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 Vla sov-type antenna be achieved by applying a flare to the launcher apert ure. A frequency domain two dimensional hybrid finite-boundary element model solves the near field time harmonic wave equation. Linear inter polation of boundary magnetic and electric fields is used for the Hank el function approximation of the far field. Three significant advantag es are noticed with flare application: (a) beam narrowing, with increa sed center peak intensity, (b) reduction in side-lobe fields, and (c) increased mode purity in the waveguide. Results are in agreement with experimental data.