Matching of a piece-wise linear TEM horn

Three techniques to match a piece-wise linear UWB TEM horn are proposed. Two of them are based on the characteristic impedance technique and the asymptotic theory using Sommerfeld solution for plane wave scattering by a wedge. The third theory uses the edge wave scattering pattern from the modified Weinstein solution for scattering by an open end of a flat waveguide. The results of analytical and numerical simulations show that the third theory gives calculations with a high accuracy of the coefficient of reflection near -10 dB level. This allows us to use the third theory to optimize a piece-wise linear UWB TEM horn with the aim of minimizing the lower frequency of matching with the given overall dimensions. The samples of analytical optimization are given.