阅读说明：本技术 一种电子产品及其形成方法 (Electronic product and forming method thereof ) 是由 张世磊 马桂帅 于 2020-06-01 设计创作，主要内容包括：本发明涉及终端技术领域,公开了一种电子产品及其形成方法,该电子产品包括正交缺陷地共面波导平面传输线结构。而该结构包括：印刷电路板,印刷电路板包括顶面和底面；共面波导平面传输线和顶层参考地,共面波导平面传输线包括沿第一方向排列的第一端口、阻抗线段和第二端口；顶层参考地设于共面波导平面传输线周侧,且顶层参考地设有两个开口朝向共面波导平面传输线的顶层凹槽；沿第二方向,两个顶层凹槽形成对照空间,阻抗线段位于对照空间；底层参考地,底层参考地具有沿第一方向延伸的底层凹槽；共面波导平面传输线在底面的正投影覆盖底层凹槽在底面的正投影。上述电子产品可以在不增加印制板尺寸的情况下实现毫米波频段超宽带阻抗匹配。(The invention relates to the technical field of terminals, and discloses an electronic product and a forming method thereof. And the structure includes: a printed circuit board including a top surface and a bottom surface; the coplanar waveguide planar transmission line comprises a first port, an impedance line segment and a second port which are arranged along a first direction; the top layer is arranged on the periphery of the coplanar waveguide planar transmission line in a reference manner, and the top layer is provided with two top layer grooves with openings facing the coplanar waveguide planar transmission line in a reference manner; along the second direction, the two top layer grooves form a contrast space, and the impedance line segment is positioned in the contrast space; a bottom layer ground reference having a bottom layer groove extending in a first direction; the orthographic projection of the coplanar waveguide planar transmission line on the bottom surface covers the orthographic projection of the bottom layer groove on the bottom surface. The electronic product can realize millimeter wave frequency band ultra wide band impedance matching under the condition of not increasing the size of the printed board.)

1. An electronic product comprising an orthogonal defected ground coplanar waveguide planar transmission line structure, the orthogonal defected ground coplanar waveguide planar transmission line structure comprising:

a printed circuit board including a top surface and a bottom surface disposed opposite to each other;

the coplanar waveguide planar transmission line comprises a first port, an impedance line segment and a second port which are arranged along a first direction, and transition sections are arranged among the impedance line segment, the first port and the second port; the top layer reference ground is arranged on the peripheral side of the coplanar waveguide plane transmission line, and two top layer grooves with openings facing the coplanar waveguide plane transmission line are arranged on the top layer reference ground; the two top-layer grooves are oppositely arranged on two sides of the coplanar waveguide planar transmission line along a second direction perpendicular to the first direction; along a second direction, a contrast space is formed between the bottoms of the two top-layer grooves, and the impedance line segment is positioned in the contrast space;

the bottom layer reference ground is arranged on the bottom surface and is provided with a bottom layer groove extending along a first direction; the orthographic projection of the coplanar waveguide planar transmission line on the bottom surface covers the orthographic projection of the bottom layer groove on the bottom surface; and the bottom layer reference ground and the top layer reference ground form an orthogonal defected ground structure so that the impedance discontinuity point of the coplanar waveguide planar transmission line is positioned outside the operating frequency band of the electronic product.

2. An electronic product according to claim 1, wherein the size of the bottom layer groove is equal to the size of the coplanar waveguide planar transmission line in the first direction.

3. The electronic product according to claim 2, wherein along the first direction, the bottom layer groove comprises a main body section and extension sections arranged on two sides of the main body section; the size of the main body segment in the first direction is equal to the size of each top layer groove in the first direction, and the size of the main body segment in the second direction is equal to the size of each top layer groove in the second direction.

4. An electronic product according to claim 3, wherein, along the first direction, a midline of an orthographic projection of the top layer groove on the bottom surface coincides with a midline of an orthographic projection of the bottom layer groove on the bottom surface.

5. An electronic product according to claim 1, wherein the coplanar waveguide planar transmission line has a gap with the top layer reference ground along the first direction.

6. An electronic product according to claim 2, wherein the size of the impedance line segment is larger than the size of the transition segment along the second direction.

7. An electronic product according to any of claims 1-6, wherein the impedance line segment is a 50 ohm impedance line segment.

8. The electronic product of claim 7, further comprising an amplifier, the orthogonal defected ground coplanar waveguide planar transmission line structure signal connected to an input of the amplifier; alternatively, the first and second electrodes may be,

the orthogonal defected ground coplanar waveguide planar transmission line structure is in signal connection with the output end of the amplifier.

9. A method of forming an electronic product including an orthogonal defectively ground coplanar waveguide planar transmission line structure, comprising:

determining the original impedance matching of the coplanar waveguide planar transmission line on the top surface of the printed circuit board in the millimeter wave working frequency band; the coplanar waveguide planar transmission line comprises a first port, an impedance line segment and a second port which are arranged along a first direction, wherein transition sections are arranged among the impedance line segment, the first port and the second port;

forming two top-layer grooves with openings facing the coplanar waveguide planar transmission line on a top-layer reference ground; the two top-layer grooves are oppositely arranged on two sides of the coplanar waveguide planar transmission line along a second direction perpendicular to the first direction; along a second direction, a contrast space is formed between the bottoms of the two top-layer grooves, and the impedance line segment is positioned in the contrast space;

forming a bottom layer groove extending along a first direction on a bottom layer reference ground, wherein the orthographic projection of the coplanar waveguide planar transmission line on the bottom surface covers the orthographic projection of the bottom layer groove on the bottom surface; the bottom layer reference ground and the top layer reference ground form an orthogonal defected ground structure, so that the impedance discontinuous point of the coplanar waveguide planar transmission line is positioned outside the working frequency band of the electronic product.

10. The method of forming as claimed in claim 9, further comprising:

and adjusting the shape of an orthogonal defect ground formed by the reference ground of the top layer and the reference ground of the bottom layer to perform impedance matching of the orthogonal defect ground and the coplanar waveguide planar transmission line.

Technical Field

The invention relates to the technical field of terminals, in particular to an electronic product and a forming method thereof.

Background

The global 5G standard 5GNR is the next generation of very important cellular mobile technology base. The FR2 frequency band in the 5GNR is a millimeter wave frequency band, and the bandwidth is up to 10 GHz. Because millimeter wave signals are attenuated quickly, the transmission line is required to be as short as possible. The existing electronic products generally form a coplanar waveguide planar transmission line structure on a printing plate to realize ultra-wideband impedance matching.

At present, typical techniques include adding branches of open-circuit or short-circuit microstrip lines and implementing impedance matching by adjusting the lengths of the branches. However, this increases the size of the transmission line and the printed board, which is not favorable for miniaturization of the terminal product.

Disclosure of Invention

The embodiment of the invention provides an electronic product and a forming method thereof, and the electronic product realizes the millimeter wave frequency band ultra wide band impedance matching under the condition of not increasing the size of a printed board.

In order to achieve the purpose, the invention provides the following technical scheme:

in a first aspect, an embodiment of the present invention provides an electronic product, including an orthogonal defected ground coplanar waveguide planar transmission line structure, including:

a printed circuit board including a top surface and a bottom surface disposed opposite to each other;

the coplanar waveguide planar transmission line comprises a first port, an impedance line segment and a second port which are arranged along a first direction, and transition sections are arranged among the impedance line segment, the first port and the second port; the top layer reference ground is arranged on the peripheral side of the coplanar waveguide plane transmission line, and two top layer grooves with openings facing the coplanar waveguide plane transmission line are arranged on the top layer reference ground; the two top-layer grooves are oppositely arranged on two sides of the coplanar waveguide planar transmission line along a second direction perpendicular to the first direction; along a second direction, a contrast space is formed between the bottoms of the two top-layer grooves, and the impedance line segment is positioned in the contrast space;

the bottom layer reference ground is arranged on the bottom surface and is provided with a bottom layer groove extending along a first direction; the orthographic projection of the coplanar waveguide planar transmission line on the bottom surface covers the orthographic projection of the bottom layer groove on the bottom surface; and the bottom layer reference ground and the top layer reference ground form an orthogonal defected ground structure so that the impedance discontinuity point of the coplanar waveguide planar transmission line is positioned outside the operating frequency band of the electronic product.

Among the above electronic products, the electronic product includes an orthogonal defected ground coplanar waveguide planar transmission line structure. And the orthogonal defected ground coplanar waveguide planar transmission line structure comprises a printed circuit board, a coplanar waveguide planar transmission line, a top layer reference ground and a bottom layer reference ground. Specifically, the printed circuit board includes a top surface and a bottom surface, which are disposed opposite to each other. The coplanar waveguide planar transmission line is disposed on the top surface. Structurally, the coplanar waveguide planar transmission line includes a first port, an impedance line segment, and a second port arranged along a first direction. Transition sections are arranged between the impedance line segment and the first port and between the impedance line segment and the second port. The top layer is also arranged on the top surface of the printed circuit board in a reference manner, and is particularly distributed on the peripheral side of the coplanar waveguide planar transmission line. The top layer is provided with two top layer grooves arranged on two sides of the coplanar waveguide planar transmission line along the second direction in a reference mode, and the opening of each top layer groove in the two top layer grooves faces the coplanar waveguide planar transmission line. Because the openings of the two top-layer grooves are opposite, a contrast space is formed between the bottoms of the two top-layer grooves, and the impedance line segment is positioned in the contrast space. In other words, the extension line of the two sides of one of the two top-layer grooves in the first direction in the second direction coincides with the extension line of the other top-layer groove in the second direction in the two sides of the first direction, and after the corresponding sides are connected, a contrast space is formed between the two top-layer grooves, and the impedance line segment is located in the contrast space. As for the bottom layer reference ground, it is formed on the bottom surface of the printed circuit board. The bottom layer reference ground is provided with a bottom layer groove extending along the first direction, and the orthographic projection of the coplanar waveguide plane transmission line on the bottom surface covers the orthographic projection of the bottom layer groove on the bottom surface.

In the electronic product provided by the invention, two top layer grooves arrayed along the second direction are formed on the top layer reference ground, and the bottom layer grooves extending along the first direction are formed on the bottom layer reference ground, namely, the top layer reference ground and the bottom layer reference ground form an orthogonal defect ground structure. Under the influence of the orthogonal defected ground structure, when the coplanar waveguide plane transmission line is coupled with the orthogonal defected ground, the impedance discontinuous point of the coplanar waveguide plane transmission line can move out of the working frequency band, so that the millimeter wave frequency band ultra-wideband impedance matching is realized under the condition of not increasing the size of a printed board.

Therefore, the electronic product realizes the millimeter wave frequency band ultra wide band impedance matching under the condition of not increasing the size of the printed board.

Optionally, in the first direction, a size of the bottom layer groove is equal to a size of the coplanar waveguide planar transmission line.

Optionally, along the first direction, the bottom groove includes a main body section and extension sections disposed on two sides of the main body section; the size of the main body segment in the first direction is equal to the size of each top layer groove in the first direction, and the size of the main body segment in the second direction is equal to the size of each top layer groove in the second direction.

Optionally, along the first direction, a midline of an orthographic projection of the top-layer groove on the bottom surface coincides with a midline of an orthographic projection of the bottom-layer groove on the bottom surface.

Optionally, the coplanar waveguide planar transmission line has a gap with the top layer reference ground along the first direction.

Optionally, the size of the impedance line segment is larger than the size of the transition segment along the second direction.

Optionally, the impedance line segment is a 50 ohm impedance line segment.

Optionally, the electronic product provided by the invention further comprises an amplifier, wherein the orthogonal defected ground coplanar waveguide planar transmission line structure is in signal connection with an input end of the amplifier; alternatively, the first and second electrodes may be,

the orthogonal defected ground coplanar waveguide planar transmission line structure is in signal connection with the output end of the amplifier.

In a second aspect, an embodiment of the present invention further provides a method for forming a coplanar waveguide planar transmission line structure with an orthogonal defected ground, including:

determining the original impedance matching of the coplanar waveguide planar transmission line on the top surface of the printed circuit board in the millimeter wave working frequency band; the coplanar waveguide planar transmission line comprises a first port, an impedance line segment and a second port which are arranged along a first direction, wherein transition sections are arranged among the impedance line segment, the first port and the second port;

forming two top-layer grooves with openings facing the coplanar waveguide planar transmission line on a top-layer reference ground; the two top-layer grooves are oppositely arranged on two sides of the coplanar waveguide planar transmission line along a second direction perpendicular to the first direction; along a second direction, a contrast space is formed between the bottoms of the two top-layer grooves, and the impedance line segment is positioned in the contrast space;

forming a bottom layer groove extending along a first direction on a bottom layer reference ground, wherein the orthographic projection of the coplanar waveguide planar transmission line on the bottom surface covers the orthographic projection of the bottom layer groove on the bottom surface; the bottom layer reference ground and the top layer reference ground form an orthogonal defected ground structure, so that the impedance discontinuous point of the coplanar waveguide planar transmission line is positioned outside the working frequency band of the electronic product.

Optionally, the method further comprises:

and adjusting the shape of an orthogonal defect ground formed by the reference ground of the top layer and the reference ground of the bottom layer to perform impedance matching of the orthogonal defect ground and the coplanar waveguide planar transmission line.

Drawings

Fig. 1 is a structural diagram of an electronic product according to an embodiment of the present invention;

FIG. 2 is a front view of the orthogonal defected coplanar waveguide planar transmission line of FIG. 1;

FIG. 3 is a further front view of the orthogonal defectively coplanar waveguide planar transmission line of FIG. 1;

FIG. 4 is a back structure view of the orthogonal defected coplanar waveguide planar transmission line of FIG. 1;

FIG. 5 is a block diagram of the orthogonal defected coplanar waveguide planar transmission line of FIG. 1;

FIG. 6 is a flowchart of a method for forming an electronic product according to an embodiment of the invention;

FIGS. 7-10 are a set of simulations of the orthogonal defected coplanar waveguide planar transmission line of FIG. 1;

fig. 11 to 14 are still another set of simulation diagrams of the orthogonal defectively coplanar waveguide planar transmission line of fig. 1.

Icon: 001-electronic products; 01-an orthogonal defected ground coplanar waveguide planar transmission line structure; 02-an amplifier; 1-a printed circuit board; 2-coplanar waveguide planar transmission lines; 21-a first port; 22-impedance line segment; 23-a second port; 3-top level reference ground; 31-top layer groove; 4-bottom layer reference ground; 41-bottom layer groove; 411-body segment; 412-extension.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention provides an electronic product 001, wherein the electronic product 001 can be a mobile phone, and is specifically shown in fig. 1. Specifically, the electronic product 001 includes an orthogonal defected coplanar waveguide planar transmission line structure 01 and an amplifier 02. And the orthogonal defected ground coplanar waveguide planar transmission line structure 01 is in signal connection with the input or output of the amplifier 02.

Now, taking the signal connection between the orthogonal defected ground coplanar waveguide planar transmission line structure 01 and the input end of the amplifier 02 as an example, the structure of the electronic product 001 will be specifically described:

referring to fig. 2, fig. 3 and fig. 4, the orthogonal defected ground coplanar waveguide planar transmission line structure 01 in the electronic product 001 provided by the present invention includes:

the printed circuit board 1, the printed circuit board 1 includes top surface and bottom surface set up oppositely;

a coplanar waveguide planar transmission line 2 and a top-level reference ground 3, the coplanar waveguide planar transmission line 2 includes a first port 21, an impedance line segment 22 (separated by a dotted line in fig. 3 for convenience of illustration), and a second port 23, which are arranged along a first direction (a direction in fig. 3), and transition sections are disposed between the impedance line segment 22 and the first port 21 and between the impedance line segment 22 and the second port 23; the top layer reference ground 3 is arranged on the peripheral side of the coplanar waveguide planar transmission line 2, and two top layer grooves 31 with openings facing the coplanar waveguide planar transmission line 2 are arranged on the top layer reference ground 3; the two top-layer grooves 31 are oppositely arranged on two sides of the coplanar waveguide planar transmission line 2 along a second direction vertical to the first direction; and along the second direction (b direction in fig. 3), a contrast space a as shown in fig. 3 is formed between the groove bottoms of the two top-layer grooves 31, and the impedance line segment 22 is located in the contrast space a;

referring to fig. 4, the bottom layer reference ground 4 is disposed on the bottom surface, and the bottom layer reference ground 4 has a bottom layer groove 41 extending along a first direction; the orthographic projection of the coplanar waveguide planar transmission line 2 on the bottom surface covers the orthographic projection of the bottom layer groove 41 on the bottom surface; and the bottom layer reference ground 4 and the top layer reference ground 3 form an orthogonal defected ground structure, so that the impedance discontinuity point of the coplanar waveguide planar transmission line 2 is positioned outside the operating frequency band of the electronic product 001.

In the above-mentioned electronic product 001, the electronic product 001 includes the orthogonal defected ground coplanar waveguide planar transmission line structure 01. The orthogonal defected ground coplanar waveguide planar transmission line structure 01 comprises a printed circuit board 1, a coplanar waveguide planar transmission line 2, a top layer reference ground 3 and a bottom layer reference ground 4. Specifically, the printed circuit board 1 includes a top surface and a bottom surface, which are disposed opposite to each other. A coplanar waveguide planar transmission line 2 is disposed on the top surface. As shown in fig. 2 and 3, the coplanar waveguide planar transmission line 2 structurally includes a first port 21, an impedance line segment 22, and a second port 23 arranged in a first direction. A transition section is provided between the impedance line segment 22 and both the first port 21 and the second port 23. The top layer reference ground 3 is also provided on the top surface of the printed circuit board 1, which is particularly distributed on the peripheral side of the coplanar waveguide planar transmission line 2. The top reference ground 3 has two top grooves 31 disposed at both sides of the coplanar waveguide planar transmission line 2 in the second direction, and each top groove 31 of the two top grooves 31 is opened toward the coplanar waveguide planar transmission line 2. Since the openings of the two top-level grooves 31 are opposite to each other, a comparison space a is formed between the groove bottoms of the two top-level grooves 31, and the impedance line segment 22 is located in the comparison space a. In other words, the extension line of the second direction of the two sides of one top-layer groove 31 in the first direction of the two top-layer grooves 31 coincides with the extension line of the second direction of the two sides of the other top-layer groove 31 in the first direction, and after connecting the corresponding sides, a contrast space is formed between the two top-layer grooves 31, and the impedance line segment 22 is located in the contrast space. As for the bottom layer reference ground 4, it is formed on the bottom surface of the printed circuit board 1. The bottom layer reference ground 4 has a bottom layer groove 41 extending along the first direction, and the orthographic projection of the coplanar waveguide planar transmission line 2 on the bottom surface covers the orthographic projection of the bottom layer groove 41 on the bottom surface.

The electronic product 001 provided by the invention is characterized in that two top layer grooves 31 arranged along the second direction are formed on the top layer reference ground 3, and a bottom layer groove 41 extending along the first direction is formed on the bottom layer reference ground 4, namely, the top layer reference ground 3 and the bottom layer reference ground 4 form an orthogonal defect ground structure. Under the influence of the orthogonal defected ground structure, when the coplanar waveguide planar transmission line 2 is coupled with the orthogonal defected ground, the impedance discontinuous point of the coplanar waveguide planar transmission line 2 can move out of the working frequency band, so that the millimeter wave frequency band ultra-wideband impedance matching is realized under the condition of not increasing the size of a printed board.

Therefore, the electronic product 001 can realize millimeter wave frequency band ultra wide band impedance matching without increasing the size of the printed board.

It should be noted that, in order to make the coplanar waveguide planar transmission line 2 in the electronic product 001 provided by the present invention normally couple with the orthogonal defected ground, in the first direction, the coplanar waveguide planar transmission line 2 and the top reference ground 3 have a gap S as shown in fig. 2; the impedance line segment 22 may be a 50 ohm impedance line segment 22.

On the basis of the above technical solution, a specific structure of the electronic product 001 is provided, which is as follows:

referring to fig. 2 to 4, along the first direction, the size of the bottom groove 41 is equal to the size of the coplanar waveguide planar transmission line 2. With reference to fig. 4, in the first direction, the bottom groove 41 includes a main body segment 411 and extension segments 412 disposed on two sides of the main body segment 411. Note that, here, for convenience of description, a schematic division is made by a dotted line in fig. 4, and it should be understood that the specific structure is not limited thereto.

Specifically, the body segment 411 has a dimension in the first direction equal to the dimension of each top-level groove 31 in the first direction, and the body segment 411 has a dimension in the second direction equal to the dimension of each top-level groove 31 in the second direction. Still in the first direction, the midline of the orthographic projection of the top groove 31 at the bottom coincides with the midline of the orthographic projection of the bottom groove 41 at the bottom.

In the above technical solution, as shown in fig. 3, along the second direction, the size of the impedance line segment 22 is larger than that of the transition segment, and certainly, the size of the impedance line segment 22 in the second direction may also be set to other values, which is not described herein again.

Referring to the structure of fig. 5, the structure shown in the figure provides a practical structure of the orthogonal defected ground coplanar waveguide planar transmission line structure 01.

The present invention also provides a method for forming an electronic product 001, wherein the electronic product 001 includes an orthogonal defected coplanar waveguide planar transmission line structure 01, and the method is as shown in fig. 6, and includes:

step S101: determining the original impedance matching of the coplanar waveguide planar transmission line 2 on the top surface of the printed circuit board 1 in a millimeter wave working frequency band; as shown in fig. 2 to 3, the coplanar waveguide planar transmission line 2 includes a first port 21, an impedance line segment 22 and a second port 23 arranged along a first direction, and transition segments are disposed between the impedance line segment 22 and the first port 21 and between the impedance line segment 22 and the second port 23;

step S102: forming two top-layer grooves 31 opening toward the coplanar waveguide planar transmission line 2 on the top-layer reference ground 3, as shown in fig. 2 to 3, wherein the two top-layer grooves 31 are oppositely arranged on two sides of the coplanar waveguide planar transmission line 2 along a second direction perpendicular to the first direction; along the second direction, a contrast space is formed between the bottoms of the two top-layer grooves 31, and the impedance line segment 22 is positioned in the contrast space;

step S103: forming a bottom layer groove 41 extending along the first direction on the bottom layer reference ground 4, wherein as shown in fig. 4 in particular, the orthographic projection of the coplanar waveguide planar transmission line 2 on the bottom surface covers the orthographic projection of the bottom layer groove 41 on the bottom surface; the bottom layer reference ground 4 and the top layer reference ground 3 form an orthogonal defected ground structure, so that the impedance discontinuity point of the coplanar waveguide planar transmission line 2 is positioned outside the operating frequency band of the electronic product 001.

It should be noted that, in the above manufacturing method, it is necessary to determine the original impedance of the coplanar waveguide planar transmission line 2 formed on the top surface of the printed circuit board 1, and then construct the orthogonal defect shape formed by the two top-layer grooves 31 and the bottom-layer groove 41 to form an orthogonal defect ground structure capable of moving the discontinuity in the original impedance of the coplanar waveguide planar transmission line 2 to the outside of the operating frequency band.

On the basis of the technical scheme, in an optional implementation mode, an orthogonal defect ground topology formed by the top layer reference ground 3 and the bottom layer reference ground 4 can be established to adjust the shape of the orthogonal defect ground formed by the top layer reference ground 3 and the bottom layer reference ground 4.

On the basis of the above technical solution, specifically, the method for establishing the orthogonal defected ground topology formed by the top layer reference ground 3 and the bottom layer reference ground 4 includes:

setting the insertion loss S21 and the reflection coefficient S11 in the S parameters of the first port 21 and the second port 23 of the coplanar waveguide planar transmission line 2 as optimization targets, wherein the target requirement of the insertion loss S21 is smaller than a first threshold value, and the target requirement of the reflection coefficient S11 is smaller than a second threshold value;

setting the size of the body section 411 of the bottom layer groove 41 in the first direction to be equal to the size of each top layer groove 31 in the first direction;

starting from the size of the bottom layer groove 41 in the first direction being a first preset value, the size is gradually decreased in steps at first set intervals;

starting from the size of the main body segment 411 in the second direction, the size of the extension segment 412 in the second direction and the size of the top layer groove 31 in the second direction being the second preset value, the sizes are increased in steps at second set intervals;

and finding the optimal solution by traversing all the sizes.

A specific example illustration of the structure forming the electronic product 001 is now provided:

a coplanar waveguide planar transmission line 2 is formed on the top surface of a printed circuit board 1, so that the working frequency ranges of the transmission line are FR2 Band n257 and Band n258 of 5G NR, and the frequency ranges from 24250MHz to 29500 MHz. As shown in fig. 2 and 4 below, wherein: the height H of the printed circuit board 1 is 0.508mm, and the dielectric constant Epsilon r is 2.2; the coplanar waveguide planar transmission line 2 has a dimension L1 of 4.57mm in the first direction, a 50-ohm impedance line width W1 of 1.2mm in the second direction, and a spacing S of 0.16mm in the second direction from the surface layer reference ground.

First, the original impedance matching of the coplanar waveguide planar transmission line 2 in fig. 2 is calculated, and the results of S-parameters calculated by using commercially available simulation software are shown in fig. 7 to 10. Wherein the return loss S11 in fig. 7 represents the reflection coefficient of the first port 21 when the second port 23 is matched; the insertion loss S12 in fig. 8 represents the reverse transmission coefficient from the second port 23 to the first port 21 when the first port 21 is matched; the insertion loss S21 in fig. 9 represents the reverse transmission coefficient from the first port 21 to the second port 23 when the second port 23 is matched; the return loss S22 in fig. 10 indicates the reflection coefficient of the second port 23 when the first port 21 is matched. As can be seen from fig. 7 to 10: obvious impedance mismatch exists at a frequency point of 27.5GHz, the reflection coefficient S11 is-5 dB, and the insertion loss S21 is-6.5 dB.

And secondly, constructing an orthogonal defected ground topology structure, wherein the top layer reference ground 3 and the bottom layer reference ground 4 jointly form an orthogonal defected ground. As shown in fig. 2 and 4, the size of the bottom layer reference ground 4 in the first direction is equal to the size L1 of the coplanar waveguide planar transmission line 2 in the first direction, the size L2 of the body segment 411 of the bottom layer groove 41 in the first direction is 1.9mm, the size W2 of the body segment 411 of the bottom layer groove 41 in the second direction is 0.75mm, and the size W3 of the extension segment 412 of the bottom layer groove 41 in the second direction is 0.25 mm; the dimension L3 of the top layer groove 31 in the first direction is 1.9mm, and the dimension W4 in the second direction is 0.75 mm.

And thirdly, repeatedly optimizing the critical dimension of the orthogonal defect ground through electromagnetic field simulation software to realize the expected impedance matching. With the S parameters (parameter S21 and parameter S11) of the two ports, i.e., the first port 21 and the second port 23, of the coplanar waveguide planar transmission line 2 as the optimization target, the target requirement of the insertion loss S21 is set to be less than-1 dB (i.e., the first threshold is-1 dB), and the target requirement of the reflection coefficient S11 is set to be less than-10 dB (i.e., the second threshold is-10 dB).

Setting L2 and L3 equal and gradually decreasing from L1 by 0.1mm of a first preset value; w2, W3, and W4 were each incremented in steps of 0.05mm (i.e., a second set interval of 0.05mm) starting at 0.1mm (i.e., a second preset value of 0.1mm), and the optimal solution was found by traversing each size. The optimal solutions obtained by calculation are L2-L3-1.9 mm, W3-0.25 mm, and W2-W4-0.75 mm, and the simulation graphs are shown in fig. 11-14, and it can be known from fig. 11-14 that after the orthogonal defect ground structure is introduced, the reflection coefficient S11 in the frequency band of 24 GHz-30 GHz is less than-10 dB, the insertion loss S21 is less than-1 dB, and the width impedance matching is realized.

It will be apparent to those skilled in the art that various changes and modifications may be made in the embodiments of the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.