HTCC waveguide transition structure with filtering characteristic

Abstract

The invention discloses an HTCC waveguide transition structure with a filtering characteristic, which comprises a first waveguide, an HTCC structure and a second waveguide, and is characterized in that the first waveguide is in airtight connection with the second waveguide through the HTCC structure; the HTCC structure comprises a first HTCC structure, a second HTCC structure and a third HTCC structure which are sequentially stacked from top to bottom; the first HTCC structure comprises a first grounding metal surface, a first ceramic dielectric layer and a second grounding metal surface which are sequentially arranged from top to bottom; the second HTCC structure comprises a third grounding metal surface, a second ceramic dielectric layer and a fourth grounding metal surface which are sequentially arranged from top to bottom; and the third HTCC structure comprises a fifth grounding metal surface, a third ceramic dielectric layer and a sixth grounding metal surface which are sequentially arranged from top to bottom. According to the invention, a filtering function can be realized while airtight transmission of millimeter wave signals is realized.

Description

Technical Field

[0001] The present application relates to the technical field of millimeter wave circuits, and in particular to a 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 become increasingly higher. Waveguide transition structures play an important role in millimeter wave circuits. Traditional waveguide transition structures are difficult to ensure performance while achieving airtightness, and have 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 a HTCC waveguide transition structure with filtering characteristics.

[0004] The present application discloses a HTCC waveguide transition structure with filtering characteristics, which includes a first waveguide, an HTCC structure, and a second waveguide, wherein the first waveguide is airtightly 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 sequentially from top to bottom; The first HTCC structure includes a first grounding metal plane, a first ceramic dielectric layer, and a second grounding metal plane arranged in sequence from top to bottom; the second HTCC structure includes a third grounding metal plane, a second ceramic dielectric layer, and a fourth grounding metal plane arranged in sequence from top to bottom; the third HTCC structure includes a fifth grounding metal plane, a third ceramic dielectric layer, and a sixth grounding metal plane arranged in sequence from top to bottom.

[0005] Furthermore, the first grounding metal surface and the second grounding metal surface have the same structure, and the parts thereof are both hollow structures; the third grounding metal surface and the fourth grounding metal surface have the same structure, and the parts thereof are both hollow structures; the fifth grounding metal surface and the sixth grounding metal surface have the same structure, and the parts thereof are both hollow structures.

[0006] Furthermore, the first grounding metal surface, the third grounding metal surface and the fifth grounding metal surface have different shapes; Different numbers of grounding metal vias are respectively arranged at different positions on the first grounding metal plane, the third grounding metal plane and the fifth grounding metal plane, so that ceramic dielectric windows with different radio frequency impedance and thickness are respectively formed on the first ceramic dielectric layer, the second ceramic dielectric layer and the third ceramic dielectric layer; the ceramic dielectric windows on the first ceramic dielectric layer are hollow structures of the first grounding metal plane and the second grounding metal plane; the ceramic dielectric windows on the second ceramic dielectric layer are hollow structures of the third grounding metal plane and the fourth grounding metal plane; and the ceramic dielectric windows on the third ceramic dielectric layer are hollow structures of the fifth grounding metal plane and the sixth grounding metal plane.

[0007] Further, the first waveguide is connected to the first ceramic dielectric layer through the hollow structure of the first grounded metal surface; the shape and size of the hollow structure of the first grounded metal surface are the same as the shape and size of the longitudinal section of the first waveguide, so that the first waveguide is connected to the first ceramic dielectric layer in an airtight manner; 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 the shape and size of the longitudinal section of the second waveguide, so that the second waveguide is airtightly connected to the third ceramic dielectric layer.

[0008] Furthermore, the hollow structures of the first grounding metal plane, the third grounding metal plane and the fifth grounding metal plane have an overlapping area in a direction perpendicular to the HTCC structure, so that after the millimeter wave signal enters from the first waveguide, it passes through the hollow structure on the first grounding metal plane to the hollow structure on the sixth grounding metal plane in sequence, and then is output from the second waveguide.

[0009] Furthermore, grounding metal vias are provided on the first grounding metal plane, the second grounding metal plane, the third grounding metal plane, the fourth grounding metal plane, the fifth grounding metal plane, and the sixth grounding metal plane; and the first HTCC structure, the second HTCC structure, and the third HTCC structure are connected through the grounding metal vias.

[0010] Furthermore, 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.

[0011] Furthermore, the first ceramic dielectric layer, the second ceramic dielectric layer and the third ceramic dielectric layer are all covered with grounded metal layers on all sides for shielding millimeter wave signals.

[0012] Furthermore, the dielectric constants, thicknesses and shapes 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.

[0013] 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, as a filtering structure, is impedance matched within the operating frequency range; When a millimeter wave signal outside the operating frequency range of the HTCC waveguide transition structure is input to the HTCC structure, the ceramic dielectric window group, as a filtering structure, is impedance mismatched within the operating frequency range.

[0014] Due to the adoption of the above technical solution, the present application has the following advantages: 1. This application adopts HTCC (High-Temperature Co-fired Ceramic) structure to achieve airtight transmission between waveguides, and sets multiple layers of different dielectric constants, thicknesses, grounded metal vias and grounded metal layers inside the HTCC to achieve miniaturized bandpass filtering characteristics, passband characteristics within a specific frequency range and RF suppression outside the specific frequency range.

[0015] 2. The HTCC waveguide transition structure with filtering characteristics proposed in this application has the advantages of simple structure, multiple functions, little impact on RF performance, and small size, and has wide application value in the field of microwave and millimeter wave circuits.

[0016] 3. The HTCC waveguide transition structure with filtering characteristics proposed in the present invention realizes the airtight transmission of millimeter wave signals through HTCC. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the embodiments of the present application. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0018] Figure 1 is an overall schematic diagram of an HTCC waveguide transition structure with filtering characteristics according to an embodiment of the present application; Figure 2 is a schematic diagram of a first ceramic dielectric layer of a HTCC waveguide transition structure with filtering characteristics according to an embodiment of the present application; Figure 3 is a schematic diagram of a second ceramic dielectric layer of a HTCC waveguide transition structure with filtering characteristics according to an embodiment of the present application; Figure 4 is a schematic diagram of a third ceramic dielectric layer of a HTCC waveguide transition structure with filtering characteristics in an embodiment of the present application; Figure 5 is a performance result diagram of a HTCC waveguide transition structure with filtering characteristics according to an embodiment of the present application; 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 DESCRIPTION

[0019] The present application is further described in conjunction with the accompanying drawings and embodiments, and the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by ordinary technicians in this field should fall within the scope of protection of the embodiments of the present application.

[0020] See also Figures 1 to 4 The present application provides an embodiment of a HTCC waveguide transition structure with filtering characteristics, which includes a first waveguide 1, an HTCC structure and a second waveguide 7, wherein the first waveguide 1 is airtightly 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 sequentially from top to bottom; 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 layers of ceramic substrates (sintering refers to heating multiple originally relatively independent ceramic substrates at high temperatures to cause changes in the physical and chemical properties of the ceramic substrates, thereby achieving connection and structural solidification between multiple ceramic substrate layers) and has airtight properties.

[0021] The first ceramic dielectric layer 2, the second ceramic dielectric layer 3 and the third ceramic dielectric layer 4 are structurally solidified through a high temperature co-firing process.

[0022] The present application can realize the filtering function while realizing the airtight transmission of millimeter wave signals.

[0023] Optionally, the first grounding metal surface and the second grounding metal surface have the same structure, and their parts are hollow structures; the third grounding metal surface and the fourth grounding metal surface have the same structure, and their parts are hollow structures; the fifth grounding metal surface 6 and the sixth grounding metal surface have the same structure, and their parts are hollow structures.

[0024] Optionally, the first grounding metal plane, the third grounding metal plane and the fifth grounding metal plane 6 have different shapes; Different numbers of grounding metal vias 5 are respectively arranged at different positions on the first grounding metal plane, the third grounding metal plane and the fifth grounding metal plane 6, so that ceramic dielectric windows with different radio frequency impedance and thickness are respectively formed on the first ceramic dielectric layer 2, the second ceramic dielectric layer 3 and the third ceramic dielectric layer 4; the ceramic dielectric windows on the first ceramic dielectric layer 2 are hollow structures of the first grounding metal plane and the second grounding metal plane; the ceramic dielectric windows on the second ceramic dielectric layer 3 are hollow structures of the third grounding metal plane and the fourth grounding metal plane; the ceramic dielectric windows on the third ceramic dielectric layer 4 are hollow structures of the fifth grounding metal plane 6 and the sixth grounding metal plane.

[0025] Optionally, the first waveguide 1 is connected to the first ceramic dielectric layer 2 through a hollow structure of the first grounded metal surface; the shape and size of the hollow structure of the first grounded metal surface are the same as the shape and size of the longitudinal section of the first waveguide 1, so that the first waveguide 1 is airtightly connected to the first ceramic dielectric layer 2; The second waveguide 7 is connected to the third ceramic dielectric layer 4 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 the shape and size of the longitudinal section of the second waveguide 7, so that the second waveguide 7 is airtightly connected to the third ceramic dielectric layer 4.

[0026] Optionally, the hollow structures of the first grounding metal plane, the third grounding metal plane and the fifth grounding metal plane 6 have an overlapping area in a direction perpendicular to the HTCC structure, so that after the millimeter wave signal enters the first waveguide 1, it passes through the hollow structure on the first grounding metal plane to the hollow structure on the sixth grounding metal plane in sequence, and then is output from the second waveguide 7.

[0027] Optionally, the first grounding metal plane, the second grounding metal plane, the third grounding metal plane, the fourth grounding metal plane, the fifth grounding metal plane 6, and the sixth grounding metal plane are provided with grounding metal vias 5; the first HTCC structure, the second HTCC structure, and the third HTCC structure are connected through the grounding metal vias 5. Specifically, the vias of the first grounding metal plane and the second grounding metal plane penetrate the first ceramic dielectric layer 2, so that the first grounding metal plane, the first ceramic dielectric layer 2, and the second grounding metal plane are connected; the vias of the third grounding metal plane and the fourth grounding metal plane penetrate the second ceramic dielectric layer 3, so that the third grounding metal plane, the second ceramic dielectric layer 3, and the fourth grounding metal plane are connected; the vias of the fifth grounding metal plane 6 and the sixth grounding metal plane penetrate the third ceramic dielectric layer 4, so that the fifth grounding metal plane 6, the third ceramic dielectric layer 4, and the sixth grounding metal plane are connected.

[0028] 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.

[0029] Optionally, the first ceramic dielectric layer 2 , the second ceramic dielectric layer 3 and the third ceramic dielectric layer 4 are all covered with a grounded metal layer on all sides to shield millimeter wave signals.

[0030] Optionally, the dielectric constants, thicknesses and shapes 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.

[0031] Optionally, 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 serves as a filtering structure and is impedance matched within the operating frequency range; When a millimeter wave signal outside the operating frequency range of the HTCC waveguide transition structure is input to the HTCC structure, the ceramic dielectric window group, as a filtering structure, is impedance mismatched within the operating frequency range.

[0032] Figure 4 In the figure, the shaded part is the grounded metal surface, and there is no shaded part in the center of the ceramic dielectric layer, indicating that there is no metal in the middle and the ceramic dielectric is exposed.

[0033] In the above embodiments of the present application: 1. Grounding metal layers of different shapes are arranged on different ceramic dielectric layers.

[0034] 2. Grounding metal vias of different positions and numbers are arranged on different ceramic dielectric layers, thereby forming ceramic dielectric windows with inconsistent impedance and thickness on each layer of ceramic dielectric substrate. That is, each layer of ceramic dielectric board is surrounded by grounding metal to shield millimeter wave signals. There is no grounding metal in the central area of ​​each layer of ceramic dielectric substrate, which serves as a dielectric window structure. The RF impedance and thickness (electrical length) of the ceramic dielectric windows between different ceramic dielectric layers are inconsistent.

[0035] 3. The ceramic dielectric windows between different ceramic dielectric layers together constitute a filtering structure within a specific frequency range.

[0036] 4. Ceramic dielectric windows can realize the transmission of millimeter-wave signals, and can also simultaneously realize 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 multilayer ceramic dielectric board 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.

[0037] 5. The principle of HTCC waveguide transition structure to achieve airtight transmission: Each layer of ceramic dielectric substrate is airtight, and the transmission waveguide is directly welded to HTCC, so the overall airtight transmission can be guaranteed.

[0038] 6. The principle of filtering achieved by the HTCC waveguide transition structure is: the dielectric constant, thickness, and shape of the central ceramic dielectric cavity of different ceramic dielectric substrates are different. Therefore, different ceramic dielectric windows have different RF impedance and electrical length, which can be understood as multiple different impedance units. Multiple impedance units jointly achieve the effect of the filter.

[0039] 7. When the millimeter wave signal within the operating frequency range is input to the HTCC through the waveguide, the filter structure composed of multiple different ceramic dielectric windows is impedance matched within the operating frequency range. Therefore, the millimeter wave signal loss within the operating frequency range is very small.

[0040] 8. When a millimeter-wave signal outside the operating frequency range is input to the HTCC, the filter 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 the millimeter-wave signal outside the operating frequency range, and the input millimeter-wave signal will be reflected, thereby achieving suppression outside the operating frequency range.

[0041] 9. The waveguide is mainly a rectangular waveguide, but it can also be other forms of waveguide.

[0042] Figure 5This is a performance result diagram of the HTCC waveguide transition structure with filtering characteristics. It can be seen that the insertion loss S21 in the frequency range of 76GHz~88GHz is less than 3dB, and RF suppression is achieved in the frequency range below 76GHz and above 88GHz.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present application rather than to limit it. Although the present application has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present application can still be modified or replaced by equivalents, and any modifications or equivalent replacements that do not depart from the spirit and scope of the present application should be included in the scope of protection of the claims of the present application.

Claims

1. A HTCC waveguide transition structure with filtering characteristics, characterized in that: The invention comprises a first waveguide, a HTCC structure and a second waveguide, wherein the first waveguide is airtightly connected to the second waveguide through the HTCC structure; the HTCC structure comprises a first HTCC structure, a second HTCC structure and a third HTCC structure which are sequentially stacked from top to bottom; The first HTCC structure includes a first grounding metal plane, a first ceramic dielectric layer, and a second grounding metal plane arranged in sequence from top to bottom; the second HTCC structure includes a third grounding metal plane, a second ceramic dielectric layer, and a fourth grounding metal plane arranged in sequence from top to bottom; the third HTCC structure includes a fifth grounding metal plane, a third ceramic dielectric layer, and a sixth grounding metal plane arranged in sequence from top to bottom.

2. The HTCC waveguide transition structure with filtering characteristics according to claim 1, characterized in that: The first grounding metal surface and the second grounding metal surface have the same structure, and the parts thereof are hollow structures; the third grounding metal surface and the fourth grounding metal surface have the same structure, and the parts thereof are hollow structures; the fifth grounding metal surface and the sixth grounding metal surface have the same structure, and the parts thereof are hollow structures.

3. The HTCC waveguide transition structure with filtering characteristics according to claim 2, characterized in that: The first grounding metal surface, the third grounding metal surface and the fifth grounding metal surface have different shapes; Different numbers of grounding metal vias are respectively arranged at different positions on the first grounding metal plane, the third grounding metal plane and the fifth grounding metal plane, so that ceramic dielectric windows with different radio frequency impedance and thickness are respectively formed on the first ceramic dielectric layer, the second ceramic dielectric layer and the third ceramic dielectric layer; the ceramic dielectric windows on the first ceramic dielectric layer are hollow structures of the first grounding metal plane and the second grounding metal plane; the ceramic dielectric windows on the second ceramic dielectric layer are hollow structures of the third grounding metal plane and the fourth grounding metal plane; and the ceramic dielectric windows on the third ceramic dielectric layer are hollow structures of the fifth grounding metal plane and the sixth grounding metal plane.

4. The HTCC waveguide transition structure with filtering characteristics according to claim 2, characterized in that: The first waveguide is connected to the first ceramic dielectric layer through the hollow structure of the first grounded metal surface; the shape and size of the hollow structure of the first grounded metal surface are the same as the shape and size of the longitudinal section of the first waveguide, so that the first waveguide is connected to the first ceramic dielectric layer in an airtight manner; 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 the shape and size of the longitudinal section of the second waveguide, so that the second waveguide is airtightly connected to the third ceramic dielectric layer.

5. The HTCC waveguide transition structure with filtering characteristics according to claim 2, characterized in that: The hollow structures of the first grounding metal plane, the third grounding metal plane and the fifth grounding metal plane have an overlapping area in a direction perpendicular to the HTCC structure, so that after the millimeter wave signal enters from the first waveguide, it passes through the hollow structure on the first grounding metal plane to the hollow structure on the sixth grounding metal plane in sequence, and then is output from the second waveguide.

6. The HTCC waveguide transition structure with filtering characteristics according to claim 2, characterized in that: The first grounding metal plane, the second grounding metal plane, the third grounding metal plane, the fourth grounding metal plane, the fifth grounding metal plane, and the sixth grounding metal plane 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.

7. The HTCC waveguide transition structure with filtering characteristics according to claim 2, characterized in that: 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.

8. The HTCC waveguide transition structure with filtering characteristics according to claim 3, characterized in that: The first ceramic dielectric layer, the second ceramic dielectric layer and the third ceramic dielectric layer are all covered with grounding metal layers on all sides for shielding millimeter wave signals.

9. The HTCC waveguide transition structure with filtering characteristics according to claim 3, characterized in that: The dielectric constants, thicknesses and shapes 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.

10. The HTCC waveguide transition structure with filtering characteristics according to claim 3, 8 or 9, characterized in that: 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; When a millimeter wave signal outside the operating frequency range of the HTCC waveguide transition structure is input to the HTCC structure, the ceramic dielectric window group, as a filtering structure, is impedance mismatched within the operating frequency range.

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