Broadband multi-branch dual-frequency antenna and radio frequency equipment

Abstract

The utility model relates to the technical field of antenna structures, and provides a broadband multi-branch dual-frequency antenna and radio frequency equipment, and the broadband multi-branch dual-frequency antenna comprises a dielectric substrate; the antenna main body unit is arranged on the dielectric substrate, and the antenna main body unit comprises a low-frequency branch knot and a high-frequency branch knot which are connected with each other; the grounding unit is connected with the antenna main body unit, and a gap structure is arranged between the grounding unit and the antenna main body unit; the first parasitic branch knot is connected with the grounding unit and is adjacent to the antenna main body unit, the bandwidth of the broadband multi-branch-knot dual-frequency antenna is expanded, and the matching characteristic of the antenna is improved.

Description

Technical Field

[0001] The present application relates to the technical field of antenna structures, and more specifically, to a broadband multi-branch dual-frequency antenna and a radio frequency device. Background Art

[0002] With the rapid development of mobile terminals, LTE technology has been widely used in the fourth-generation mobile communication system. Therefore, mobile terminals are required to achieve high communication quality in the low-frequency bandwidth of 700-960MHz and the high-frequency bandwidth of 1700-2700MHz. This not only increases the bandwidth and radiation performance of the antenna, but also takes into account the performance requirements of low profile, light weight, and multiple frequency bands expected by consumers in the design. These requirements bring huge challenges to LTE antenna design.

[0003] The main problem with the printed LTE antenna in the prior art is that due to size limitations, the antenna has a narrow bandwidth in the low-frequency 800MHz-960MHz band, poor matching and low radiation efficiency, which makes it difficult to meet the use requirements. The printed LTE antenna in the prior art has a wide bandwidth, so it is difficult to meet the matching performance requirements of the entire working frequency band. Utility Model Content

[0004] The main purpose of the utility model is to provide a broadband multi-branch dual-frequency antenna, aiming to solve the technical problem of poor antenna matching characteristics of LTE antennas in the prior art.

[0005] To achieve the above object, the technical solution adopted by the utility model is: a broadband multi-branch dual-frequency antenna, which includes:

[0006] dielectric substrate;

[0007] An antenna main body unit, the antenna main body unit is arranged on the dielectric substrate, and the antenna main body unit includes a low-frequency branch and a high-frequency branch connected to each other;

[0008] A grounding unit, wherein the grounding unit is connected to the antenna main unit, and a gap structure is provided between the grounding unit and the antenna main unit;

[0009] A first parasitic stub is connected to the ground unit and is adjacent to the antenna main unit.

[0010] Furthermore, the first parasitic branch is located in the gap structure.

[0011] Further, the first parasitic branch includes a first branch section and a second branch section, one end of the first branch section is connected to the grounding unit, and the other end of the first branch section is connected to the second branch section.

[0012] Furthermore, the first section of branches and the second section of branches are connected to form an L-shaped structure.

[0013] Furthermore, the number of the first parasitic branches is at least 2.

[0014] Furthermore, the broadband multi-branch dual-band antenna also includes a second parasitic branch arranged on the dielectric substrate, the second parasitic branch is farther away from the antenna main unit than the first parasitic branch, and the second parasitic branch is not connected to the ground unit.

[0015] Further, the antenna main body unit includes a main structure, the low-frequency branch includes a first low-frequency branch and a second low-frequency branch connected to the main structure, the high-frequency branch includes a first high-frequency branch and a second high-frequency branch connected to the main structure, the first low-frequency branch, the second low-frequency branch and the first high-frequency branch are arranged in sequence in a direction away from the grounding unit, the second high-frequency branch is connected to a side of the main structure away from the first low-frequency branch, the second low-frequency branch and the first high-frequency branch, and the second high-frequency branch extends toward the grounding unit and is spaced from the grounding unit.

[0016] Furthermore, a U-shaped groove structure is formed between the first low-frequency branch and the second low-frequency branch, and a U-shaped groove structure is formed between the second low-frequency branch and the first high-frequency branch.

[0017] Furthermore, the antenna main body unit is connected to the ground unit via a feeding structure, and the feeding structure gradually narrows toward the ground unit.

[0018] In addition, the utility model also provides a radio frequency device, wherein the radio frequency device includes the above-mentioned broadband multi-branch dual-frequency antenna.

[0019] The broadband multi-branch dual-frequency antenna provided by the present application has the following beneficial effects:

[0020] In the broadband multi-branch dual-frequency antenna provided by the embodiment of the utility model, the antenna main body unit includes low-frequency branches and high-frequency branches connected to each other, and a first parasitic branch connected to the ground unit and adjacent to the antenna main body unit is provided, which can form a new resonance point by coupling, which is equivalent to the first parasitic branch itself becoming an antenna working at a certain frequency, thereby expanding the bandwidth of the antenna, for example, broadening the bandwidth of the antenna in the 1710MHz-2690MHz frequency band, and improving the antenna matching characteristics. In addition, the antenna greatly improves the radiation efficiency by separately designing the high-frequency radiation structure (high-frequency branches) and the low-frequency radiation structure (low-frequency branches), and obtains better low-frequency performance and high-frequency performance.

[0021] In a further solution, multiple U-shaped grooves are opened in the antenna main unit to increase the current path and effectively widen the antenna bandwidth. The feed structure gradually narrows toward the ground unit, which can effectively improve the matching performance. This antenna adopts a multi-branch structure, and the length of each branch is independently adjustable. By adjusting the length of each branch and optimizing the mutual coupling effect between them, the required operating frequency band and better standing wave characteristics can be obtained. By designing a unique suspended parasitic branch (second parasitic branch), the high-frequency matching performance is improved without affecting the low-frequency operation, the high-frequency bandwidth is significantly improved, and the impedance matching effect is optimized. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 A schematic plan view of a broadband multi-branch dual-band antenna provided by an embodiment of the present application;

[0024] Figure 2 A curve diagram of the reflection coefficient of a simulation test of a broadband multi-branch dual-frequency antenna provided in one embodiment of the present application;

[0025] Figure 3 An efficiency curve diagram of a broadband multi-branch dual-band antenna provided in an embodiment of the present application tested in the 800MHz-960MHz frequency band;

[0026] Figure 4 This is a test efficiency curve of a broadband multi-branch dual-band antenna provided by an embodiment of the present application in the 1710MHz-2690MHz frequency band;

[0027] Figure 5 The antenna radiation 3D pattern corresponding to the 850MHz frequency band of the broadband multi-branch dual-frequency antenna provided by one embodiment of the present application;

[0028] Figure 6 An embodiment of the present application provides a broadband multi-branch dual-band antenna with a 3D radiation pattern corresponding to a 2300 MHz frequency band.

[0029] The reference numerals in the above drawings are as follows:

[0030] 1- dielectric substrate; 2- grounding unit;

[0031] 3-gap structure; 4-second parasitic branch;

[0032] 100-antenna main unit; 101-main structure;

[0033] 102-first low-frequency branch; 103-second low-frequency branch;

[0034] 104-first high frequency branch; 105-second high frequency branch;

[0035] 106-feeding structure; 200-first parasitic branch;

[0036] 201-the first section; 202-the second section. DETAILED DESCRIPTION

[0037] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0038] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0039] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0040] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0041] In order to illustrate the technical solution described in this application, a detailed description is given below in conjunction with specific drawings and embodiments.

[0042] See also Figure 1 The present utility model provides a broadband multi-branch dual-frequency antenna, which includes:

[0043] The dielectric substrate 1 may be a substrate with a relative dielectric constant of 4.4, which is a commonly used board in PCB design, but is not limited to this specific board;

[0044] The antenna main body unit 100 is arranged on the dielectric substrate 1. The antenna main body unit 100 includes low-frequency branches and high-frequency branches connected to each other. As the name implies, the high-frequency branches enable the antenna to work in a high-frequency band (for example, but not limited to the 1710MHz to 2690MHz frequency band), and the low-frequency branches enable the antenna to work in a low-frequency band (for example, but not limited to the 800MHz to 960MHz frequency band). The utility model is described in detail with an LTE antenna working in the 800MHz to 960MHz frequency band and the 1710MHz to 2690MHz frequency band;

[0045] A grounding unit 2, the grounding unit 2 is connected to the antenna main unit 100, and a gap structure 3 is provided between the grounding unit 2 and the antenna main unit 100, and the grounding unit 2 may specifically refer to a PCB floor;

[0046] The first parasitic stub 200 is connected to the ground unit 2 and is adjacent to the antenna main unit 100 .

[0047] In the broadband multi-branch dual-band antenna provided by the embodiment of the utility model, the antenna main body unit 100 includes low-frequency branches and high-frequency branches connected to each other, and a first parasitic branch 200 connected to the ground unit 2 and adjacent to the antenna main body unit 100 is provided. A new resonance point can be formed by coupling, which is equivalent to the first parasitic branch 200 itself becoming an antenna working at a certain frequency, thereby expanding the bandwidth of the antenna, for example, broadening the bandwidth of the antenna in the 1710MHz-2690MHz frequency band, and improving the antenna matching characteristics.

[0048] See also Figure 1 According to one embodiment of the utility model, the first parasitic branch 200 is located in the slot structure 3, which greatly utilizes the space on the dielectric substrate 1, is conducive to the compact and reasonable layout of the antenna structure, and can improve the space utilization rate of the antenna layout. Of course, as other embodiments, the first parasitic branch 200 is not limited to being located in the slot structure 3, but can be as close to the antenna main unit 100 as possible.

[0049] According to a specific embodiment of the utility model, the first parasitic branch 200 includes a first branch section 201 and a second branch section 202. One end of the first branch section 201 is connected to the grounding unit 2, and the other end of the first branch section 201 is connected to the second branch section 202. Of course, there can be an angle between the first branch section 201 and the second branch section 202, which is convenient for layout in a small space.

[0050] See also Figure 1 According to one embodiment of the utility model, the length of the first branch section 201 is smaller than the length of the second branch section 202. At this time, the second branch section 202 can be called a long arm, and the first branch section 201 can be called a short arm. Preferably, the first branch section 201 and the second branch section 202 are connected to form an L-shaped structure.

[0051] In the specific design, the first parasitic branch 200 can be introduced at the position where the current of the grounding unit 2 is strong, and the position is determined by simulating and observing the field distribution, and the best arrangement position of the first parasitic branch 200 is optimized. The size of the first parasitic branch 200 is determined by its length. The longer the length, the resonance point shifts to the low frequency, and the shorter the length, the higher the frequency.

[0052] According to one embodiment of the utility model, the shape of the first parasitic branch 200 can be L-shaped, and the second branch 202 (long arm) can be set to a spiral, gradient or other structure. Theoretically, as long as the current path is long enough (expressed as the length of the L-shaped structure), any shape of the first parasitic branch 200 is feasible. The L-shaped structure composed of two rectangles has the advantages of simple structure and convenient setting. In actual design, theoretically, designing the second branch 202 (long arm) as a gradient structure can improve the bandwidth, but the effect is not obvious in this application, so the simplest structure (L-shaped structure) is selected. The L-shaped structure also has the advantages of low height and very high debugging flexibility. In actual debugging, if the length is not enough, the copper foil at the end of the L-shaped structure can be directly supplemented to adjust the resonant frequency. Other complex structures are difficult to debug. In this application, the low height of the L-shaped structure can facilitate the first parasitic branch 200 to be set in the gap structure 3 between the ground unit 2 and the antenna main unit 100.

[0053] According to an embodiment of the utility model, the number of the first parasitic branches 200 can be 2, and the number of the first parasitic branches 200 is determined according to the demand. If there are no two first parasitic branches 200, then in the frequency band of 1900MHz to 2100MHz, the standing wave is unqualified. In addition, the bandwidth of a single parasitic branch is very narrow, so the present application preferably introduces two first parasitic branches 200 with similar structural sizes to generate a resonance point in this frequency band, so that the matching performance is qualified. In actual design, according to the bandwidth of the antenna main unit 100, the number can be flexibly selected, and more first parasitic branches 200 can be designed.

[0054] See also Figure 1 According to a specific embodiment of the present invention, the first branch section 201 is perpendicular to the grounding unit 2, and the second branch section 202 is parallel to the grounding unit 2. Of course, the specific direction arrangement of the first branch section 201 and the second branch section 202 in the first parasitic branch section 200 is not limited to this embodiment.

[0055] According to an embodiment of the present invention, the number of the first parasitic branches 200 is at least 2, but as mentioned above, the number of the first parasitic branches 200 is not limited to 2, and more can be designed according to actual conditions.

[0056] See also Figure 1 According to an embodiment of the utility model, the broadband multi-branch dual-frequency antenna also includes a second parasitic branch 4 arranged on the dielectric substrate 1. The second parasitic branch 4 is farther away from the antenna main unit 100 than the first parasitic branch 200, and the second parasitic branch 4 is not connected to the grounding unit 2 (can be called a suspended parasitic branch), which is equivalent to a low-pass capacitive filter. It itself only serves as a structure to improve high-frequency impedance matching, which can significantly improve the matching of the antenna high-frequency band without affecting the low-frequency performance.

[0057] In this embodiment, the number, shape, etc. of the second parasitic branch nodes 4 can be designed with reference to the first parasitic branch nodes 200. For example, an L-shaped structure can be adopted, which has the advantages of simple configuration and convenient length adjustment. By adjusting its position and size, the bandwidth of the antenna in the high frequency 1710MHz-2690MHz frequency band can be widened, and the antenna matching characteristics can be improved.

[0058] See also Figure 1 According to a specific embodiment of the utility model, the antenna main unit 100 includes a main structure 101, the low-frequency branch includes a first low-frequency branch 102 and a second low-frequency branch 103 connected to the main structure 101, and the high-frequency branch includes a first high-frequency branch 104 and a second high-frequency branch 105 connected to the main structure 101. The first low-frequency branch 102, the second low-frequency branch 103 and the first high-frequency branch 104 are arranged in sequence in a direction away from the grounding unit 2. The second high-frequency branch 105 is connected to a side of the main structure 101 away from the first low-frequency branch 102, the second low-frequency branch 103 and the first high-frequency branch 104. The second high-frequency branch 105 extends toward the grounding unit 2 and is spaced from the grounding unit 2. In practice, the number of branches can be increased according to the antenna design requirements to further improve the performance of the antenna. This antenna greatly improves the radiation efficiency by separately designing the high-frequency radiation structure and the low-frequency radiation structure, and obtains better low-frequency performance and high-frequency performance, especially by independently adjusting the performance of the two working frequency bands of the antenna, and obtains good performance in both working frequency bands.

[0059] In this embodiment, since the first low-frequency branch 102, the second low-frequency branch 103 and the first high-frequency branch 104 are arranged in sequence in the direction away from the grounding unit 2, preferably, a U-shaped groove structure (coupling groove) is formed between the first low-frequency branch 102 and the second low-frequency branch 103, and a U-shaped groove structure (coupling groove) is formed between the second low-frequency branch 103 and the first high-frequency branch 104, which can increase the current path and effectively widen the antenna bandwidth. Specifically, the U-shaped groove between the first low-frequency branch 102 and the second low-frequency branch 103 can increase the current path, increase the low-frequency bandwidth and improve the low-frequency matching, and the U-shaped groove structure between the second low-frequency branch 103 and the first high-frequency branch 104 can generate a high-frequency resonance peak. This antenna adopts a multi-branch structure, and the length of each branch is independently adjustable. By adjusting the length of each branch and optimizing the mutual coupling effect between them, the required operating frequency band and better standing wave characteristics can be obtained. The antenna operating frequency is designed to be 800MHz~960MHz and 1710MHz~2690MHz. The multi-branch structure and the mutual coupling between them can also be used to broaden the antenna bandwidth and design other broadband antennas.

[0060] Of course, the first low-frequency branch 102 and the second low-frequency branch 103 are not limited to forming a U-shaped groove structure. Since there is a gap between the first low-frequency branch 102 and the second low-frequency branch 103, groove structures of other shapes can be formed therebetween. Similarly, the second low-frequency branch 103 and the first high-frequency branch 104 are not limited to forming a U-shaped groove structure.

[0061] See also Figure 1 In addition, the antenna main unit 100 is connected to the ground unit 2 through the feeding structure 106. The feeding structure 106 gradually narrows toward the ground unit 2, which can make the current path smoother, thereby effectively improving the matching performance. Specifically, a trapezoidal structure can be adopted.

[0062] See also Figures 2 to 4 It can be seen that the broadband multi-branch dual-band antenna provided by the embodiment of the utility model has a reflection coefficient of less than -9.6dB in the 800MHz-960MHz range, and an average radiation efficiency of greater than 68%; in the 1710MHz-2690MHz frequency band, the reflection coefficient is less than -10dB, and the average radiation efficiency is greater than 76%.

[0063] The radiation 3D pattern of the broadband multi-branch dual-frequency antenna provided by the embodiment of the utility model is shown in Figure 5 and Figure 6 , since the main parameters of LTE antennas are reflection coefficient and radiation efficiency, the requirements for the directional pattern are not clear at present. Therefore, the directional pattern characteristics of the broadband multi-branch dual-frequency antenna provided by the embodiment of the utility model meet the design requirements.

[0064] In summary, the broadband multi-branch dual-frequency antenna provided by the embodiment of the utility model optimizes the characteristics of the relevant branches themselves, the coupling effect between each branch and the effect with the PCB floor, and finally obtains excellent matching characteristics, high radiation efficiency and ideal radiation characteristics in the 800MHz-960MHz frequency band and the 1710MHz-2690MHz frequency band. The low-frequency working characteristics and high-frequency working characteristics of the antenna can be debugged separately. In practical applications, the antenna debugging efficiency is high and the antenna matching debugging difficulty is relatively small; the broadband multi-branch dual-frequency antenna The invention relates to an LTE antenna which can be printed and has the advantage of low cost. In the design of LTE antenna, low radiation efficiency is a difficult problem to solve. The broadband multi-branch dual-band antenna provided by the utility model has a radiation efficiency higher than 68% in the low-frequency 800MHz-960MHz band and the high-frequency 1710MHz-2690MHz band, and has excellent radiation performance and great application potential. The broadband multi-branch dual-band antenna has excellent performance, a reflection coefficient of less than -9.6dB in the entire working frequency band, and is a printed antenna with extremely low cost and extremely high practical value.

[0065] In addition, the utility model also provides a radio frequency device, wherein the radio frequency device includes the above-mentioned broadband multi-branch dual-frequency antenna. The radio frequency device obviously has all the advantages of the above-mentioned broadband multi-branch dual-frequency antenna, which will not be repeated here.

[0066] The above description is only an optional embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A broadband multi-branch dual-frequency antenna, characterized in that: include: dielectric substrate; An antenna main body unit, the antenna main body unit is arranged on the dielectric substrate, and the antenna main body unit includes a low-frequency branch and a high-frequency branch connected to each other; A grounding unit, wherein the grounding unit is connected to the antenna main unit, and a gap structure is provided between the grounding unit and the antenna main unit; A first parasitic stub is connected to the ground unit and is adjacent to the antenna main unit.

2. The broadband multi-branch dual-frequency antenna according to claim 1, characterized in that: The first parasitic branch is located in the gap structure.

3. The broadband multi-branch dual-frequency antenna according to claim 1, characterized in that: The first parasitic branch includes a first branch section and a second branch section, one end of the first branch section is connected to the grounding unit, and the other end of the first branch section is connected to the second branch section.

4. The broadband multi-branch dual-frequency antenna according to claim 3, characterized in that: The first section of branches and the second section of branches are connected to form an L-shaped structure.

5. The broadband multi-branch dual-frequency antenna according to any one of claims 1 to 4, characterized in that: The number of the first parasitic branches is at least 2.

6. The broadband multi-branch dual-frequency antenna according to any one of claims 1 to 4, characterized in that: The broadband multi-branch dual-frequency antenna further includes a second parasitic branch disposed on the dielectric substrate. The second parasitic branch is farther away from the antenna main unit than the first parasitic branch, and the second parasitic branch is not connected to the ground unit.

7. The broadband multi-branch dual-frequency antenna according to any one of claims 1 to 4, characterized in that: The antenna main body unit includes a main structure, the low-frequency branch includes a first low-frequency branch and a second low-frequency branch connected to the main structure, the high-frequency branch includes a first high-frequency branch and a second high-frequency branch connected to the main structure, the first low-frequency branch, the second low-frequency branch and the first high-frequency branch are arranged in sequence in a direction away from the grounding unit, the second high-frequency branch is connected to a side of the main structure away from the first low-frequency branch, the second low-frequency branch and the first high-frequency branch, and the second high-frequency branch extends toward the grounding unit and is spaced from the grounding unit.

8. The broadband multi-branch dual-frequency antenna according to claim 7, characterized in that: A U-shaped groove structure is formed between the first low-frequency branch and the second low-frequency branch, and a U-shaped groove structure is formed between the second low-frequency branch and the first high-frequency branch.

9. The broadband multi-branch dual-frequency antenna according to any one of claims 1 to 4, characterized in that: The antenna main body unit is connected to the ground unit via a feeding structure, and the feeding structure gradually narrows toward the ground unit.

10. A radio frequency device, characterized in that: The radio frequency device comprises the broadband multi-branch dual-frequency antenna as described in any one of claims 1 to 9.

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