Electrovacuum SHF apparatus

A vacuum SHF apparatus comprising:

• means for forming a charged-particle beam to be directed along the longitudinal axis of the apparatus;
• an accelerating tube arranged at the output of said beam forming means, for imparting a velocity close to that of light to the charged particles of the beam;
• a first deflection yoke for circular scanning of the beam at an input signal frequency, said first yoke being arranged behind said tube, along the beam path, and coaxially with said beam forming means;
• an additional magnetic deflection yoke arranged successively along the beam path behind said first yoke and coaxially therewith, for deflecting the scanned beam outwardly from the longitudinal axis;
• a hollow annular resonator arranged successively behind said additional yoke and coaxially therewith along the beam path;
• said resonator having broader walls that are parallel with the longitudinal axis;
• annular slots being provided in said resonator walls for the beam, that has been deflected by said additional yoke, to pass through said slots;
• annular permanent magnets of said additional yoke arranged in planes perpendicular to the longitudinal axis, said magnets being magnetized in a direction parallel to the axis and being of such radius and height that the particle beam passes through said slots at a velocity close to zero in the axial direction and with a specific ratio between azimuth and radial components;
• the internal dimensions and shape of said resonator being such that it can maintain an electromagnetic wave traveling along said resonator at a frequency equal to the standing frequency of the beam or its multiple, the electromagnetic wave having an electric field substantially parallel to the path of the beam particles;
• a collector arranged successively behind said resonator, along the beam path for receiving the charged-particle beam as it leaves said resonator;
• and means for deriving SHF power from said resonator.