Analysis of flared end for Vlasov-type antenna: comparison of 2D finite element analysis with experiment

Improved beam focusing of high powered microwaves radiating from a Vlasov-type antenna can be achieved by applying a flare to the launcher aperture. A frequency domain two dimensional hybrid finite-boundary element model solves the near field time harmonic wave equation. Linear interpolation of boundary magnetic and electric fields is used for the Hankel function approximation of the far field. Three significant advantages are noticed with flare application: (a) beam narrowing, with increased center peak intensity, (b) reduction in side-lobe fields, and (c) increased mode purity in the waveguide. Results are in agreement with experimental data.<>