US 4,520,293 AGranted

High frequency amplifier

AssigneeKernforschungszentrum Karlsruhe GmbH

InventorKlaus-Rainer Muller

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Abstract

A high frequency amplifier for a frequency range from 300 MHz to 3 GHz and having output power in the megawatt range. A beam generating device for generating a rotating electron beam includes an input resonator ring rotationally symmetric with respect to the amplifier axial axis and which presents a concentric input gap. A cathode ring disposed in front of the input gap generates the electron beam in response to an HF electrical field. The azimuthal angle width of that electron beam can be adjusted by means of a direct voltage between cathode ring and grid ring. An output resonator ring converts the kinetic energy of the beam electrons into HF power in dependence on the azimuthal angle width of the entering beam. The output resonator is rotationally symmetric with respect to the amplifier axis, axially spaced from and biassed with respect to the input resonator by a direct voltage. The axial space between the input and output resonators constitutes a direct voltage acceleration path which the electron beam traverses within an annular cylindrical region coaxial with the amplifier axis. A grid ring disposed opposite the cathode ring allows passage of the beam but prevents passage of an electrical field from the input resonator into the acceleration path. A collector is disposed on the side of the output resonator remote from the input resonator. The beam generating device, acceleration path, output resonator and collector are axially disposed one behind the other.

A high frequency amplifier for a frequency range from 300 MHz to 3 GHz and having an output power in the megawatt range, said amplifier having an axial axis and comprising:

(a) means for generating a rotating electron beam including
(1) a ring shaped input resonator which is rotationally symmetric with respect to the amplifier axis, said input resonator being formed to present an input gap concentric to the amplifier axis,
(2) means for generating a high frequency electrical field in said input resonator, and
(3) a cathode ring disposed in front of said input gap for generating the rotating electron beam in response to the high frequency electrical field;
(b) a ring shaped output resonator constructed for passage therethrough of the beam and for converting the kinetic energy of the electrons in the beam into high frequency power, said output resonator being rotationally symmetric with respect to the amplifier axis, axially spaced from said input resonator and electrically biased by a direct voltage potential difference with respect to said input resonator, wherein the axial space between said input resonator and said output resonator constitutes a direct voltage acceleration path for the electrons emitted from said beam generating means, the electron beam traverses the acceleration path within an annular cylindrical region coaxial with the amplifier axis, the electrons of the beam enter said output resonator with substantially identical velocities, and the kinetic energy of the electrons is converted in said output resonator to high frequency power in dependence on the azimuthal angle width of said beam;
(c) a grid ring disposed at the side of said input resonator between said cathode ring and said output resonator, the electron beam exiting said beam generating means through said grid ring and said grid ring restricting the passage of an electrical field from into said input resonator;
and
(d) a collector disposed on the side of said output resonator remote from said input resonator;
(e) wherein said beam generating means, said acceleration path, said output resonator and said collector are axially disposed one behind the other in the direction of the amplifier axis.

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Abstract

Claims10