CN202839527U

CN202839527U - Folding-frame slow-wave structure

Info

Publication number: CN202839527U
Application number: CN 201220563671
Authority: CN
Inventors: 魏彦玉; 郭彍; 徐进; 殷海荣; 宫玉彬; 唐涛; 黄民智; 王文祥
Original assignee: University of Electronic Science and Technology of China
Current assignee: University of Electronic Science and Technology of China
Priority date: 2012-10-30
Filing date: 2012-10-30
Publication date: 2013-03-27
Anticipated expiration: 2022-10-30

Abstract

The utility model provides a folding-frame slow-wave structure, belonging to the technical field of microwave vacuum electron devices. The folding-frame slow-wave structure comprises upper and lower metal bottom plates (2 and 1) which are same in shape and size and are parallel to each other; two dielectric layers (3 and 4) are arranged on the opposite surfaces of the upper and lower metal bottom plates (2 and 1) respectively; two layers of metal microstrip wires (5 and 6) are arranged on the opposite surfaces of the two dielectric layers (3 and 4) respectively, are same in width, are both periodically folded and are in mirror symmetry; and the corresponding folding vertexes of the upper and lower metal microstrip wires (5 and 6) are connected with each other by a metal connection wire (7). Compared with the existing slow-wave structure with symmetric double V-shaped microstrip wires, the folding-frame slow-wave structure provided by the utility model has the advantage of having a higher coupling impedance value in a whole working band so as to further improve the gain and the efficiency of a traveling-wave tube. In addition, the folding-frame slow-wave structure can be manufactured by virtue of a microfabrication technology and has wide application prospect.

Description

A kind of Folding frame slow wave structure

Technical field

The utility model belongs to microwave electron tube technical field, relates to travelling-wave tube amplifier spare.

Background technology

Travelling wave tube has advantages of that other electron tubes such as broadband, high-gain and low noise are incomparable, is widely used in the fields such as radar, communication, microwave remote sensing, guidance and electronic countermeasures.Along with the development of modern microwave electronic technology, aerospace engineering and military equipment have proposed requirements at the higher level to broadband, high efficiency, the miniaturization of Millimeter-Wave Source.Yet, compare with existing Solid Source, although travelling wave tube is bulky having advantage aspect high power, the broadband, operating voltage is higher.Slow wave structure directly affects the efficient of notes-Bo mutual effect and the technical merit of whole travelling wave tube as the core component of travelling wave tube.Helix and coupling cavity are to use two kinds of the most general slow wave structures in the travelling wave tube.Helix TWT has very wide frequency band range, but because thermal capacity is little, dissipation capabilities is low, has limited the raising of helix TWT power output.The heat dispersion of coupled-cavity TWT obviously is better than helix, and power output is large, but bandwidth of operation is narrower.Therefore, exploration broadband, slow wave structure high-power, small size are important directions of present travelling wave tube development.

Symmetrical double V-shaped microstrip line slow wave structure as shown in Figure 1, is the novel plane slow wave structure of annotating transmission applicable to ribbon-like electron of a class.This structure comprise vertical symmetry up and down two metal base plates 1 and 2, lay respectively at the two

layer medium

3 and 4 on metal base plate 1 and 2, and the planar metal microstrip line 5 and 6 that lays respectively at

dielectric layer

3 and 4 surfaces forms.Wherein, described planar metal microstrip line 5 and 6 goes down at

dielectric layer

3 and 4 surperficial V-shaped curved shape periodic arrangement respectively about the axis full symmetric, forms the planar microstrip slow wave circuit.Symmetrical double V-shaped microstrip line slow wave structure adopts ribbon-like electron notes 7 to carry out mutual effect with ripple.

The stereochemical structure size schematic diagram of symmetrical double V-shaped microstrip line slow wave structure as shown in Figure 2.Wherein,

dielectric layer material

3 and 4 dielectric constant are ε, thickness of dielectric layers is h, and the distance between the dielectric layer is l, and the dielectric layer width is a, planar metal microstrip line 5 and 6 live width are w, the thickness of planar metal microstrip line is t, and the transverse width of planar metal microstrip line is b, and it is p that adjacent two planar metal microstrip lines consist of the V-arrangement width, " V " font angle is 2 θ, and satisfied 2 θ＜180 °.

Symmetrical double V-shaped microstrip line slow wave structure travelling wave tube has the characteristics such as broadband, large electric current and low-work voltage, be a kind of very potential microminiature millimeter wave traveling wave tube, have good application prospect in fields such as corresponding electronic system and broadband millimeter-wave communications.But the coupling impedance of symmetrical double V-shaped microstrip line slow wave structure travelling wave tube is less, thereby has limited its application development.

Summary of the invention

Realize the manufacturing of slow wave structure in order to use Micrometer-Nanometer Processing Technology, can under comparable size, improve simultaneously the coupling impedance of symmetrical double V-shaped microstrip line slow wave structure, the utility model proposes a kind of Folding frame slow wave structure, can further satisfy change system to such device at bandwidth of operation, the requirement of power output and miniaturization aspect.

The technical solution adopted in the utility model is:

A kind of Folding frame slow wave structure as shown in Figure 3, comprises lower metal base plate 1 and upper metal base plate 2, and the shape of described lower metal base plate 1 and upper metal base plate 2 is identical and be parallel to each other with size; The upper surface of lower metal base plate 1 has lower dielectric layer 3, and the lower surface of upper metal base plate 2 has upper dielectric layer 4, and the dielectric material of described lower dielectric layer 3 and upper dielectric layer 4 is identical with thickness; The upper surface of lower dielectric layer 3 has lower metal micro-strip line 5, and the lower surface of upper dielectric layer 4 has upper metal micro-strip line 6; Described lower metal micro-strip line 5 is identical with upper metal micro-strip line 6 live widths, be separately periodically rugosity, and is each other Mirror Symmetry; The folding summit of each of lower metal micro-strip line 5 and upper metal micro-strip line 6 adopt metal connecting line 7 to link to each other between the corresponding folding summit.

In the above-mentioned Folding frame slow wave structure, described lower metal micro-strip line 5 or upper metal micro-strip line 6 can be V-shaped, U-shaped or sine curve type rugosity periodically, shown in Fig. 4 (a) and (b), (c).

Such as Fig. 4 and shown in Figure 6, the Folding frame slow wave structure that the utility model provides, if defining the width of upper and lower

dielectric layer

3 or 4 is a, upper and lower metal micro-strip line 5 or 6 live width are that w, transverse width are b, vertically Cycle Length is p, angle between adjacent two folding units is 2 θ, then satisfies: 2 θ＜180 °, 0＜b≤a, 0＜2w＜p.Other relative dimensions may be defined as: upper and lower

dielectric layer

3 or 4 thickness are h, and the distance between the upper and lower dielectric layer is l, and upper and lower metal micro-strip line 5 or 6 thickness are t.

The Folding frame slow wave structure that the utility model provides, with upper and lower metal micro-strip line 5 wherein and 6 and upper and lower metal micro-strip line 5 and 6 between metal connecting line 7 between the corresponding folding summit launch, will form periodically rectangular metal wire-frame graphics, wherein the rectangular metal wire frame in single cycle as shown in Figure 5.Because upper and lower metal micro-strip line 5 and 6 and upper and lower metal micro-strip line 5 and 6 between metal connecting line 7 between the corresponding folding summit launch to form periodically rectangular metal wire-frame graphicses, so the slow wave structure that the utility model provides is defined as the Folding frame slow wave structure.

Through 3 D electromagnetic simulation software simulating, verifying (take V-type Folding frame slow wave structure as example), the Folding frame slow wave structure that the utility model provides is compared with the double V-shaped microstrip line slow wave structure of existing symmetry, (all have higher coupling impedance value in the 40GHz ~ 80GHz), thereby can further improve gain and the efficient of travelling wave tube at whole working band.

Description of drawings

Fig. 1 is the schematic diagram that loads the symmetrical double V-shaped microstrip line slow wave structure of stripe electron beam.

Fig. 2 is the stereochemical structure size schematic diagram of symmetrical double V-shaped microstrip line slow wave structure.

Fig. 3 is the perspective view of the Folding frame slow wave structure that provides of the utility model.

Fig. 4 is the perspective view of the V-type (a) that provides of the utility model, U-shaped (b), sine curve type (c) Folding frame slow wave structure.

Fig. 5 is the sectional dimension mark figure of the V-type Folding frame slow wave structure that provides of the utility model.

Fig. 6 is the two-dimensional mark figure of the V-type Folding frame slow wave structure that provides of the utility model.

Fig. 7 is the dispersion characteristics comparison diagram of V-type Folding frame slow wave structure and symmetrical double V-shaped microstrip line slow wave structure.

Fig. 8 is the coupling impedance comparison diagram of V-type Folding frame slow wave structure and symmetrical double V-shaped microstrip line slow wave structure.

Specific embodiments

A kind of Folding frame slow wave structure as shown in Figure 3, comprises lower metal base plate 1 and upper metal base plate 2, and the shape of described lower metal base plate 1 and upper metal base plate 2 is identical and be parallel to each other with size; The upper surface of lower metal base plate 1 has lower dielectric layer 3, and the lower surface of upper metal base plate 2 has upper dielectric layer 4, and the dielectric material of described lower dielectric layer 3 and upper dielectric layer 4 is identical with thickness; The upper surface of lower dielectric layer 3 has lower metal micro-strip line 5, and the lower surface of upper dielectric layer 4 has upper metal micro-strip line 6; Described lower metal micro-strip line 5 is identical with upper metal micro-strip line 6 live widths, be separately periodically rugosity, and is each other Mirror Symmetry; The folding summit of each of lower metal micro-strip line 5 and upper metal micro-strip line 6 adopt metal connecting line 7 to link to each other between the corresponding folding summit.Shown in Fig. 4 (a), described lower metal micro-strip line 5 or upper metal micro-strip line 6 V-shaped periodicity rugosities, whole Folding frame slow wave structure is V-type Folding frame slow wave structure.

The width that defines upper and lower

dielectric layer

Such as Fig. 3, Fig. 5 and Fig. 6, take V-type Folding frame slow wave structure as example, the physical dimension of concrete scheme is following, and (dimensional units: mm): upper and lower

dielectric layer

3 or 4 dielectric constant (ε) are 4, h=0.05, l=0.31, a=0.88, w=0.02, t=0.01, p=0.124, b=0.44,2 θ=12 °.Utilize the 3 D electromagnetic simulation software that the V-type Folding frame slow wave structure that the utility model provides is carried out emulation, obtain its dispersion characteristics and coupling impedance, and with have same media layer material DIELECTRIC CONSTANT ε, same media layer thickness h, between the same media layer apart from l, same media layer width a, same level microstrip line live width w, same level microstrip line thickness t, identical vertical Cycle Length is p, same lateral width b, the double V-shaped microstrip line slow wave structure of the existing symmetry of identical V-arrangement angle 2 θ relatively.Simulation result as shown in Figure 7 and Figure 8.Wherein, wherein, curve 11 and curve 13 are respectively dispersion characteristic curve, the coupling impedance curves of the V-type Folding frame slow wave structure that provides of the utility model; Curve 12 and curve 14 are respectively symmetrical double V-shaped microstrip line slow wave structure dispersion characteristic curve, coupling impedance curve.

From Fig. 7 curve 11 and curve 12 more as can be known: (20GHz ~ 110GHz), the phase velocity of V-type Folding frame slow wave structure provided by the utility model is a little less than the double V-shaped microstrip line slow wave structure of symmetry in whole frequency band.

From Fig. 8 curve 13 and curve 14 more as can be known: than the double V-shaped microstrip line slow wave structure of symmetry, V-type Folding frame slow wave structure provided by the utility model all has higher coupling impedance value in whole frequency band, thereby can further improve gain and the efficient of travelling wave tube.

In addition, those skilled in the art are according to the description of the utility model specification, vertical Cycle Length p that also can design upper and lower metal micro-strip line 5 or 6 is the variable period Folding frame slow wave structure of linear increment or linear decrease, to satisfy the application demand of specific occasion.

Claims

1. a Folding frame slow wave structure comprises lower metal base plate (1) and upper metal base plate (2), and the shape of described lower metal base plate (1) and upper metal base plate (2) is identical and be parallel to each other with size; The upper surface of lower metal base plate (1) has lower dielectric layer (3), and the lower surface of upper metal base plate (2) has upper dielectric layer (4), and described lower dielectric layer (3) is identical with thickness with the dielectric material of upper dielectric layer (4); The upper surface of lower dielectric layer (3) has lower metal micro-strip line (5), and the lower surface of upper dielectric layer (4) has upper metal micro-strip line (6); Described lower metal micro-strip line (5) is identical with upper metal micro-strip line (6) live width, be separately periodically rugosity, and is each other Mirror Symmetry; It is characterized in that, adopt metal connecting line (7) to link to each other between the folding summit corresponding with upper metal micro-strip line (6), each folding summit of lower metal micro-strip line (5).

2. Folding frame slow wave structure according to claim 1 is characterized in that, V-shaped, the U-shaped or sine curve type of described lower metal micro-strip line (5) or upper metal micro-strip line (6) is rugosity periodically.

3. Folding frame slow wave structure according to claim 1, it is characterized in that, the width that defines upper and lower dielectric layer (3 or 4) is a, the live width of upper and lower metal micro-strip line (5 or 6) is that w, transverse width are b, vertically Cycle Length is p, angle between adjacent two folding units is 2 θ, then satisfies: 2 θ＜180 °, 0＜b≤a, 0＜2w＜p.

4. Folding frame slow wave structure according to claim 1 is characterized in that, vertical Cycle Length p of described upper and lower metal micro-strip line (5 or 6) is linear increment or linear decrease, makes whole Folding frame slow wave structure become variable period Folding frame slow wave structure.