HF-Verstärkungsröhre mit integralem Polstück für Millimeterwellenfrequenzen

摘要

A focusing system for an electron beam within an RF amplification tube is provided. The focusing system comprises a plurality of magnetic polepieces each having a centrally disposed aperture, and a plurality of electrically conductive non-magnetic plates alternatingly and integrally provided with the polepieces, the non-magnetic plates each having a centrally disposed aperture. The apertures of the polepieces are aligned with the apertures of the non-magnetic plates to provide a beam tunnel through which the electron beam travels. At least one permanent magnet is coupled to the polepieces, the magnet having magnetic flux which flows through the magnetic polepieces to provide an axial magnetic field within the beam tunnel. The diameter of the beam tunnel is selected to be greater than a separation distance between adjacent ones of said polepieces, and the axial magnetic field varies substantially across a cross section of the beam tunnel. The axial magnetic field has a greatest RMS value at an outermost portion of the beam tunnel.