustrate the behavior of refl
ection in terms of the slab permittivity, frequency, and coaxial-line geome
try.