Suspended slot line structure filled with air medium

Abstract

The invention discloses an air medium-filled suspended slot line structure, which is an air medium-filled suspended slot line structure based on an MISL platform and is formed by stacking a plurality of layers of metal plates, a self-packaging structure is formed, a slot line structure of a main circuit is arranged on one layer of metal plate inside, and the other layer of metal plate is arranged on the other layer of metal plate inside. And hollow cavities filled with air are formed in the metal plates above and below the slot line structure of the main circuit through partial cutting. According to the invention, a multi-layer metal plate stacking structure is adopted to form a multi-layer self-packaging structure, etching can be carried out on the internal metal plates to form a slot structure, and mediums in the slot structure and above and below the metal plates where the slot structure is located are air, so that dielectric loss caused by a slot line structure designed based on a traditional PCB is thoroughly eliminated, and the reliability of the slot line structure is improved. And therefore, relatively low loss can be realized. Due to the adoption of a self-packaging structure, an electric field is mainly distributed in air in the packaging structure, so that the radiation loss of the slot line can be greatly reduced.

Description

Technical Field

[0001] The invention relates to the technical field of radio frequency microwave terahertz circuits, and in particular to a novel air-filled integrated suspended slotline (AFISSL) structure. Background Art

[0002] Slotline is a transmission line widely used in RF and microwave circuits. It has a unique structure and performance. Its main advantages include easy processing and large impedance, which makes it perform well in the microwave frequency band. In addition, the compactness of slotline enables it to efficiently transmit signals in a limited space, which is suitable for the needs of modern miniaturized devices. Slotline is also easy to integrate with other transmission lines (such as microstrip lines), which is convenient for design and manufacturing. However, slotline also has some disadvantages. Its bandwidth may be limited. In addition, especially in high-frequency applications, it has large dielectric and radiation losses. These disadvantages may make it unable to meet all design requirements. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings and defects of the prior art and to provide a novel air-filled integrated suspended slotline (AFISSL) structure based on a MISL platform. Since the MISL platform is made of pure metal, it completely eliminates dielectric loss, so that the air-filled integrated suspended slotline structure of the present invention can achieve a higher Q value.

[0004] An air dielectric filled suspended slot line structure is an air dielectric filled suspended slot line structure based on a fully metal integrated MISL platform, which is formed by stacking multiple layers of metal plates to form a self-encapsulation structure. A slot line structure of a main circuit is arranged on an internal layer of metal plates, and the metal plates above and below the slot line structure of the main circuit are partially cut off to form an air-filled hollow cavity.

[0005] Wherein, feeding structures are arranged at both ends of the slot line structure of the main circuit.

[0006] Wherein, the feeding structure is arranged symmetrically.

[0007] Among them, the slot line structure of the main circuit includes a dual-frequency filter, which includes three pairs of resonators, each of which has a length of half a wavelength; each pair of resonators produces two resonance points, and by cascading the three pairs of resonators, a third-order dual-frequency filter response is generated.

[0008] Wherein, the dual-frequency filter utilizes a coplanar waveguide to directly feed the circuit.

[0009] The multi-layer metal plates are connected by countersunk holes, rivets or soldering to form a self-encapsulated structure.

[0010] Wherein, the metal plates are all made of stainless steel, copper, aluminum or metal alloy.

[0011] Wherein, the metal plate is formed by a metal etching process.

[0012] Wherein, the main circuit includes a microwave radio frequency circuit, which is formed by etching on a metal plate.

[0013] Wherein, holes are punched on each layer of the metal plates and penetrate all the metal plates to form a closed cavity structure inside the air medium filled suspension slot line structure.

[0014] The present invention adopts a multi-layer metal plate stacking structure to form a multi-layer self-encapsulation structure, and can realize etching on the internal metal plate to form a slot structure. Since the medium inside the slot structure and above and below the metal plate where it is located are all air, it completely eliminates the dielectric loss caused by the slot line structure based on the traditional PCB board design, thereby achieving lower loss. Since it adopts a self-encapsulation structure, the electric field is mainly distributed in the air inside the encapsulation structure, so the radiation loss of the slot line can be greatly reduced.

[0015] The air dielectric filled suspension slot line structure of the present invention can realize flexible design of various circuits, and each layer of metal plate structure can be processed independently and finally integrated by riveting or soldering. It has significant advantages over the traditional waveguide structure that is integrally formed using complex processes.

[0016] Since the characteristic impedance of the slot line is inversely proportional to the width of the slot line, a narrower slot line can be used to achieve lower impedance. Compared with the traditional microstrip line, it is smaller in size. At the same time, the wider slot line is not only easier to process but also can achieve higher impedance than the microstrip line. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the AFISSL structure based on the all-metal integrated MISL platform;

[0018] Figure 2 This is a schematic diagram of the equivalent simplified structure of the AFISSL structure based on the all-metal integrated MISL platform;

[0019] Figure 3 yes Figure 2 A top view schematic diagram of an equivalent simplified structure;

[0020] Figure 4 This is a schematic diagram of the dual-band filter designed by AFISSL based on the all-metal integrated MISL platform;

[0021] Figure 5 This is a schematic diagram of the structure of the circuit of the third metal plate of the dual-band filter designed by AFISSL based on the all-metal integrated MISL platform; Figure 6 It is a schematic diagram of the structure of each layer of the dual-band filter designed by AFISSL based on the all-metal integrated MISL platform and manufactured using metal aluminum processing. DETAILED DESCRIPTION

[0022] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0023] The Metal Integrated Suspended Line (MISL) platform uses advanced metal processing technology and has significant advantages such as high processing accuracy and low cost. Therefore, the circuit designed based on MISL not only has a high quality factor (Q value), but also exhibits good heat dissipation. When applied to the present invention, the proposed air dielectric filled suspended slot line structure based on the MISL platform can achieve a high Q value.

[0024] Please refer to the accompanying drawings. In the embodiment of the present application, the air-filled integrated suspended slotline (AFISSL) structure based on the MISL platform is implemented based on the all-metal MISL multi-layer metal circuit structure to realize the air-filled integrated suspended slotline structure (AFISSL).

[0025] like Figure 1 The figure shows the overall structure of a single slot line based on the MISL platform. The metal integrated suspension line platform MISL is composed of multiple layers of metal plates. Taking the metal integrated suspension line platform MISL composed of five layers of metal plates as an example, it consists of Figure 1 The metal plates M1-M5 are stacked, and a slot line (AFISSL) structure of the main circuit is arranged on the third metal plate M3, which is formed by etching or hollowing out the metal plate according to a preset shape, such as Figure 1 As shown, a slot line (AFISSL) structure is formed by a linear slot line, wherein the second metal plate M2 and the fourth metal plate M4 are partially cut away to form a hollow cavity filled with air.

[0026] It should be noted that the multi-layer metal plate of the circuit board involved in the embodiment of the present invention is not limited to a five-layer metal plate. Figure 1 Just take five layers of metal plate as an example

[0027] The metal plates of each layer can be made of stainless steel, copper, aluminum or other metal alloys through metal etching and other processes.

[0028] Wherein, feeding structures 12 are arranged at both ends of the slot line structure of the main circuit, and the feeding structures 22 are arranged symmetrically.

[0029] The main circuit involved in the present invention includes a microwave radio frequency circuit, which can be etched (hollowed out) on the third metal plate M3 (it can also be designed on any other layer) to realize the AFISSL structure. Specifically, in the five-layer structure of the embodiment of the present application, the first metal plate and the fifth metal plate are non-hollowed out structures (excluding surrounding metal holes), and the middle parts of the second metal plate M2 and the fourth metal plate M4 are cut off, such as Figure 6 See Figure 1 , 2 As shown in FIG6 , the second metal plate M2 and the fourth metal plate M4 each form two U-shaped structural parts, which are separated and not connected to each other and are symmetrically arranged to correspond to the feed line 11 of the circuit of the third metal plate M3, thereby realizing direct feeding of the circuit using the classic coplanar waveguide (CPW).

[0030] Furthermore, the MISL proposed in the present invention can be externally connected by conventional rivet technology or soldering, etc. The thickness of each metal plate can be customized to any size according to actual needs.

[0031] In order to form a closed cavity structure, holes are drilled in each metal plate and penetrate all the metal plates.

[0032] The multi-layer circuit board or metal plate is connected by countersunk holes, rivets or soldering to form a self-encapsulated structure. The rivet holes 11 on the metal plate are as shown in FIG. Figure 1 , Figure 4 shown.

[0033] In the embodiment of the present application, an air-filled integrated suspended slotline (AFISSL) structure is based on the MISL platform. Since the filler of this structure is only air, a circuit structure with a higher quality factor (Q value) can be designed by etching the slotline structure on the metal layer, so a higher quality factor (Q value) can be achieved.

[0034] like Figure 2 Shown Figure 1 An alternative model, in which the first metal plate M1 and the fifth metal plate M5 can be equivalent to the outer wall of the air box 13 shown, and the second metal plate M2 and the fourth metal plate M4 can be equivalent to the air medium.

[0035] like Figure 4 As shown in the figure, there are three pairs of resonators in this figure, and the length of each resonator is half a wavelength. Each pair of resonators can produce two resonance points. By cascading three pairs of resonators, a third-order dual-frequency filter response can be generated. There is a feed line on the outside of the metal plate where the dual-frequency filter is located. Each pair of resonators is composed of two coupled AFISSL resonators. They are nested together to form a double U-shape as shown in the figure. The opening direction of the middle resonator is opposite to the opening direction of the two resonators on both sides. It is formed by hollowing out the metal plate. Please refer to the combination Figure 5 As shown, the white part is a hollow structure, and the multiple circular holes on the outside are metal holes, and the two sides are symmetrically hollowed out to form a feed line 11, as shown in FIG. Figure 5 shown.

[0036] like Figure 5 The figure shows the schematic diagram of the structure of the dual-frequency filter on the third metal plate M3, including the coupled AFISSL and the matching feeding structure. It is a symmetrical structure and can use the classic coplanar waveguide (CPW) to directly feed the circuit.

[0037] like Figure 6 The figure shows a physical picture of a dual-frequency filter made of aluminum, in which each layer of metal plate is arranged separately. The upper left side is the first layer of metal plate M1, the upper right side is the second layer of metal plate M2, the middle is the third layer of metal plate M3, the lower left side is the fourth layer of metal plate M4, and the lower right side is the fifth layer of metal plate M5.

[0038] The basic principles and main features of the present invention and the advantages of the present invention are shown and described above. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention.

[0039] Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is therefore intended that all changes falling within the meaning and range of equivalent elements of the claims are included in the present invention.

[0040] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. Air medium filled suspension slot line structure, characterized in that: It is an air-medium-filled suspended slot-line structure based on the MISL platform, which is composed of multiple layers of metal plates stacked to form a self-encapsulation structure. The slot-line structure of the main circuit is arranged on an internal layer of metal plates, and the metal plates above and below the slot-line structure of the main circuit are partially cut off to form an air-filled hollow cavity.

2. The air medium filled suspension slot wire structure according to claim 1, characterized in that: Feeding structures are arranged at both ends of the slot line structure of the main circuit.

3. The air medium filled suspension slot wire structure according to claim 2, characterized in that: The feeding structures are arranged symmetrically.

4. The air medium filled suspension slot wire structure according to claim 1, characterized in that: The slot line structure of the main circuit includes a dual-frequency filter, which includes three pairs of resonators, each of which has a half-wavelength length; each pair of resonators generates two resonance points, and by cascading the three pairs of resonators, a third-order dual-frequency filter response is generated.

5. The air medium filled suspension slot wire structure according to claim 4, characterized in that: The dual-band filter utilizes coplanar waveguides to directly feed the circuit.

6. The air medium filled suspension slot wire structure according to claim 1, characterized in that: The multi-layer metal plates are connected by countersunk holes, rivets or soldering to form a self-encapsulated structure.

7. The air medium filled suspension slot wire structure according to claim 1, characterized in that: The metal plates are all made of stainless steel, copper, aluminum or metal alloy.

8. The air medium filled suspension slot wire structure according to claim 1, characterized in that: The metal plate is formed by a metal etching process.

9. The air medium filled suspension slot wire structure according to claim 1, characterized in that: The main circuit includes a microwave radio frequency circuit, which is formed by etching on a metal plate.

10. The air medium filled suspension slot wire structure according to claim 1, characterized in that: Holes are punched on each layer of the metal plates and penetrate through all the metal plates to form a closed cavity structure inside the air medium filled suspension slot line structure.

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