Miniaturized high frequency selective multilayer substrate integrated waveguide filter cross

Abstract

The present application relates to the technical fields of microwave filter, and especially relates to a miniaturized high-frequency selective multilayer substrate integrated waveguide filter cross, which comprises a metal layer group, a second metal layer, a third metal layer and a fourth metal layer; a plurality of slot openings for coupling are arranged on the second metal layer and the third metal layer, a first input port, an interdigital slot line and a first output port are arranged on the first metal layer; a dielectric substrate group comprises a first dielectric substrate, a second dielectric substrate and a third dielectric substrate, the first dielectric substrate is arranged between the first metal layer and the second metal layer, the second dielectric substrate is arranged between the second metal layer and the third metal layer, and the third dielectric substrate is arranged between the third metal layer and the fourth metal layer; the first dielectric substrate is provided with a first resonant cavity and a second resonant cavity; the second dielectric substrate is provided with a third resonant cavity; and the third dielectric substrate is provided with a fourth resonant cavity and a fifth resonant cavity.

Description

Technical Field

[0001] This invention relates to the field of microwave filter technology, and in particular to a miniaturized, high-frequency selective multilayer substrate integrated waveguide filter crossover. Background Technology

[0002] Compared to rectangular waveguides, substrate-integrated waveguides offer advantages such as smaller size and easier integration with planar circuits; however, they are still waveguide structures, and their size remains significantly larger than planar structures. In microwave and millimeter-wave integrated circuit design, there is an increasing demand for miniaturization and high integration.

[0003] The filter crossover (Compact-Balanced BPF and Filtering Crossover With Intrinsic Common-Mode Suppression Using Single-Layered SIW Cavity) published in IEEE Microwave and Wire Component Letters, Volume 30, employs a multi-layer structure. The filtering crossover characteristics are also achieved through the orthogonal mode method. Its common resonant cavity is composed of TE102 and TE201 modes, and the four resonant cavities around it are TE102 modes. It uses a dielectric substrate with a dielectric constant of 2.2 and a thickness of 0.508 mm. Under the conditions of a center frequency of 10.2 GHz and an absolute bandwidth of 3.1%, the size is approximately 68 mm * 68 mm * 0.52 mm.

[0004] Therefore, a technique is still needed to further reduce the size under the same absolute bandwidth conditions to meet the requirements for miniaturization and high integration in microwave and millimeter-wave integrated circuit design. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and to provide a miniaturized, high-frequency selective multilayer substrate integrated waveguide filter crossover, comprising:

[0006] The metal layer group includes four metal layers: a first metal layer, a second metal layer, a third metal layer, and a fourth metal layer.

[0007] The second and third metal layers are provided with a plurality of slots for coupling, the first metal layer is provided with a first input port, an interdigitated slot line and a first output port, and the fourth metal layer is provided with a second input port, an interdigitated slot line and a second output port.

[0008] A dielectric substrate assembly includes a first dielectric substrate, a second dielectric substrate, and a third dielectric substrate, wherein the first dielectric substrate is disposed between a first metal layer and a second metal layer, the second dielectric substrate is disposed between a second metal layer and a third metal layer, and the third dielectric substrate is disposed between a third metal layer and a fourth metal layer.

[0009] The first dielectric substrate is provided with a first resonant cavity and a second resonant cavity; the second dielectric substrate is provided with a third resonant cavity; and the third dielectric substrate is provided with a fourth resonant cavity and a fifth resonant cavity.

[0010] Furthermore, the first dielectric substrate forms the first resonant cavity and the second resonant cavity by providing a plurality of metallized vias; the second dielectric substrate forms the third resonant cavity by providing a plurality of metallized vias; and the third dielectric substrate forms the fourth resonant cavity and the fifth resonant cavity by providing a plurality of metallized vias.

[0011] The long side of the first resonant cavity is connected to the long side of the second resonant cavity, and the long side of the fourth resonant cavity is connected to the long side of the fifth resonant cavity.

[0012] Furthermore, the first resonant cavity, the second resonant cavity, the fourth resonant cavity, and the fifth resonant cavity have the same size, and the length-to-width ratio is 2.1:1.

[0013] Furthermore, the first resonant cavity, the second resonant cavity, the fourth resonant cavity, and the fifth resonant cavity are symmetrical about the Z-axis by rotating 90°.

[0014] Furthermore, the length-to-width ratio of the third resonant cavity is 1:1.

[0015] Furthermore, the second metal layer is provided with four slots of equal size, the long sides of the four slots are parallel to the long sides of the second metal layer, and the intersection of the diagonals of the four slots can form a rectangle. Each slot has a diagonal intersection point, and the position of the four diagonal intersection points corresponds one-to-one with the position of the midpoint of the short side of the first resonant cavity and the second resonant cavity.

[0016] Furthermore, the third metal layer is provided with four slots, the size of which is the same as that of the slots on the second metal layer, and the position of the intersection of the diagonals of the four slots on the third metal layer corresponds one-to-one with the position of the midpoint of the short side of the fourth and fifth resonant cavities.

[0017] Furthermore, the first resonant cavity, the second resonant cavity, the fourth resonant cavity, and the fifth resonant cavity generate TE. 101 The third resonant cavity generates TE. 102 / TE 201 mold.

[0018] Furthermore, the interdigitated slot line, used to introduce cross coupling, is located at the intersection of the diagonals of the first metal layer and the fourth metal layer. The first input port, the first output port, and the interdigitated slot line are located on the same straight line, as are the second input port, the second output port, and the interdigitated slot line.

[0019] This invention also provides a method for operating a miniaturized high-frequency selective multilayer substrate integrated waveguide filter crossover, comprising: a first input port exciting a first resonant cavity; the first resonant cavity and the third resonant cavity being coupled through two slots on the left side of the second metal layer; the third resonant cavity and the second resonant cavity being coupled through two slots on the right side of the second metal layer; and the second resonant cavity being coupled to the first output port for output; simultaneously, the first input port exciting the interdigital slot line and coupling it to the first output port for output.

[0020] The second input port excites the fourth resonant cavity, which is coupled to the third resonant cavity through two slots on the front side of the third metal layer. The two slots on the front side are corresponding to the midpoint of the short side of the fourth resonant cavity. The third resonant cavity is coupled to the fifth resonant cavity through two slots on the rear side of the third metal layer. The fifth resonant cavity is coupled to the second output port for output. At the same time, the second input port excites the interdigital slot line and is coupled to the second output port for output.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] (1) The present invention adopts a multi-layer stacked substrate integrated waveguide multi-coupling path method, which reduces the size by about 66% under the same absolute bandwidth conditions compared with a single-layer structure. It has the advantages of miniaturization, compact structure, high space utilization, and high frequency selectivity.

[0023] (2) The center position of the slot on the second metal layer of the present invention is located at the center position of the narrow side of the first resonant cavity and the second resonant cavity, respectively. The center position of the slot on the third metal layer is located at the center position of the narrow side of the fourth resonant cavity and the fifth resonant cavity, respectively. By using the TE102 / TE201 mode, a 180° phase difference is generated in the first resonant cavity, the second resonant cavity, the fourth resonant cavity, and the fifth resonant cavity, respectively. The first resonant cavity, the second resonant cavity, the fourth resonant cavity, and the fifth resonant cavity are symmetrical about the Z-axis by rotating 90°, which has the characteristics of high isolation.

[0024] (3) The present invention introduces cross coupling through interdigitated slot lines, which has adjustable bandwidth characteristics. Attached Figure Description

[0025] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0026] In the attached diagram:

[0027] Figure 1 This is a schematic diagram of the miniaturized, high-frequency selective multilayer substrate integrated waveguide filter crossover structure of the present invention;

[0028] Figure 2 This is a schematic diagram of the magnetic coupling topology of the miniaturized high-frequency selective multilayer substrate integrated waveguide filter crossover of the present invention;

[0029] Figure 3 This is a schematic diagram of the dielectric substrate structure of the miniaturized high-frequency selective multilayer substrate integrated waveguide filter crossover of the present invention;

[0030] Figure 4 This is a schematic diagram of the TE101 mode and TE102 / TE201 mode excited by each resonant cavity of the miniaturized high-frequency selective multilayer substrate integrated waveguide filter crossover based on the present invention.

[0031] Figure 5 The frequency response curve of the miniaturized, high-frequency selective multilayer substrate integrated waveguide filter crossover of this invention is shown.

[0032] Figure Labels

[0033] 11: First metal layer; 12: Second metal layer; 13: Third metal layer; 14: Fourth metal layer; 15: Groove opening; 16: Interdigitated groove line;

[0034] 111: First input port; 112: First output port;

[0035] 141: Second input port; 142: Second output port;

[0036] 21: First dielectric substrate; 22: Second dielectric substrate; 23: Third dielectric substrate;

[0037] 211: First resonant cavity; 212: Second resonant cavity;

[0038] 221: Third resonant cavity;

[0039] 231: Fourth resonant cavity; 232: Fifth resonant cavity;

[0040] 3: Metallized vias. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of this invention clearer, the 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.

[0042] Example 1

[0043] Please see Figure 1 The technical solution provided in this embodiment based on a miniaturized, high-frequency selective multilayer substrate integrated waveguide filter crossover includes the following:

[0044] The metal layer group includes four metal layers: a first metal layer 11, a second metal layer 12, a third metal layer 13, and a fourth metal layer 14.

[0045] The second metal layer 12 and the third metal layer 13 are provided with a plurality of slots 15 for coupling, the first metal layer 11 is provided with a first input port 111, an interdigitated slot line 16 and a first output port 112, and the fourth metal layer 14 is provided with a second input port 141, an interdigitated slot line 16 and a second output port 142.

[0046] A dielectric substrate assembly includes a first dielectric substrate 21, a second dielectric substrate 22, and a third dielectric substrate 23, wherein the first dielectric substrate 21 is disposed between the first metal layer 11 and the second metal layer 12, the second dielectric substrate 22 is disposed between the second metal layer 12 and the third metal layer 13, and the third dielectric substrate 23 is disposed between the third metal layer 13 and the fourth metal layer 14.

[0047] The first dielectric substrate 21 is provided with a first resonant cavity 211 and a second resonant cavity 212; the second dielectric substrate 22 is provided with a third resonant cavity 221; and the third dielectric substrate 23 is provided with a fourth resonant cavity 231 and a fifth resonant cavity 232.

[0048] Specifically, the first dielectric substrate 21 forms the first resonant cavity 211 and the second resonant cavity 212 by providing a plurality of metallized vias 3; the second dielectric substrate 22 forms the third resonant cavity 221 by providing a plurality of metallized vias 3; and the third dielectric substrate 23 forms the fourth resonant cavity 231 and the fifth resonant cavity 232 by providing a plurality of metallized vias 3.

[0049] The long side of the first resonant cavity 211 is connected to the long side of the second resonant cavity 212, and the long side of the fourth resonant cavity is connected to the long side of the fifth resonant cavity 232.

[0050] Specifically, the first resonant cavity 211, the second resonant cavity 212, the fourth resonant cavity 231, and the fifth resonant cavity 232 have the same size, and the length-to-width ratio is 2.1:1.

[0051] Specifically, the first resonant cavity 211, the second resonant cavity 212, the fourth resonant cavity 231, and the fifth resonant cavity 232 are symmetrical about the Z-axis by rotating 90°.

[0052] Specifically, the length-to-width ratio of the third resonant cavity 221 is 1:1.

[0053] Specifically, the second metal layer 12 is provided with four slots 15 of equal size. The long sides of the four slots 15 are parallel to the long sides of the second metal layer 12. The intersection of the diagonals of the four slots 15 can form a rectangle. Each slot 15 has a diagonal intersection point. The positions of the four diagonal intersection points correspond one-to-one with the positions of the midpoints of the short sides of the first resonant cavity 211 and the second resonant cavity 212.

[0054] Specifically, the third metal layer 13 is provided with four slots 15. The slots 15 on the third metal layer 13 are the same size as those on the second metal layer 12. The position of the intersection of the diagonals of the four slots 15 on the third metal layer 13 corresponds one-to-one with the position of the midpoint of the short side of the fourth resonant cavity 231 and the fifth resonant cavity 232.

[0055] Specifically, the first resonant cavity 211, the second resonant cavity 212, the fourth resonant cavity 231, and the fifth resonant cavity 232 generate TE. 101 The third resonant cavity 221 generates TE. 102 / TE 201 mold.

[0056] Specifically, the first metal layer 11 is provided with a first input port 111 and a first output port 112, and the fourth metal layer 14 is provided with a second input port 141 and a second output port 142. At the intersection of the diagonals of the first metal layer 11 and the fourth metal layer 14, there is an interdigitated slot line 16 for introducing cross-coupling. The first input port 111, the first output port 112 and the interdigitated slot line 16 are located on the same straight line, and the second input port 141, the second output port 142 and the interdigitated slot line 16 are also located on the same straight line.

[0057] Example 2

[0058] This invention also provides a method for operating a miniaturized, high-frequency selective multilayer substrate integrated waveguide filter crossover, such as... Figure 1-5As shown, the first input port 111 excites the first resonant cavity 211. The first resonant cavity 211 is coupled to the third resonant cavity 221 through two slots 15 on the left side of the second metal layer 12. The third resonant cavity 221 is coupled to the second resonant cavity 212 through two slots 15 on the right side of the second metal layer 12. The second resonant cavity 212 is coupled to the first output port 112 for output. At the same time, the first input port 111 excites the interdigital slot line 16 and is coupled to the first output port 112 for output.

[0059] The second input port 141 excites the fourth resonant cavity 231. The fourth resonant cavity 231 is coupled to the third resonant cavity 221 through two slots 15 on the front side of the third metal layer 13. The two slots 15 on the front side are corresponding to the midpoint of the short side of the fourth resonant cavity 231. The third resonant cavity 221 is coupled to the fifth resonant cavity 232 through two slots 15 on the rear side of the third metal layer 13. The fifth resonant cavity 232 is coupled to the second output port 142 for output. At the same time, the second input port 141 excites the interdigital slot line 16 and is coupled to the second output port 142 for output.

[0060] Example 3

[0061] Combination Figure 1 Please refer to Figures 3-4 The center frequency of the miniaturized, high-frequency selective multilayer substrate integrated waveguide filter crossover is controlled at 9.4 GHz. The substrate material used for the first dielectric substrate 21, the second dielectric substrate 22, and the third dielectric substrate 23 is Rogers RO5880, with a dielectric constant of 2.2 and a thickness of 0.508 mm. The diameter of all metallized vias 3 on the first dielectric substrate 21, the second dielectric substrate 22, and the third dielectric substrate 23 is d = 0.5 mm. The width W1 = 11.2 mm and the length L1 = 23.5 mm of the first resonant cavity 211, the second resonant cavity 212, the fourth resonant cavity 231, and the fifth resonant cavity 232 are approximately 2.1:1. The length and width of the third resonant cavity 221 are both L3 = 23.5 mm, with a length-to-width ratio of 1:1. The length of the slot 15 on the second metal layer 12 and the third metal layer 13 is L2 = 4.8 mm and the width is W2 = 1.1 mm.

[0062] Please refer to Figure 5 It can be seen that the center frequency of the above-mentioned miniaturized high-frequency selective multilayer substrate integrated waveguide filter crossover is 9.4GHz: with an absolute bandwidth of 4.3%, the return loss is better than 19dB and the isolation is better than 30dB.

[0063] Finally, it should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A miniaturized, high-frequency selective multilayer substrate integrated waveguide filter crossover, characterized in that, include: The metal layer group includes four metal layers: a first metal layer, a second metal layer, a third metal layer, and a fourth metal layer. The second and third metal layers are provided with a plurality of slots for coupling, the first metal layer is provided with a first input port, an interdigitated slot line and a first output port, and the fourth metal layer is provided with a second input port, an interdigitated slot line and a second output port. A dielectric substrate assembly includes a first dielectric substrate, a second dielectric substrate, and a third dielectric substrate, wherein the first dielectric substrate is disposed between a first metal layer and a second metal layer, the second dielectric substrate is disposed between a second metal layer and a third metal layer, and the third dielectric substrate is disposed between a third metal layer and a fourth metal layer. The first dielectric substrate is provided with a first resonant cavity and a second resonant cavity; the second dielectric substrate is provided with a third resonant cavity; and the third dielectric substrate is provided with a fourth resonant cavity and a fifth resonant cavity. The first input port excites the first resonant cavity. The first resonant cavity and the third resonant cavity are coupled through two slots on the left side of the second metal layer. The third resonant cavity and the second resonant cavity are coupled through two slots on the right side of the second metal layer. The second resonant cavity is coupled to the first output port for output. At the same time, the first input port excites the interdigital slot line and is coupled to the first output port for output. The second input port excites the fourth resonant cavity, which is coupled to the third resonant cavity through two slots on the front side of the third metal layer. The two slots on the front side are corresponding to the midpoint of the short side of the fourth resonant cavity. The third resonant cavity is coupled to the fifth resonant cavity through two slots on the rear side of the third metal layer. The fifth resonant cavity is coupled to the second output port for output. At the same time, the second input port excites the interdigital slot line and is coupled to the second output port for output.

2. The miniaturized high-frequency selective multilayer substrate integrated waveguide filter crossover according to claim 1, characterized in that... : The first dielectric substrate forms the first resonant cavity and the second resonant cavity by providing a plurality of metallized vias; the second dielectric substrate forms the third resonant cavity by providing a plurality of metallized vias. The third dielectric substrate is provided with a plurality of metallized vias to form a fourth resonant cavity and a fifth resonant cavity; The long side of the first resonant cavity is connected to the long side of the second resonant cavity, and the long side of the fourth resonant cavity is connected to the long side of the fifth resonant cavity.

3. The miniaturized high-frequency selective multilayer substrate integrated waveguide filter crossover according to claim 1, characterized in that... : The first resonant cavity, the second resonant cavity, the fourth resonant cavity, and the fifth resonant cavity have the same size, and the length-to-width ratio is 2.1:

1.

4. The miniaturized high-frequency selective multilayer substrate integrated waveguide filter crossover according to claim 1, characterized in that... The first resonant cavity, the second resonant cavity, the fourth resonant cavity, and the fifth resonant cavity are symmetrical about the Z-axis by rotating 90°.

5. The miniaturized high-frequency selective multilayer substrate integrated waveguide filter crossover according to claim 1, characterized in that... The length-to-width ratio of the third resonant cavity is 1:

1.

6. The miniaturized high-frequency selective multilayer substrate integrated waveguide filter crossover according to claim 1, characterized in that... : The second metal layer has four slots of equal size. The long sides of the four slots are parallel to the long side of the second metal layer. The intersection of the diagonals of the four slots can form a rectangle. Each slot has a diagonal intersection point. The position of the four diagonal intersection points corresponds one-to-one with the position of the midpoint of the short side of the first resonant cavity and the second resonant cavity.

7. The miniaturized high-frequency selective multilayer substrate integrated waveguide filter crossover according to claim 1, characterized in that... The third metal layer has four slots, which are the same size as the slots on the second metal layer. The position of the intersection of the diagonals of the four slots on the third metal layer corresponds one-to-one with the position of the midpoint of the short side of the fourth resonant cavity and the fifth resonant cavity.

8. The miniaturized high-frequency selective multilayer substrate integrated waveguide filter crossover according to claim 1, characterized in that... The first resonant cavity, the second resonant cavity, the fourth resonant cavity, and the fifth resonant cavity produce the following: mold; The third resonant cavity produces / mold.

9. The miniaturized high-frequency selective multilayer substrate integrated waveguide filter crossover according to claim 1, characterized in that... The interdigitated slot line is used to introduce cross coupling and is located at the intersection of the diagonals of the first metal layer and the fourth metal layer. The first input port, the first output port and the interdigitated slot line are located on the same straight line, and the second input port, the second output port and the interdigitated slot line are located on the same straight line.

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