Extended interaction device comprising a core and shell device body for supporting ring-shaped resonant cavities, electron beam tunnels and a coupling groove therein and an output waveguide at a middle portion of the shell

Abstract

A millimeter-wave extended interaction device, including: a device body; resonant cavities; electron beam tunnels; an output waveguide; and a coupling hole. The device body includes a shell and a core, and an annular coupling channel is disposed between the shell and the core. The resonant cavities are a set of ring-shaped cavities with a radial height of 2/5, to 3/5, parallel and equally spaced around an axis of the core. The electron beam tunnels are arranged at equal radian intervals and parallel to the axis of the core. The output waveguide is disposed in the middle of the shell and communicates with the annular coupling channel through a coupling hole. The core and the inner surface of the shell are sealed and fixed, and the output waveguide and the shell are sealed and fixed.

Claims

1. A millimeter-wave extended interaction device, comprising: a device body comprising a shell and a core; the core comprising resonant cavities, a coupling groove, and electron beam tunnels; and the shell comprising a coupling hole; and an output waveguide; wherein: the shell and the core are in a cylindrical shape, and are coaxially disposed around a longitudinal axis; the core is disposed within the shell; the coupling groove is in a cylindrical shape, and is recessed inward from an outer surface of the core; the resonant cavities are a set of ring-shaped cavities with a radial height of 2/5, to 3/5, are coaxially disposed around the longitudinal axis, and are parallel to each other and equally spaced from each other; wherein , represents an operating wavelength; the resonant cavities are connected to the coupling groove; the electron beam tunnels are arranged at equal radian intervals and parallel to the longitudinal axis, and each electron beam tunnel is connected to the resonant cavities and extends between two end walls of the core; the coupling hole extends outward from an inner surface of the shell; the coupling hole is connected to the coupling groove; the output waveguide is disposed at a middle portion of the shell between two ends of the shell, and is connected to the coupling hole; the resonant cavities are coupled to the output waveguide via the coupling groove and the coupling hole; and the core and the shell are sealed and fixed to each other, and the output waveguide and the shell are sealed and fixed to each other.

2. The device of claim 1, wherein a radial height of the coupling groove is in the range from /10 to /5, and an axial width thereof is equal to a distance between outer walls of the two resonant cavities that are respectively adjacent to the two end walls of the core.

3. The device of claim 1, wherein the resonant cavities are 5 to 19 in number, and a respective width of the resonant cavities along an axial direction parallel to the longitudinal axis is related to an operating voltage; when the operating voltage is 5-40 kV, the respective width of the resonant cavities is 0.15-5 mm.

4. The device of claim 1, wherein the electron beam tunnels are 5-20 in number and a respective diameter of each electron beam tunnel along a plane that is perpendicular to the longitudinal axis is /7 to /5; a space between two adjacent electron beam tunnels is 1-3 times a diameter of a respective electron beam tunnel.

5. The device of claim 1, wherein the coupling hole is rectangular or circular.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic drawing of a millimeter-wave extended interaction device according to one embodiment of the invention;

(2) FIG. 2 is a cutaway view taken from line II-II in FIG. 1.

(3) FIG. 3 is a cutaway view taken from line IV-IV in FIG. 1.

(4) FIG. 4 is a part cutaway view of a millimeter-wave extended interaction device according to one embodiment of the invention.

(5) In the drawings, the following reference numbers are used: 1: Core, 2: Shell, 3: Electron beam tunnel, 4: Ring-shaped resonant cavity, 5: Annular coupling channel, 6: Coupling hole, 7: Output waveguide.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(6) The implementation method takes a 94 GHz (the corresponding operating wavelength is about 3.2 mm) EID operated in fundamental mode (TM.sub.010 mode) at the operating voltage of 20 kV for example.

(7) As shown in FIGS. 1-4, the nominal diameter and the axial length of the core 1 (FIGS. 1 and 4) are 8.7 mm and 8.0 mm respectively. The nominal size of the shell 2 is as follows: the diameter of 8.7 mm, the outer diameter of 12 mm, and the axial length of 8.0 mm. The material is oxygen free copper. This method sets 7 ring-shaped resonant cavities 4 (FIGS. 1, 2, and 4) in the core 1. The inner and outer radius of each ring-shaped resonant cavity is 2.4 mm and 4.0 mm (the radial height of the resonant cavity is /2) respectively. The axial width of each ring-shaped resonant cavity is 0.40 mm and the space between two adjacent resonant cavities is 0.52 mm. The axial length of the annular coupling channel 5 is 5.92 mm and its inner, outer radius is 4.0 mm, 4.35 mm respectively. Namely, the radial gap of the annular coupling channel is 0.35 mm. In the central lines of the ring-shaped resonant cavities 4 place 16 electron beam tunnels with the diameter of 0.5 mm which are arranged at equal radian intervals and pass through the core 1. The shell 2 is provided with the output waveguide 7 (FIGS. 1, 2, and 4) and the coupling hole 6 (FIGS. 1, 2, and 4), and the distance between the central lines of which and the core 1 is 4.0 mm. Among, the output waveguide 7 is a standard W-band rectangular waveguide and the coupling hole 6 is a circular hole with the diameter of 0.85 mm.

(8) This method was implemented by simulation tests. The operating frequency is 94 GHz when the device operates in fundamental mode at 20 kV. The total beam current of 16 electron beam tunnels obtains 16 A, each beam tunnel 3 having current of 1.0 A.

(9) The input beam power of the device is 320 kW and the output microwave power over 16.5 kW can be achieved. The output efficiency is about 5.15%.

(10) Unless otherwise indicated, the numerical ranges involved in the invention include the end values. While particular embodiments of the invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects, and therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention.