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US 4,553,068 AGranted
High power millimeter-wave source
AssigneeThe United States of America as represented by the Secretary of the Army
InventorHoward E. Brandt
Life of this patent
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Abstract
A simple method and apparatus are disclosed for producing high power gigat level millimeter radiation from an intensely oscillating relativistic turbulent electron plasma created in and beyond the gap of a high voltage diode configuration. The diode is comprised of an explosive cathode emitter and an extended anode structure connected to the inner and outer conductors, respectively, of a high voltage pulse line under conditions of space charge saturation. The gap spacing and voltage determine the dominate mode of the turbulent longitudinal waves which are directly converted into free transverse waves polarized parallel to the electron beam. A simple coaxial reflector-antenna system is also utilized to direct and focus the resultant radiation.
Claims20
A device called a turbutron for producing millimeter wave pulses in the gigawatt power range, comprising in combination:
- a high voltage diode configuration which is maintained under vacuum and comprised of an explosive, cylindrical cathode;
- an extended cylindrical anode structure and a gap spacing between said anode and cathode;
- a megavolt coaxial pulse line for producing a beam of electrons under conditions of charge saturation, said beam of electrons being explosively emitted from said cathode to create an intensely oscillating relativistic turbulent electron plasma in and beyond said gap of said diode configuration, thereby producing pulsed high power millimeter waves radiating out radially and polarized parallel to the axis of said electron beam;
- a plurality of microwave windows located transverse to the diode configuration gap at the outer cylindrical wall of said anode structure;
- annular magnet coils located external and coaxial to said diode configuration that produce a strong uniform axial magnetic field in order to restrict the electrons in said turbulent electron plasma to pure longitudinal motion along said magnetic field;
- wherein said relativistic turbulent electron plasma is predominately confined between said emission cathode and a virtual cathode and confined radially about said electron beam axis;
- and
- wherein said virtual cathode is an imaginary boundary beyond which few electrons pass and is oscillating both in electrical potential and position, the latter centered at a distance which is approximately twice the cathode anode gap.
5 more elements
A device called a turbutron for producing millimeter wave pulses in the gigawatt power range, comprising in combination:
- a high voltage diode configuration, which is maintained at a vacuum, comprised of an explosive cylindrical cathode, an extended cylindrical anode structure and a gap spacing of near 3 mm between said anode and end of said cathode;
- a megavolt coaxial pulse line for producing a beam of electrons under conditions of charge saturation, said beam of electrons being explosively emitted from said cathode to create an intensely oscillating relativistic turbulent electron plasma in and beyond said gap of said diode configuration, thereby producing pulsed high power millimeter waves radiating out radially and polarized parallel to the axis of said electron beam, said millimeter waves having a pulse length in the range of 10 nanoseconds and a dominant frequency of 35 gigahertz enabling propagation through the atmosphere;
- wherein said relativistic turbulent electron plasma is predominantly confined between said emission cathode and a virtual cathode, said plasma having a broad turbulent spectrum of longitudinal modes of oscillation however peaking at 35 gigahertz and being directly converted into free transverse millimeter waves;
- wherein said anode structure includes a circular primary anode surface made of aluminized Mylar foil of near micron thickness, located 3 millimeters axially from the end of said emission cathode and joined to the cylindrical wall of said anode structure, wherein the wall of said anode structure is made of steel and is sufficiently distant from said emitter cathode to avoid wall breakdown and cavity resonance;
- a plurality of microwave windows located transverse to said gap of said diode configuration at the outer cylindrical wall of said anode structure;
- annular magnet coils located external and coaxial to said diode configuration to aid in confining said turbulent electron plasma radially along the diode axis;
- and
- a microwave reflector/antenna located coaxially with said cylindrical anode structure and externally to said magnet coils to reflect said microwaves out parallel and external to said diode axis and wherein said antenna is shaped in a curved, dishlike manner to produce a prescribed gain pattern.
5 more elements
A device called a turbutron for producing millimeter wave pulses in the gigawatt power range, comprising in combination:
- a high voltage diode configuration, which is maintained at a vacuum, comprised of an explosive cylindrical cathode, an extended cylindrical anode structure and a gap spacing of near 3 mm between said anode and end of said cathode;
- a megavolt coaxial pulse line having its center and outer conductors connected to said cathode and anode respectively, for producing a beam of electrons under conditions of charge saturation, said beam of electrons being explosively emitted from said cathode to create an intensely oscillating relativistic turbulent electron plasma in and beyond said gap of said diode configuration, thereby producing pulsed high power millimeter waves radiating out radially and polarized parallel to the axis of said electron beam, said millimeter waves having a pulse length in the range of 10 nanoseconds and a dominant frequency of 35 gigahertz enabling propagation through the atmosphere;
- wherein said relativistic turbulent electron plasma is predominantly confined between said emission cathode and a virtual cathode, said plasma having a broad turbulent spectrum of longitudinal modes of oscillation, however peaking at 35 gigahertz and being directly converted into free transverse millimeter waves;
- wherein said anode structure includes a circular primary anode surface made of aluminized Mylar foil of near micron thickness, located 3 millimeters axially from the end of said emission cathode and joined to the cylindrical wall of said anode structure, wherein the wall of said anode structure is made of steel and is sufficiently distant from said emitter cathode to avoid wall breakdown and cavity resonance;
- a plurality of microwave windows located transverse to said gap of said diode configuration at the outer cylindrical wall of said anode structure;
- annular magnet coils located external and coaxial to said diode configuration that produce a strong uniform axial magnetic field of at least one tesla in order to restrict the electrons in said turbulent electron plasma to pure longitudinal motion along said magnetic field;
- and
- a microwave reflector/antenna located coaxially with said cylindrical anode structure and externally to said magnet coils to reflect said microwaves out parallel and external to said diode axis and wherein said antenna is shaped in a curved, dishlike manner to produce a prescribed gain pattern.
5 more elements
Dependencies are inferred from the claim text.