A low-profile ultra-wideband antenna

Abstract

The ultra-wideband antenna disclosed in this invention achieves a wider coverage area by utilizing a tapered feed copper post and metalized vias, addressing the relatively narrow bandwidth of microstrip antennas. By replacing the circular ground plane with a square ground plane, the ultra-wideband antenna disclosed in this invention achieves a smaller overall size, resolving the problem of a ground plane diameter exceeding one wavelength found in most microstrip antenna solutions. Its low profile also allows for better packaging in portable devices. Furthermore, the ultra-wideband antenna disclosed in this invention features a simple structure, is easy to manufacture, and offers low cost, making it suitable for mass production and application.

Description

Technical Field

[0001] The present disclosure relates to wireless communications, and more particularly, to a low-profile ultra-wideband antenna. Background Art

[0002] With the rapid growth of data and multimedia services, and the increasing demand for location information based on short-range, high-speed wireless communications, the demand is also growing. Positioning and monitoring within large buildings, densely populated urban areas, and areas such as bridges, dams, mountains, and foundation pits facilitates personnel safety monitoring, emergency rescue, material transportation management, distribution, and dispatch, as well as natural disaster prevention and monitoring. However, due to dense buildings, obstructions, and complex environments with limited monitoring space, GPS and Beidou signals often lack deep coverage, making spatial positioning difficult.

[0003] In the existing technology, the positioning of a specified target in a specific area is achieved through a self-built positioning system. UWB (UltraWideband) is a carrier-free communication technology that uses non-sinusoidal narrow pulses in the nanosecond to picosecond range to transmit data. UWB has many advantages, such as narrow pulse width, strong anti-interference performance, high transmission rate, extremely wide bandwidth, low power consumption, and low transmission power. It is widely used in indoor communications, high-speed wireless LAN, home networks, cordless phones, security detection, position determination, radar and other fields. A positioning system that uses UWB signals as positioning signals can make up for areas that are not covered by satellites in the sky, is easy to deploy, and can realize displacement monitoring in small spaces. The UWB antenna used to transmit and receive UWB positioning signals is a key factor affecting positioning performance.

[0004] Antennas used as terminals in UWB positioning systems must meet the following requirements: 1. Operating frequency band covering the UWB standard of 6 to 9 GHz; 2. Omnidirectional pattern to cover a sufficiently large airspace; 3. Small physical size and low profile; 4. Easy integration and simple processing. Currently, the mainstream solution for UWB antennas is the printed monopole antenna. While this approach partially meets the bandwidth and pattern performance requirements, its high profile restricts installation locations and is unsightly.

[0005] Therefore, researching an antenna with a simple structure, easy processing, small physical size, low profile, and conforming to the working characteristics of UWB has become an urgent problem that researchers in this field need to solve. Summary of the Invention

[0006] According to one aspect of the present invention, a low-profile ultra-wideband antenna is disclosed, comprising: a dielectric substrate (1) having an upper surface and a lower surface; a main radiating element (3) electroplated on the upper surface of the dielectric substrate (1); an antenna floor (4) electroplated on the lower surface of the dielectric substrate (1); wherein the main radiating element (3) is a circular copper foil patch, and the antenna floor (4) is a square copper foil floor; 8 metallized vias (2) are uniformly arranged on the circumference of the main radiating element (3) at 45° concentric angles, and the metallized vias (2) penetrate the dielectric substrate (1) and are connected to the antenna. The invention relates to a line floor (4) to realize the electrical connection between the main radiation unit (3) and the antenna floor (4); the ultra-wideband antenna also includes a feeding copper column (6), the feeding copper column (6) has an upper top surface and a lower bottom surface, the diameter of the upper top surface is larger than the diameter of the lower bottom surface, wherein the upper top surface is coupled to the center of the main radiation unit (3), the center of the antenna floor (4) has a circular through hole (5) with a diameter in a certain proportional relationship with the diameter of the lower bottom surface of the feeding copper column (6), and the lower bottom surface of the feeding copper column (6) is fed through the circular through hole (5) of the antenna floor (4) and the feeding interface.

[0007] The ultra-wideband antenna disclosed in this invention achieves a wider coverage area by utilizing a tapered feed copper post and metalized vias, addressing the relatively narrow bandwidth of microstrip antennas. By replacing the circular ground plane with a square ground plane, the ultra-wideband antenna disclosed in this invention achieves a smaller overall size, resolving the problem of a ground plane diameter exceeding one wavelength found in most microstrip antenna solutions. Its low profile also allows for better packaging in portable devices. Furthermore, the ultra-wideband antenna disclosed in this invention features a simple structure, is easy to manufacture, and offers low cost, making it suitable for mass production and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 A top view of a low-profile ultra-wideband antenna structure according to an embodiment of the present invention is provided;

[0009] Figure 2 A bottom view of a low-profile ultra-wideband antenna structure according to an embodiment of the present invention is provided;

[0010] Figure 3 A schematic cross-sectional view of a low-profile ultra-wideband antenna structure according to an embodiment of the present invention is provided;

[0011] Figure 4 Given as Figures 1 to 3 Return loss characteristic curves of the ultra-wideband antenna structure simulation and test of the embodiment shown.

[0012] The specific meanings of the symbols in the accompanying drawings are as follows:

[0013] 1——Dielectric substrate;

[0014] 2——Metalized vias;

[0015] 3——main radiation unit;

[0016] 4 – antenna floor;

[0017] 5——circular through hole;

[0018] 6——Feeding copper column. DETAILED DESCRIPTION

[0019] Specific embodiments of the present invention will be described in detail below. It should be noted that the embodiments described herein are for illustrative purposes only and are not intended to limit the present invention. In the following description, numerous specific details are set forth to provide a thorough understanding of the present invention. However, it will be apparent to one of ordinary skill in the art that these specific details are not necessarily required to practice the present invention. In other instances, well-known circuits, materials, or methods are not described in detail to avoid obscuring the present invention.

[0020] Throughout this specification, references to "one embodiment," "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in connection with that embodiment or example is included in at least one embodiment of the present invention. Therefore, the phrases "in one embodiment," "in an embodiment," "an example," or "an example" appearing in various places throughout this specification do not necessarily all refer to the same embodiment or example. Furthermore, particular features, structures, or characteristics may be combined in any suitable combinations and / or subcombinations in one or more embodiments or examples. Furthermore, those skilled in the art will appreciate that the figures provided herein are for illustrative purposes only and are not necessarily drawn to scale. It should be understood that when an "element" is referred to as being "connected to" or "coupled to" another element, it can be directly connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being "directly connected to" or "directly coupled to" another element, there are no intervening elements. Identical reference numerals indicate identical elements. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0021] In order to make the design principle and technical features of the present invention clearer, the embodiments are further described in detail below with reference to the accompanying drawings.

[0022] Figure 1 、 Figure 2 and Figure 3 The top view, bottom view and cross-sectional view of a low-profile ultra-wideband antenna structure according to an embodiment of the present invention are respectively given. Figures 1 to 3 , the ultra-wideband antenna structure of the present invention is described.

[0023] The ultra-wideband antenna of the present invention comprises a dielectric substrate (1) having an upper surface and a lower surface; a main radiating unit (3) electroplated on the upper surface of the dielectric substrate (1); and an antenna floor (4) electroplated on the lower surface of the dielectric substrate (1). The main radiating unit (3) is a circular copper foil patch with a radius of rp, and the antenna floor (4) is a square copper foil floor with a side length of ws. Eight metallized vias (2) are uniformly arranged at 45° concentric angles around the circumference of the main radiating unit (3). The metallized vias (2) penetrate the dielectric substrate (1) and are connected to the antenna floor (4) to achieve electrical connection between the main radiating unit (3) and the antenna floor (4).

[0024] In one embodiment, the metallized via (2) can be replaced by a metal short-circuit column.

[0025] The diameter of the metallized via (2) is vr, and the distance between the center of the metallized via (2) and the center of the main radiating unit (3) is ra. In one embodiment, the ratio of the distance ra from the center of the metallized via (2) to the center of the main radiating unit (3) to the radius rp of the main radiating unit (3) is 0.86 to 0.89.

[0026] The ultra-wideband antenna further comprises a feeding copper post (6), wherein the feeding copper post (6) has an upper top surface and a lower bottom surface, wherein the diameter fr of the upper top surface is greater than the diameter fd of the lower bottom surface, wherein the upper top surface is coupled to the center of the main radiation unit (3). The center of the antenna floor (4) comprises a circular through hole (5) whose diameter is in a certain proportional relationship with the diameter fd of the lower bottom surface of the feeding copper post (6), and the lower bottom surface of the feeding copper post (6) is fed via the circular through hole (5) of the antenna floor (4) and the feeding interface.

[0027] In one embodiment, the diameter fr of the upper surface of the feeding copper column (6) is twice the diameter fd of the lower surface.

[0028] In another embodiment, the ratio of the diameter fr of the upper surface of the feeding copper column (6) to the distance ra from the center of the metallized via (2) to the center of the main radiation unit (3) is 0.2 to 0.26.

[0029] In one embodiment, the feed interface is an SMA (SubMiniature version A) interface, and when the filling medium between the inner conductor and the outer conductor of the interface is air, the diameter of the circular through hole (5) on the antenna floor (4) is fr×2.33.

[0030] In one embodiment, the dielectric substrate (1) is an AD255C dielectric plate with a thickness of H, a dielectric constant of 2.55, and a loss tangent of 0.0012-0.0014 (10 GHz).

[0031] In one embodiment, the feeding copper column (6) is connected by a cylinder and a frustum to form a gradient structure, wherein the height of the frustum is ha.

[0032] Table 1 is a parameter table of an ultra-wideband antenna according to a preferred embodiment of the present invention.

[0033] Table 1 (Unit: mm)

[0034] rp ws H fr fd vr ha ra 12.9 37 4 2.4 1.2 0.8 2 11.4

[0035] Figure 4 Given as Figures 1 to 3 The return loss characteristic curves of the ultra-wideband antenna structure of the illustrated embodiment are shown in simulation and testing. It can be seen that during the simulation phase, the return loss performance of the ultra-wideband structure disclosed in the present invention is good within the 6-9 GHz frequency range supported by the ultra-wideband, and the test results are generally consistent with the simulation results. The ultra-wideband structure disclosed in the present invention can operate well within the frequency band supported by the ultra-wideband.

[0036] In one embodiment, the ultra-wideband antenna disclosed in the present invention can be used in an ultra-wideband positioning base station and an ultra-wideband positioning terminal to transmit and / or receive ultra-wideband positioning signals.

[0037] The present invention generates a TM02 mode through a circular patch microstrip antenna on the upper surface of a dielectric substrate, and adds 8 metallized vias around it to generate a TM01 mode. The feeding copper post can generate a monopole mode. By superimposing three resonant modes, it covers an operating bandwidth of 6 to 9 GHz, and generates omnidirectional directional pattern coverage within the entire operating frequency band. A circular patch with a diameter of 40 mm is not enough to excite the monopole radiation mode. A square floor with a maximum aperture of approximately 52 mm and a side length of 37 mm can simultaneously excite the three radiation modes of TM01, TM02 and monopole, reducing the size from 40 mm to 37 mm, and providing a wider bandwidth. The 8 metallized vias form a cavity with the antenna floor and the circular patch, similar to a coaxial line. The impedance matching of the antenna radiation patch is achieved by adjusting the radius of the feeding copper post. The feeding copper post adopts a gradient structure to achieve impedance matching with a 50-ohm SMA connector.

[0038] The ultra-wideband antenna disclosed in this invention achieves a wider coverage area by utilizing a tapered feed copper post and metalized vias, addressing the relatively narrow bandwidth of microstrip antennas. By replacing the circular ground plane with a square ground plane, the ultra-wideband antenna disclosed in this invention achieves a smaller overall size, resolving the problem of a ground plane diameter exceeding one wavelength found in most microstrip antenna solutions. Its low profile also allows for better packaging in portable devices. Furthermore, the ultra-wideband antenna disclosed in this invention features a simple structure, is easy to manufacture, and offers low cost, making it suitable for mass production and application.

[0039] As mentioned above, although the preferred embodiments of the present invention have been illustrated and described, many changes may be made without departing from the spirit and scope of the present invention. Thus, the scope of the present invention is not limited by the disclosure of the preferred embodiments. Rather, the present invention should be determined entirely by reference to the claims that follow.

Claims

1. A low-profile ultra-wideband antenna for covering an operating bandwidth of 6 to 9 GHz, comprising: A dielectric substrate (1) having an upper surface and a lower surface; A main radiation unit (3) is electroplated on the upper surface of the dielectric substrate (1); The antenna floor (4) is electroplated on the lower surface of the dielectric substrate (1); The main radiating unit (3) is a circular copper foil patch, and the antenna floor (4) is a square copper foil floor; eight metallized vias (2) are evenly arranged at 45° concentric angles on the circumference of the main radiating unit (3); the metallized vias (2) penetrate the dielectric substrate (1) and are connected to the antenna floor (4) to achieve electrical connection between the main radiating unit (3) and the antenna floor (4); The ultra-wideband antenna further comprises a feeding copper post (6), wherein the feeding copper post (6) has an upper top surface and a lower bottom surface, wherein the diameter of the upper top surface is larger than the diameter of the lower bottom surface, wherein the upper top surface is coupled to the center of the main radiation unit (3), and the center of the antenna floor (4) has a circular through hole (5) whose diameter is in a certain proportional relationship with the diameter of the lower bottom surface of the feeding copper post (6), and the lower bottom surface of the feeding copper post (6) is fed via the circular through hole (5) of the antenna floor (4) and the feeding interface; The ratio of the distance from the center of the metallized via (2) to the center of the main radiation unit (3) to the radius of the main radiation unit (3) is 0.86 to 0.89; The feeding copper column (6) is connected by a cylinder and a frustum to form a gradient structure, and the height of the frustum is 2 mm; The radius of the main radiating unit (3) is 12.9 mm, the side length of the antenna floor (4) is 37 mm, the diameter of the upper top surface of the feeding copper column (6) is 2.4 mm, the diameter of the lower bottom surface of the feeding copper column (6) is 1.2 mm, the diameter of the metallized via (2) is 0.8 mm, and the distance between the center of the metallized via (2) and the center of the main radiating unit (3) is 11.4 mm.

2. The ultra-wideband antenna according to claim 1, wherein The metallized via (2) is replaced by a metal short-circuit column.

3. The ultra-wideband antenna according to claim 1, wherein: The feeding interface is an SMA interface, and the diameter of the circular through hole (5) on the antenna floor (4) is 2.2 times the diameter of the bottom surface of the feeding copper column (6).

4. The ultra-wideband antenna according to claim 1, wherein The dielectric substrate (1) is an AD255C dielectric plate with a thickness of 4 mm and a dielectric constant of 2.

55.

5. The ultra-wideband antenna according to any one of claims 1 to 4, wherein: The ultra-wideband antenna is used in an ultra-wideband positioning base station and an ultra-wideband positioning terminal to transmit and / or receive ultra-wideband positioning signals.

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