CN105609902A - Reflection-type phase shifter, accelerator and operation method of reflection-type phase shifter - Google Patents

Abstract

The invention relates to a phase shifter, a method for its operation and an accelerator, the phase shifter comprising a first part (1) and a second part (2), the first part (1) having a first cavity (5), the The second component (2) is arranged in the first cavity (5), the phase shifter is configured so that microwaves can be reflected back inside it, and the first port of the first cavity serves as its entrance and the outlet; the distance between the inner wall of the cavity (5) and the outer wall of the second part (2) changes periodically and continuously in the circumferential direction, so that when the first part (1) and the second part ( 2) There is a phase shift between adjacent microwave pulses at the exit of the phase shifter during relative rotation. The mechanical phase shifter of the present invention has a simple structure and strong controllability, which is reflected in that the phase shift range can be controlled by changing the structural parameters of the components, and the phase shift speed can be controlled by changing the rotation speed.

Description

Reflective Phase Shifter and Accelerator and Method of Operation

technical field

The invention relates to the field of microwave conduction technology and the field of accelerators, in particular to a reflective phase shifter, an accelerator and an operating method thereof.

Background technique

The phase shifter is one of the very important microwave devices in microwave applications, and it is widely used in the fields of radar, accelerator, communication and instrumentation. The current phase shifters all insert dielectric sheets, pins or ferrites into the structure to change the waveguide coefficient, thereby changing the lower phase of the microwave.

The phase shifter is a kind of phase shifter that can change the microwave phase, and has a unique application in the synthesis and distribution of high-power microwaves. The faster the phase change rate, the higher the repetition rate of system operation can be. High-power phase shifters have been studied abroad. In some existing technologies, ferrites or ferroelectrics of a certain geometric size are placed in the waveguide, and the ferrite or ferroelectric phase is changed through the peripheral high-voltage external circuit. The material parameters of the body can then change the phase shift. The design of these phase shifters requires relatively high requirements for external circuits, and if a fast phase shift is to be achieved, the external pulse voltage usually needs to be several thousand volts, and the requirements for the rising edge of the pulse are also very high. In addition, in order to make the microwave have good transmission characteristics in these phase shifters, some other media are usually added to the structure, so the design is more complicated.

A common phase shifter is a two-port microwave component, and the microwave enters through one port and transmits through the other port. The change of phase is realized by adding diaphragm, ferrite, etc. in the transmission section. However, the phase shifter in the prior art that changes the parameters of the ferrite material through an external circuit has the following defects:

(1) Limited phase shift: Although the design schemes given in the current literature can achieve rapid phase changes in a relatively short period of time, the range of phase changes is very small and cannot achieve a 180° phase change;

(2) Poor stability: At present, the phase shifter adopts the method of external circuit control, and the change of the microwave phase is realized by changing the electrical or magnetic parameters of the material. This requires relatively high stability of the external circuit voltage. Most of the current designs are in From the measurement results, a section with a better interception effect is taken as the design result;

(3) Material limitation: The current existing phase shifters need to add ferrite materials or other materials inside the phase shifter, which increases the difficulty of design;

(4) Limitation of the external circuit: the parameters of the material are changed through the external circuit to change the size of the phase. The voltage of the external circuit is usually several thousand volts, and it is difficult to apply high voltage.

For the solutions in the prior art, according to the experimental results in the literature, a single phase shifter has not yet achieved a 180° change. The main reason is that the transmission of microwaves is limited, and when microwaves pass through the phase shifter, the power will be reduced. , At the same time, some microwaves will be reflected, and the ferrite-based phase shifter must ensure small reflection, low loss, and fast speed, these are limiting factors.

Contents of the invention

The object of the present invention is to propose a reflective phase shifter, an accelerator and a control method thereof, which can conveniently realize a phase shift between adjacent microwave pulses at the exit of the phase shifter.

To achieve the above object, the present invention provides a reflective phase shifter, comprising a first component and a second component, the first component has a first cavity, and the second component is arranged in the first cavity , the phase shifter is configured so that microwaves can be reflected back inside it, and the first port of the first cavity serves as its entrance and exit;

The distance between the inner wall of the cavity and the outer wall of the second part changes periodically and continuously in the circumferential direction, so that when the relative rotation between the first part and the second part, the phase shifter There is a phase shift between adjacent microwave pulses at the exit.

Further, the distance between the inner wall of the first cavity and the outer wall of the second component changes continuously in a period of 180° in the circumferential direction.

Further, the phase shift is in the range of 0° to 180°.

Further, the cylinder of the second component is arranged in the first cavity, and the cross section of one of the first cavity and the cylinder is circular and stationary, and the first The distance between the cross-section of the other of the cavity and the cylinder and its center of rotation varies periodically and continuously in the circumferential direction.

Further, the cross-section of the other of the first cavity and the cylinder is an ellipse, a rectangle, a regular triangle or a regular polygon.

Further, the first part is also provided with a second cavity, the second cavity communicates with the first end of the first cavity, and the second cavity has a first port close to the first port. A guiding part is used for guiding the microwaves into the first cavity.

Further, the first guide part includes a square waveguide and a first transition part, the square waveguide is a cavity with a square cross section, and the square waveguide communicates with the first cavity through the first transition part.

Further, the second component includes a second guide portion adjacent to the first port for guiding the microwave between the first cavity and the second component Space.

Further, the second guide part includes a cylindrical part and a second gradual change part, and the cylindrical part is connected with the cylinder of the second component through the second gradual change part.

Further, it also includes a circulator arranged at the first port, for separating the incoming microwave and the reflected microwave.

Further, it also includes a choke structure, the choke structure is arranged between the first part and the second part and adjacent to the second port of the first cavity, and is used for controlling all incoming The microwaves are reflected.

In addition, the present invention also provides an accelerating tube for accelerating electrons in the accelerator, the above-mentioned reflective phase shifter and a driving device, the driving device is used to make the first part and the second part rotate relatively .

Further, the accelerator includes a first accelerating tube and a second accelerating tube, the first accelerating tube is located upstream of the second accelerating tube, and the reflective phase shifter is arranged in the second accelerating tube.

In addition, the present invention also provides a control method for the above-mentioned accelerator, wherein the column of the second component is arranged in the first cavity, and the transverse portion of one of the first cavity and the column is The cross-section is circular and stationary, the cross-section of the other of the first cavity and the cylinder is elliptical, and the control method includes:

transmitting microwave pulses into said accelerator at a repetition rate v hertz;

The driving device drives the first cavity and the other one of the cylinder to rotate at a speed of n revolutions per minute, where n=15vm, m is an odd number, 1, 3, 5..., so that each time When microwave pulses are emitted, the major axis of the elliptical cross-section rotates to a horizontal or vertical state, and the phase shift between adjacent microwaves at the exit of the phase shifter is 180 degrees.

Based on the above technical solution, the phase shifter of the embodiment of the present invention belongs to a mechanically controlled phase shifter, and the distance between the inner wall of the first part and the outer wall of the second part is configured to change periodically and continuously in the circumferential direction , after the microwave enters the gap between the first part and the second part from the inlet, the cross-sectional orientation of the gap is changed by the relative rotation of the first part and the second part, so that the microwave enters and leaves the first port The phase of the time has a phase shift. This method has a simple structure and strong controllability. It is reflected in that the range of the phase shift can be controlled by changing the structural parameters of the components, and the speed of the phase shift can be controlled by changing the rotation speed.

Description of drawings

The accompanying drawings described here are used to provide a further understanding of the present invention and constitute a part of the application. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations to the present invention. In the attached picture:

Fig. 1 is the structural representation of an embodiment of phase shifter of the present invention;

Fig. 2 is a schematic diagram of the curve of the microwave phase changing with the relative rotation angle of the first part and the second part during the working process of the phase shifter of the present invention;

3 is a schematic diagram of microwave state changes of a phase shifter in the prior art;

Fig. 4 is a schematic structural diagram of an accelerator including a phase shifter of the present invention.

Explanation of reference signs

1-first part; 2-second part; 3-square waveguide; 4-first gradient part; 5-circular waveguide; 6-cylindrical part; 7-second gradient part; 8-ellipse part; 9-choke structure; 10—drive connection part.

detailed description

The present invention will be described in detail below. In the following paragraphs, different aspects of the embodiments are defined in more detail. Aspects so defined may be combined with any other aspect or aspects unless specifically stated otherwise. In particular, any feature which is considered to be preferred or advantageous may be combined with one or more other features which are considered to be preferred or advantageous.

Terms such as "first" and "second" appearing in the present invention are only for convenience of description, to distinguish different components with the same name, and do not indicate a sequence or a primary and secondary relationship.

In the description of the present invention, it should be understood that the orientations or positional relationships indicated by the terms "inner", "outer", "front", "rear", "left" and "right" are based on those shown in the accompanying drawings. Orientation or positional relationship is only for the convenience of describing the present invention, but does not indicate or imply that the referred device must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as limiting the protection scope of the present invention.

The present invention changes the method of changing the parameters of the ferrite material through an external circuit to realize microwave phase shifting in the prior art, and provides a reflective phase shifter, as shown in Figure 1, the phase shifter includes a first component 1 and The second part 2, the first part 1 has a first cavity, the second part 2 (preferably coaxial) is arranged in the first part 1, and the phase shifter is configured so that the microwaves are reflected back therein so that the incoming The directions of the microwaves and the emitted microwaves are opposite, and the first port of the first cavity is used as a microwave inlet and a microwave outlet; the distance between the inner wall of the first part 1 and the outer wall of the second part 2 changes periodically and continuously in the circumferential direction, so that When the relative rotation between the first part 1 and the second part 2 occurs, when the orientation of the cross-section between the first part 1 and the second part 2 changes continuously, adjacent microwave pulses will encounter different cross-sectional orientations, A phase shift occurs between adjacent microwave pulses.

As shown in Figure 1, the relative rotation between the first part 1 and the second part 2, so that for a specific geometric design, the cross section of the gap between the inner wall of the first part 1 and the outer wall of the second part 2 can be changed Orientation, so that adjacent microwave pulses encounter different cross-sectional orientations when passing through it, which requires the rotation of components with non-circular cross-sections to achieve the purpose of phase shifting.

As shown in Figure 1, in an exemplary embodiment, if the second component 2 rotates, a drive connection part 10 may also be provided, and the drive connection part 10 is located at the second port of the first cavity 5 for communicating with the drive The parts are connected to control the rotation of the second part 2 . Wherein, the driving component can be a motor or other driving components, for example, the motor can be installed on the end surface of the first component 1 , and the shaft of the motor can be connected with the second component 2 . By controlling the rapid rotation of the motor, a fast phase shift can be realized, and the phase shift time can be realized by controlling the motor speed.

Optionally, the distance between the inner wall of the first part 1 and the outer wall of the second part 2 changes continuously in the circumferential direction with a cycle of 180°, which can be changed by the relative rotation between the first part 1 and the second part 2 The cross-section of the gap is oriented such that a phase shift occurs between adjacent microwave pulses.

When the distance between the inner wall of the first cavity 5 of the first part 1 and the outer wall of the second part 2 changes continuously with a cycle of 180° in the circumferential direction, the distance between adjacent microwave pulses leaving the phase shifter The phase shift can be in the range of 0° to 180°.

According to the above-mentioned core design idea, different shapes can be selected for the first part 1 and the second part 2 to realize microwave phase shifting, and several specific implementation forms will be given below.

In the first embodiment, corresponding to the structure shown in FIG. 1, the first cavity includes a circular waveguide 5, the circular waveguide 5 is a cavity with a circular cross section, and the second component 2 is arranged in the circular waveguide 5, The second component 2 includes an elliptical part 8 , which is a cylinder with an elliptical cross section. When the phase shifter works, the rotation of the second component 2 needs to be controlled.

The cross-sectional shape of the first inner cavity 11 may be a rectangle, an equilateral triangle or a regular polygon, as long as the cross-sectional shape is symmetrical with respect to the rotation center.

In the second embodiment, the first cavity includes an elliptical waveguide, the elliptical waveguide is a cavity with an elliptical cross section, the second part 2 is arranged in the elliptical waveguide, the second part 2 includes a cylindrical part, and when the phase shifter works It is necessary to control the rotation of the first part 1 .

In the third embodiment, the first cavity includes a circular waveguide 5, the circular waveguide 5 is a cavity with a circular cross section, the second part 2 is arranged in the circular waveguide 5, and the second part 2 includes a rectangular part, an equilateral triangle part or regular polygonal part, rectangular part, regular triangle part or regular polygonal part are cylinders with a cross section of rectangle, regular triangle or regular polygon respectively, and the rotation of the second part 2 needs to be controlled when the phase shifter works.

Further, the first component 1 also includes a second cavity, the second cavity communicates with the first cavity through the first end of the first cavity, and the second cavity includes a first guide portion close to the first port, for to guide microwaves into the first cavity.

Specifically, the first guiding part includes a square waveguide 3 and a first transition part 4, the square waveguide 3 is a cavity with a square cross section, and the first transition part 4 is connected between the square waveguide 3 and the circular waveguide 5, realizing the first The component 1 gradually changes from a square waveguide 3 to a circular waveguide 5 . The design of the first transition part 4 mainly considers the smooth transition between the square waveguide 3 and the circular waveguide 5 in structure, and is easy to process. In addition, the square waveguide 3 and the first tapering part 4 can also adopt other shapes, but the current structure of the phase shifter is mainly a square waveguide, which is for single-mode transmission during microwave transmission. However, if in a special application, it is not limited to the square waveguide 3, a circular waveguide is also possible.

Further, the second component 2 also includes a second guiding part, which is located at the first port, and is used to guide the incoming microwaves to the space between the circular waveguide 5 and the elliptical part 8, the main purpose of which is to realize the structural The smooth transition on the surface makes the field inside the phase shifter more uniform, and the cylinder is easier to process.

Specifically, the second component 2 also includes a cylindrical portion 6 and a second gradual change portion 7, the second gradual change portion 7 is connected between the cylindrical portion 6 and the elliptical portion 8, the cylindrical portion 6 is located near the end of the first port of the first cavity, Realized that the second part 2 gradually changes from the cylindrical part 6 to the elliptical part 8 . The design of the second gradient portion 7 mainly considers the structurally smooth transition between the cylindrical portion 6 and the elliptical portion 8 and is easy to process. In addition, the cylindrical part 6 and the second gradual change part 7 can also take other shapes.

For the phase shifter of the above-mentioned embodiment, since one end of the phase shifter is used as the microwave inlet and the microwave outlet at the same time, in order to prevent the incident microwave and the outgoing microwave from mixing together, the phase shifter of the present invention also includes a first cavity located in the first cavity. A circulator (not shown in the figure) at the port is used to separate incident microwaves and reflected microwaves. Specifically, the separation can be performed by controlling the timing of incident microwaves and outgoing microwaves.

For the phase shifter of the present invention, in order to realize microwave isolation, a choke structure 9 also needs to be provided, and the choke structure 9 can be arranged between the first part 1 and the second part 2 and close to the The position of the second port of the first cavity, or it can also be arranged on the second component 2, is used to isolate the microwave on one side of the choke structure 9, so as to reflect the incident microwave after being phase-shifted, it In fact, the short-circuit surface is transferred. In the embodiment shown in FIG. 1 , the choke structure 9 is located between the drive connection 10 and the ellipse 8 .

For the phase shifter with the circular waveguide 5 and the elliptical part 8, its working principle is: the microwave enters the cavity from the square waveguide 3 and starts to transmit continuously, and passes through the gap between the circular waveguide 5 and the elliptical part 8 during transmission. , by controlling the rotation of the second part 2, adjacent microwaves will encounter different cross-sectional orientations when passing through the gap, so that microwave pulses at different times meet different cross-sectional orientations through the mechanical structure, and realize adjacent The phase shift between the microwave pulses. The rapid change of the microwave phase can be realized by controlling the high-speed rotation of the second part 2 by the driving part.

Figure 2 shows the change curve of the microwave phase with the rotation angle of the ellipse. Different rotation angles correspond to different times, and the overall curve basically conforms to the law of sinusoidal variation.

The phase shifter of the present invention can be used as a high-power phase shifter. High power refers to high microwave power. Now the power directly from the power source is pulse power, not average power, which can reach 50MW, and can reach more than 200MW through pulse compression.

In the embodiment of the phase shifter of the present invention, the parameter design of each component is mainly considered from the following angles, the selection of the diameter of the circular waveguide 5 is related to the frequency of the microwave, and the selection of the length is mainly related to the phase shift. The length is also longer. Except for the ellipse, other parts will not change the phase shift. It is precisely because the relative rotation of the circular waveguide 5 and the ellipse 8 changes the internal boundary conditions and changes the phase shift constant. The geometric parameters of the ellipse, the major axis a and the minor axis b, are the main parameters that change the phase shift. The greater the difference between the major axis a and the minor axis b, the greater the phase shift for the same distance. In addition, the ellipse is only a part of the design of the geometric parameters, and any size adjustment and change of the geometric mechanism of the rotating part including the cylindrical part 6 and the second gradient part 7 may also realize the phase shift.

Through the aforementioned analysis, it can be seen that this kind of phase shifter can change the time required to achieve the same phase shift by adjusting the relative rotation speed of the first part 1 and the second part 2, and the relative rotation of the first part 1 and the second part 2 The faster the speed, the shorter the time it takes for the microwaves to undergo the same phase shift, so fast phase shifting of the phase shifter can be achieved by controlling the rotational speed of the rotating part.

In terms of the technical effect that the phase shifter of the present invention can achieve, for the embodiment of Fig. 1, since the cavity inside the first component 1 is sequentially composed of a square waveguide 3, a first gradient portion 4 and a circular waveguide from the first end 5 components, the cross-sectional area increases sequentially, the cavity is easy to process, and the phase shifter can realize a gap between adjacent microwaves by changing the orientation of the cross-sectional area of the gap between the first part 1 and the second part 2 Phase shift, so the phase shifter can use a shorter length, which also facilitates the processing of the phase shifter. In addition, the short length of the phase shifter can also minimize the power loss of the microwave, and the size of the phase shifter is related to the microwave band.

In addition, the present invention also provides an accelerator, which includes an accelerating tube for accelerating electrons in the accelerator, the above-mentioned reflective phase shifter and a driving device, and the driving device is used to make the first part 1 and the second part 2 relative rotation.

As shown in Fig. 4, the dual-energy accelerator includes two accelerating tubes, the first accelerating tube accelerates electrons, and the microwave phase of the second accelerating tube is controlled by the phase shifter of the present invention. The electron beam is accelerated by the first acceleration tube and then passes through the second acceleration tube, which will produce two kinds of electron beams with different energies.

For example, the repetition frequency of microwave pulses is 50Hz, which means that 50 microwave pulses are emitted per second. When the first microwave pulse enters the accelerator, the phase shifter is in the first phase, and the accelerated electrons are an energy. When the adjacent second microwave pulse enters the accelerator, because the phase shifter is in the second phase, the phase of the second microwave changes, so the accelerated electrons have another energy. There will be multiple electron beams with different energies being accelerated within 1 second.

The above is the basic implementation process of the dual-energy accelerator based on the phase shifter. The phase shifter here can be of ferrite type or mechanical rotation type.

The following relates to the control method of the accelerator of the present invention, wherein the relationship between the number of revolutions of the motor and the repetition frequency of microwave pulses is as follows. Figure 3 is a schematic diagram of the orientation of an elliptical waveguide in a phase shifter versus pulse time. Assume that the phase corresponding to the horizontal elliptical waveguide is 0°, and the phase corresponding to the vertical elliptical waveguide is 180°. Assume that the speed of the motor is n revolutions per minute, so the time for each revolution is 60/n seconds. Assuming that the repetition frequency of microwave pulses is v Hz, the time interval between adjacent microwave pulses is 1/v. It can be seen from Fig. 3 that the elliptical waveguide corresponding to adjacent microwave pulses can rotate m times of 1/4 turn, where m is an odd number, 1, 3, 5.... If m*(60/n)/4=1/v, it is ensured that the phase shift between adjacent microwave pulses is 180°, and the relationship between the motor speed and the repetition frequency of microwave pulses is: n=15vm/ Minutes, m is an odd number, 1, 3, 5.... When a microwave pulse is emitted, the elliptical waveguide rotates to one of the long-axis horizontal and vertical states, and when the next adjacent microwave pulse is emitted, the elliptical waveguide rotates to the other of the long-axis horizontal and vertical states. Since the phase shift of the elliptical waveguide encountered by adjacent microwave pulses is 180 degrees, the phase shift of adjacent microwave pulses at the exit of the phase shifter is 180 degrees.

It can be seen from Fig. 3 that every time a period of 90° is experienced, that is, the ellipse 8 rotates 1/4 of a circle, the phase shift of the microwave when entering and leaving is 180°, which corresponds to 1/4 of the period of the sinusoidal curve, In practice, the elliptical part 8 can be controlled to rotate 90° starting from any position so that the phase shift of the microwave is 180°.

Of course, the phase shift between adjacent microwaves can also be other values in the range of 0° to 180°, so this characteristic can be applied to various types of accelerators, for example:

(1) The phase shifter of the present invention has a unique application in the synthesis and distribution of high-power waves, which refers to the synthesis of multiple waveforms with different phases, or the extraction of a waveform into waveforms with different phases. When microwaves are combined, the phases of the two microwaves may be different, so the power of the combined microwaves is not large enough. If a phase shifter is added to one of the channels, the phases of the two channels of microwaves can be the same. This is the application of synthesis. In addition, the microwave power distribution can be used in conjunction with a microwave device such as a phase shifter and a 3dB coupler or a magic T, which can achieve any ratio of microwave distribution. The most important thing is the phase shift of the two microwaves, which can be used phase shifter implementation.

(2) When accelerating electrons, the phases of microwaves in different accelerating tubes can be adjusted to realize synchronous acceleration of electrons.

(3) A multi-energy accelerator can be realized. The microwave state diagram shown in Figure 3 is a dual-energy accelerator. A dual-energy accelerator means that the microwave can only achieve two discrete phase shift states, while a multi-energy accelerator means There are multiple ellipses with gradually changing angles between the ellipses, and the angle changes of multiple ellipses are in a continuous state. Realizing a multi-energy accelerator is one of the main purposes of designing this phase shifter. Multifunctional accelerators can be used in security inspection equipment and can scan to stereoscopic images.

Moreover, in each application example of the above-mentioned phase shifter, the faster the microwave phase changes, the higher the repetition frequency of the system can be. It can be seen from Figure 3 that each pulse corresponds to an ellipse, and the time between two pulses is the period T. If the ellipse rotates faster, the T between two pulses will be smaller, and the repetition frequency 1/T will be larger. Different ellipses correspond to different phases, so the faster the phase change, the faster the repetition rate. What is shown in FIG. 3 is only a dual-energy phase shifter, and the phase shifter of the present invention can realize a multi-energy phase shifter.

A reflective phase shifter and an accelerator provided by the present invention and an operation method thereof have been introduced in detail above. In this paper, specific examples are used to illustrate the principles and implementation modes of the present invention, and the descriptions of the above examples are only used to help understand the method and core idea of the present invention. It should be pointed out that for those skilled in the art, without departing from the principle of the present invention, some improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims (14)

1. A reflective phase shifter, characterized in that it comprises a first part (1) and a second part (2), the first part (1) has a first cavity (5), and the second The component (2) is arranged in the first cavity (5), the phase shifter is configured so that microwaves can be reflected back inside it, and the first port of the first cavity serves as its entrance and exit; The distance between the inner wall of the cavity (5) and the outer wall of the second part (2) changes periodically and continuously in the circumferential direction, so that when the first part (1) is opposite to the second part (2) Upon rotation, there is a phase shift between adjacent microwave pulses at the exit of the phase shifter. 2. The reflective phase shifter according to claim 1, characterized in that, the distance between the inner wall of the first cavity (5) and the outer wall of the second part (2) is in the circumferential direction by 180° is a periodic continuous change. 3. The reflective phase shifter according to claim 2, wherein the phase shift is in the range of 0° to 180°. 4. The reflective phase shifter according to claim 1, characterized in that, the cylinder (8) of the second component (2) is arranged in the first cavity (5), and the first The cross-section of one of the cavity (5) and the cylinder (8) is circular and stationary, and the cross-section of the other of the first cavity (5) and the cylinder (8) The distance between the section and its center of rotation changes periodically and continuously in the circumferential direction. 5. The reflective phase shifter according to claim 4, characterized in that, the cross section of the other in the first cavity (5) and the cylinder (8) is ellipse, rectangle, regular triangle or regular polygon. 6. reflective phase shifter according to claim 1, is characterized in that, described first component (1) is also provided with second cavity, and described second cavity and described first cavity (5 ), the second cavity has a first guide portion (3, 4) close to the first port for guiding the microwave into the first cavity (5). 7. The reflective phase shifter according to claim 6, characterized in that, the first guiding portion comprises a square waveguide (3) and a first gradient portion (4), and the square waveguide (3) has a cross section of A square cavity, the square waveguide (3) communicates with the first cavity (5) through the first gradient portion (4). 8. The reflective phase shifter according to claim 4, characterized in that, the second component (2) comprises a second guide portion (6, 7), and the second guide portion (6, 7) is adjacent to The first port is used to guide the microwaves to the space between the first cavity (5) and the second component (2). 9. The reflective phase shifter according to claim 8, characterized in that, the second guiding portion comprises a cylindrical portion (6) and a second gradient portion (7), and the cylindrical portion (6) passes through the The second gradient portion (7) is connected to the column (8) of the second component (2). 10 . The reflective phase shifter according to claim 1 , further comprising a circulator disposed at the first port for separating the incoming microwave and the reflected microwave. 11 . 11. The reflective phase shifter according to claim 1, further comprising a choke structure (9), the choke structure (9) being arranged between the first component (1) and the second The position between the two components (2) and adjacent to the second port of the first cavity (5) is used for reflecting the incoming microwaves. 12. A kind of accelerator, it is characterized in that, comprise the accelerator tube that is used to accelerate the electron in the accelerator, reflective phase shifter and driving device according to claim 1, described driving device is used for making described first part ( 1) Rotate relative to the second part (2). 13. The accelerator according to claim 12, characterized in that, the accelerator comprises a first accelerating tube and a second accelerating tube, the first accelerating tube is located upstream of the second accelerating tube, and the reflective displacement The phaser is arranged in the second accelerating tube. 14. A control method for an accelerator according to claim 12, characterized in that, the cylinder (8) of the second component (2) is set in the first cavity (5), and the first One of the cavity (5) and the column (8) has a circular cross-section and is stationary, and the other of the first cavity (5) and the column (8) The cross section is elliptical, and the control method includes: transmitting microwave pulses into said accelerator at a repetition rate v hertz; The driving device drives the other of the first cavity (5) and the cylinder (8) to rotate at a speed of n revolutions per minute, where n=15vm, m is an odd number, 1, 3, 5 ...so that when each microwave pulse is emitted, the major axis of the elliptical cross-section rotates to a horizontal or vertical state, and the phase shift between adjacent microwaves at the outlet of the phase shifter is 180 degrees.