A microwave source used in the radiotherapy device can be provided. The microwave source may include an anode block and one or more cathodes. The cathode of the microwave source may include a cathode support element having a plurality of slots. The plurality of slots can be axially around a circumference of the cathode support element. The microwave source may include a cathode heater including at least one filament. A first part of the at least one filament may be wound around the cathode support element along a first direction and received by a first portion of the plurality of slots, and a second part of the at least one filament may be wound around the cathode support element along a second direction and received by a second portion of the plurality of slots.

Provided is a low-cost magnetron that is excellent in productivity without any adverse effect on characteristics. Two large and small strap rings 11 (11A and 11B) are only disposed at lower ends, or input sides, of a plurality of vanes 10 (10A and 10B) in the direction of a tube axis m. Diameter Rip of a protruding flat surface 41 of an input side pole piece 18 is larger than diameter Rop of a protruding flat surface 40 of an output side pole piece 17. Therefore, it is possible to provide a practical magnetron without a significant decrease in productivity or characteristics from a conventional one, while cutting costs by reducing the number of parts with the use of two strap rings on one side.

Provided is a low-cost magnetron that is excellent in productivity without any adverse effect on characteristics. Two large and small strap rings 11 (11A and 11B) are only disposed at lower ends, or input sides, of a plurality of vanes 10 (10A and 10B) in the direction of a tube axis m. Diameter Rip of a protruding flat surface 41 of an input side pole piece 18 is larger than diameter Rop of a protruding flat surface 40 of an output side pole piece 17. Therefore, it is possible to provide a practical magnetron without a significant decrease in productivity or characteristics from a conventional one, while cutting costs by reducing the number of parts with the use of two strap rings on one side.

An injection locked magnetron system based on filament injection is provided, which includes a magnetron, an excitation cavity, and a load. The magnetron is installed on the excitation cavity and connected to the excitation cavity, the excitation cavity is detachably connected to the load, the magnetron is provided with an injection antenna, and the injection antenna is used to receive an injected external signal and couple the injected external signal into the magnetron for realizing injection locking. The injected external signal is injected by a monopole antenna, and coupled into the magnetron resonant cavity through a magnetron filament, and the output microwave of the magnetron is output through the excitation cavity, and passes through the waveguide directional coupler, and is finally absorbed by the load, such that the output microwave of the magnetron can be locked by the injected external signal.

There is provided an anode for a magnetron, the anode comprising: a cylindrical shell defining a longitudinal axis, a centre of the shell for accommodating a cathode of the magnetron; a plurality of vanes arranged at angular intervals around the shell, wherein an angular separation between each vane and its adjacent vane is configured to provide a cavity resonator of the magnetron, wherein each vane has a width extending radially inwardly from the shell toward the centre of the shell, and has a length extending longitudinally in parallel with the longitudinal axis of the shell; and a plurality of annular strap rings for setting a resonant mode spectrum of the cavity resonator, wherein the strap rings are arranged at longitudinal intervals and concentrically with the longitudinal axis of the shell, wherein alternate vanes are configured to support the alternate strap rings, such that each vane couples alternate strap rings and each strap ring couples alternate vanes, wherein a cross-sectional dimension of at least a first strap ring of the plurality of strap rings is different from the cross-sectional dimension of at least a second strap ring of the plurality of strap rings.

There is provided herein an anode for a magnetron, the anode comprising: a cylindrical shell defining a longitudinal axis, a centre of the shell for accommodating a cathode of the magnetron; a plurality of vanes arranged at angular intervals around the shell, wherein an angular separation between each vane and its adjacent vane is configured to provide a cavity resonator of the magnetron, wherein each vane has a width extending radially inwardly from the shell toward the centre of the shell, and has a length continuously extending longitudinally in parallel with the longitudinal axis of the shell; and a plurality of annular strap rings for setting a resonant mode spectrum of the cavity resonator, wherein the strap rings are arranged at longitudinal intervals and concentrically with the longitudinal axis of the shell, wherein each vane comprises an inner vane segment arranged to face the cathode and a respective outer vane segment connected to the inner vane segment and interposed between the inner vane segment and the shell, and wherein the plurality of vanes are configured to support the plurality of strap rings between the respective inner and outer vane segments such that each vane couples alternate strap rings and each strap ring couples alternate vanes.

A magnetron is provided and includes a tube body with a plurality of communicated first cavities therein, a plurality of anodes in the first cavities including a cylinder and a plurality of vanes, outer ends of the vanes are connected with an inner circumferential surface of the cylinder; a first resonant cavity and a second resonant cavity are formed between the adjacent vanes, the cylinder is provided with a plurality of coupling slots arranged at intervals and running through the cylinder to communicate the first resonant cavity with the first cavity; a plurality of cathode arranged in and coaxially with the cylinder; the cathodes and inner ends of the vanes are spaced apart; at least part of the cathodes are located inside vanes, and an output slot is defined on the tube body for communicating the first cavity with an outside.

A magnetron is provided and includes a tube body with a plurality of communicated first cavities therein, a plurality of anodes in the first cavities including a cylinder and a plurality of vanes, outer ends of the vanes are connected with an inner circumferential surface of the cylinder; a first resonant cavity and a second resonant cavity are formed between the adjacent vanes, the cylinder is provided with a plurality of coupling slots arranged at intervals and running through the cylinder to communicate the first resonant cavity with the first cavity; a plurality of cathode arranged in and coaxially with the cylinder; the cathodes and inner ends of the vanes are spaced apart; at least part of the cathodes are located inside vanes, and an output slot is defined on the tube body for communicating the first cavity with an outside.

A magnetron is provided and includes a tube body with a plurality of communicated first cavities therein, a plurality of anodes in the first cavities including a cylinder and a plurality of vanes, outer ends of the vanes are connected with an inner circumferential surface of the cylinder; a first resonant cavity and a second resonant cavity are formed between the adjacent vanes, the cylinder is provided with a plurality of coupling slots arranged at intervals and running through the cylinder to communicate the first resonant cavity with the first cavity; a plurality of cathode arranged in and coaxially with the cylinder; the cathodes and inner ends of the vanes are spaced apart; at least part of the cathodes are located inside vanes, and an output slot is defined on the tube body for communicating the first cavity with an outside.

A magnetron is provided and includes a tube body with a plurality of communicated first cavities therein, a plurality of anodes in the first cavities including a cylinder and a plurality of vanes, outer ends of the vanes are connected with an inner circumferential surface of the cylinder; a first resonant cavity and a second resonant cavity are formed between the adjacent vanes, the cylinder is provided with a plurality of coupling slots arranged at intervals and running through the cylinder to communicate the first resonant cavity with the first cavity; a plurality of cathode arranged in and coaxially with the cylinder; the cathodes and inner ends of the vanes are spaced apart; at least part of the cathodes are located inside vanes, and an output slot is defined on the tube body for communicating the first cavity with an outside.