A multi-band microstrip MIMO antenna for the WiFi / UWB frequency bands

Abstract

The present invention discloses a multi-frequency microstrip MIMO antenna for WiFi / UWB frequency bands, wherein a rectangular metal floor is provided at the bottom of the rectangular parallelepiped dielectric substrate; an improved metal radiator and a microstrip line are provided at the top of the rectangular parallelepiped dielectric substrate. The improved metal radiator is evolved from the following process: an OK-shaped metal radiator is provided at the upper right of the microstrip feeder, and an "L"-shaped metal patch is provided below it. A "T"-shaped metal patch and a rectangular patch are added to the right sides of the bottom and top of the microstrip feeder, respectively; an L-shaped branch is provided on the left side of the microstrip feeder, and a rectangular groove is etched on the top thereof. Finally, the entire radiator is rotated 180° around the center of the dielectric substrate to obtain another part of the metal radiator, and a "Z"-shaped metal patch is added to the middle part of the dielectric substrate; the microstrip feeder is made of metal material, and the microstrip feeder structure is provided with a feeding point. The present invention can cover the 2.40-2.51 GHz and 3.65-9.76 GHz frequency bands, the maximum peak gain of the antenna is 3.62 dBi, the antenna has a simple structure and a small size, and has good practical value in mobile terminal communications.

Description

Technical Field

[0001] The present invention relates to the technical field of multi - frequency wireless communication, and specifically to a multi - frequency microstrip MIMO antenna in the WiFi / UWB frequency bands. Background Art

[0002] A large number of studies on wireless communication for WiFi and UWB have been carried out at home and abroad. Many of these studies only cover some frequency bands. The single - frequency band and narrow bandwidth of the antenna have a great impact on the high - speed transmission and low latency of the wireless communication network. Therefore, achieving multi - frequency coverage of the antenna is a key issue.

[0003] Currently, there are more and more types of electronic products, and different communication methods use different frequencies. This requires the development of a single mobile device that includes multiple frequency bands to meet the use of mainstream frequency bands such as WiFi and UWB. Summary of the Invention

[0004] The purpose of the present invention is to provide a multi - frequency microstrip MIMO antenna for the WiFi / UWB frequency bands; the invention has the advantages of simple structure and wide bandwidth.

[0005] To achieve the purpose of the present invention, the following technical solutions are adopted:

[0006] A multi - frequency microstrip MIMO antenna for the WiFi / UWB frequency bands includes a cuboid dielectric substrate. It is characterized in that two rectangular metal floors are provided at the bottom of the cuboid dielectric substrate; the top of the dielectric substrate consists of an improved metal radiator and microstrip feed lines. The improved metal is formed by adding three curved rectangular metal patches to the upper right of the feed line, adding a circular metal iron sheet to the left of the three curved rectangular metal patches, etching a circular groove in the center of the circular metal iron sheet to form an "OK" shape, and having an "L" - shaped metal patch below the "OK" shape. A "T" - shaped metal patch is added to the bottom right of the microstrip feed line; a rectangular patch is added to the top right of the microstrip feed line; there is an L - shaped stub on the left of the microstrip feed line, and a rectangular groove is etched at the top of the L - shaped stub. Finally, the entire radiator is rotated 180° around the center of the dielectric substrate to obtain another part of the metal radiator, and a "Z" - shaped metal patch is added to the middle part of the dielectric substrate; the microstrip line is composed of a metal material and is loaded on the top of the dielectric substrate, and the microstrip line structure is provided with a feeding point.

[0007] Preferably, the cuboid serves as the dielectric substrate, and the microstrip line is used for feeding the antenna. A "T" - shaped metal patch is added to the right side of the metal, and the "T" - shaped metal patch on the dielectric substrate is used to increase the bandwidth of the antenna, and the "Z" - shaped metal patch is used to improve the isolation.

[0008] Preferably, the rectangular dielectric substrate is made of FR-4 with a dielectric constant of 4.4, a length of 80 mm, a width of 43 mm, and a height of 1.6 mm. The side with the printed microstrip line is the front of the dielectric substrate, and the side with the printed metal floor is the back of the dielectric substrate.

[0009] Preferably, the microstrip line is centered, and there is a "T"-shaped metal patch on the right side of the microstrip line. The edge of the "T"-shaped metal patch is 1.5 mm away from the feeder, the long side is 8 mm long and 2 mm wide, the short side is 6 mm long and 1.5 mm wide. The length of the microstrip line is 23 mm, and the width of the microstrip line is 3 mm.

[0010] Preferably, the radius of the circular patch is 4.5 mm, the radius of the circular groove at its center is 1.5 mm, and it is located above the metal radiator. A "Z"-shaped metal patch is added above the metal radiator, which is composed of three rectangular metal patches with lengths of 7 mm, 7 mm, and 20 mm respectively, and widths of 2 mm each. There is an L-shaped stub on the left side of the feeder, and a rectangular groove is etched at the top of the L-shaped stub. The length and width of the rectangular groove are 6 mm and 0.4 mm respectively. The length of the floor is 43 mm, and the width is 10.2 mm.

[0011] Preferably, the edge of the "T"-shaped metal is 1.5 mm away from the feeder.

[0012] Preferably, the back of the dielectric substrate is tinned according to the structure of the floor, and the front of the dielectric substrate is tinned according to the improved metal radiator structure and microstrip line structure.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] (1) The antenna of the present invention can cover the WiFi / UWB frequency bands, with the frequency bands being 2.40 - 2.51 GHz and 3.64 - 9.76 GHz, and the relative bandwidths being 4.48% and 91.42% respectively. The antenna gain is between 1.35 - 3.62 dBi within the frequency bands.

[0015] (2) The gains at the resonant frequencies of 2.45 GHz, 3.85 GHz, 7.10 GHz, and 9.40 GHz are 1.62 dBi, 2.42 dBi, 2.77 dBi, and 2.67 dBi respectively.

[0016] (3) The antenna structure of the present invention is simple, easy to process, and has a low manufacturing cost. It has the advantages of high communication capacity and low-latency wireless communication, and has high practical value in mobile terminal applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic structural diagram of the present invention.

[0018] Figure 2 It is a front view schematic diagram of the structure of the present invention.

[0019] Figure 3 It is a rear view schematic diagram of the structure of the present invention.

[0020] Figure 4 It is a simulation diagram of the S11 parameter of the antenna of the present invention.

[0021] Figure 5 It is a simulated radiation pattern of the present invention at 2.45 GHz.

[0022] Figure 6 It is a simulated radiation pattern of the present invention at 3.85 GHz.

[0023] Figure 7 It is a simulated radiation pattern of the present invention at 7.10 GHz.

[0024] Figure 8 It is a simulated radiation pattern of the present invention at 9.40 GHz.

[0025] Figure 9 It is a simulated gain diagram of the antenna of the present invention. Detailed implementation manners

[0026] The present invention will be further explained and illustrated below through specific implementations, but the present invention is not limited to these specific implementation manners. Those skilled in the art should be aware that the present invention covers all alternative solutions, improvement solutions, and equivalent solutions that may be included within the scope of the claims.

[0027] As Figure 1 shown, a multi - frequency microstrip MIMO antenna for the WiFi / UWB band includes a dielectric substrate 1. One improved metal radiator 2 and a microstrip feeder 3 are loaded on the top of the dielectric substrate 1. Three curved rectangular metal patches 4 are added at the upper right of the radiator. Then, a circular metal patch 5 is added to the left of the rectangular metal patch, and a circular groove 6 is drilled at the center of the circular metal patch. A rectangular metal patch 7 is added to the right of the top of the feeder. Then, there is an L - shaped stub 8 on the left of the feeder, and a rectangular slot 9 is etched at the top of the L - shaped stub. A "T" - shaped metal patch 10 is added to the right of the bottom of the microstrip feeder, and its function is to increase the bandwidth of the antenna; a "Z" - shaped metal patch 11 is added to the middle part of the dielectric substrate, and its function is to increase the isolation of the antenna; a rectangular ground plane 12 is provided at the bottom of the dielectric substrate, and the microstrip line is provided with a feeding point 13 for feeding. The structure of the present invention is simple and has a small requirement for the antenna clearance area.

[0028] The improved metal radiator is formed by 2 - 10. 2 is on the right side of the metal radiator. 4, 5, and 6 are all above 2. 7 is on the right side of the top of the feeder 3. 8 and 9 are both on the left side of the feeder 3. 10 is on the right side of the bottom of the feeder 3.

[0029] The added "Z"-shaped metal patch 11 is located at the center of the dielectric substrate.

[0030] In this embodiment, the length of the microstrip line 3 is 9.5 mm, the width is 3 mm, and it is located on the top of the dielectric substrate. The edge of the T-shaped metal patch 10 is 1 mm away from the feeder, the long side is 8 mm long and 2 mm wide; the short side is 6 mm long and 1.5 mm wide.

[0031] The "L"-shaped metal patch 2 is composed of two rectangular metal patches. The lengths of the two rectangular metal patches are 14.5 mm and 9 mm respectively, and the widths are 3 mm and 6 mm respectively. The radius of the circular patch 5 is 4.5 mm, and the radius of the circular groove 6 is 1.5 mm.

[0032] The added rectangular metal iron sheet 7 has a long side length of 7 mm and a width of 3 mm. A "Z"-shaped metal patch is added in the middle of the metal radiator, which is composed of three rectangular metal patches with lengths of 7 mm, 7 mm, and 20 mm respectively, and the widths are all 2 mm.

[0033] There is an L-shaped stub 8 on the left side of the feeder. The stub is composed of two rectangular metal patches. The lengths of the two rectangular metal patches are 13 mm and 6.5 mm respectively, and the widths are both 2 mm. A rectangular groove 9 is etched at the top of the L-shaped stub. The length and width of the rectangular groove are 6 mm and 0.4 mm respectively. The length of the ground plane 12 is 43 mm and the width is 10.2 mm.

[0034] The antenna structure described in this embodiment is etched on the dielectric substrate 1. The material of the dielectric substrate is FR-4, the dielectric constant is 4.4, the height is 1.6 mm, and one side is tinned according to the structure of the microstrip line and the improved metal radiator; the other side is tinned according to the structure of the ground plane to be an infinite large ground plane.

[0035] The specific implementation is as follows:

[0036] This implementation uses the printed circuit board etching technology to etch out Figure 2 the structure of the radiator and the microstrip line on one side of a PCB board with a thickness of 1.6 mm. The size of the entire dielectric substrate is 80 mm × 43 mm × 1.6 mm, where the feeding point position is not tinned. At the same time, this etching technology is also used to etch out Figure 3 the structure of the ground plane on the other side of an FR-4 substrate with a thickness of 1.6 mm.

[0037] The system was simulated using the electromagnetic simulation software ANSYS Electronics Desktop 2019.2. The results of the S-parameters are as attached Figure 4 shown. It can be seen from them that the simulation results can cover the WiFi / UWB frequency bands. The designed antenna gain is between 1.35 - 3.62 dBi, meeting the requirements of wireless communication.

[0038] As attached Figure 5 , attached Figure 6 , attached Figure 7 and attached Figure 8 are the two-dimensional radiation patterns of the antenna obtained by simulation.

[0039] As attached Figure 9 shown, the simulated gain diagram of the antenna is given. The gain is between 1.35 - 3.62 dBi within the working frequency band, and the proposed antenna performance can be applied to multi-band wireless communication.

Claims

1. A multi - band microstrip MIMO antenna for the WiFi / UWB frequency bands, comprising a cuboid dielectric substrate, characterized in that, Two metal floors are provided at the bottom of the cuboid dielectric substrate; A pair of rotationally symmetric metal radiators and a microstrip feeder are provided on the top of the dielectric substrate; The metal radiator includes: connecting an L-shaped metal patch to the top right of the microstrip feeder, extending three curved rectangular metal patches above the L-shaped metal patch, connecting a circular metal patch to the left of the three curved rectangular metal patches, etching a circular groove in the center of the circular metal patch to form a shape like an "OK" gesture; providing a "T"-shaped metal patch on the bottom right of the microstrip feeder; extending and connecting a rectangular patch above the top of the microstrip feeder; connecting an L-shaped stub to the top left of the microstrip feeder, etching a rectangular groove on the top of the L-shaped stub; finally rotating the entire radiator 180° around the center of the dielectric substrate to obtain the other part of the metal radiator, and providing a "Z"-shaped metal patch in the middle part of the dielectric substrate; The microstrip feeder is composed of a metal material, and the microstrip feeder structure is provided with a feeding point; The back of the dielectric substrate is tinned according to the structure of the metal floor, and the front of the dielectric substrate is tinned according to the structures of the metal radiator and the microstrip feeder.

2. The multi-band microstrip MIMO antenna for WiFi / UWB bands according to claim 1, wherein The microstrip feeder is used for feeding the antenna, the "T"-shaped metal patch on the dielectric substrate is used to increase the bandwidth of the antenna, and the "Z"-shaped metal patch is used to increase the isolation of the antenna.

3. The multi-band microstrip MIMO antenna for WiFi / UWB bands according to claim 2, characterized in that, The material of the cuboid dielectric substrate is FR-4, with a length of 80 mm, a width of 43 mm, and a height of 1.6 mm; The side with the printed metal radiator and microstrip feeder is the front of the dielectric substrate, and the side with the printed metal floor is the back of the dielectric substrate.

4. A multi-band microstrip MIMO antenna for the WiFi / UWB band according to claim 3, characterized in that, The length of the microstrip feeder is 23 mm and the width is 3 mm; etching a circular groove in the center of the circular metal patch, with the radius of the circular groove being 1.5 mm; The L-shaped metal patch is composed of two rectangular metal patches, with the lengths of the two rectangular metal patches being 14.5 mm and 9 mm respectively, and the widths being 3 mm and 6 mm respectively; providing a "T"-shaped metal patch on the bottom right of the microstrip feeder, with the edge of the "T"-shaped metal patch being 1.5 mm away from the feeder, the long side being 8 mm long and 2 mm wide; the short side being 6 mm long and 1.5 mm wide; extending and connecting a rectangular metal patch above the top of the microstrip feeder, with its length and width being 7 mm and 3 mm respectively; connecting an L-shaped stub to the top left of the microstrip feeder, which is composed of two rectangular metal patches, with the lengths of the two rectangular metal patches being 13 mm and 6.5 mm respectively, and the widths being both 2 mm; etching a rectangular groove on the top of the L-shaped stub, with the length and width being 6 mm and 0.4 mm respectively; providing a "Z"-shaped metal patch between the two metal radiators, which is composed of three rectangular metal patches, with the lengths being 7 mm, 7 mm, and 20 mm respectively, and the widths being both 2 mm; The length of the metal floor is 43 mm and the width is 10.2 mm.

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