Transition structure from substrate integrated waveguide to strip line

Abstract

The invention discloses a transition structure from a substrate integrated waveguide to a strip line, particularly relates to the technical field of microwaves, and solves the technical problem that in the prior art, the loss of the transition structure from the substrate integrated waveguide to the strip line is still large. According to the technical scheme, microwave signal transmission is all bound in a closed structure, and radiation loss is avoided; the filter has extremely low insertion loss, and can be applied to a millimeter wave frequency band microwave wireless communication system.

Description

Technical Field

[0001] The invention relates to the field of microwave technology, and in particular to a substrate integrated waveguide to stripline transition structure. Background Art

[0002] In order to achieve the connection between various modules, designing the transition conversion circuit from one transmission line to another is very critical in microwave circuits and systems. As a matching interface between different transmission lines, the microwave transition circuit needs to achieve the smallest possible reflection and energy loss and the widest possible working bandwidth.

[0003] Substrate integrated waveguide is a new form of microwave transmission line, which uses metal through-holes to realize the propagation mode of waveguide on dielectric substrate. Substrate integrated waveguide takes into account the advantages of traditional waveguide and microstrip transmission line, and can realize high-performance microwave millimeter wave planar circuit. Stripline is a high-frequency transmission wire placed in a dielectric between two parallel ground planes, which has the advantages of high Q value, low loss and small size. The existing transition structure loss from substrate integrated waveguide to stripline is still relatively large, and it is in urgent need of improvement. Summary of the invention

[0004] Therefore, the present invention solves the technical problem in the prior art that the loss of the transition structure from substrate integrated waveguide to stripline is still relatively large; the present invention provides a transition structure from substrate integrated waveguide to stripline, in which microwave signal transmission is completely confined in a closed structure without radiation loss, so that the transition structure from substrate integrated waveguide to stripline provided by the present invention has extremely small insertion loss and can be applied to millimeter wave frequency band microwave wireless communication systems.

[0005] The present invention provides a substrate integrated waveguide to stripline transition structure, comprising a first metal layer stacked, an upper dielectric substrate, a plurality of first metallized through holes, a plurality of second metallized through holes, a plurality of third metallized through holes, a second metal layer and a rectangular metal strip, a lower dielectric substrate, a plurality of fourth metallized through holes, a plurality of fifth metallized through holes, and a third metal layer; the first metal layer is on the upper surface of the upper dielectric substrate;

[0006] Further, the upper dielectric substrate is provided with a plurality of first metallized through holes, a plurality of second metallized through holes, and a plurality of third metallized through holes; the second metal layer is connected to the rectangular metal strip and is located between the upper dielectric substrate and the lower dielectric substrate; the lower dielectric substrate is provided with a plurality of fourth metallized through holes and a plurality of fifth metallized through holes; and the lower surface of the lower dielectric substrate is provided with a third metal layer;

[0007] Further, the first metal layer and the third metal layer pass through the upper dielectric substrate and the lower dielectric substrate through the multiple second metallized through holes, the multiple third metallizations, the multiple fourth metallized through holes, and the multiple fifth metallized through holes to form a closed structure; the first metal layer, the upper dielectric substrate, the lower dielectric substrate, the third metal layer, the multiple second metallized through holes, the multiple third metallized through holes, the multiple fourth metallized through holes, and the multiple fifth metallized through holes form a first substrate integrated waveguide; the multiple first metallized through holes are located inside the second metallized through holes and are distributed in an arc shape; the first metal layer, the upper dielectric substrate, the second metal layer, the multiple first metallized through holes, and the third metallized through holes form a second substrate integrated waveguide; the second metal layer, the lower dielectric substrate, the third metal layer, the multiple fourth metallized through holes, and the multiple fifth metallized through holes form a third substrate integrated waveguide; the matrix metal strips form a stripline structure with the first metal layer, the upper dielectric substrate, the lower dielectric substrate, and the third metal layer.

[0008] In the above technical solution, the technical effects and advantages provided by the present invention are:

[0009] 1. The present invention provides a substrate integrated waveguide to stripline transition structure, in which microwave signal transmission is completely confined in a closed structure without radiation loss, so that the substrate integrated waveguide to stripline transition structure provided by the present invention has extremely small insertion loss and can be applied to millimeter wave frequency band microwave wireless communication systems.

[0010] 2. The present invention provides a substrate integrated waveguide to stripline transition structure, which utilizes the characteristic that the phase shifting capabilities of substrate integrated waveguide structures of unequal widths are different, thereby realizing the transition from substrate integrated waveguide to stripline. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0012] Figure 1 3D schematic diagram of a substrate integrated waveguide to stripline transition structure in an embodiment of the present invention.

[0013] Figure 2 The present invention Figure 1 A top perspective view of a substrate integrated waveguide to stripline transition structure in the illustrated embodiment.

[0014] Figure 3 The present invention Figure 2 Electric field distribution diagram from cross section AA' to cross section EE'.

[0015] Figure 4 The present invention Figure 1 The S parameter simulation result diagram of the embodiment shown;

[0016] Description of reference numerals:

[0017] 1. First metal layer; 2. Upper dielectric substrate; 3. First metallized through hole; 4. Second metallized through hole; 5. Third metallized through hole; 6. Second metal layer; 7. Rectangular metal strip; 8. Fourth metallized through hole; 9. Fifth metallized through hole; 10. Lower dielectric substrate; 11. Third metal layer. DETAILED DESCRIPTION

[0018] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0019] Embodiment 1:

[0020] This embodiment provides a substrate integrated waveguide to stripline transition structure, referring to Figure 1 and Figure 2 In this embodiment, the substrate integrated waveguide to stripline transition structure includes a first metal layer 1 stacked, an upper dielectric substrate 2, a plurality of first metallized through holes 3, a plurality of second metallized through holes 4, a plurality of third metallized through holes 5, a second metal layer 6, a rectangular metal strip 7, a plurality of fourth metallized through holes 8, a plurality of fifth metallized through holes 9, a lower dielectric substrate 10 and a third metal layer 11; the upper dielectric substrate 2 is provided with a plurality of first metallized through holes 3, a plurality of second metallized through holes 4, and a plurality of third metallized through holes 5; the second metal layer 6 is connected to the rectangular metal strip 7 and is located between the upper dielectric substrate 2 and the lower dielectric substrate 10; the lower dielectric substrate 10 is provided with a plurality of fourth metallized through holes and fifth metallized through holes; The first metal layer 1 and the third metal layer 11 pass through the upper dielectric substrate 2 and the lower dielectric substrate 10 through the plurality of second metallized through holes 4, the plurality of third metallized through holes 5, the plurality of fourth metallized through holes 8, and the plurality of fifth metallized through holes 9 to form a first substrate integrated waveguide; the first metal layer 1, the second metal layer 6, the upper dielectric substrate 2 and the plurality of first metallized through holes 3 and the plurality of third metallized through holes 5 form a second substrate integrated waveguide; the second metal layer 6, the lower dielectric substrate 10, the third metal layer 11 and the plurality of fourth metallized through holes 8 and the fifth metallized through holes 9 form a third substrate integrated waveguide; the matrix metal strip 7 forms a stripline structure with the first metal layer 1, the upper dielectric substrate 2, the lower dielectric substrate 10, and the third metal layer 11.

[0021] Specifically, the basic principle of the present invention is to convert the electric field distribution of the substrate integrated waveguide into the electric field distribution of the stripline. When the microwave signal propagates in the x-axis direction, after passing through the first substrate integrated waveguide, it is divided into two parts, an upper part and an lower part, by the second metal layer 6. The electric field energies of these two parts are equal and in the same direction, and the two parts enter the second substrate integrated waveguide and the third substrate integrated waveguide respectively. Due to the difference in width between the second substrate integrated waveguide and the third substrate waveguide in the y-axis direction, the same microwave signal will produce a phase difference when transmitted in the two. Therefore, when the two parts of the microwave signal are transmitted to the contact surface between the second metal layer 6 and the matrix metal strip 7, they become signals with equal energy and opposite directions. This electric field distribution conforms to the electric field distribution of the stripline, thereby realizing the transition from substrate integrated waveguide to stripline. In order to clearly show the changes in the electric field distribution, Figure 3 a to e show Figure 2 The electric field distribution on the five cross sections (AA'-EE') in Fig. Figure 3 It can be clearly seen from the electric field distribution change diagram that the transition structure gradually changes from the electric field distribution of the substrate integrated waveguide to the electric field distribution of the stripline along the x-axis direction.

[0022] Since the transition structure is completely enclosed between the metal ground and the metallized through hole, there is no additional radiation loss. Therefore, the transition structure has a very small insertion loss.

[0023] Embodiment 2:

[0024] In this embodiment, the upper dielectric substrate 2 and the lower dielectric substrate 10 are made of Rogers 5880 material, and the thickness of the lower dielectric substrate 2 and the upper dielectric substrate 10 are both 0.381 mm; the diameter of the plurality of first metallized through holes 3 is 0.4 mm, the horizontal distance between the holes is 0.85 mm, and the vertical distance is 0.1 mm. The diameter of the plurality of second metallized through holes 4, the plurality of third metallized through holes 5, the plurality of fourth metallized through holes 8, and the plurality of fifth metallized through holes 9 are all 0.4 mm, and the distance between the holes is 0.8 mm.

[0025] In the substrate integrated waveguide to stripline transition structure described in the present invention, the width of the rectangular metal strip 7 is 0.7 mm.

[0026] In the substrate integrated waveguide to stripline transition structure of the present invention, the size of the second metal layer 6 is 10 mm×5 mm.

[0027] It can be understood that the various dimensional parameters involved in this embodiment are only the situation under a preferred implementation mode, which should not be used as conditions to limit the scope of protection of the present invention. The various dimensional parameters can be changed accordingly according to actual needs.

[0028] Figure 4The S parameter simulation and test results of one of the above embodiments of the present invention show that the working bandwidth of the substrate integrated waveguide to stripline transition structure covers the frequency band of 26.5 GHz to 29.5 GHz. At the same time, according to the simulation results, the insertion loss of the transition structure is less than 0.3 dB, so that the invented substrate integrated waveguide to stripline transition structure has very small loss.

[0029] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A substrate integrated waveguide to stripline transition structure, characterized in that: The invention comprises a first metal layer (1), an upper dielectric substrate (2), a second metal layer (6), a lower dielectric substrate (10) and a third metal layer (11) which are arranged in sequence from top to bottom; the upper dielectric substrate (2) is provided with a plurality of first metallized through holes (3), a plurality of second metallized through holes (4) and a plurality of third metallized through holes (5); the lower dielectric substrate (10) is provided with a plurality of fourth metallized through holes (8) and a fifth metallized through hole (9).

2. The substrate integrated waveguide to stripline transition structure according to claim 1, characterized in that: A rectangular metal strip (7) is arranged on the second metal layer (6).

3. The substrate integrated waveguide to stripline transition structure according to claim 2, characterized in that: The connection point between the rectangular metal strip (7) and the second metal layer (6) is located between the upper dielectric substrate (2) and the lower dielectric substrate (10).

4. The substrate integrated waveguide to stripline transition structure according to claim 3, characterized in that: The first metal layer (1) and the third metal layer (11) are connected through the upper dielectric substrate (2) and the lower dielectric substrate (10) via a plurality of the second metallized through holes (4), a plurality of the third metallized through holes (5), a plurality of the fourth metallized through holes (8), and a plurality of the fifth metallized through holes (9) to form a first substrate integrated waveguide.

5. The substrate integrated waveguide to stripline transition structure according to claim 4, characterized in that: The first metal layer (1), the second metal layer (6), the upper dielectric substrate (2), the plurality of the first metallized through holes (3), and the plurality of the third metallized through holes (5) form a second substrate integrated waveguide.

6. The substrate integrated waveguide to stripline transition structure according to claim 5, characterized in that: The second metal layer (6), the lower dielectric substrate (10), the third metal layer (11), the plurality of fourth metallized through holes (8) and the fifth metallized through holes (9) form a third substrate integrated waveguide.

7. The substrate integrated waveguide to stripline transition structure according to claim 6, characterized in that: The rectangular metal strip (7) forms a stripline structure with the first metal layer (1), the upper dielectric substrate (2), the lower dielectric substrate (10), and the third metal layer (11).

8. The substrate integrated waveguide to stripline transition structure according to claim 7, characterized in that: The plurality of first metallized through holes (3) provided on the upper dielectric substrate (2) are distributed in an arc shape.

9. The substrate integrated waveguide to stripline transition structure according to claim 8, characterized in that: The plurality of first metallized through holes (3) are located inside the plurality of second metallized through holes (4).

10. The substrate integrated waveguide to stripline transition structure according to claim 9, characterized in that: The second metallized through hole (4) and the fourth metallized through hole (8) are completely aligned in the z-axis direction; and the third metallized through hole (5) and the fifth metallized through hole (9) are completely aligned in the z-axis direction.

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