Low-profile broadband antenna

Abstract

The invention discloses a low-profile broadband antenna, and relates to the field of radio antennas. The low-profile broadband antenna comprises an antenna body, the antenna body comprises a radiation patch unit, a dielectric substrate, a metal floor and a differential feed port, the radiation patch unit and the metal floor are oppositely arranged on the first surface and the second surface of the dielectric substrate, and the differential feed port is connected with the radiation patch unit and the metal floor; wherein the radiation patch unit comprises a rectangular patch etched with an open-circuit narrow groove and an open-circuit wide groove, and a metal through hole arranged on the rectangular patch, the open-circuit narrow groove is used for exciting a reversed-phase TM20 mode and a reversed-phase TM22 mode, and the open-circuit wide groove is used for removing radiation zero points of the TM12 mode and the reversed-phase TM22 mode. Compared with the prior art, the antenna disclosed by the invention is simple in structure, low in profile and high in bandwidth.

Description

Technical Field

[0001] The present invention relates to the technical field of radio antennas, and more specifically, to a low-profile broadband antenna. Background Art

[0002] The broadband technology of antennas is of great significance in modern communication systems. However, traditional broadband antennas have complex structures and higher profiles, which limits the application of antennas.

[0003] The multi-mode resonance technology is a new method to increase the bandwidth. By exciting two or more modes and making the resonance frequencies of the modes close to each other, the antenna bandwidth is increased. However, the bandwidth increased by exciting two resonance modes is limited. Exciting more modes can further increase the bandwidth but may cause radiation distortion or even radiation nulls, and the radiation pattern of the antenna is inconsistent throughout the frequency band, resulting in a mismatch between the radiation bandwidth and the impedance bandwidth. Summary of the Invention

[0004] The present invention provides a low-profile broadband antenna to overcome the defect of the performance bottleneck existing in the broadband antennas described in the above prior art.

[0005] To solve the above technical problems, the technical solution of the present invention is as follows:

[0006] In a first aspect, it includes an antenna main body, and the antenna main body includes a radiation patch unit, a dielectric substrate, a metal floor, and a differential feeding port. The radiation patch unit and the metal floor are oppositely arranged on the first surface and the second surface of the dielectric substrate, and the differential feeding port is respectively connected to the radiation patch unit and the metal floor;

[0007] Among them, the radiation patch unit includes a rectangular patch etched with an open-circuit narrow slot and an open-circuit wide slot, and a metal through-hole arranged on the rectangular patch;

[0008] The open-circuit narrow slot is used to excite the anti-phase TM 20 mode and the anti-phase TM 22 mode, and the open-circuit wide slot is used to remove the radiation nulls of the TM 12 mode and the anti-phase TM 22 mode.

[0009] In a second aspect, a broadband antenna array includes at least two low-profile broadband antennas described in the first aspect.

[0010] In a third aspect, a communication terminal includes the low-profile broadband antenna described in the first aspect or the broadband antenna array described in the second aspect.

[0011] Compared with the prior art, the beneficial effect of the technical solution of the present invention is:

[0012] The present invention discloses a low-profile broadband antenna, which excites the anti-phase TM mode through an open narrow slot, where the anti-phase TM 20 mode has an improved radiation reverse pattern and generates lateral radiation; the lateral zero radiation of the anti-phase TM 22 mode is transformed into lateral radiation through an open wide slot. Based on the introduction of the open narrow slot and the open wide slot, the bandwidth of the anti-phase TM 22 mode is effectively increased; in addition, the introduction of metal vias can make the resonance frequencies of the anti-phase TM 20 mode and the anti-phase TM 22 mode approach each other, while improving the impedance matching of the antenna and realizing broadband characteristics. Compared with the prior art, the low-profile broadband antenna disclosed by the present invention has a reasonable design, a simple structure, a low profile, excellent bandwidth and radiation performance, and can be applied to communication systems with high requirements for antenna performance. Description of the Drawings

[0013] Figure 1 It is a top view structural schematic diagram of a low-profile broadband antenna in Embodiment 1 of the present application.

[0014] Figure 2 It is a structural cross-sectional schematic diagram of a low-profile broadband antenna in Embodiment 1 of the present application.

[0015] Figure 3 It is a comparison diagram of lateral simulation gains of the antenna before and after opening the wide slot in Embodiment 1 of the present application.

[0016] Figure 4 It is a simulation result diagram of the reflection coefficient of the anti-phase TM 22 mode during the antenna optimization process in Embodiment 1 of the present application.

[0017] Figure 5 It is a simulation result diagram of the reflection coefficient of the antenna before and after loading metal vias in Embodiment 1 of the present application.

[0018] Figure 6 It is a simulation and test result diagram of the radiation reflection coefficient of the low-profile broadband antenna in Embodiment 1 of the present application.

[0019] Figure 7 It is a simulation and test result diagram of the radiation gain of the low-profile broadband antenna in Embodiment 1 of the present application.

[0020] Figure 8 It is a simulation and test radiation pattern of the low-profile broadband antenna operating at 6.5 GHz in Embodiment 1 of the present application.

[0021] Figure 9 It is a simulation and test radiation pattern of the low-profile broadband antenna operating at 7.5 GHz in Embodiment 1 of the present application.

[0022] Figure 10 This is the simulated and tested radiation pattern of the low-profile broadband antenna in Embodiment 1 of this application when operating at 8.5 GHz.

[0023] Among them, the reference numerals are explained as follows:

[0024] 1 - Radiation patch element; 2 - Dielectric substrate; 3 - Metal floor; 4 - Differential feeding port; 5 - Rectangular patch; 6 - Open-circuit narrow slot; 7 - Open-circuit wide slot; 8 - Metal through-hole. Detailed implementation manners

[0025] In the description of the present application, the terms "first", "second", etc. in the specification, claims and the above drawings are used to distinguish similar objects, and do not necessarily describe a specific order or sequence. It should be understood that such terms can be interchanged under appropriate circumstances, which is only a way of distinguishing objects with the same attributes in the description of the embodiments of the present application. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion, so that a process, method, system, product or device including a series of units does not have to be limited to those units, but may include other units not clearly listed or inherent to these processes, methods, products or devices. The term "determine" broadly covers a variety of actions, which may include obtaining, calculating, computing, processing, deriving, researching, searching (e.g., searching in a table, database or other data structure), ascertaining, and similar actions, may also include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory) and similar actions, may also include generating, creating, establishing and similar actions, as well as parsing, selecting, choosing and similar actions, etc. The relevant definitions of other terms will be given in the following description.

[0026] It should be noted that when an element is considered to be "connected" to another element, it can be directly connected to the other element or connected to the other element through an intermediate element. In addition, in the following embodiments, "connection", if there is a transmission of electrical signals or data between the connected objects, should be understood as "electrical connection", "communication connection", etc.

[0027] The drawings are only for illustrative purposes and cannot be construed as a limitation of this patent;

[0028] To better illustrate this embodiment, some components in the drawings are omitted, enlarged or reduced, which do not represent the dimensions of the actual product;

[0029] For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0030] The technical solutions of the present invention will be further described below with reference to the drawings and embodiments.

[0031] Embodiment 1

[0032] This embodiment provides a low-profile broadband antenna. Refer to Figure 1 and Figure 2 , including an antenna body. The antenna body includes a layer of radiation patch units, a layer of dielectric substrate, a layer of metal floor, and differential feeding ports. The radiation patch units and the metal floor are oppositely arranged on the first surface and the second surface (such as the upper surface and the lower surface) of the dielectric substrate. The differential feeding ports are respectively connected to the radiation patch units and the metal floor;

[0033] Among them, the radiation patch unit includes a rectangular patch etched with an open-circuit narrow slot and an open-circuit wide slot, and metal vias arranged on the rectangular patch;

[0034] The open-circuit narrow slot (abbreviated as "narrow slot") is used to excite the anti-phase TM 20 mode and the anti-phase TM 22 mode. The open-circuit wide slot (abbreviated as "wide slot") is used to remove the radiation null points of the TM 12 mode and the anti-phase TM 22 mode.

[0035] It should be noted that since the open-circuit narrow slot cancels the anti-phase current generated between the differential feeding ports, the combination of the differential feeding method and the narrow slot can excite the anti-phase TM 20 mode and the anti-phase TM 22 mode. In addition, the setting of the open-circuit wide slot can make the magnetic currents on the radiation edges in the same direction, thereby removing the radiation null points of the anti-phase TM 22 mode. Therefore, by etching the open-circuit narrow slot and the open-circuit wide slot, the bandwidth of the anti-phase TM 22 mode can be significantly improved. Compared with the prior art, the low-profile broadband antenna in this embodiment suppresses the radiation null points within the working frequency band based on the excitation of two anti-phase TM modes, thereby improving the antenna bandwidth. At the same time, the size of the antenna structure is not increased, making the antenna structure simpler and more compact.

[0036] It should be emphasized that the introduction of the open-circuit narrow slot provides another similar resonance frequency for the anti-phase TM 22 mode, increasing the bandwidth of the mode. The introduction of the open-circuit wide slot makes the radiation edge of the antenna closer to the feeding port and is mutually coupled with the open-circuit narrow slot, radiating more energy, increasing the radiation loss, reducing the quality factor of the mode, and thus further increasing the bandwidth of the anti-phase TM 22 mode.

[0037] In some preferred embodiments, an even number of the open-circuit narrow slots are symmetrically distributed on the long side of the rectangular patch (such as Figure 1in the y-axis direction, an even number of the open wide slots are symmetrically distributed on the short side of the rectangular patch (such as Figure 1 in the x-axis direction).

[0038] In some specific implementation processes, during the manufacturing process of the low-profile broadband antenna, a pair of open narrow slots, a pair of open wide slots, and four metal vias are etched in sequence, effectively enhancing the impedance bandwidth of the antenna.

[0039] In some alternative embodiments, the length of the open narrow slot along the extension direction of the short side of the rectangular patch is much greater than its length along the extension direction of the long side of the rectangular patch.

[0040] It should be emphasized that the length of the open narrow slot along the y-axis is much larger than the length along the x-axis, which can reshape the direction of the reverse current near the differential feeding port, thereby exciting the anti-phase TM 20 mode and the anti-phase TM 22 mode. Due to the cancellation of the reverse current, the lateral radiation pattern of the anti-phase TM 20 mode has a higher gain and no side lobes.

[0041] In some alternative embodiments, by adjusting the length of the open wide slot along the extension direction of the short side of the rectangular patch, the radiation null points of the TM 12 mode and the anti-phase TM 22 mode are removed, so that the antenna obtains a consistent radiation pattern within the entire operating frequency band.

[0042] It should be noted that the length of the open wide slot along the y-axis direction and the length along the x-axis direction are not much different. The introduction of the open wide slot changes the magnetic current direction of the radiation edge of the anti-phase TM 22 mode from reverse to the same direction, thereby suppressing the zero radiation generated by the mode and obtaining a lateral radiation pattern consistent with the anti-phase TM 20 mode.

[0043] In addition, by adjusting the length of the open wide slot along the y-axis direction, the resonant frequency of the unwanted TM 12 mode within the operating frequency band is significantly increased, while the resonant frequencies of the anti-phase TM 20 mode and the anti-phase TM 22 mode remain basically unchanged, thereby removing the unwanted TM 12 mode. Based on the operation of only the anti-phase TM 20 and the anti-phase TM 22 two modes, the low-profile broadband antenna described in this embodiment has a consistent radiation pattern.

[0044] In some preferred embodiments, the central feeding pin of the differential feeding port is connected to the rectangular patch, and the outer conductor of the differential feeding port is connected to the metal floor.

[0045] In some preferred embodiments, referring to Figure 2 , each of the differential feeding ports has two ports, which are respectively used to input differential signals with the same amplitude and opposite phases, so as to make the electric fields around the feeding ports in antiphase.

[0046] It should be emphasized that since the open narrow slot cancels the antiphase current generated between the two differential feeding ports, the combination of the differential feeding method and the open narrow slot can excite the antiphase TM 20 mode and the antiphase TM 22 mode.

[0047] In some preferred embodiments, an even number of the metal vias are symmetrically distributed in the middle area of the rectangular patch enclosed by the open wide slot and the open narrow slot, and the impedance matching of the antenna and the resonant frequency of the operating mode are adjusted by adjusting the radius of the metal vias.

[0048] In some specific implementation processes, 2 metal vias (i.e., a total of 4) are symmetrically distributed at both ends of the middle area enclosed by the open wide slot and the open narrow slot.

[0049] It should be noted that by symmetrically loading metal vias in the middle of the rectangular patch, the resonant frequency of the antiphase TM 20 mode is increased and is close to the antiphase TM 22 mode, so that the two antiphase TM modes are combined with each other. At the same time, loading the metal vias significantly improves the impedance matching of the whole antenna. With the evolution of the antenna structure, the bandwidth is significantly increased, and the impedance bandwidth matches the radiation bandwidth.

[0050] In some preferred embodiments, the antenna body has a planar structure.

[0051] In this embodiment, the above-mentioned low-profile broadband antenna is also simulated and tested to verify its performance.

[0052] Figure 3 The comparison results of the side gain before and after etching the open wide slot on the rectangular patch are shown. It can be seen that when the open wide slot is not etched, radiation nulls of two modes will appear, which are respectively generated by the TM 12 mode and the antiphase TM 22 mode. When the open wide slot with a width of 8 mm is etched (i.e., SW 2 = 8 mm), since the magnetic current direction in the middle of the radiation edge is changed from reverse to the same direction, the antiphase TM 22Radiation nulls generated by the mode. When the width of the open wide slot is continuously increased to 12 mm (SW 2 = 12 mm), since the resonant frequency of the TM 12 mode increases significantly beyond the operating frequency band, the radiation nulls generated by the TM 12 mode are further removed. Therefore, the low-profile broadband antenna described in this embodiment can achieve the performance of having a consistent radiation pattern and stable gain within the operating frequency band.

[0053] It should be emphasized that this embodiment proposes a method of removing the radiation nulls generated by the mode by adjusting the magnetic current direction of the radiation edge, and the magnetic current distributions of different modes are different. In some implementation processes, an open wide slot is introduced in the middle of the short side of the rectangular patch to suppress the radiation nulls of the anti-phase TM 22 mode. It should be understood that for different operating modes, the size and position of the slot can be different, which can be determined by those skilled in the art according to the actual situation.

[0054] Figure 4 Shows the simulation result diagram of the reflection coefficient (S 22 ) of the anti-phase TM 11 operating mode of the antenna during the optimization process. It can be seen that with the structural evolution process of introducing a narrow slot, a wide slot, and loading metal vias, the bandwidth of the anti-phase TM 22 mode of the antenna is enhanced. The introduction of the open narrow slot provides another resonant point for the operating mode, the open wide slot further broadens the bandwidth of the resonant point, and finally metal vias are loaded to improve the impedance matching.

[0055] Figure 5 Shows the reflection coefficient results of the antenna before and after loading metal vias. It can be seen that the resonant frequency of the anti-phase TM 20 mode increases significantly to be close to the resonant frequency of the anti-phase TM 22 mode after loading metal vias, thus combining the two operating modes. Finally, the relative bandwidth of the antenna increases to 45.7%.

[0056] It should be noted that this embodiment relates to two parameters, the bandwidth and the quality factor, and by introducing a wide slot to reduce the quality factor, the bandwidth of the anti-phase TM 22 mode is increased. In fact, this method can also be used for other operating modes or antenna structures.

[0057] Figure 6 Shows the simulation and test results of the radiation reflection coefficient of the low-profile broadband antenna. It can be seen that the bandwidth with a reflection coefficient less than -10 dB can cover the frequency range of 5.9 GHz - 9.4 GHz, and its relative bandwidth is 45.7%.

[0058] Figure 7The simulation and test results of the radiation gain of the low-profile broadband antenna are shown. It can be seen that the gain of the antenna is basically stable, and the maximum gain during the test is 9.48 dBi.

[0059] Figures 8 - 10 The simulated and tested radiation patterns of the E-plane and H-plane of the low-profile broadband antenna operating at 6.5 GHz, 7.5 GHz, and 8.5 GHz are shown respectively. It can be seen that the low-profile broadband antenna has a consistent side radiation pattern, with low radiation side lobes and good radiation performance.

[0060] Embodiment 2

[0061] This embodiment provides a broadband antenna array, including at least two low-profile broadband antennas described in Embodiment 1.

[0062] This embodiment also provides a communication terminal, including the low-profile broadband antenna described in Embodiment 1 or the broadband antenna array described in this embodiment.

[0063] It can be understood that the optional items in the above Embodiment 1 are equally applicable to this embodiment, so they will not be described repeatedly here.

[0064] The same or similar reference numerals correspond to the same or similar components;

[0065] The terms describing the positional relationship in the drawings are only for illustrative purposes and should not be construed as a limitation to this application;

[0066] It should be noted that, without conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0067] In different specific implementations, the method or system described in this application can be implemented in software, hardware, or a combination of them. In addition, the order of the steps of the method can be changed, and various elements can be added, reordered, combined, omitted, modified, etc.

[0068] Obviously, the above embodiments of this application are merely examples for clearly explaining this application, rather than limitations on the implementation manners of this application, and are not used to limit this application. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. Each discrete structure / functional module or unit can be integrated together to form an independent part, or each module can exist alone, or two or more modules can be integrated to form an independent part. The structures and functions of the discrete components can be implemented as a combined structure or component. It is not necessary and impossible to enumerate all the implementation manners here. Any modification, equivalent replacement, and improvement made within the spirit and principle of this application shall be included in the protection scope of the claims of this application.

Claims

1. A low-profile broadband antenna, comprising an antenna body, characterized in that: The antenna body comprises a radiation patch unit, a dielectric substrate, a metal floor and a differential feeding port, wherein the radiation patch unit and the metal floor are arranged on the first surface and the second surface of the dielectric substrate opposite to each other, and the differential feeding port is connected to the radiation patch unit and the metal floor respectively; Wherein, the radiation patch unit comprises a rectangular patch etched with an open narrow groove and an open wide groove, and a metal through hole arranged on the rectangular patch; The open narrow slot is used to excite the anti-phase TM 20 Mode and InvertingTM 22 mode, the open wide slot is used to remove the TM 12 Mode and InvertingTM 22 The radiation zero point of the pattern.

2. A low-profile broadband antenna according to claim 1, characterized in that: An even number of the open narrow slots are symmetrically distributed on the long sides of the rectangular patch, and an even number of the open wide slots are symmetrically distributed on the short sides of the rectangular patch.

3. A low-profile broadband antenna according to claim 2, characterized in that: The length of the open narrow groove along the extending direction of the short side of the rectangular patch is much greater than the length of the open narrow groove along the extending direction of the long side of the rectangular patch.

4. A low-profile broadband antenna according to claim 2, characterized in that: The TM is removed by adjusting the length of the open wide groove along the extending direction of the short side of the rectangular patch. 12 Mode and InvertingTM 22 The radiation zero point of the mode is determined so that the antenna can obtain a consistent radiation pattern throughout the entire operating frequency band.

5. The low-profile broadband antenna according to claim 1, characterized in that: The central feeding pin of the differential feeding port is connected to the rectangular patch, and the outer conductor of the differential feeding port is connected to the metal floor.

6. The low-profile broadband antenna according to claim 1, characterized in that: Each of the differential feeding ports has two ports, which are respectively used to input differential signals with the same amplitude and opposite phases.

7. The low-profile broadband antenna according to claim 1, characterized in that: An even number of the metal through holes are symmetrically distributed in the middle area of ​​the rectangular patch surrounded by the open wide slot and the open narrow slot. The impedance matching of the antenna is improved and the resonant frequency of the working mode is adjusted by adjusting the radius of the metal through holes.

8. A low-profile broadband antenna according to any one of claims 1 to 7, characterized in that: The antenna body is in a planar structure.

9. A broadband antenna array, characterized in that: The invention comprises at least two low-profile broadband antennas according to any one of claims 1 to 8.

10. A communication terminal, characterized in that: It comprises the low-profile broadband antenna according to any one of claims 1 to 8 or the broadband antenna array according to claim 9.

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