Vacuum tube including grid-cathode assembly with resonant slow-wave structure

A grid for current modulating an electron beam in response to a high-frequency signal having a predetermined bandwidth comprising plural parallel meander lines resonant to said signal, a first central electrically conducting area and a second peripheral electrically conducting area surrounding the first area, the first and second electrically conducting areas respectively defining first and second opposite terminals for said parallel meander lines, said meander lines being electrically connected between said first and second areas, each of said lines including first electrically conducting segments extending radially between said first and second electrically conducting areas and second segments extending generally transverse to said first segments, said first and second segments of each line being connected in series with each other and to said areas.

The grid for a vacuum tube for amplifying an r.f. signal having a predetermined frequency, the grid comprising an electrically conductive structure, the structure being configured for current modulating in response to the signal an electron beam of the tube passing therethrough, the current modulated beam having a current variation that is a replica of the signal to be amplified, and a slow-wave circuit approximately resonant to the predetermined frequency of the signal electrically coupled to the structure, the grid including a support member for the electrically conductive structure, the support member being a structure separate from the electrically conductive structure so the beam which passes through the electrically conductive structure does not pass through the support member, the slow-wave circuit being on the support member.

A grid for a vacuum tube for amplifying an r.f. signal having a predetermined frequency comprising an electrically conductive structure for current modulating in response to the signal an electron beam of the tube, the structure when located in the tube being positioned and configured so that the beam passes through the structure, and a slow-wave circuit approximately resonant to the frequency of the signal electrically coupled to the structure, the electrically conductive structure including a slow-wave circuit including a meander line radially extending segments connected to arcuately extending segments.

A grid for a vacuum tube for amplifying an r.f. signal having a predetermined frequency comprising an electrically conductive structure for current modulating in response to the signal an electron beam of the tube, the structure when located in the tube being positioned and configured so that the beam passes through the structure, and a slow-wave circuit approximately resonant to the frequency of the signal electrically coupled to the structure, the electrically conductive structure including the slow-wave structure, the slow-wave circuit including plural electrically parallel meander liens, each of the lines extending from a central conductive region defining a first common terminal for said lines to a peripheral conductive region defining a second common terminal for said lines.

A grid for a vacuum tube for amplifying an r.f. signal having a predetermined frequency, the grid comprising an electrically conductive structure, the structure including means for current modulating in response to the signal an electron beam of the tube passing therethrough so that the current modulated beam has a current variation that is a replica of the signal to be amplified, the structure including a slow-wave circuit having a length that is approximately an odd integral multiple of a quarter wavelength at the predetermined frequency of the signal so the slow-wave structure is approximately resonant at the predetermined frequency.

A vacuum tube for amplifying a high-frequency signal comprising a cathode electrode for emitting an electron beam, a grid electrode responsive to said signal for current modulating said beam, one of said grid and cathode electrodes including a slow-wave structure approximately resonant to a frequency of said signal, a collector for said beam, electrode means for accelerating said beam toward the collector, means for focusing said beam, and a cavity resonant to the frequency of said signal positioned between said grid and collector, said cavity being reactively coupled to the beam, the grid electrode being spaced from the cathode electrode by a distance no greater than the distance an electron emitted from the cathode electrode traverses in a quarter cycle of the r.f. signal, means for establishing electric fields between the grid and cathode electrodes so that the electon beam flows only during approximately one-half cycle of the r.f. signal.

A grid for a vacuum tube for amplifying an r.f. signal having a predetermined frequency comprising an electrically conductive structure for current modulating in response to the signal an electron beam of the tube, the structure when located in the tube being positioned and configured so that the beam passes through the structure, and a slow-wave circuit approximately resonant to the frequency of the signal electrically coupled to the structure, the slow-wave structure being a meander line including a spiral.

A vacuum tube for amplifying a high-frequency signal comprising a cathode electrode for emitting a hollow electron beam having a path, a grid electrode responsive to said signal for current modulating said electron beam so that the current modulated beam has a current variation that is a replica of the signal to be amplified, a collector for said electron beam, electrode means for accelerating said electron beam toward the collector, a focusing electrode for said electron beam positioned around the electron beam upstream in the direction of electron flow in the path from the cathode of the grid, and a cavity resonant to the frequency of said signal positioned between said grid and collector, said cavity being coupled to the current modulated electron beam, said grid electrode including a slow wave structure approximately resonant to a frequency of the signal.

A slow-wave circuit comprising an electrically conducting surface at a reference potential, and plural electrically parallel electrically conducting meander liens spaced from said conducting surface so that an electric field subsists between the lines and surface, said meander lines extending between a common central region and a common outer region coaxial with the central region, each of the meander lines including radially extending elements having predetermined longitudinal extents and circumferentially extending elements having predetermined angular extents, the predetermined extents of one of said elements changing as the radii of the meander lines increase so that the rate of increase of electric length with distance of the liens varies as the distance of the structure increases from the central region.

A grid for current modulating an electron beam in response to an r.f. signal comprising plural electrically parallel electrically conducting meander lines adapted to be mounted in the path of the electron beam for establishing an r.f. electric field in a space between the grid and a source of the beam, said meander lines extending between a common central region and a common outer region coaxial with the central region, each of the meander lines including radially extending elements having predetermined longitudinal extents and circumferentially extending elements having predetermined angular extents, the predetermined extents of one of said elements changing as the radius of the grid increases so that the rate of increase of electric length of the lines varies, as the distance of the structure increases from the central region.

A vacuum tube for amplifying an r.f. signal having a predetermined frequency comprising a cathode for emitting an electron beam, a grid for current modulating the electron beam in response to the signal so that the current modulated beam has a current variation that is a replica of the signal to be amplified, the grid including an electrically conductive structure having spaces between elements thereof through which the beam passes and a slow-wave circuit approximately resonant at the frequency of the signal electrically connected to the structure, and output means responsive to the current modulated beam.