US 5,767,625 A · High frequency vacuum tube with closely spaced cathode and non-emissive grid · patentgrep

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Abstract

A vacuum tube for handling an r.f. signal having a predetermined frequency range comprises a cathode, a heater, and a non-electron emissive grid. The grid is positioned from the cathode by the distance an emitted electron from the cathode can travel in a quarter cycle of the r.f. signal. Outer and inner metal tubes forming a resonant line of a signal coupler are respectively connected to the grid and cathode. R.F. absorbers absorb r.f. fields in an interaction region between an anode and the grid. In one embodiment a coupling loop is between metal tubes at an end of the tubes spaced n.lambda./4 from the grid and cathode. In a second embodiment the coupler includes a coaxial line having an inner conductor connected to a first metal face, spaced from a second opposed metal face by a solid dielectric. An outer conductor is connected to a third metal face, spaced from a fourth opposed metal face by the dielectric. The third and fourth faces surround the first and second faces. The first and third faces are at ground potential while the second and fourth faces are at high negative DC voltages. The second and fourth faces are respectively at common ends of interior and exterior coaxial metal tubes forming a .lambda./2 coupler. Hollow inductive structures extend between the inner and outer metal tubes and at different locations along the tubes. Bias leads may be inserted into the inductive structures for shielding.

Claims13

Dependent claims

A vacuum tube for handling an r.f. signal having a predetermined frequency range comprising:

a cathode for emitting a linear electron beam:
a grid comprised of non-electron emissive material for current modulating the beam, the grid being positioned from the cathode no farther than a distance in which electrons emitted from the cathode can travel in a quarter cycle of the r.f. signal;
an anode for accelerating the beam;
an electrode for collecting the beam;
an output cavity resonant to a frequency of the r.f. signal positioned between the grid and electrode for collecting the beam;
a coupler responsive to the r.f. signal connected to the grid and cathode so electrons from the cathode upon passing through the grid and accelerated toward the anode are in bundles in an interaction region between the anode and grid to cause r.f. fields that are responsive to the r.f. signal to be derived in the interaction region;
r.f. absorbing material coupled to the interaction region for absorbing the r.f. fields that are responsive to the r.f. signal so there is non-regenerative coupling of the r.f. signal to the region;
wherein the coupler is resonant to a frequency of a source of the signal, and further including means for changing the resonant frequency of the coupler;
wherein the coupler includes a pair of fixed length, fixedly positioned concentric metal tubes electrically insulated from each other for DC current flow, and the changing means includes a metal, inductive structure extending between the tubes and at different axial locations along the tubes;
and
wherein the inductive structure comprises a cylinder of conductive material having a hollow portion therethrough.

8 more elements

A vacuum tube for handling an r.f. signal having a predetermined frequency range comprising:

cathode for emitting an electron beam,
a heater for the cathode positioned in close proximity to the cathode;
a grid comprised of non-electron emissive material for current modulating the beam, the grid being positioned from the cathode no farther than a distance in which electrons emitted from the cathode can travel in a quarter cycle of the r.f. signal;
an anode for accelerating the beam, an electrode for collecting the beam, an output cavity, resonant to a frequency of the r.f. signal, positioned between the grid and electrode for collecting the beam;
a non-regenerative coupler for the r.f. signal connected to the grid and cathode so electrons from the cathode upon passing through the grid and accelerated toward the anode are in bundles in an interaction region between the anode and the closely spaced grid and cathode, the coupler including:
inner and outer coaxial metal tubes which collectively comprise a resonant line having a length of at least 1/2, where 1 is the wavelength of the r.f. signal, the outer and inner tubes being electrically connected to the grid and cathode, respectively, the grid and outer coaxial tube being DC isolated from the cathode and inner coaxial tube, enabling different DC voltages to be applied to the grid and cathode;
and
first, second and third leads for respectively biasing the grid and cathode and for supplying current to the heater, the first and second leads being respectively connected to the outer and inner metal tubes and the third lead extending through the inner metal tube, a plurality of inductive structures extending between the inner and outer metal tubes and at different axial locations along the inner and outer metal tubes, the inductive structures each having a hollow portion extending therethrough so that the second and third leads are within the hollow portion and are shielded from r.f. fields generated within the coupler.

5 more elements

A vacuum tube for handling an r.f. signal having a predetermined frequency range comprising:

a cathode for emitting a linear electron beam;
a grid comprised of non-electron emissive material for current modulating the beam, the grid being positioned from the cathode no farther than a distance in which electrons emitted from the cathode can travel in a quarter cycle of the r.f. signal;
an anode for accelerating the beam;
an electrode for collecting the beam positioned downstream of the anode;
an output cavity, resonant to a frequency of the r.f. signal, positioned between the grid and electrode for collecting the beam;
a non-regenerative resonant coupler for the r.f. signal connected to the grid and cathode so electrons from the cathode upon passing through the grid and accelerated toward the anode are in bundles in an interaction region between the anode and the closely spaced grid and cathode, the coupler including:
inner and outer coaxial metal tubes which collectively comprise a resonant line, the outer and inner metal tubes being respectively electrically connected to the grid and cathode, the grid and outer coaxial tube being DC isolated from the cathode and inner coaxial tube enabling different DC voltages to be applied to the grid and cathode, a loop disposed in a space between the outer and inner tubes at an end of the outer and inner tubes remote from the grid and cathode, the resonant coupler having a length of about n.lambda./4 between the grid and loop, where .lambda. is the wavelength of a frequency of the r.f. signal in the predetermined frequency range, and n is an odd integer;
a signal source for generating the r.f. signal, said signal source having an outputs;
a driver for amplifying the r.f. signal, said driver having an input connected to said output of said signal source, and a driver output;
a vacuum tube system adapted to receive the vacuum tube and having a first input connected to said driver output for receiving the r.f. signal, a power input, a coolant input, and a load output;
a load element having an input connected to said load output;
a DC power source having an output connected to said power input;
and
a cooling system having an output connected to said coolant input to provide cooling to the vacuum tube system.

11 more elements

A vacuum tube for handling an r.f. signal having a predetermined frequency range comprising:

a cathode for emitting an electron beam;
a grid comprised of non-electron emissive material for current modulating the beam, the grid being positioned from the cathode no farther than a distance in which electrons emitted from the cathode can travel in a quarter cycle of the r.f. signal;
an anode for accelerating the beam;
an electrode for collecting the beam, an output cavity, resonant to a frequency of the r.f. signal, positioned between the grid and electrode for collecting the beam;
a non-regenerative coupler for the r.f. signal connected to the grid and cathode so electrons from the cathode upon passing through the grid and accelerated toward the anode are in bundles in an interaction region between the anode and the closely spaced grid and cathode, the coupler including:
a low voltage coaxial line having inner and outer conductors connected to a source of the r.f. signal, the inner conductor being connected to a first metal face, the first metal face being spaced from a second opposed metal face by a solid dielectric, the outer conductor being connected to a third metal face, the third face being spaced from a fourth opposed metal face by the solid dielectric, the third and fourth faces respectively being on structures surrounding the first and second faces, each of the metal faces having a respective periphery, the dielectric extending beyond the respective periphery of the metal faces so a substantial DC voltage can be established between the corresponding faces;
the first and third faces being connected to a DC ground terminal, the second and fourth faces being connected to high negative DC voltage terminals, the second and fourth faces being respectively at common ends of inner and outer coaxial metal tubes thereby defining a half-wavelength coaxial coupler, the other ends of the inner and outer tubes being respectively connected to the cathode and grid;
a signal source for generating the r.f. signal, said signal source having an outputs;
a driver for amplifying the r.f. signal, said driver having an input connected to said output of said signal source, and a driver output;
a vacuum tube system adapted to receive the vacuum tube and having a first input connected to said driver output for receiving the r.f. signal, a
power input, a coolant input, and a load output;
a load element having an input connected to said load output;
a DC power source having an output connected to said power input;
and
a cooling system having an output connected to said coolant input to provide cooling to the vacuum tube system.

12 more elements

A vacuum tube for handling an r.f. signal having a predetermined frequency range comprising:

a cathode for emitting an electron beam;
a heater for the cathode positioned in close proximity to the cathode;
a grid comprised of non-electron emissive material for current modulating the beam, the grid being positioned from the cathode no farther than a distance in which electrons emitted from the cathode can travel in a quarter cycle of the r.f. signal;
an anode for accelerating the beam;
an electrode for collecting the beam;
an output cavity, resonant to a frequency of the r.f. signal, positioned between the grid and electrode for collecting the beam;
a non-regenerative coupler for the r.f. signal connected to the grid and cathode so electrons from the cathode upon passing through the grid and accelerated toward the anode are in bundles in an interaction region between the anode and the closely spaced grid and cathode, the coupler including:
inner and outer coaxial metal tubes which collectively comprise a resonant line having a length of at least 1/2, where .lambda. is the wavelength of the r.f. signal. the outer and inner tubes being electrically connected to the grid and cathode, respectively, the grid and outer coaxial tube being DC isolated from the cathode and inner coaxial tube, thereby enabling different DC voltages to be applied to the grid and cathode, first, second and third leads for respectively biasing the grid and cathode and for supplying current to the heater the first and second leads being respectively connected to the outer and inner metal tubes at positions approximately n.sub.1 .lambda./4 from the grid and cathode and the third lead extending through the inner tube at a position approximately n.sub.1 .lambda./4 from the grid and cathode, where n.sub.1 is an odd integer;
a signal source for generating the r.f. signal, said signal source having an output;
a driver for amplifying the r.f. signal, said driver having an input connected to said output of said signal source, and a driver output;
a vacuum tube system adapted to receive the vacuum tube and having a first input connected to said driver output for receiving the r.f. signal, a power input, a coolant input, and a load output;
a load element having an input connected to said load output;
a DC power source having an output connected to said power input;
and
a cooling system having an output connected to said coolant input to provide cooling to the vacuum tube system.

12 more elements

A vacuum tube for handling an r.f. signal having a predetermined frequency range comprising:

a cathode for emitting a linear electron beam;
a grid comprised of non-electron emissive material for current modulating the beam, the grid being positioned from the cathode no farther than a distance in which electrons emitted from the cathode can travel in a quarter cycle of the r.f. signal;
an anode for accelerating the beam, an electrode for collecting the beam, an output cavity, resonant to a frequency of the r.f. signal, positioned between the grid and electrode for collecting the beam;
a coupler responsive to the r.f. signal connected to the grid and cathode so electrons from the cathode upon passing through the grid and accelerated toward the anode are in bundles in an interaction region between the anode and grid to cause r.f. fields that are responsive to the signal to be derived in the interaction region, and r.f. absorbing material coupled to the interaction region for absorbing the r.f. fields so there is non-regenerative coupling of the r.f. signal to the region and there is heavy loading of the interaction region and formation of a resonant impedance in the interaction region is prevented, the heavy loading by the r.f. absorbing material of the interaction region and absorption of the r.f. fields tended to be generated by the bundled electrons in the interaction region being sufficiently great that there is no need to connect a capacitor or other high frequency low impedance component or circuit in shunt with the interaction region to by-pass the r.f. fields that tend to be generated by the bundled electrons;
a signal source for generating the r.f. signal, said signal source having an output;
a driver for amplifying the r.f. signal, said driver having an input connected to said output of said signal source, and a driver outputs;
a vacuum tube system adapted to receive the vacuum tube and having afirst input connected to said driver output for receiving the r.f. signal, a power input, a coolant input, and a load output;
a load element having an input connected to said load output;
a DC power source having an output connected to said power input;
and
a cooling system having an output connected to said coolant input to provide cooling to the vacuum tube system.

8 more elements

Dependencies are inferred from the claim text.

Facts

Application: 08/632,589Filed 15 Apr 1996 · continuation in part
Priority: 1 Jun 1993
Granted: 16 Jun 1998
Term ends: Not estimatedThe source records don’t support an estimate.

Classification9 codes

H01J 23/12
Details of transit-time tubes of the types covered by group H01J25/00: vessels; Containers
H01J 23/005
Details of transit-time tubes of the types covered by group H01J25/00: cooling methods or arrangements
H01J 23/065
Electron or ion guns: producing a solid cylindrical beam
H01J 23/14
Details of transit-time tubes of the types covered by group H01J25/00: leading-in arrangements; Seals therefor

Family

Serial69,705Parent of this continuation-in-part · filed 1 Jun 1993
US 5,572,092 AParent of this continuation-in-part
US 5,767,625 AThis patent

From the US filing history. Foreign family members aren’t listed.

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