A number of low voltage vacuum tube circuits include using supply voltages well below the manufacturer's recommended voltages applied to the plate or screen grid. Some of the tube circuits operate at near zero plate and or screen grid voltages. Other low voltage circuits have forward biasing on one or more grids that are normally biased at a non positive voltage or a grid that is normally connected a cathode. Substantially lower supply voltages allow for example, the filament supply to also supply voltage to the plate and or grid for providing an output signal at a grid and or a plate.

A number of low voltage vacuum tube circuits include using supply voltages well below the manufacturer's recommended voltages applied to the plate or screen grid. Some of the tube circuits operate at near zero plate and or screen grid voltages. Other low voltage circuits have forward biasing on one or more grids that are normally biased at a non positive voltage or a grid that is normally connected a cathode. Substantially lower supply voltages allow for example, the filament supply to also supply voltage to the plate and or grid for providing an output signal at a grid and or a plate.

A thermoelectric conditioning arrangement may comprise a first antenna/splitter configured to transmit a power & control signal, a second antenna/splitter configured to receive the power & control signal, a waveguide coupled between the first antenna/splitter and the second antenna/splitter, wherein the power & control signal is guided from the first antenna/splitter to the second antenna/splitter via the waveguide, a power converter configured to receive the power & control signal from the second antenna/splitter and generate a direct current (DC) signal, and a thermoelectric cooler (TEC) configured to receive the DC signal from the power converter.

To provide a magnetron capable of balancing cost reduction and effective suppression of high frequency components.

A choke 30 is formed as a separated part from an output side metal sealing body 7. A Cu-plated metal layer 7C is formed on the metal sealing body 7, and a Sn-plated metal layer 30F which is cheaper and has a lower melting point than the Cu-plated part is formed on the choke 30. Thereby, in a brazing process, the tightly-adhered part of the Cu-plated part on the metal sealing body 7 and the Sn-plated part on the choke 30 is melted and becomes Cu-Sn alloy, and the choke 30 is joined to the metal sealing body 7 as firm as the case of using brazing materials. Thus, plating costs and brazing costs can be reduced; it enables to balance cost reduction and effective suppression of high frequency components in comparison with conventional magnetrons.

To provide a magnetron capable of balancing cost reduction and effective suppression of high frequency components.

A choke 30 is formed as a separated part from an output side metal sealing body 7. A Cu-plated metal layer 7C is formed on the metal sealing body 7, and a Sn-plated metal layer 30F which is cheaper and has a lower melting point than the Cu-plated part is formed on the choke 30. Thereby, in a brazing process, the tightly-adhered part of the Cu-plated part on the metal sealing body 7 and the Sn-plated part on the choke 30 is melted and becomes Cu-Sn alloy, and the choke 30 is joined to the metal sealing body 7 as firm as the case of using brazing materials. Thus, plating costs and brazing costs can be reduced; it enables to balance cost reduction and effective suppression of high frequency components in comparison with conventional magnetrons.

A thermoelectric conditioning arrangement may comprise a first antenna/splitter configured to transmit a power & control signal, a second antenna/splitter configured to receive the power & control signal, a waveguide coupled between the first antenna/splitter and the second antenna/splitter, wherein the power & control signal is guided from the first antenna/splitter to the second antenna/splitter via the waveguide, a power converter configured to receive the power & control signal from the second antenna/splitter and generate a direct current (DC) signal, and a thermoelectric cooler (TEC) configured to receive the DC signal from the power converter.

According to one embodiment, an introduction-side rectangular waveguide tube and a lead-out-side rectangular waveguide tube are each connected to a circular connection plate connected to an end surface of the circular waveguide tube, and at least one connection plate includes, in an outer circumference thereof, the other welding collar welded to the one welding collar, and both the one welding collar and the other welding collar include grooves or holes for a rotation regulation jig to regulate rotation in a circumferential direction, and an entire portion along the circumferential direction including the grooves or holes is welded and fixed thereto.

A magnetron characterized by a supporting cylinder, a field emission cathode, a slow wave structure, and a waveguide. The slow wave structure includes an anode block positioned coaxial with and surrounded by the field emission cathode. The anode block includes sixteen radially-projecting vane panels defining sixteen resonant cavities therebetween. Each of the resonant cavities may comprise a resonant channel portion positioned radially proximate to and axially coextensive with a center axis of the anode block. A void between the anode block and the field emission cathode, along with the resonant cavities, define an interaction region. The waveguide, comprising a cylinder characterized by an exterior layer surrounding an interior void, is capacitively coupled to the slow wave structure and configured to deliver radio frequency (RF) energy extracted from the interaction region by one (or, optionally, two) excitation rings mounted at a downstream end of the anode block.

A magnetron characterized by a supporting cylinder, a field emission cathode, a slow wave structure, and a waveguide. The slow wave structure includes an anode block positioned coaxial with and surrounded by the field emission cathode. The anode block includes sixteen radially-projecting vane panels defining sixteen resonant cavities therebetween. Each of the resonant cavities may comprise a resonant channel portion positioned radially proximate to and axially coextensive with a center axis of the anode block. A void between the anode block and the field emission cathode, along with the resonant cavities, define an interaction region. The waveguide, comprising a cylinder characterized by an exterior layer surrounding an interior void, is capacitively coupled to the slow wave structure and configured to deliver radio frequency (RF) energy extracted from the interaction region by one (or, optionally, two) excitation rings mounted at a downstream end of the anode block.

A cylindrical waveguide with a mode converter transforms a whispering gallery mode from a gyrotron cylindrical waveguide with a helical cut launch edge to a quasi-Gaussian beam suitable for conveyance through a corrugated waveguide. This quasi-Gaussian beam is radiated away from the waveguide using a spiral cut launch edge, which is in close proximity to a first mode converting reflector. The first mode converting reflector is coupled to a second mode converting reflector which provides an output free-space HE11 mode wave suitable for direct coupling into a corrugated waveguide. The radiated beam produced at the output of the second mode converting reflector is substantially circular.