A microwave energy tool including a sheet beam klystron that includes a tube body for carrying an electron sheet beam that has a plurality of cavities and a magnetic solenoid wound directly on the tube body.

The purpose is to make it possible to autonomously suppress a reduction in an electron beam without providing a means for supervising the electron beam intensity of a monitor or the like. An electron gun, provided with: a heater (12) in which one terminal serves as a heater terminal (H) and the other terminal serves as a shared terminal (HK), and in which a low-voltage power supply (21) is connected between the terminals, the heater (12) generating heat due to a current being supplied from the low-voltage power supply (21); and a cathode electrode (11) connected to the shared terminal (HK) and heated by the heater (12) to discharge thermal electrons. A cathode current (Ik) due to the thermal electrons discharged from the cathode electrode (11), and a current (Ih) due to the low-voltage power supply, flow in opposite directions through the heater (12).

The purpose is to make it possible to autonomously suppress a reduction in an electron beam without providing a means for supervising the electron beam intensity of a monitor or the like. An electron gun, provided with: a heater (12) in which one terminal serves as a heater terminal (H) and the other terminal serves as a shared terminal (HK), and in which a low-voltage power supply (21) is connected between the terminals, the heater (12) generating heat due to a current being supplied from the low-voltage power supply (21); and a cathode electrode (11) connected to the shared terminal (HK) and heated by the heater (12) to discharge thermal electrons. A cathode current (Ik) due to the thermal electrons discharged from the cathode electrode (11), and a current (Ih) due to the low-voltage power supply, flow in opposite directions through the heater (12).

The purpose is to make it possible to autonomously suppress a reduction in an electron beam without providing a means for supervising the electron beam intensity of a monitor or the like. An electron gun, provided with: a heater (12) in which one terminal serves as a heater terminal (H) and the other terminal serves as a shared terminal (HK), and in which a low-voltage power supply (21) is connected between the terminals, the heater (12) generating heat due to a current being supplied from the low-voltage power supply (21); and a cathode electrode (11) connected to the shared terminal (HK) and heated by the heater (12) to discharge thermal electrons. A cathode current (Ik) due to the thermal electrons discharged from the cathode electrode (11), and a current (Ih) due to the low-voltage power supply, flow in opposite directions through the heater (12).

Provided are a traveling wave tube and a high-frequency circuit system such that the product life span of the traveling wave tube operating in multiple modes can be extended while variations in gain and amplification efficiency that accompany switching of the operation modes can be suppressed. The traveling wave tube comprises: an electron gun equipped with a cathode that releases electrons, and a heater that provides the cathode with heat energy for releasing the electrons; a helix causing an RF signal to interact with an electron beam formed from the electrons released by the electron gun; a collector for catching the electron beam emitted by the helix; an anode whereby the electrons released from the electron gun are guided into the helix; and a magnetic field application device for generating a magnetic field in order to change the diameter of the electron beam, said magnetic field application device being supplied with electric power for generating the magnetic field from the outside.

Provided are a traveling wave tube and a high-frequency circuit system such that the product life span of the traveling wave tube operating in multiple modes can be extended while variations in gain and amplification efficiency that accompany switching of the operation modes can be suppressed. The traveling wave tube comprises: an electron gun equipped with a cathode that releases electrons, and a heater that provides the cathode with heat energy for releasing the electrons; a helix causing an RF signal to interact with an electron beam formed from the electrons released by the electron gun; a collector for catching the electron beam emitted by the helix; an anode whereby the electrons released from the electron gun are guided into the helix; and a magnetic field application device for generating a magnetic field in order to change the diameter of the electron beam, said magnetic field application device being supplied with electric power for generating the magnetic field from the outside.

A compact magnet system for use in a high-power microwave tube includes an electromagnetic coil surrounded on three sides by permanent magnets. More particularly, constituent components include a first tubular retaining member; the electromagnetic coil that fits within the first tubular retaining member and that has a central cavity; first permanent magnets positioned to extend radially from the central cavity so that like poles of the first permanent magnets wrap around the central cavity along a first side of the solenoid coil; and second permanent magnets positioned to extend radially from the central cavity so that opposite poles to the first permanent magnets wrap around the central axis along the second side of the solenoid coil. Optional added components include two sets of permanent magnets, one set on each side of the coil and a pole piece located adjacent to an end of the first tubular retaining member.

A compact magnet system for use in a high-power microwave tube includes an electromagnetic coil surrounded on three sides by permanent magnets. More particularly, constituent components include a first tubular retaining member; the electromagnetic coil that fits within the first tubular retaining member and that has a central cavity; first permanent magnets positioned to extend radially from the central cavity so that like poles of the first permanent magnets wrap around the central cavity along a first side of the solenoid coil; and second permanent magnets positioned to extend radially from the central cavity so that opposite poles to the first permanent magnets wrap around the central axis along the second side of the solenoid coil. Optional added components include two sets of permanent magnets, one set on each side of the coil and a pole piece located adjacent to an end of the first tubular retaining member.

A travelling-wave tube includes an input apparatus, a control circuit, an electron gun, a slow-wave circuit, and an output apparatus. The input apparatus may be configured to receive a radio frequency signal, and feed the radio frequency signal into the slow-wave circuit. The control circuit may be configured to determine a quantity N of electron beams and currents of the N electron beams, and control the electron gun to emit the N electron beams. Further, the slow-wave circuit may perform beam-wave interaction with the N electron beams, to amplify power of the radio frequency signa, and because the slow-wave circuit works in a saturation region, electronic efficiency of the travelling-wave tube can be greater than or equal to a first threshold. The output apparatus may output an amplified radio frequency signal.

A travelling-wave tube includes an input apparatus, a control circuit, an electron gun, a slow-wave circuit, and an output apparatus. The input apparatus may be configured to receive a radio frequency signal, and feed the radio frequency signal into the slow-wave circuit. The control circuit may be configured to determine a quantity N of electron beams and currents of the N electron beams, and control the electron gun to emit the N electron beams. Further, the slow-wave circuit may perform beam-wave interaction with the N electron beams, to amplify power of the radio frequency signa, and because the slow-wave circuit works in a saturation region, electronic efficiency of the travelling-wave tube can be greater than or equal to a first threshold. The output apparatus may output an amplified radio frequency signal.