A wide electron beam channel staggered grid slow wave interaction circuit

Abstract

The embodiment of the present application discloses a wide electron injection channel staggered grid slow wave interaction circuit including: a staggered grid and a strip electron injection channel; wherein the staggered grid is composed of two rows of rectangular grooves; the width w of the strip electron injection channel is greater than the width a of the rectangular groove. The present application improves the design flexibility by increasing the electron injection channel width parameter w, so that a better compromise can be made in terms of dispersion, coupling impedance and channel size during design. The present application increases the electron injection channel width w, and compensates for the dispersion and coupling impedance of the working frequency band by adjusting the parameters a and h, thereby reducing the current density, increasing the current, alleviating the lateral focusing pressure of the magnetic field, improving the electron injection flow rate, effectively reducing the electron injection interception probability, and improving the flow rate.

Description

Technical Field

[0001] The present application relates to the field of microwave vacuum electronic technology, and more specifically, to a wide electron beam channel staggered grid slow wave interaction circuit. Background Art

[0002] As the most widely used linear microwave vacuum electronic device in the microwave frequency band, the traveling wave tube has broad development prospects in the fields of communication, electronic countermeasures, radar systems, etc. The slow-wave structure is the most core component of the traveling wave tube to achieve microwave signal generation or amplification, and its high-frequency performance directly affects the various output indicators of the traveling wave tube. With the increase of the operating frequency band of the traveling wave tube, the slow-wave structure and the size of the electron beam channel are drastically reduced. When a circular electron beam is still used, the current allowed to pass is significantly reduced, resulting in a significant decrease in the power level of the traveling wave tube. The ribbon electron beam is an effective technical approach to overcome this problem, and is therefore one of the current research hotspots in the field of terahertz vacuum electronic devices.

[0003] Among the many strip injection slow wave structures, the staggered grid circuit is a full metal slow wave structure with the advantages of simple structure, large power capacity and wide bandwidth. The basic structure of the staggered grid circuit is as follows Figure 1 As shown, a is the gate width, 2b is the distance between the upper and lower gates, h is the gate height, p is the period, and t is the gate thickness. A natural electron beam channel is formed between the two gates, and its size can be regarded as a×2b. The influence of the above structural parameters on the cold characteristics of the slow-wave structure is well known. The lateral width a determines the operating frequency band and the position of the operating point (i.e., the center frequency f0 and the lower cutoff frequency f c The ratio of the two has a decisive influence on coupling impedance, dispersion and loss. A major contradiction in the design using the basic structure is that increasing the coupling impedance requires reducing the lateral dimension a, but at the same time it will lead to increased dispersion and reduced bandwidth. Moreover, the reduction of the lateral dimension a also means that the width of the strip beam transmission channel is reduced, which is not conducive to strip beam focusing and transmission. Therefore, the design flexibility of the staggered grid circuit of the basic structure is poor, especially it is difficult to take into account both the coupling impedance (improvement) and the channel width (increase). Summary of the invention

[0004] The present invention provides a wide electron beam channel staggered grid slow wave interaction circuit from the perspective of improving design flexibility and improving strip beam transmission, which can increase the electron beam channel width without significantly increasing the structural complexity and keep the coupling impedance basically unchanged.

[0005] In order to achieve at least one of the above purposes, the present application adopts the following technical solutions:

[0006] In a first aspect, the present application provides a wide electron beam channel staggered grid slow wave interaction circuit, comprising:

[0007] Staggered grid and ribbon electron beam channels;

[0008] Wherein, the staggered grid is composed of two rows of rectangular grooves;

[0009] The width w of the band-shaped electron injection channel is greater than the width a of the rectangular groove.

[0010] In a specific embodiment, the two rows of rectangular grooves are two upper and lower rows of rectangular grooves along the y direction of the three-dimensional coordinate system;

[0011] The upper and lower rows of rectangular grooves are staggered by half a structural period along the z direction of the three-dimensional coordinate system, the groove width along the x direction is a, the groove depth along the y direction is h, the wall thickness between two adjacent grooves is t, and the structural period is p.

[0012] In a specific embodiment, the strip-shaped electron injection channel is formed between the upper and lower rows of rectangular grooves;

[0013] The size of the band-shaped electron channel is w×2b;

[0014] Wherein, w is the width of the electron injection channel, and 2b is the distance between the upper and lower rows of rectangular grooves.

[0015] In a specific embodiment, the electron beam channel width w is adjusted according to the electron beam size, and w≥a.

[0016] A second aspect of the present application provides a wide electron beam channel staggered grid slow wave interaction circuit, comprising:

[0017] Staggered grid and ribbon electron beam channels;

[0018] Wherein, the staggered grid is composed of two rows of rounded rectangular grooves;

[0019] The width w of the strip-shaped electron injection channel is greater than the width a of the rounded rectangular groove.

[0020] In a specific embodiment, the two rows of rounded rectangular grooves are two upper and lower rows of rounded rectangular grooves along the y direction of the three-dimensional coordinate system;

[0021] The upper and lower rows of rounded rectangular grooves are staggered by half a structural period along the z direction of the three-dimensional coordinate system, the groove width along the x direction is a, the groove depth along the y direction is h, the wall thickness between two adjacent grooves is t, and the structural period is p.

[0022] In a specific embodiment, the strip-shaped electron injection channel is formed between the upper and lower rows of rounded rectangular grooves;

[0023] The size of the band-shaped electron channel is w×2b;

[0024] Wherein, w is the width of the electron injection channel, and 2b is the distance between the upper and lower rows of rounded rectangular grooves.

[0025] In a specific embodiment, the electron beam channel width w is adjusted according to the electron beam size, and w≥a.

[0026] The beneficial effects of this application are as follows:

[0027] In view of the problems existing in the current prior art, the present application provides a wide electron beam channel staggered grid slow wave interaction circuit, which improves the design flexibility by increasing the electron beam channel width parameter w, so that a better compromise can be made in terms of dispersion, coupling impedance and channel size during design. The present application increases the electron beam channel width w, and compensates for the dispersion and coupling impedance of the working frequency band by adjusting the parameters a and h, thereby reducing the current density, increasing the current, alleviating the lateral focusing pressure of the magnetic field, improving the electron beam flow rate, effectively reducing the electron beam interception probability, and improving the flow rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The specific implementation modes of the present invention are further described in detail below in conjunction with the accompanying drawings.

[0029] Figure 1 The basic structure of a staggered-gate slow-wave interaction circuit in the prior art is shown.

[0030] FIG. 2( a ) shows a cross-sectional view of a wide electron beam channel staggered-gate slow-wave interaction circuit structure in one embodiment of the present application.

[0031] FIG. 2( b ) shows a physicalized structure diagram of two rows of groove gaps in a wide electron injection channel staggered-gate slow-wave interaction circuit in one embodiment of the present application.

[0032] FIG. 2( c ) shows a side view of a two-row trench gap physical structure of a wide electron injection channel staggered-gate slow-wave interaction circuit in one embodiment of the present application.

[0033] FIG. 3( a ) shows a comparative dispersion curve diagram of a wide electron beam channel staggered-gate slow-wave interaction circuit and an existing staggered-gate slow-wave structure in one embodiment of the present application.

[0034] FIG3( b ) shows a normalized phase velocity curve diagram comparing a wide electron beam channel staggered-gate slow-wave interaction circuit and an existing staggered-gate slow-wave structure in one embodiment of the present application.

[0035] Figure 4 A circuit coupling impedance curve diagram showing a comparison between a wide electron beam channel staggered gate slow-wave interaction circuit in one embodiment of the present application and an existing staggered gate slow-wave structure.

[0036] FIG. 5( a ) shows a cross-sectional view of a staggered-gate slow-wave interaction circuit in a conventional structure.

[0037] FIG5( b ) shows a cross-sectional view of a wide electron beam channel staggered-gate slow-wave interaction circuit in one embodiment of the present application.

[0038] FIG6( a ) shows a structural diagram of a wide electron beam channel staggered-gate slow-wave interaction circuit in one embodiment of the present application.

[0039] FIG6( b ) shows a model diagram of the actual processing of a wide electron beam channel staggered grid slow wave interaction circuit in one embodiment of the present application. DETAILED DESCRIPTION

[0040] In the following description, for the purpose of explanation, in order to provide a thorough understanding of one or more embodiments, numerous specific details are set forth. However, it is apparent that these embodiments may also be implemented without these specific details.

[0041] In the description of the present application, it should be noted that the terms "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0042] It should also be noted that, in the description of the present application, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of further restrictions, the elements defined by the statement "comprise one..." do not exclude the presence of other identical elements in the process, method, article or equipment including the elements.

[0043] In order to solve the problems existing in the prior art, an embodiment of the present application provides a wide electron beam channel staggered grid slow wave interaction circuit, as shown in Figures 2(a), (b) and (c), comprising:

[0044] Staggered grid 100 and strip-shaped electron injection channel 200;

[0045] Wherein, the staggered grid is composed of two rows of rectangular grooves 101 and 102;

[0046] The width w of the strip-shaped electron injection channel 200 is greater than the width a of the rectangular groove.

[0047] In a specific embodiment, the two rows of rectangular grooves are upper and lower rows of rectangular grooves 101 and 102 along the y direction of the three-dimensional coordinate system;

[0048] The upper and lower rows of rectangular grooves are staggered by half a structural period along the z direction of the three-dimensional coordinate system, the groove width along the x direction is a, the groove depth along the y direction is h, the wall thickness between two adjacent grooves is t, and the structural period is p.

[0049] The structure between the upper and lower rows of rectangular grooves is shown in FIG2(b), and its side view is shown in FIG2(c).

[0050] In a specific embodiment, the strip-shaped electron injection channel 200 is formed between the upper and lower rows of rectangular grooves 101 and 102;

[0051] The size of the band-shaped electron channel is w×2b;

[0052] Wherein, w is the width of the electron injection channel, and 2b is the distance between the upper and lower rows of rectangular grooves.

[0053] In a specific embodiment, the electron beam channel width w is adjusted according to the electron beam size, and w≥a. When w=a, it is a structure of the prior art, such as Figure 1 shown.

[0054] The lateral dimension w of the slow-wave structure can determine the operating frequency band and the operating point. Therefore, when w changes, the dispersion, coupling impedance and loss of the staggered grating slow-wave interaction circuit structure will change to a certain extent. The above performance can be compensated by adjusting the gate width a and the gate height h.

[0055] The difference between a cross-sectional view of a staggered-gate slow-wave interaction circuit in a specific embodiment of the present application and the prior art is shown in FIG5( a ) and FIG5( b );

[0056] In the basic structure of the existing staggered gate circuit, as shown in FIG5(a), the electron beam channel width and the gate width are both a. As shown in Table 1, when a = 0.75 mm, the major axis 2d of the elliptical electron beam is 0.60 mm, and the minor axis 2e is 0.10 mm, the electron beam lateral filling ratio is 80%. If the required current is 100 mA, the current density J0 is 212.2 A / cm 2 ;

[0057] In the structure of the present application, as shown in FIG5(b), it can be seen from Table 1 that when the electron injection channel is widened to w = 0.85 mm, the electron injection lateral filling ratio is kept unchanged (80%), and the electron injection major axis is increased to 0.68 mm. At a current of 100 mA, the current density is reduced to 187.2 A / cm 2 , which is 11.8% lower than the original staggered gate structure. 2 ), the current of the structure of the present application can be increased to 114 mA, which is 14% higher than the existing staggered gate structure.

[0058] Table 1

[0059]

[0060] The present application improves the design flexibility by increasing the electron beam channel width parameter w, so that a better compromise can be made in terms of dispersion, coupling impedance and channel size during design.

[0061] In a specific embodiment of the present application, the present application compensates for the dispersion and coupling impedance of the working frequency band by increasing the electron beam channel width w and adjusting the parameters a and h, as shown in Figures 3(a), 3(b) and Figure 4 shown.

[0062] The second aspect of the present application provides a wide electron beam channel staggered grid slow wave interaction circuit, as shown in FIG6(a), comprising:

[0063] Staggered grid and ribbon electron beam channels;

[0064] Wherein, the staggered grid is composed of two rows of rounded rectangular grooves;

[0065] The width w of the strip-shaped electron injection channel is greater than the width a of the rounded rectangular groove.

[0066] In a specific embodiment, the two rows of rounded rectangular grooves are two upper and lower rows of rounded rectangular grooves along the y direction of the three-dimensional coordinate system;

[0067] The upper and lower rows of rounded rectangular grooves are staggered by half a structural period along the z direction of the three-dimensional coordinate system, the groove width along the x direction is a, the groove depth along the y direction is h, the wall thickness between two adjacent grooves is t, and the structural period is p.

[0068] In a specific embodiment, the strip-shaped electron injection channel is formed between the upper and lower rows of rounded rectangular grooves;

[0069] The size of the band-shaped electron channel is w×2b;

[0070] Wherein, w is the width of the electron injection channel, and 2b is the distance between the upper and lower rows of rounded rectangular grooves.

[0071] In a specific embodiment, the electron beam channel width w is adjusted according to the electron beam size, and w≥a.

[0072] In a specific embodiment, w = 0.80 mm, a = 0.69 mm, h = 0.45 mm, 2b = 0.15 mm, p = 0.505 mm, t = 0.125 mm, and the fillet size is between R0.08 and 0.12

[0073] Preferably, in the actual processing process, a perfect right angle cannot be machined along the gate height direction, so the actual structure is composed of rounded rectangular grooves, as shown in FIG. 6( a ), where the rounded corner size depends on the tool size.

[0074] In a specific embodiment, the structure can be actually processed into two parts along the xz plane, each part including a row of grooves and half of the electron injection channel, as shown in FIG6( b ).

[0075] The present application provides a wide electron beam channel staggered grid slow wave interaction circuit, which improves the design flexibility by increasing the electron beam channel width parameter w, so that a better compromise can be made in terms of dispersion, coupling impedance and channel size during design. The present application increases the electron beam channel width w, and compensates for the dispersion and coupling impedance of the working frequency band by adjusting the parameters a and h, reduces the current density, increases the current, relieves the lateral focusing pressure of the magnetic field, improves the electron beam flow rate, effectively reduces the electron beam interception probability, and improves the flow rate.

[0076] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. A wide electron beam channel staggered grid slow wave interaction circuit, characterized in that: include: Staggered grid and ribbon electron beam channels; Wherein, the staggered grid is composed of two rows of rectangular grooves; The width w of the strip electron injection channel is greater than the width a of the rectangular groove; The two rows of rectangular grooves are two upper and lower rows of rectangular grooves along the y direction of the three-dimensional coordinate system; The upper and lower rows of rectangular grooves are staggered by half a structural period along the z direction of the three-dimensional coordinate system, the groove width along the x direction is a, the groove depth along the y direction is h, the wall thickness between two adjacent grooves is t, and the structural period is p; The strip-shaped electron injection channel is formed between the upper and lower rows of rectangular grooves; The size of the strip electron injection channel is w×2b; Wherein, w is the width of the electron injection channel, and 2b is the distance between the upper and lower rows of rectangular grooves.

2. A wide electron beam channel staggered grid slow wave interaction circuit, characterized in that: include: Staggered grid and ribbon electron beam channels; Wherein, the staggered grid is composed of two rows of rounded rectangular grooves; The width w of the strip-shaped electron injection channel is greater than the width a of the rounded rectangular groove; The two rows of rounded rectangular grooves are two upper and lower rows of rounded rectangular grooves along the y direction of the three-dimensional coordinate system; The upper and lower rows of rounded rectangular grooves are staggered by half a structural period along the z direction of the three-dimensional coordinate system, the groove width along the x direction is a, the groove depth along the y direction is h, the wall thickness between two adjacent grooves is t, and the structural period is p; The strip-shaped electron injection channel is formed between the upper and lower rows of rounded rectangular grooves; The size of the strip electron injection channel is w×2b; Wherein, w is the width of the electron injection channel, and 2b is the distance between the upper and lower rows of rounded rectangular grooves.

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