A three-frequency microstrip antenna with a circular ring in-embedded branch and tunable

Abstract

This utility model discloses a tunable tri-band microstrip antenna with embedded stubs in a circular ring, relating to the field of antenna technology. It includes a dielectric substrate, a radiating patch, a feed line, and a bottom ground plane. The radiating patch is located on the upper surface of the dielectric substrate and distributed along the central axis of the substrate. The radiating patch is connected to the feed line. The bottom ground plane is attached to the lower surface of the dielectric substrate. The radiating patch consists of a circular ring radiating element, a pair of embedded symmetrical inverted L-shaped radiating elements, and a circular radiating element. This novel radiating patch structure employs an innovative shape, expanding the multi-frequency characteristics of a single-band circular ring monopole antenna by adopting a tunable embedded symmetrical inverted L-shaped structure, thereby achieving the goal of multi-frequency conversion of a single-band circular ring monopole antenna.

Description

Technical Field

[0001] This utility model relates to the field of antenna technology, and more specifically to a three-frequency microstrip antenna with tunable stubs embedded in a circular ring. Background Technology

[0002] With the rapid development of information technology, the demand for electronic components in contemporary society has increased significantly, and the application scenarios have gradually extended from various traditional terminal devices to smart home appliances. Taking Xiaomi home appliances as an example, its voice assistant "Xiao Ai" effectively realizes voice control of smart home systems through interactive sensing. These control processes all rely on stable signal transmission equipment, and the widespread adoption of such devices inevitably leads to high-frequency communication needs. Microstrip patch antennas, as part of the communication carrier, have been reliably applied in the field of radio. The widespread adoption of WLAN technology has brought wireless networks into the basic scenarios of daily home and social business, while WiMAX technology has effectively demonstrated significant performance in long-distance broadband transmission. The synergistic development of these two technologies has not only restructured people's busy work and leisure activities but also provided support for the upgrading of components in global communication infrastructure. Based on this advantage, and considering the current demand for multi-frequency signal transmission in miniaturized devices, how to design a multi-frequency tunable microstrip antenna to adapt to diverse communication application needs is a problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0003] In view of this, the present invention provides a tunable tri-band microstrip antenna with embedded stubs in a circular ring to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: a tunable tri-band microstrip antenna with embedded stubs in a circular ring, comprising a dielectric substrate, a radiating patch, a feed line, and a bottom ground plane; the radiating patch is located on the upper surface of the dielectric substrate and distributed along the central axis of the dielectric substrate; the radiating patch is connected to the feed line; the bottom ground plane is attached to the lower surface of the dielectric substrate; wherein, the radiating patch is composed of a circular ring radiating element, a pair of embedded symmetrical inverted L-shaped radiating elements, and a circular radiating element.

[0005] Preferably, the inner diameter of the annular radiating unit is 7.5 mm and the outer diameter is 9.5 mm; the short side of the symmetrical inverted L-shaped radiating unit is connected to the inner circle of the annular radiating unit, and the long side is parallel to the central axis of the dielectric substrate; the circular radiating unit is located in the middle of the symmetrical inverted L-shaped radiating unit, has a radius of 3 mm, and its center is on the central axis of the dielectric substrate, and shares the same center with the annular radiating unit.

[0006] Preferably, the dielectric substrate is a square with a side length of 40mm, a thickness of 0.8mm, and is made of FR-4 material.

[0007] Preferably, the feed line is located below the annular radiating unit on which the radiating patch is attached to the dielectric substrate, and includes a first feed line and a second feed line; the first feed line and the second feed line are connected and conductive through two microstrip transmission lines of different widths; the first feed line is connected to the annular radiating unit and is symmetrical about the central axis of the radiating patch, with a width of 2mm and a length of 7mm; the second feed line has a width of 3.2mm and a length of 6mm and is connected to the first feed line, and is conductive through a lumped port and the bottom ground plane.

[0008] Preferably, the bottom ground plane is a rectangular structure with a length of 40mm and a width of 11mm.

[0009] Preferably, the radiating patch is fed by a coplanar microstrip line, and the feed line connects the upper and lower surfaces, achieving coplanar attachment with the patch antenna structure.

[0010] Preferably, the short side of the symmetrical inverted L-shaped radiating unit is 4 mm, the long side is 8.2 mm, and the width of the symmetrical inverted L-shaped radiating unit is 1 mm.

[0011] As can be seen from the above technical solution, compared with the prior art, this utility model discloses a tunable tri-frequency microstrip antenna with embedded stubs in a circular ring, which has the following beneficial technical effects: It adopts an innovative radiating patch structure, and makes structural improvements and innovations on the basis of the single-frequency antenna of the circular ring monopole. By adopting a tunable embedded symmetrical inverted L-shaped structure, it expands the multi-frequency characteristics that it did not originally have, so as to achieve the purpose of multi-frequencyization of the single-frequency antenna of the circular ring monopole, so as to adapt to the diversified communication application needs. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0013] Figure 1 This is a schematic diagram of the antenna structure of this utility model;

[0014] Figure 2 This is a return loss curve diagram of this utility model;

[0015] Figure 3 This is a voltage standing wave ratio (VSWR) curve of this utility model;

[0016] Figure 4 This is a far-field analysis diagram of the present invention in the xOy and yOz planes at 2.4 GHz;

[0017] Figure 5 This is a far-field analysis diagram of the present invention in the xOy and yOz planes at 3.8 GHz;

[0018] Figure 6 This is a far-field analysis diagram of the present invention in the xOy and yOz planes at 5.8 GHz;

[0019] Figure 7 This is a 3D radiation diagram of the present invention at 2.4 GHz;

[0020] Figure 8 This is a 3D radiation diagram of the present invention at 3.8 GHz;

[0021] Figure 9 This is a 3D radiation diagram of the present invention at 5.8 GHz. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0023] This utility model discloses a tunable tri-band microstrip antenna with embedded stubs in a circular ring, such as... Figure 1 As shown, it includes a dielectric substrate, a radiating patch, a feed line, and a bottom ground plane; the radiating patch is located on the upper surface of the dielectric substrate and is distributed along the central axis of the dielectric substrate; the radiating patch is connected to the feed line; the bottom ground plane is attached to the lower surface of the dielectric substrate; wherein, the radiating patch is composed of annular radiating units, a pair of embedded symmetrical inverted L-shaped radiating units, and circular radiating units.

[0024] Furthermore, the dielectric substrate is a square with a side length of 40mm, a thickness of 0.8mm, and is made of FR-4 material.

[0025] Furthermore, the radiating patch structure is an innovative antenna topology proposed in this invention. The main body consists of a circular radiating element connected to the feed line, a pair of embedded symmetrical inverted L-shaped radiating elements, and a circular radiating element. The inner diameter of the circular radiating element is 7.5 mm, and the outer diameter is 9.5 mm. The short side T3 = 4 mm of the symmetrical inverted L-shaped radiating element is connected to the inner circle of the circular radiating element, and the long side T2 = 8.2 mm is parallel to the central axis of the square dielectric substrate. The width W1 = 1 mm of the symmetrical inverted L-shaped radiating element is 1 mm. The circular radiating element is sandwiched in the middle of the symmetrical inverted L-shaped radiating element, with a radius of 3 mm. The center of the circle is on the central axis of the dielectric substrate and shares the same center with the circular radiating element.

[0026] The radiating patch is fed by a coplanar microstrip line, with the feed line connecting the upper and lower surfaces to achieve coplanar attachment with the patch antenna structure.

[0027] The feed lines are located below the annular radiating unit on which the radiating patch is attached to the dielectric substrate, and include a first feed line and a second feed line. The first and second feed lines are connected and conductive via two microstrip transmission lines of different widths. The first feed line is connected to the annular radiating unit and is symmetrical about the central axis of the radiating patch, with a width of 2 mm and a length of 7 mm. The second feed line is 3.2 mm wide and 6 mm long, connected to the first feed line, and is also symmetrical about the central axis of the radiating patch, and is conductive via a lumped port and the underlying ground plane. The feed lines are made of metallic conductors.

[0028] Furthermore, the bottom ground plane is a rectangular structure with a length of 40mm and a width of 11mm, and the material is a metal conductor.

[0029] A tunable tri-frequency microstrip antenna with embedded stubs in a circular ring was developed. Through optimized design of the three-frequency resonant model, the finished product parameters are as follows: return loss S11 is -19.1204dB at 2.440GHz, return loss S11 is -19.4138dB at 3.830GHz, and return loss S11 is -48.5712dB at 7.10GHz.

[0030] Figure 2 The return loss curve of a tunable tri-band antenna with an embedded stub in a circular ring, as disclosed in this utility model, is shown below. Figure 2 As can be seen from the data, the return loss of this antenna is less than -10dB in the frequencies of 2.38-2.58GHz, 3.78-3.91GHz and 5.74-7.94GHz. Figure 3 The voltage standing wave ratio (VSWR) curve for this embodiment shows that the VSWR of the antenna is less than 2 in the above frequency band. Figure 4 , Figure 5 , Figure 6The figures 1 and 2 are the radiation patterns of the antenna in this example at frequencies of 2.4 GHz, 3.8 GHz, and 5.8 GHz, respectively. Figure 7 , Figure 8 , Figure 9 These are the 3D radiation diagrams of the antenna in this example at frequencies of 2.4 GHz, 3.8 GHz, and 5.8 GHz. As can be seen from these data distribution diagrams, this embodiment exhibits a certain degree of directivity across the entire frequency band, meeting the design requirements. Based on a circular monopole single-frequency antenna, the introduction of dual resonant frequencies is achieved by employing a tunable, embedded symmetrical inverted L-shaped stub, thereby realizing the goal of multi-frequency antenna operation.

[0031] This utility model discloses a tunable tri-band antenna with an embedded stub in a circular ring, which resonates at three different frequencies: 2.4 GHz, 3.8 GHz, and 7.1 GHz. The frequency bandwidths with a return loss S11 less than -10 dB are 2.38-2.58 GHz, 3.78-3.91 GHz, and 5.74-7.94 GHz. The spectrum coverage of this antenna can be applied to devices such as Bluetooth devices, wireless access communication devices, wireless LANs, and the Internet of Things (IoT).

[0032] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0033] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A tunable tri-band microstrip antenna with embedded stubs in a circular ring, characterized in that, It includes a dielectric substrate, a radiating patch, a feed line, and a bottom ground plane; the radiating patch is located on the upper surface of the dielectric substrate and distributed along the central axis of the dielectric substrate; the radiating patch is connected to the feed line; the bottom ground plane is attached to the lower surface of the dielectric substrate; wherein, the radiating patch is composed of annular radiating units, a pair of embedded symmetrical inverted L-shaped radiating units, and circular radiating units.

2. The tunable tri-band microstrip antenna with embedded stubs in a circular ring according to claim 1, characterized in that, The annular radiating unit has an inner diameter of 7.5 mm and an outer diameter of 9.5 mm. The short side of the symmetrical inverted L-shaped radiating unit is connected to the inner circle of the annular radiating unit, and the long side is parallel to the central axis of the dielectric substrate. The circular radiating unit is located in the middle of the symmetrical inverted L-shaped radiating unit, has a radius of 3 mm, and its center is on the central axis of the dielectric substrate, sharing the same center with the annular radiating unit.

3. A tunable tri-band microstrip antenna with embedded stubs in a circular ring according to claim 1, characterized in that, The dielectric substrate is a square with a side length of 40mm and a thickness of 0.8mm. The material is FR-4.

4. A tunable tri-band microstrip antenna with embedded stubs in a circular ring according to claim 1, characterized in that, The feed lines are located below the annular radiating unit on which the radiating patch is attached to the dielectric substrate, and include a first feed line and a second feed line. The first feed line and the second feed line are connected and conductive through two microstrip transmission lines of different widths. The first feed line is connected to the annular radiating unit and is symmetrical about the central axis of the radiating patch, with a width of 2 mm and a length of 7 mm. The second feed line has a width of 3.2 mm and a length of 6 mm and is connected to the first feed line, and is conductive through a lumped port and the bottom ground plane.

5. A tunable tri-band microstrip antenna with embedded stubs in a circular ring according to claim 1, characterized in that, The bottom ground plane is a rectangular structure with a length of 40mm and a width of 11mm.

6. A tunable tri-band microstrip antenna with embedded stubs in a circular ring according to claim 1, characterized in that, The radiating patch is fed by a coplanar microstrip line, and the feed line connects the upper and lower surfaces, achieving coplanar attachment with the patch antenna structure.

7. A tunable tri-band microstrip antenna with embedded stubs in a circular ring according to claim 1, characterized in that, The short side of the symmetrical inverted L-shaped radiating unit is 4 mm, and the long side is 8.2 mm; the width of the symmetrical inverted L-shaped radiating unit is 1 mm.

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