CN108550510A - A kind of gyrotron traveling wave tube input coupler with high electronic beam current passband - Google Patents

Abstract

A kind of gyrotron traveling wave tube input coupler with high electronic beam current passband of the disclosure of the invention, is related to microwave, millimetric wave device technical field.The present invention introduces a kind of electronics note/microwave channel structure on the basis of traditional gyrotron traveling wave tube input coupler.The cut-off circular waveguide radius of traditional input coupler is 0.7 times or so of input coupler circular waveguide radius, cut-off waveguide in the present invention is replaced by three cascade reflection cylinder resonators, transmission waveguide radius between cylinder resonator is identical as input circular waveguide, therefore the channel of electronics note is big compared with traditional input coupler, electronics beam passband higher can thus be deteriorated to avoid the circulation of electron beam and changeover portion is burnt.Certain thickness load attenuating material is arranged in cascade reflection cylindrical cavity, for the competitive mode for TE01 moulds of decaying, in the total reflection that TE01 moulds may be implemented by optimizing cylinder resonator size, the content and purity of output circular waveguide TE01 moulds are improved, working band can be effectively expanded.

Description

A Gyrotron TWT Input Coupler with High Electron Beam Flux Rate

technical field

The invention relates to the technical field of microwave and millimeter wave devices, in particular to a cyclotron traveling wave tube input coupler with high electron beam flux rate.

Background technique

The cyclotron traveling wave tube is an important microwave and millimeter wave signal amplifier. It adopts the fast wave transverse transduction method. Compared with the traditional electric vacuum device, it not only has the advantages of high power and high frequency, but also has the same working bandwidth as the Devices such as klystrons and oscillating tubes have great advantages in comparison, and have very important application prospects in the fields of millimeter-wave imaging radar, millimeter-wave communication systems, and electronic warfare, so they have attracted international attention.

The input coupler is one of the core components of the gyro TWT. The input coupler is a high-frequency device that completes the mode conversion of the input signal and modulates the energy or speed of the cyclotron. It is closely related to the clustering state of the electron beam, and its performance directly affects the performance of the cyclotron TWT. The input coupler of the gyrotron TWT is a three-port device, including an input rectangular port and two output circular waveguide ports, one of the output ports is connected to the electron gun area of the gyrotron TWT through a transition section, and the other output port is directly connected to the The high frequency interaction section of the gyro traveling wave tube is connected. For the traditional gyro TWT input coupler, in order to improve the mode conversion efficiency and prevent the input electromagnetic wave from propagating to the electron gun area, thereby affecting the stability of the gyro TWT, a pair of working pairs is usually set between the input coupler and the transition section. Cutoff waveguide for mode cutoff. However, the radius of the cut-off waveguide is usually only about 0.7 times the radius of the circular waveguide of the input coupler. When the electron beam passes through the cut-off section, a considerable part of the electron beam will be intercepted by the cut-off section, resulting in poor circulation of the electron beam. In addition, in a high duty cycle or continuous wave state, this part of the intercepted electron beam is likely to cause burning of the transition section due to the high energy carried by it. Based on this background, the present invention proposes a novel input coupler structure with high electron beam flux.

Contents of the invention

In order to solve the problem of electron beam circulation and transition section burning in the conventional input coupler of the gyrotron TWT, the present invention proposes a structure of the input coupler of the gyrotron TWT with high electron beam flux rate.

The invention introduces an electron beam/microwave channel structure on the basis of the traditional gyrotron input coupler. The radius of the cut-off circular waveguide of the traditional input coupler is about 0.7 times of the radius of the circular waveguide of the input coupler. The cut-off waveguide in the present invention is replaced by three cascaded reflection cylindrical resonators, and the radius of the transmission waveguide between the cylindrical resonators is the same as that of the input circle The waveguide is the same, so the channel of the electron beam is larger than that of the traditional input coupler, and the flow rate of the electron beam is higher, so that the deterioration of the flow of the electron beam and the burning of the transition section can be avoided. The cascaded reflective cylindrical cavity is set with a certain thickness to load the attenuating material to attenuate the competing mode of the TE01 mode. By optimizing the size of the cylindrical resonant cavity, the total reflection of the TE01 mode can be realized, and the content and purity of the output circular waveguide TE01 mode can be improved. Can effectively expand the working frequency band.

The technical solution of the present invention is an input coupler for a convoluted traveling wave tube with a high flux rate of electron beams. The coupler includes: an input rectangular waveguide (1), an output circular waveguide (4), a coaxial resonant circular waveguide (2), Three-stage cascaded circular reflective waveguide (5); the input rectangular waveguide is arranged on the outer wall of the coaxial resonant circular waveguide; the three-stage cascaded circular reflective waveguide includes first-stage circular reflective waveguides arranged at intervals, The second-stage circular reflective waveguide, the third-stage circular reflective waveguide, and the inner cavity radius lengths of the first-stage to the third-stage circular reflective waveguides are all the same; the output circular waveguide (4), coaxial resonant circular waveguide ( 2), the three-stage cascaded circular reflective waveguide is coaxial; the outer wall of the output circular waveguide is provided with a coaxial resonant circular waveguide (2), the first-stage circular reflective waveguide, the second-stage circular reflective waveguide, and the third-stage The circular reflective waveguide, the end of the output circular waveguide protrudes from the third-stage circular reflective waveguide; the output circular waveguide is located on the outer wall of the coaxial resonant circular waveguide cavity, and a rectangular coupling gap is opened; the cavity of the output circular waveguide is connected to the third-stage The cavities at all levels of the connected circular reflective waveguide are completely connected; the coaxial resonant circular waveguide (2) is closely attached to the first-stage circular reflective waveguide.

Further, the length of the output circular waveguide is 10mm, and the radius is 5.72mm; the length of the coaxial resonant circular waveguide is 15.26mm, and the radius is 9.1mm; the length of the first-stage circular reflective waveguide is 5mm, and the radius is 12.5mm; The length of the second-stage circular reflective waveguide is 5 mm, and the radius is 12.5 mm; the length of the third-stage circular reflective waveguide is 5 mm, and the radius is 12.5 mm.

Further, five rectangular coupling slots are evenly opened on the outer wall of the output circular waveguide located in the cavity of the coaxial resonant circular waveguide, and one of the coupling slots is opened below the input rectangular waveguide.

Further, the outer wall of the cavity of the circular reflective waveguides at each level is provided with ceramic attenuating material; in order to fully attenuate the TE01 mode competition mode, the thickness of the ceramic attenuating material outside the cavity of the circular reflective waveguide at all levels is sequentially increased.

The beneficial effects of the present invention are:

(1) Compared with the traditional input coupler, the cascaded resonant cavity is used instead of the cut-off circular waveguide to increase the channel of the electron beam, so that the flow rate of the electron beam is higher, and the flow of the electron beam is avoided and the transition section is avoided. burn.

(2) The cascaded reflective cylindrical cavities realize the total reflection of the TE01 mode, ensuring that the TE10 mode is output from the output circular waveguide in one direction while the attenuating material loaded on the outside, attenuating the competition mode of the TE01 mode, and improving the purity of the output circular waveguide TE01 mode. Improve the stability of the whole tube.

Description of drawings

Fig. 1 is a schematic diagram of a novel input coupler with high electron beam flux;

Fig. 2 The front view of the input coupler with high electron beam flux;

Fig. 3 is a side view of a novel input coupler with high electron beam flux;

Fig. 4 The transmission parameters between the input coupler TE10-TE01 of the new type of high electron beam flux;

Figure 5. Mode-to-mode transmission parameters of the novel high electron beam flux input coupler.

Detailed ways

Below in conjunction with a design example and the accompanying drawings of the input coupler of the novel high electron beam flow that work in the Ka wave band, the present invention will be further elaborated:

Main waveguide working mode: TE01 mode;

Input signal mode: rectangular waveguide TE10 mode;

Working frequency band: Ka band (32GHz-36GHz);

Accompanying drawing 1 is the schematic diagram of the input coupler of high electron beam flow of the present invention; Fig. 2 is the front view of the new type high electron beam flow input coupler; Fig. 3 is the side view of the new type high electron beam flow input coupler. The invention includes: input rectangular waveguide (1), output circular waveguide (4), coaxial resonant circular waveguide (2), three-stage cascaded circular reflective waveguide (5); the input rectangular waveguide is arranged on the coaxial resonant circular waveguide The outer wall of the waveguide; the three-stage cascaded circular reflective waveguide includes a first-stage circular reflective waveguide arranged at intervals, a second-stage circular reflective waveguide, a third-stage circular reflective waveguide, the first-stage to the third-stage The radius of the circular reflective waveguide is the same, and the thickness of the side wall increases sequentially; the output circular waveguide (4), the coaxial resonant circular waveguide (2), and the three-stage cascaded circular reflective waveguide are coaxial; the outer wall of the output circular waveguide is sequentially A coaxial resonant circular waveguide (2), a first-stage circular reflective waveguide, a second-stage circular reflective waveguide, and a third-stage circular reflective waveguide are set, and the end of the output circular waveguide protrudes from the third-stage circular reflective waveguide; the output The outer wall of the circular waveguide located in the cavity of the coaxial resonant circular waveguide is provided with a rectangular coupling slit; the cavity of the output circular waveguide is fully connected with the cavities of all levels of the three-stage cascaded circular reflective waveguide; the coaxial resonant circular waveguide ( 2) Closely attached to the first-stage circular reflection waveguide. Input the rectangular waveguide (1) and input the TE10 mode to the coaxial resonant circular waveguide (2), the TE10 mode enters the coaxial resonant circular waveguide (3) and transforms into the TE511 mode between the inner and outer conductors, and the TE511 mode is input to the output circular waveguide through the coupling slot In (5), the mode is converted from the TE511 mode to the TE01 mode in the output circular waveguide at the same time, so as to provide the TE01 mode of the circular waveguide required for the work of the convoluted TWT. in:

Input rectangular waveguide (1): adopt standard rectangular waveguide model BJ320, wide side 7.12mm, narrow side 3.56mm, length 9.0mm.

Coaxial resonant circular waveguide (2): the radius of the inner conductor is r2=6.12mm, the thickness of the inner wall cavity is 0.4mm, the radius of the outer conductor is r3=9.1mm, and the length is 15.26mm.

The rectangular coupling slot (3): width 0.2 mm, length 4.6 mm, distance from the upper and lower edges of the coaxial inner conductor is 5.33 mm, a total of 5 coupling slots, the angle between the first slot and the center of the rectangular waveguide is 36 degrees, and the angle between adjacent coupling joints is 72 degrees.

Output circular waveguide (4): the radius is r1=5.72mm, and the length is 10mm.

Three-stage cascaded circular reflection waveguide (5): the radius is r4=12.5mm, and the length is 5mm. The thickness of the outer wall is 1mm, 2mm, 3mm in turn.

FIG. 4 shows the transmission parameters between the input couplers TE10-TE01 of the present invention with high electron beam flux. It can be seen from the figure that the 3dB bandwidth coverage of the transmission parameters of the new input coupler with high electron beam flux ranges from 32.41GHz to 35.18GHz, indicating that the input coupler has a wide operating bandwidth.

FIG. 5 shows the transmission parameters between the input coupler with high electron beam flux and other modes in the present invention. It can be seen from the figure that the transmission parameters from the TE10 mode at the input end to other modes are relatively low. In the frequency range from 32.77GHz to 34.87GHz, they are all below -25dB. It can be seen that the transmission parameters from the TE10 mode to the input end TE01 mode are better. Suppression of TE10-TE01 high-efficiency mode conversion is achieved, and the circular waveguide TE01 mode with higher purity is output.

The above examples are only for convenience to illustrate the present invention, and the novel convoluted TWT input coupler proposed by the present invention can also be applied to other frequency bands, and the specific size is determined by the corresponding frequency band and working mode.

Claims (4)

1. a kind of gyrotron traveling wave tube input coupler with high electronic beam current passband, the coupler include：Input rectangular waveguide (1), output circular waveguide (4), coaxial resonance circular waveguide (2), three-stage cascade circle reflection waveguide (5)；The input rectangular waveguide It is set to the lateral wall of coaxial resonance circular waveguide；The three-stage cascade circle reflection waveguide includes that the spaced first order is round Waveguide is reflected, second level circle reflects waveguide, and third level circle reflects waveguide, and the first order to third level circle reflects the interior of waveguide Chamber radius length all same；The output circular waveguide (4), coaxial resonance circular waveguide (2), the reflection waveguide of three-stage cascade circle are coaxial Line；The output circular waveguide outer wall sets gradually coaxial resonance circular waveguide (2), the reflection waveguide of first order circle, and the second level is round Waveguide is reflected, third level circle reflects waveguide, and output circular waveguide end protrudes from the reflection waveguide of third level circle；Export circular waveguide Rectangle coupling gap is offered on the outer wall in coaxial resonance circular waveguide cavity；Export the cavity and three-stage cascade of circular waveguide The cavitys at different levels of circle reflection waveguide are connected to completely；The coaxial resonance circular waveguide (2) is tightly attached to the reflection waveguide of first order circle.

2. a kind of gyrotron traveling wave tube input coupler with high electronic beam current passband as described in claim 1, feature exist In it is described output circular waveguide length be 10mm, radius 5.72mm；The length of coaxial resonance circular waveguide is 15.26mm, and radius is 9.1mm；The length that first order circle reflects waveguide is 5mm, radius 12.5mm；The length of second level circle reflection waveguide is 5mm, radius 12.5mm；The length that third level circle reflects waveguide is 5mm, radius 12.5mm.

3. a kind of gyrotron traveling wave tube input coupler with high electronic beam current passband as described in claim 1, feature exist Gap is coupled in being uniformly provided with 5 rectangles on the outer wall that the output circular waveguide is located in coaxial resonance circular waveguide cavity, In one coupling gap be opened in input rectangular waveguide lower section.

4. a kind of gyrotron traveling wave tube input coupler with high electronic beam current passband as described in claim 1, feature exist In being provided with ceramic attenuator material on the chamber outer walls of the round reflection waveguides at different levels；For the TE01 mode competitions fully decayed Pattern, the ceramic attenuator material thickness that circles at different levels reflect on the outside of the cavitys of waveguides successively increase.