Air dielectric filled suspended slot line structure

Abstract

The application discloses an air medium filling suspended slot line structure, which is based on an MISL platform, is stacked by multiple metal plates, and forms a self-encapsulation structure; a slot line structure of a main circuit is arranged on an inner layer of the metal plates; and air-filled hollow cavities are formed in the metal plates above and below the slot line structure of the main circuit by partially cutting the metal plates. The air medium filling suspended slot line structure adopts a multi-layer metal plate stacking structure to form a multi-layer self-encapsulation structure, can etch the inner metal plates to form a gap structure, and completely eliminates the medium loss caused by the slot line structure based on a traditional PCB plate design because the medium in the gap structure and the upper and lower metal plates is air, so that low loss can be realized. Because the air medium filling suspended slot line structure adopts a self-encapsulation structure, electric field is mainly distributed in the air in the encapsulation structure, so that the radiation loss of the slot line can be greatly reduced.

Description

Technical Field

[0001] This invention relates to the field of radio frequency microwave terahertz circuit technology, and in particular to a novel air-filled integrated suspended slotline (AFISSL) structure. Background Technology

[0002] Slotlines are widely used transmission lines in radio frequency (RF) and microwave circuits, possessing unique structures and performance characteristics. Their main advantages include ease of fabrication and the ability to achieve high impedance, resulting in excellent performance in the microwave frequency band. Furthermore, the compactness of slotlines allows for efficient signal transmission within limited space, meeting the demands of modern miniaturized devices. Slotlines are also easily integrated with other transmission lines, such as microstrip lines, simplifying design and manufacturing. However, slotlines also have some disadvantages. Their bandwidth may be limited. Additionally, particularly in high-frequency applications, their high dielectric properties and radiation losses may prevent them from meeting all design requirements. Summary of the Invention

[0003] The purpose of this 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 the MISL platform. Since the MISL platform is made of pure metal, it completely eliminates dielectric loss, which results in the air-filled suspended slotline structure of this invention achieving a high Q value.

[0004] An air-filled suspension groove structure is an air-filled suspension groove structure based on an all-metal integrated MISL platform. It is composed of multiple layers of metal plates stacked together to form a self-encapsulating structure. The groove structure of the main circuit is arranged on the inner layer of metal plate. The metal plates above and below the groove structure of the main circuit are partially cut out to form an air-filled hollow cavity.

[0005] The main circuit has power supply structures arranged at both ends of the slotted structure.

[0006] The power supply structure is arranged symmetrically.

[0007] The main circuit's slotted structure includes a dual-frequency filter, which comprises three pairs of resonators, each with a length of half a wavelength. Each pair of resonators generates two resonant points, and by cascading the three pairs of resonators, a third-order dual-frequency filter response is generated.

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

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

[0010] The metal plates are all made of stainless steel, copper, aluminum or metal alloys.

[0011] The metal plate is formed by metal etching process.

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

[0013] In this structure, each of the metal plates has through holes that penetrate all the metal plates, forming a closed cavity structure inside the air medium-filled suspension groove structure.

[0014] This invention employs a multi-layer metal plate stacking structure to form a multi-layer self-encapsulated structure. It allows for etching of the internal metal plates to create a slot structure. Since the dielectric medium inside the slot structure and above and below the metal plates is air, it completely eliminates the dielectric loss caused by slot structures in traditional PCB designs, thus achieving lower losses. Due to its self-encapsulated structure, the electric field is mainly distributed in the air inside the encapsulation structure, significantly reducing the radiation loss of the slot lines.

[0015] The air-dielectric-filled suspension groove structure of the present invention enables flexible design of various circuits. 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 which is integrally formed by complex processes.

[0016] Since the characteristic impedance of a slot line is inversely proportional to its width, a narrower slot line can achieve a lower impedance. Compared to traditional microstrip lines, it is smaller in size, and the wider slot line is not only easier to fabricate but can also achieve a higher impedance than microstrip lines. Attached Figure Description

[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 simplified equivalent structural diagram of the AFISSL structure based on the all-metal integrated MISL platform.

[0019] Figure 3 yes Figure 2 A top view diagram of the equivalent simplified structure.

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

[0021] Figure 5 This is a schematic diagram of the circuit structure of the third metal plate of a dual-frequency filter designed by AFISSL based on the all-metal integrated MISL platform.

[0022] Figure 6 This is a schematic diagram of each layer of a dual-frequency filter designed by AFISSL based on the all-metal integrated MISL platform and manufactured using aluminum metal processing. Detailed Implementation

[0023] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0024] The Metal Integrated Suspended Line (MISL) platform utilizes advanced metal processing technology, offering significant advantages such as high machining accuracy and low cost. Therefore, circuits designed based on MISL not only possess a high quality factor (Q value) but also exhibit excellent heat dissipation. Applied to this invention, the proposed air-filled suspension groove structure based on the MISL platform can achieve a high Q value.

[0025] Please refer to the accompanying drawings. In this embodiment of the application, the air-filled integrated suspended slotline (AFISSL) based on the MISL platform is implemented based on an all-metal MISL multilayer metal circuit structure.

[0026] like Figure 1 The diagram shows the overall structure of a single cable tray based on the MISL platform. The MISL platform is composed of multiple stacked metal plates. Taking a five-layer MISL platform as an example, it consists of... Figure 1 The structure consists of stacked metal plates M1-M5. The main circuit's slotted lines (AFISSL) are arranged on the third metal plate M3, formed by etching or hollowing out the metal plates according to a predetermined shape. Figure 1 As shown, a grooved structure (AFISSL) is formed by a linear groove; in which the second metal plate M2 and the fourth metal plate M4 are partially removed to form an air-filled hollow cavity.

[0027] It should be noted that the multilayer metal board of the circuit board involved in the embodiments of the present invention is not limited to a five-layer metal board. Figure 1 This explanation uses a five-layer metal plate as an example.

[0028] Each layer of metal plate can be made of stainless steel, copper, aluminum or other metal alloys through processes such as metal etching.

[0029] The main circuit has power supply structures 12 arranged at both ends of the slotted structure, and the power supply structures 12 are arranged symmetrically.

[0030] The main circuit involved in this invention includes a microwave radio frequency circuit, which can be etched (cut out) on the third metal plate M3 (or designed on any other layer) to realize the AFISSL structure. Specifically, in the five-layer structure of this application embodiment, the first and fifth metal plates are non-cutout structures (excluding surrounding metal holes), and the middle portion of the second metal plate M2 and the fourth metal plate M4 is cut out, as shown below. Figure 6 As shown, please refer to Figure 1 , Figure 2 as well as Figure 6 As shown, the second metal plate M2 and the fourth metal plate M4 each form two U-shaped structural parts, which are separated from each other and not connected. They are arranged symmetrically to correspond to the feed lines of the circuit of the third metal plate M3, so as to realize the direct feeding of the circuit using the classic coplanar waveguide (CPW).

[0031] Furthermore, the MISL proposed in this invention can be externally connected using traditional riveting or soldering processes. The thickness of each metal plate can be customized to any size according to actual needs.

[0032] In order to form a closed cavity structure, holes are drilled through each metal plate and run through all the metal plates.

[0033] In this structure, multilayer circuit boards or metal plates are connected by countersunk holes, rivets, or soldering to form a self-encapsulating structure. The rivet holes 11 on the metal plate are as follows: Figure 1 , Figure 4 As shown.

[0034] The embodiment of this application is based on the MISL platform and features an air-filled integrated suspended slotline (AFISSL) structure. Since the filling material of this structure is only air, a circuit structure with a high quality factor (Q value) can be designed by etching the slotline structure on the metal layer, thus achieving a high quality factor (Q value).

[0035] like Figure 2 As shown Figure 1 Alternative models, Figure 3 yes Figure 2A top view of the equivalent simplified structure, wherein 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.

[0036] like Figure 4 The diagram shows a schematic of a dual-band filter designed based on AFISSL. It features three pairs of resonators, each half a wavelength in length. Each pair generates two resonant points. Cascading these three pairs produces a third-order dual-band filter response. The metal plate containing the filter has a feed line on its outer side. Each pair of resonators consists of two coupled AFISSL resonators nested together in a double U-shape, as shown in the diagram. The opening direction of the middle resonator is opposite to that of the two side resonators. This is achieved by hollowing out the metal plate. Please refer to the diagram for further details. Figure 5 As shown, the white area represents a hollow structure, with multiple round holes on the outer side being metal holes. Symmetrical hollows on both sides form feed lines, as shown. Figure 5 As shown.

[0037] like Figure 5 The diagram shows the structure of the dual-frequency filter on the third metal plate M3, including the coupling AFISSL and the corresponding feeding structure. It is a symmetrical structure and can be directly fed by the classic coplanar waveguide (CPW).

[0038] like Figure 6 The image shown is a physical diagram of the metal plates of a dual-frequency filter made of aluminum, arranged separately. The upper left is the first metal plate M1, the upper right is the second metal plate M2, the middle is the third metal plate M3, the lower left is the fourth metal plate M4, and the lower right is the fifth metal plate M5.

[0039] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention.

[0040] Therefore, the embodiments should be regarded as exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of the equivalents of the claims be included within the invention.

[0041] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An air-medium filled suspension groove structure, characterized in that, It is an air-filled suspended slot structure based on the MISL platform, which is composed of multiple layers of stacked metal plates to form a self-encapsulating structure. The slot structure of the main circuit is arranged on the inner layer of metal plate. The metal plates above and below the slot structure of the main circuit are partially cut out to form an air-filled hollow cavity. The slot structure of the main circuit includes a dual-frequency filter, which includes three pairs of resonators, each of which is half a wavelength long. Each pair of resonators generates two resonant points. By cascading three pairs of resonators, a third-order dual-frequency filter response is generated. Each pair of resonators consists of two coupled AFISSL resonators nested together in a double U-shape. The opening direction of the middle resonator is opposite to that of the two resonators on either side, and this is achieved by hollowing out a metal plate.

2. The air-medium filled suspension groove structure according to claim 1, characterized in that, The main circuit has power supply structures arranged at both ends of the slotted structure.

3. The air-medium filled suspension groove structure according to claim 2, characterized in that, The power supply structure is arranged symmetrically.

4. The air-medium filled suspension groove structure according to claim 1, characterized in that, The dual-frequency filter utilizes a coplanar waveguide to directly feed the circuit.

5. The air-medium filled suspension groove structure according to claim 1, characterized in that, Multilayer metal plates are connected by countersunk holes, rivets, or soldering to form a self-encapsulating structure.

6. The air-medium filled suspension groove structure according to claim 1, characterized in that, The metal plates are all made of stainless steel, copper, aluminum, or metal alloys.

7. The air-medium filled suspension groove structure according to claim 1, characterized in that, The metal plate is formed by metal etching process.

8. The air-medium filled suspension groove 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.

9. The air-medium filled suspension groove structure according to claim 1, characterized in that, Through holes are drilled in each of the metal plates and extend through all the metal plates to form a closed cavity structure inside the air medium-filled suspension groove structure.

Images