An HTCC waveguide transition structure with filtering characteristics

Abstract

The present application discloses an HTCC waveguide transition structure with filtering characteristics, which includes a first waveguide, an HTCC structure, and a second waveguide. The first waveguide is hermetically connected to the second waveguide through the HTCC structure. The HTCC structure includes a first HTCC structure, a second HTCC structure, and a third HTCC structure stacked in sequence from top to bottom. The first HTCC structure includes a first grounding metal surface, a first ceramic dielectric layer, and a second grounding metal surface arranged in sequence from top to bottom. The second HTCC structure includes a third grounding metal surface, a second ceramic dielectric layer, and a fourth grounding metal surface arranged in sequence from top to bottom. The third HTCC structure includes a fifth grounding metal surface, a third ceramic dielectric layer, and a sixth grounding metal surface arranged in sequence from top to bottom. The present application can achieve a filtering function while realizing the hermetic transmission of millimeter-wave signals.

Description

Technical Field

[0001] This application relates to the technical field of millimeter-wave circuits, and particularly to an HTCC waveguide transition structure with filtering characteristics. Background Art

[0002] In recent years, the development of millimeter-wave waveguide circuits has been extremely rapid, and the requirements for waveguide transmission in various application environments have also become higher and higher. The waveguide transition structure plays an important role in millimeter-wave circuits. The traditional waveguide transition structure is difficult to ensure performance while achieving airtightness, and has problems such as complex structure and single function. Summary of the Invention

[0003] In order to solve the problems existing in the traditional millimeter-wave waveguide transition structure, the present invention proposes an HTCC waveguide transition structure with filtering characteristics.

[0004] This application discloses an HTCC waveguide transition structure with filtering characteristics, which includes a first waveguide, an HTCC structure, and a second waveguide. The first waveguide is hermetically connected to the second waveguide through the HTCC structure. The HTCC structure includes a first HTCC structure, a second HTCC structure, and a third HTCC structure stacked in sequence from top to bottom.

[0005] The first HTCC structure includes a first ground metal surface, a first ceramic dielectric layer, and a second ground metal surface arranged in sequence from top to bottom. The second HTCC structure includes a third ground metal surface, a second ceramic dielectric layer, and a fourth ground metal surface arranged in sequence from top to bottom. The third HTCC structure includes a fifth ground metal surface, a third ceramic dielectric layer, and a sixth ground metal surface arranged in sequence from top to bottom.

[0006] Further, the first ground metal surface and the second ground metal surface have the same structure, and both have a hollow structure in the middle. The third ground metal surface and the fourth ground metal surface have the same structure, and both have a hollow structure in the middle. The fifth ground metal surface and the sixth ground metal surface have the same structure, and both have a hollow structure in the middle.

[0007] Further, the first ground metal surface, the third ground metal surface, and the fifth ground metal surface have different structures.

[0008] The first ground metal plane, the third ground metal plane, and the fifth ground metal plane are respectively provided with different numbers of ground metal vias at different positions, so as to form ceramic dielectric windows with different RF impedances and thicknesses on the first ceramic dielectric layer, the second ceramic dielectric layer, and the third ceramic dielectric layer; the ceramic dielectric window on the first ceramic dielectric layer is a hollow structure of the first ground metal plane and the second ground metal plane; the ceramic dielectric window on the second ceramic dielectric layer is a hollow structure of the third ground metal plane and the fourth ground metal plane; the ceramic dielectric window on the third ceramic dielectric layer is a hollow structure of the fifth ground metal plane and the sixth ground metal plane.

[0009] Further, the first waveguide is connected to the first ceramic dielectric layer through the hollow structure of the first ground metal plane; the shape and size of the hollow structure of the first ground metal plane are the same as the shape and size of the longitudinal section of the first waveguide, so as to make the first waveguide and the first ceramic dielectric layer be hermetically connected;

[0010] The second waveguide is connected to the third ceramic dielectric layer through the hollow structure of the sixth ground metal plane; the shape and size of the hollow structure of the sixth ground metal plane are the same as the shape and size of the longitudinal section of the second waveguide, so as to make the second waveguide and the third ceramic dielectric layer be hermetically connected.

[0011] Further, the hollow structures of the first ground metal plane, the third ground metal plane, and the fifth ground metal plane have an overlapping area in the direction perpendicular to the HTCC structure, so that after the millimeter-wave signal enters from the first waveguide, it sequentially passes through the hollow structure on the first ground metal plane to the hollow structure on the sixth ground metal plane and then is output from the second waveguide.

[0012] Further, the first ground metal plane, the second ground metal plane, the third ground metal plane, the fourth ground metal plane, the fifth ground metal plane, and the sixth ground metal plane are provided with ground metal vias; the first HTCC structure, the second HTCC structure, and the third HTCC structure are connected through the ground metal vias.

[0013] Further, the dielectric constants and thicknesses of the first ceramic dielectric layer, the second ceramic dielectric layer, and the third ceramic dielectric layer are all different.

[0014] Further, the peripheries of the first ceramic dielectric layer, the second ceramic dielectric layer, and the third ceramic dielectric layer are all covered with a ground metal layer for shielding millimeter-wave signals.

[0015] Further, the dielectric constants, thicknesses, and sizes of the ceramic dielectric windows on the first ceramic dielectric layer, the second ceramic dielectric layer, and the third ceramic dielectric layer are all different.

[0016] Further, when a millimeter-wave signal within the operating frequency range of the HTCC waveguide transition structure is input into the HTCC structure through the waveguide, the ceramic dielectric window acts as a filtering structure and is impedance-matched within the operating frequency range;

[0017] When a millimeter-wave signal outside the operating frequency range of the HTCC waveguide transition structure is input into the HTCC structure, the ceramic dielectric window group acts as a filtering structure and is impedance-mismatched within the operating frequency range.

[0018] Due to the adoption of the above technical solutions, the present application has the following advantages:

[0019] 1. The present application uses an HTCC (High-Temperature Co-fired Ceramic) structure to achieve airtight transmission between waveguides, and multiple layers with different dielectric constants, thicknesses, ground metal vias, and ground metal layers are arranged inside the HTCC, realizing miniaturized bandpass filtering characteristics, passband characteristics within a specific frequency range, and radio frequency suppression outside a specific frequency range.

[0020] 2. An HTCC waveguide transition structure with filtering characteristics proposed by the present application has the advantages of simple structure, multiple functions, small impact on radio frequency performance, and small size, and has wide application value in the field of microwave and millimeter-wave circuits.

[0021] 3. An HTCC waveguide transition structure with filtering characteristics proposed by the present invention realizes airtight transmission of millimeter-wave signals through the HTCC method. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings described below are only some embodiments recorded in the embodiments of the present application, and those of ordinary skill in the art can also obtain other drawings based on these drawings.

[0023] Figure 1 is an overall schematic diagram of an HTCC waveguide transition structure with filtering characteristics according to an embodiment of the present application;

[0024] Figure 2 is a schematic diagram of the first ceramic dielectric layer of an HTCC waveguide transition structure with filtering characteristics according to an embodiment of the present application;

[0025] Figure 3 Schematic diagram of the second ceramic dielectric layer of an HTCC waveguide transition structure with filtering characteristics according to an embodiment of the present application;

[0026] Figure 4 Schematic diagram of the third ceramic dielectric layer of an HTCC waveguide transition structure with filtering characteristics according to an embodiment of the present application;

[0027] Figure 5 Performance result diagram of an HTCC waveguide transition structure with filtering characteristics according to an embodiment of the present application;

[0028] Among them, 1 is the first waveguide, 2 is the first ceramic dielectric layer, 3 is the second ceramic dielectric layer, 4 is the third ceramic dielectric layer, 5 is the grounding metal via, 6 is the fifth grounding metal surface, and 7 is the second waveguide. Detailed implementation manners

[0029] The present application will be further described in conjunction with the accompanying drawings and embodiments. The described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art shall fall within the scope of protection of the embodiments of the present application.

[0030] See Figures 1 to 4 , the present application provides an embodiment of an HTCC waveguide transition structure with filtering characteristics, which includes a first waveguide 1, an HTCC structure, and a second waveguide 7. The first waveguide 1 is hermetically connected to the second waveguide 7 through the HTCC structure; the HTCC structure includes a first HTCC structure, a second HTCC structure, and a third HTCC structure stacked in sequence from top to bottom;

[0031] The first HTCC structure includes a first grounding metal surface, a first ceramic dielectric layer 2, and a second grounding metal surface arranged in sequence from top to bottom; the second HTCC structure includes a third grounding metal surface, a second ceramic dielectric layer 3, and a fourth grounding metal surface arranged in sequence from top to bottom; the third HTCC structure includes a fifth grounding metal surface 6, a third ceramic dielectric layer 4, and a sixth grounding metal surface arranged in sequence from top to bottom. The HTCC (High Temperature Co-fired Ceramic) process is an advanced microelectronic packaging technology that can stack and sinter multiple ceramic substrates layer by layer (sintering means causing physical and chemical properties of multiple originally relatively independent ceramic substrates to change through high-temperature heating, thereby realizing the connection and structural solidification between multiple ceramic substrate layers), and has hermetic characteristics.

[0032] The first ceramic dielectric layer 2, the second ceramic dielectric layer 3, and the third ceramic dielectric layer 4 are structurally solidified through the high-temperature co-firing process.

[0033] The present application can realize the filtering function while realizing the hermetic transmission of millimeter-wave signals.

[0034] Optionally, the first ground metal surface and the second ground metal surface have the same structure, and both of their middle parts are hollow structures; the third ground metal surface and the fourth ground metal surface have the same structure, and both of their middle parts are hollow structures; the fifth ground metal surface 6 and the sixth ground metal surface have the same structure, and both of their middle parts are hollow structures.

[0035] Optionally, the first ground metal surface, the third ground metal surface, and the fifth ground metal surface 6 have different structures;

[0036] The first ground metal surface, the third ground metal surface, and the fifth ground metal surface 6 are respectively provided with different numbers of ground metal vias 5 at different positions, so as to form ceramic dielectric empty windows with different RF impedances and thicknesses on the first ceramic dielectric layer 2, the second ceramic dielectric layer 3, and the third ceramic dielectric layer 4 respectively; the ceramic dielectric empty window on the first ceramic dielectric layer 2 is the hollow structure of the first ground metal surface and the second ground metal surface; the ceramic dielectric empty window on the second ceramic dielectric layer 3 is the hollow structure of the third ground metal surface and the fourth ground metal surface; the ceramic dielectric empty window on the third ceramic dielectric layer 4 is the hollow structure of the fifth ground metal surface 6 and the sixth ground metal surface.

[0037] Optionally, the first waveguide 1 is connected to the first ceramic dielectric layer 2 through the hollow structure of the first ground metal surface; the shape and size of the hollow structure of the first ground metal surface are the same as the shape and size of the longitudinal section of the first waveguide 1, so as to make the first waveguide 1 and the first ceramic dielectric layer 2 airtight connection;

[0038] The second waveguide 7 is connected to the third ceramic dielectric layer 4 through the hollow structure of the sixth ground metal surface; the shape and size of the hollow structure of the sixth ground metal surface are the same as the shape and size of the longitudinal section of the second waveguide 7, so as to make the second waveguide 7 and the third ceramic dielectric layer 4 airtight connection.

[0039] Optionally, the hollow structures of the first ground metal surface, the third ground metal surface, and the fifth ground metal surface 6 have overlapping regions in the direction perpendicular to the HTCC structure, so that after the millimeter wave signal enters from the first waveguide 1, it passes through the hollow structures on the first ground metal surface to the hollow structures on the sixth ground metal surface in sequence, and then is output from the second waveguide 7.

[0040] Optionally, via holes are provided on the first ground metal surface, the second ground metal surface, the third ground metal surface, the fourth ground metal surface, the fifth ground metal surface 6, and the sixth ground metal surface; the first HTCC structure, the second HTCC structure, and the third HTCC structure are connected through the via holes. Specifically, the via holes of the first ground metal surface and the second ground metal surface penetrate through the first ceramic dielectric layer 2 to connect the first ground metal surface, the first ceramic dielectric layer 2, and the second ground metal surface; the via holes of the third ground metal surface and the fourth ground metal surface penetrate through the second ceramic dielectric layer 3 to connect the third ground metal surface, the second ceramic dielectric layer 3, and the fourth ground metal surface; the via holes of the fifth ground metal surface 6 and the sixth ground metal surface penetrate through the third ceramic dielectric layer 4 to connect the fifth ground metal surface 6, the third ceramic dielectric layer 4, and the sixth ground metal surface.

[0041] Optionally, the dielectric constants and thicknesses of the first ceramic dielectric layer 2, the second ceramic dielectric layer 3, and the third ceramic dielectric layer 4 are all different.

[0042] Optionally, the peripheries of the first ceramic dielectric layer 2, the second ceramic dielectric layer 3, and the third ceramic dielectric layer 4 are all covered with a ground metal layer for shielding millimeter-wave signals.

[0043] Optionally, the dielectric constants, thicknesses, and sizes of the ceramic dielectric windows on the first ceramic dielectric layer 2, the ceramic dielectric windows on the second ceramic dielectric layer 3, and the ceramic dielectric windows on the third ceramic dielectric layer 4 are all different.

[0044] Optionally, when millimeter-wave signals within the operating frequency range of the HTCC waveguide transition structure are input from the waveguide to the HTCC structure, the ceramic dielectric windows serve as filtering structures and are impedance-matched within the operating frequency range;

[0045] When millimeter-wave signals outside the operating frequency range of the HTCC waveguide transition structure are input to the HTCC structure, the ceramic dielectric window group serves as a filtering structure and is impedance-mismatched within the operating frequency range.

[0046] Figure 4 In, the shaded part is the ground metal surface, and the non-shaded part in the center of the ceramic dielectric layer indicates that there is no metal in the middle and the ceramic dielectric is exposed.

[0047] In the above embodiments of the present application:

[0048] 1. Ground metal layers with different shapes are provided on different ceramic dielectric layers.

[0049] 2. Ground metal vias with different positions and quantities are provided on different ceramic dielectric layers, thereby forming ceramic dielectric windows with inconsistent impedance and thickness on each layer of ceramic dielectric layer. That is, the periphery of each layer of ceramic dielectric plate is grounded metal for shielding millimeter-wave signals. The central area of each layer of ceramic dielectric layer has no grounded metal and serves as a dielectric window structure. The radio frequency impedance and thickness (electrical length) of the ceramic dielectric windows between different ceramic dielectric layers are inconsistent.

[0050] 3. The ceramic dielectric windows between different ceramic dielectric layers together constitute a filtering structure within a specific frequency range.

[0051] 4. The ceramic dielectric window can achieve the transmission of millimeter-wave signals and can also simultaneously achieve different responses to millimeter-wave signals of different frequencies. That is, for millimeter-wave signals within the operating frequency range, the filtering structure composed of the ceramic dielectric windows of the multi-layer ceramic dielectric plate can allow the millimeter-wave signals within the operating frequency range to pass through with low loss; for millimeter-wave signals within the operating frequency range, suppression can be achieved.

[0052] 5. Principle of the HTCC waveguide transition structure to achieve airtight transmission: Each layer of ceramic dielectric layer is airtight, and the transmission waveguide is directly welded to the HTCC, so overall airtight transmission can be ensured.

[0053] 6. The principle of the HTCC waveguide transition structure to achieve filtering is as follows: The dielectric constants, thicknesses, and shapes of the central ceramic dielectric cavities of different ceramic dielectric layers are all different. Therefore, different ceramic dielectric windows all have different radio frequency impedances and electrical lengths, which can be understood as multiple different impedance units, and multiple impedance units together achieve the effect of the filter.

[0054] 7. When millimeter-wave signals within the operating frequency range are input from the waveguide to the HTCC, the filtering structure composed of multiple different ceramic dielectric windows is impedance-matched within the operating frequency range. Therefore, the millimeter-wave signals within the operating frequency range have very little loss.

[0055] 8. When millimeter-wave signals outside the operating frequency range are input to the HTCC, the filtering structure composed of multiple different ceramic dielectric windows is impedance-mismatched within the operating frequency range. At this time, the HTCC has a high suppression of millimeter-wave signals outside the operating frequency range, and the input millimeter-wave signals will be reflected, thereby achieving suppression outside the operating frequency range.

[0056] 9. The waveguide is mainly a rectangular waveguide, and can also be other forms of waveguides.

[0057] Figure 5It is a performance result diagram of an HTCC waveguide transition structure with filtering characteristics. It can be seen that the insertion loss S21 in the frequency range of 76 GHz to 88 GHz is less than 3 dB, and radio frequency suppression is achieved when the frequency range is less than 76 GHz and greater than 88 GHz.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and not to limit them. Although the present application has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: modifications or equivalent replacements can still be made to the specific implementation manners of the present application, and any modification or equivalent replacement that does not depart from the spirit and scope of the present application should be covered by the protection scope of the claims of the present application.

Claims

1. An HTCC waveguide transition structure with filtering characteristics, characterized in that, It includes a first waveguide, an HTCC structure, and a second waveguide. The first waveguide is hermetically connected to the second waveguide through the HTCC structure. The HTCC structure includes a first HTCC structure, a second HTCC structure, and a third HTCC structure stacked in sequence from top to bottom. The first HTCC structure includes a first grounding metal surface, a first ceramic dielectric layer, and a second grounding metal surface arranged in sequence from top to bottom. The second HTCC structure includes a third grounding metal surface, a second ceramic dielectric layer, and a fourth grounding metal surface arranged in sequence from top to bottom. The third HTCC structure includes a fifth grounding metal surface, a third ceramic dielectric layer, and a sixth grounding metal surface arranged in sequence from top to bottom. The first grounding metal surface and the second grounding metal surface have the same structure, and both of their middle parts are hollow structures. The third grounding metal surface and the fourth grounding metal surface have the same structure, and both of their middle parts are hollow structures. The fifth grounding metal surface and the sixth grounding metal surface have the same structure, and both of their middle parts are hollow structures. The first waveguide is connected to the first ceramic dielectric layer through the hollow structure of the first grounding metal surface. The shape and size of the hollow structure of the first grounding metal surface are the same as those of the longitudinal section of the first waveguide, so that the first waveguide is hermetically connected to the first ceramic dielectric layer. The second waveguide is connected to the third ceramic dielectric layer through the hollow structure of the sixth grounding metal surface. The shape and size of the hollow structure of the sixth grounding metal surface are the same as those of the longitudinal section of the second waveguide, so that the second waveguide is hermetically connected to the third ceramic dielectric layer. Grounding metal vias with different positions and quantities are arranged on different ceramic dielectric layers, so as to form ceramic dielectric empty windows with inconsistent impedance and thickness on each layer of ceramic dielectric layer.

2. The HTCC waveguide transition structure with filtering characteristics according to claim 1, characterized in that The structures of the first grounding metal surface, the third grounding metal surface, and the fifth grounding metal surface are different. The first grounding metal surface, the third grounding metal surface, and the fifth grounding metal surface are respectively provided with different numbers of grounding metal vias at different positions, so as to form ceramic dielectric empty windows with different radio frequency impedances and thicknesses on the first ceramic dielectric layer, the second ceramic dielectric layer, and the third ceramic dielectric layer respectively. The ceramic dielectric empty window on the first ceramic dielectric layer is the hollow structure of the first grounding metal surface and the second grounding metal surface. The ceramic dielectric empty window on the second ceramic dielectric layer is the hollow structure of the third grounding metal surface and the fourth grounding metal surface. The ceramic dielectric empty window on the third ceramic dielectric layer is the hollow structure of the fifth grounding metal surface and the sixth grounding metal surface.

3. The HTCC waveguide transition structure with filtering characteristics according to claim 1, characterized in that, The hollow structures of the first grounding metal surface, the third grounding metal surface, and the fifth grounding metal surface have overlapping regions in the direction perpendicular to the HTCC structure, so that after the millimeter-wave signal enters from the first waveguide, it passes through the hollow structures from the first grounding metal surface to the sixth grounding metal surface in sequence and then is output from the second waveguide.

4. The HTCC waveguide transition structure with filtering characteristics according to claim 1, characterized in that, The first grounding metal surface, the second grounding metal surface, the third grounding metal surface, the fourth grounding metal surface, the fifth grounding metal surface, and the sixth grounding metal surface are provided with grounding metal vias; the first HTCC structure, the second HTCC structure, and the third HTCC structure are connected through the grounding metal vias.

5. The HTCC waveguide transition structure with filtering characteristics according to claim 1, wherein The dielectric constants and thicknesses of the first ceramic dielectric layer, the second ceramic dielectric layer, and the third ceramic dielectric layer are all different.

6. The HTCC waveguide transition structure with filtering characteristics according to claim 2, characterized in that, The peripheries of the first ceramic dielectric layer, the second ceramic dielectric layer, and the third ceramic dielectric layer are all covered with a grounding metal layer for shielding millimeter-wave signals.

7. The HTCC waveguide transition structure with filtering characteristics according to claim 2, characterized in that, The dielectric constants, thicknesses, and sizes of the ceramic dielectric windows on the first ceramic dielectric layer, the ceramic dielectric windows on the second ceramic dielectric layer, and the ceramic dielectric windows on the third ceramic dielectric layer are all different.

8. The HTCC waveguide transition structure with filtering characteristics according to claim 2 or 6 or 7, characterized in that, When millimeter-wave signals within the operating frequency range of the HTCC waveguide transition structure are input into the HTCC structure through the waveguide, the ceramic dielectric windows act as a filtering structure and are impedance-matched within the operating frequency range; When millimeter-wave signals outside the operating frequency range of the HTCC waveguide transition structure are input into the HTCC structure, the ceramic dielectric window group acts as a filtering structure and is impedance-mismatched within the operating frequency range.

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