Ultra-wideband low-profile transparent ceiling antenna

Abstract

The invention relates to the technical field of wireless communication, and provides an ultra-wideband low-profile transparent ceiling antenna which comprises an antenna part and a transparent plate, the antenna part is attached to the transparent plate, the antenna part comprises an oscillator and a floor, one end of the oscillator and the floor jointly form a coplanar waveguide feed structure through a first conduction band, and the other end of the oscillator and the floor form a second conduction band; the oscillator comprises a first semi-ellipse and a second semi-ellipse which are different in structural size, the first semi-ellipse is transversely placed in the polarization direction, the second semi-ellipse is longitudinally placed in the polarization direction, the short axis of the second semi-ellipse coincides with the long axis of the first semi-ellipse, and the length between the short axis of the second semi-ellipse and the long axis of the first semi-ellipse is equal. The oscillator has the characteristic of ultra-wide frequency and is matched with the coplanar waveguide feed structure of the semicircular floor and the first guide plate, ultra-wide working frequency band coverage is achieved, the voltage standing-wave ratio in the full frequency band is smaller than 1.5, and the strict requirement of the indoor distribution antenna in the field of mobile communication is met. The problem that the standing-wave ratio of a planar ultra-wideband antenna is too high is solved, and the stability and the high efficiency of signal transmission are guaranteed.

Description

Technical Field

[0001] This application belongs to the field of wireless communication technology, and specifically relates to an ultra-wideband low-profile transparent ceiling antenna. Background Technology

[0002] In the field of indoor distributed wireless communication, ceiling antennas, as core devices for transmitting and receiving wireless signals, have been widely used in various building scenarios. Traditional ceiling antennas mostly use a biconical metal vibrator, fed by a coaxial cable. The inner conductor of the coaxial cable is welded to the apex of one cone of the biconical vibrator, and the outer conductor is welded to the cone of the other cone. After the radio frequency signal is transmitted to the vibrator through the coaxial cable, the guided wave is converted into a radio wave and radiated into space.

[0003] With the rapid development of 5G communication and IoT technologies, indoor distribution systems face two core technical demands that traditional ceiling antennas can no longer meet: First, the need for upgraded frequency band coverage. The gradual large-scale application of the 3.5GHz band in 5G communication requires the operating frequency of a single ceiling antenna to be extended to 800-3700MHz, while traditional ceiling antennas only support 800-2700MHz. Insufficient bandwidth has become a key bottleneck restricting their adaptation to 5G and IoT scenarios. Second, the need for environmental integration and aesthetics. In places with high requirements for architectural aesthetics, such as large shopping malls, high-end hotels, and top-tier hospitals, traditional ceiling antennas, due to the structural limitations of their biconical elements, often have conical shells with high profiles. After installation, they protrude from the ceiling, damaging the overall aesthetics of the building and easily causing public concerns and complaints about electromagnetic radiation, severely limiting the flexibility of site selection.

[0004] To address the aforementioned issues, existing technologies have explored bandwidth expansion and antenna aesthetics, but both suffer from significant drawbacks. Regarding bandwidth expansion, current solutions often employ planar printed ultra-wideband monopole antennas, consisting of a monopole patch (rectangular, circular, elliptical, etc.) adhered to a dielectric substrate and a conductive ground plane (rectangular or trapezoidal), fed by a microstrip line or coplanar waveguide located at the center of the ground plane. While these antennas can achieve ultra-wideband operation, their voltage standing wave ratio (VSWR) typically only meets the requirement of ≤2.0, while the standard VSWR for indoor distributed antennas in mobile communications is no more than 1.5, making it difficult to meet practical application requirements for impedance matching. Regarding antenna aesthetics, existing technologies have developed solutions using transparent PET films as carriers, fabricating antenna elements and feed lines onto the carrier using metal mesh or nano-silver processes. These solutions offer high light transmittance and have been applied to aesthetic antenna applications such as automotive glass and spotlight antennas. However, this transparent process has not yet been extended to indoor distributed ceiling antennas, failing to address the issues of traditional ceiling antennas' unsightly appearance and poor environmental integration.

[0005] In summary, existing technologies either fail to meet the stringent VSWR requirements of indoor distributed antenna systems (DAS) or fail to integrate transparent antenna technology with ceiling-mounted antennas to achieve environmental integration. Consequently, they cannot simultaneously address the three core requirements: "frequency band extension to 800-3700MHz," "VSWR ≤ 1.5," and "low profile, high light transmittance, and environmental stealth." Therefore, there is an urgent need for a novel ceiling-mounted antenna that integrates ultra-wideband coverage, excellent impedance matching, and environmental integration capabilities to overcome existing technological bottlenecks and meet the development needs of indoor distributed systems in the 5G and IoT era. Summary of the Invention

[0006] To address the aforementioned issues, this application provides an ultra-wideband low-profile transparent ceiling-mounted antenna, comprising: an antenna section and a transparent plate. The antenna section is attached to the transparent plate. The antenna section includes an element and a ground plane. One end of the element and the ground plane together form a coplanar waveguide feeding structure via a first conductive strip. The element includes a first semi-ellipse and a second semi-ellipse with different structural dimensions. The first semi-ellipse is placed laterally along the polarization direction, and the second semi-ellipse is placed longitudinally along the polarization direction. The minor axis of the second semi-ellipse coincides with the major axis of the first semi-ellipse, and the lengths between the minor axis of the second semi-ellipse and the major axis of the first semi-ellipse are equal. Optionally, the length of the major axis of the first semi-ellipse is 1 / 4 of the wavelength corresponding to the lowest frequency point of 800MHz in the operating frequency band.

[0007] Optionally, the axial ratio of the first semiellipse is 3.0-5.0.

[0008] Optionally, the floor can be a semi-circular structure.

[0009] Optionally, a first groove is provided in the middle of the floor, and a first guide strip with metal mesh is provided in the first groove, the first guide strip being connected to a second semi-ellipse.

[0010] Optionally, the outlet position of the first groove is set to a flared shape.

[0011] Optionally, the feed point in the waveguide feed structure is located at the center of the transparent plate.

[0012] Optionally, a coupling plate is also included, which is coaxially mounted on the floor.

[0013] Optionally, the coupling plate includes a first coupling plate, a second coupling plate, and a second guide strip. The first coupling plate is disposed on the second coupling plate and the two are connected by a metallized via. A second groove is provided at the center of the first coupling plate, and a fixing groove is opened on the second coupling plate. The center of the fixing groove has a third groove. The second guide strip is disposed in the fixing groove. The second groove and the third groove are positioned correspondingly to form a guide strip groove. One end of the second guide strip is located in the guide strip groove. The second coupling plate is located on the floor, and the positions of the first guide strip and the second guide strip coincide.

[0014] Optionally, a pad is provided on the second guide strip, the pad is adjacent to the guide strip groove, and the pad is fixedly connected to the feed line.

[0015] Compared with the prior art, this application has the following advantages: The vibrator structure, which combines a first semi-ellipse and a second semi-ellipse according to a predetermined shape and size, possesses ultra-wideband characteristics. Combined with a coplanar waveguide feeding structure consisting of a semi-circular ground plane and a first guide plate, it achieves an ultra-wide operating frequency band coverage of 800-3700MHz, with a voltage standing wave ratio (VSWR) of less than 1.5 across the entire band, meeting the stringent requirements of indoor distributed antennas in the mobile communication field. Furthermore, the advantage of this combination method lies in its ability to flexibly optimize the dimensional parameters of the first semi-ellipse, thereby specifically improving frequency bands with poor VSWR curves. This solves the problem of traditional planar ultra-wideband antennas having a high VSWR (only reaching ≤2.0), ensuring the stability and efficiency of signal transmission.

[0016] Other features and advantages of this application will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the application. The objectives and other advantages of this application may be realized and obtained by means of the structures pointed out in the description, claims and drawings. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application 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 some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This paper shows an overall schematic diagram of an ultra-wideband low-profile transparent ceiling-mounted antenna according to an embodiment of this application. Figure 2 A schematic diagram of the vibrator structure of an ultra-wideband low-profile transparent ceiling antenna according to an embodiment of this application is shown; Figure 3 A schematic diagram of the coupling plate structure of an ultra-wideband low-profile transparent ceiling antenna according to an embodiment of this application is shown; Figure 4 A schematic diagram of the coupling plate installation and positioning of an ultra-wideband low-profile transparent ceiling antenna according to an embodiment of this application is shown.

[0019] In the picture: 1. Antenna section; 11. Vibrator; 111. First semi-ellipse; 112. Second semi-ellipse; 12. Ground plane; 13. First groove; 14. First conductor strip; 2. Transparent plate; 3. Coupler plate; 31. First coupling plate; 32. Second coupling plate; 33. Second conductor strip; 34. Conductor strip groove; 35. Metallized via; 36. Pad; 37. Positioning hole; 4. Feeder line; 5. Bolt; 50. Countersunk groove; 51. Positioning post. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] like Figure 1 As shown, the ultra-wideband low-profile transparent ceiling antenna of this application is used for signal transmission and reception in indoor distributed wireless communication scenarios. The whole includes a transparent plate 2, an antenna part 1, a coupling plate 3, a feed line 4, bolts 5 and a bottom cover. All components are coaxially assembled, with a compact structure and low profile height, realizing the synergistic functions of ultra-wideband coverage, high light transmittance stealth and stable power supply.

[0022] The transparent plate 2 serves as the mounting carrier for the antenna section 1; the antenna section 1 includes a composite vibrator 11 and a semi-circular ground plane 12, forming a radiating element and a coplanar waveguide feeding structure; the coupling plate 3 is coupled to the antenna section 1 to achieve stable signal transmission; the feed line 4 is the input and output channel for radio frequency signals; the bolts 5 are used to fix the various components (mainly for fixing the coupling plate 3) to ensure accurate coupling gaps; the lower cover provides installation support and protection for the overall structure.

[0023] The transparent panel 2 uses high-transparency organic glass as the substrate, such as acrylic sheet, with the thickness selected as needed. It combines good light transmittance with mechanical strength, providing a flat and stable mounting base for the antenna section 1. Its dimensions can be adjusted according to the actual application scenario, typically designed as a circle with a diameter suitable for indoor ceiling installation requirements, ensuring seamless integration with the environment after installation. The metal mesh has a line width between 2-20μm and a line spacing between 20-200μm, balancing light transmittance and radiation efficiency. Therefore, this application has the advantages of high light transmittance, low profile, and strong environmental integration. The antenna part 1 is printed on a high-transparency organic glass substrate using metal mesh or nano-silver technology. The line width of the metal mesh is controlled at 2-20μm and the line spacing is 20-200μm, which achieves high light transmittance while ensuring radiation efficiency. The overall profile height of the antenna is as low as 2mm. After installation, it can be hidden and blended into the ceiling environment, avoiding damage to the architectural aesthetics. It solves the problems of traditional conical ceiling antennas being abruptly exposed, causing concerns about electromagnetic radiation, and being limited in site selection. It is suitable for large shopping malls, high-end hotels, tertiary hospitals and other scenarios with high requirements for aesthetics.

[0024] like Figure 2 As shown, the antenna section 1 is printed on the upper surface of the transparent plate 2 using a metal mesh or nano-silver process, including the vibrator 11, the ground plane 12 and the first conductive strip 14, which are arranged in the same layer to facilitate precise coupling.

[0025] The oscillator 11 is composed of a first semi-ellipse 111 and a second semi-ellipse 112. The two have different structural dimensions and work together to achieve ultra-wideband radiation and impedance matching.

[0026] The first semi-ellipse 111 is placed laterally along the polarization direction. Its major axis length is 1 / 4 of the wavelength corresponding to the lowest frequency point of 800MHz in the operating frequency band, and the axial ratio (major axis / minor axis) is 3.0-5.0, which can be selected as 4.0.

[0027] The second semi-ellipse 112 is placed longitudinally along the polarization direction and forms the main radiating part of the oscillator 11. Its minor axis coincides with and is equal in length to the major axis of the first semi-ellipse 111. The major axis dimension is designed according to the ultra-wideband coverage requirements, and a multi-resonant circuit is formed through a gradually changing edge shape to ensure ultra-wideband characteristics. The function of the first semi-ellipse 111 is to make the end cut-off position of the second semi-ellipse 112 have a gradually changing structure and also have adjustability, which is used to optimize the standing wave ratio (VSWR) of a specific frequency band. The advantage of this combination is that it can flexibly optimize the dimensional parameters of the first semi-ellipse 111, thereby specifically improving the frequency bands with relatively poor VSWR curves.

[0028] The oscillator 11, composed of a first semi-ellipse 111 and a second semi-ellipse 112, operates as follows: The introduction of the first semi-ellipse 111 adds a resonant stage, which can specifically improve impedance matching in the mid-to-high frequency band of 1700-3700MHz. By adjusting the axial length and axial ratio parameters of the two oscillators, the oscillator 11 achieves stable radiation across the entire frequency band of 800-3700MHz, avoiding the problem of a high VSWR in a single elliptical oscillator 11, thus achieving the goal of optimizing impedance matching. It should be noted that the truncated position of the second semi-ellipse 112 is its minor axis (in reality, it does not necessarily have to be limited to this position). The chord length at the truncated position serves as the major axis of the first semi-ellipse 111. The lower half of the structure of the second semi-ellipse 112 and the half of the structure of the first semi-ellipse 111 are combined to form the oscillator 11. As can be seen from the above, the structure of this application is flexible and adjustable, with wide adaptability. The two semi-ellipses of the oscillator 11 can be adjusted by adjusting the axis length and axis ratio parameters to optimize the VSWR performance of specific frequency bands and adapt to the frequency band requirements of different communication scenarios. The transparent substrate is made of organic glass, which has both lightweight and mechanical strength. Combined with the modular coupling plate 3 design, it can be flexibly adjusted according to the size requirements of different application scenarios such as indoor buildings, and has a wide range of applications.

[0029] The floor 12 has a semi-circular structure with a diameter that is half the wavelength corresponding to the lowest frequency point of the operating band, 800MHz. It works in conjunction with the oscillator 11 to form a complete radiator, thereby improving radiation efficiency.

[0030] A first groove 13 is provided in the middle of the floor 12. The outlet of the first groove 13 is set in the shape of a horn mouth to achieve a smooth transition of the characteristic impedance of the coplanar waveguide from low to high, and further optimize the impedance matching in the mid-to-high frequency band.

[0031] like Figure 1 and Figure 3 As shown, the first guide strip 14 is made of metal mesh and is set in the first groove 13. One end is fixedly connected to the bottom of the second semi-ellipse 112, and the other end extends into the first groove 13 in the center area of ​​the floor 12, forming a coupling with the second guide strip 33 of the coupling plate 3.

[0032] The first guide strip 14 and the first groove 13 together form a coplanar waveguide feeding structure. The width of the guide strip is designed with at least three levels of gradient. By changing the length and width of each segment, impedance matching from the feed line 4 to the vibrator 11 is achieved, ensuring efficient transmission of RF signals. It should be noted that the vibrator 11 and the ground plane 12 are attached to the same layer of the transparent substrate. This is to facilitate the setting of the coupling feed. The structure of the ceiling antenna determines that the feed point of the coaxial cable is located at the center of the disc antenna, which is aesthetically pleasing and balanced. This results in a relatively short transmission line that can run on the antenna board. Generally, for ultra-wideband monopole antennas fed from the bottom, the transmission line is one of the key factors for impedance matching. To achieve impedance matching from the coaxial line to the antenna within a short transmission line, the coplanar waveguide transmission line designed here undergoes multiple levels of impedance transformation: on the one hand, the width of the first guide strip 14 undergoes at least three levels of variation; on the other hand, the opening of the first groove 13 of the ground plane 12 is set as a horn. By optimizing the length and width of each segment of the guide strip and the size of the horn opening, the characteristic impedance of the transmission line is changed, achieving the purpose of matching.

[0033] The coupling plate 3 is a circular PCB board with copper cladding on both sides, and is coaxially mounted on the ground plane 12 of the antenna section 1. It is used to achieve stable coupling and power supply between the feed line 4 and the antenna section 1, replacing the traditional soldering method and improving the connection reliability.

[0034] like Figure 3 As shown, the coupling plate 3 includes a first coupling plate 31, a second coupling plate 32, and a second guide strip 33. The first coupling plate 31 is a semi-circular copper-clad structure, which is disposed on the upper surface of the second coupling plate 32, and a second groove is provided at the center position. The second coupling plate 32 is a circular structure with a fixing groove on its upper surface. A third groove is provided in the center of the fixing groove. The second groove and the third groove are positioned correspondingly to form the guide groove 34. The second guide strip 33 is disposed in the fixed groove. The second guide strip 33 has a raised structure, with one end extending into the guide strip groove 34 and a solder pad 36 provided on the second guide strip 33. The solder pad 36 is adjacent to the guide strip groove 34. The first coupling plate 31 and the second coupling plate 32 are connected by metallized vias 35 to ensure electrical continuity between the upper and lower copper layers. It should be noted that there are multiple metallized vias, located along the edge of the first coupling plate 31, and distributed along the central axis of the second coupling plate 32. The second conductor strip 33 and the first conductor strip 14 overlap in position, and their outlines are the same or substantially the same. The ground plane on the coupling plate 3 is divided into upper and lower layers, with the inner outline of the lower layer being the same or substantially the same as the inner outline of a portion of the ground plane 12 on the transparent plate 2.

[0035] The second coupling plate 32 is located on the ground plane 12. The contours and positions of the first conductive strip 14 and the second conductive strip 33 precisely overlap to form a coupling capacitor structure, achieving efficient coupling and transmission of radio frequency signals. It should be noted that the radio frequency signal is transmitted to the coupling plate 3 via a coaxial cable, and the coupling plate 3 couples the signal to the coplanar waveguide structure of the transparent antenna plate. Essentially, this coupling structure forms a planar capacitor structure at the coupling surface, equivalent to connecting a large capacitor in series in a circuit, with a capacitive reactance of... Where j is the imaginary unit, f is the operating frequency, and C is the equivalent capacitance. To achieve efficient coupling, the capacitive reactance should be as small as possible, therefore C should be as large as possible, according to the formula for calculating a parallel plate capacitor. , It is the dielectric constant of the dielectric material filling the space between the parallel plates, and k is the electrostatic constant, k = 9.0 × 10⁹ N·m. 2 / C 2 In this example, the equivalent dielectric constants of the protective film covering the transparent substrate surface and the solder resist ink on the coupling PCB surface are given. d is the distance between the conductors of the parallel plate capacitor, and S is the area between the conductors facing each other. Under the premise of ensuring a certain area facing each other, a sufficiently small d is needed to obtain a sufficiently large coupling capacitance. Therefore, the structural design must ensure the alignment of the coupling contour through precise positioning, and clamp the coupling plate 3 and the antenna plate through the locking bolt 5 pan head and the lower cover to ensure zero gap between the two, thereby achieving stable coupling.

[0036] Feed line 4 (coaxial feed line 4) is soldered to pad 36, and the outer conductor is soldered to the semi-circular copper cladding of the first coupling plate 31 to form a reliable signal input and output channel.

[0037] like Figure 4 As shown, bolt 5 is a hollow tubular plastic bolt 5 with a groove 50 at the bottom pan head. Multiple positioning posts 51 are provided in the groove 50, corresponding to multiple positioning holes 37 on the coupling plate 3, so as to achieve precise positioning of the coupling plate 3, ensure the overlap accuracy of the first guide strip 14 and the second guide strip 33, and make the coupling accuracy of the coupling plate 3 and the ground 12 line high, thereby ensuring the precise overlap of the coupling line and the line on the transparent antenna board. As can be seen from the above embodiments, the power supply of this application is stable and reliable, and the assembly is precise and convenient. The coupling power supply method replaces the traditional welding. The signal is transmitted through the precise overlap of the coupling plate 3 and the transparent antenna plate, avoiding the risk of welding detachment. The coupling plate 3 and the transparent antenna plate are positioned by the positioning post 51 and the positioning hole 37, and then locked by the bolt 5 to achieve zero gap fit, ensuring coupling stability and impedance matching accuracy. The overall structure consists of a lower cover, a transparent antenna plate, a coupling plate 3, bolts 5 and coaxial feed line 4. The assembly process is simple and convenient for mass production and on-site installation.

[0038] The lower cover is a circular plastic shell, which is connected to bolt 5 by self-tapping screws. The feed line 4 passes through the hollow pipe pad 36 of bolt 5 to ensure the stability and protection of the overall structure.

[0039] Feeder 4 can be a 50-ohm coaxial cable. Its core function is to transmit radio frequency signals to coupling plate 3, and then to the first guide strip 14 of antenna section 1 through coupling. Finally, the vibrator 11 converts the guided wave into radio waves and radiates them into space. At the same time, it receives space radio waves and transmits them in reverse through vibrator 11, guide strip, and coupling plate 3 to the back-end equipment, realizing bidirectional signal transmission and reception.

[0040] The overall workflow is as follows: Signal transmission (transmission mode): The radio frequency signal is input through the feeder 4 and transmitted to the second guide strip 33 of the coupling plate 3 through the pad 36. Since the second guide strip 33 and the first guide strip 14 on the transparent plate 2 are precisely overlapped and bonded with zero gap, a coupling capacitor structure is formed, and the signal is transmitted to the first guide strip 14 through the coupling effect. The coplanar waveguide feeding structure formed by the first guide strip 14 and the first groove 13 transmits the signal to the vibrator 11 efficiently. The first semi-ellipse 111 and the second semi-ellipse 112 of the vibrator 11 work together to convert the guided wave into radio waves in the 800-3700MHz frequency band and radiate them uniformly into the indoor space.

[0041] Signal reception (reception mode): Radio waves in the indoor space are captured by the vibrator 11, converted into guided waves and transmitted to the coupling area via the first guide band 14; through the coupling effect of the first guide band 14 and the second guide band 33, the signal is transmitted to the feeder 4 and finally transmitted to the back-end communication equipment to complete signal reception.

[0042] The double semi-elliptical splicing structure of the oscillator 11 increases the resonant level. The gradual change of the conduction band width of the coplanar waveguide feeding structure and the horn mouth design realize multi-level impedance transformation. The precise coupling between the coupling plate 3 and the antenna part 1 further optimizes the impedance continuity. The three work together to ensure that the standing wave ratio is ≤1.5 in the whole frequency band, ensuring that the signal transmission is reflection-free and low-loss.

[0043] Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. An ultra-wideband, low-profile transparent ceiling-mounted antenna, characterized in that, include: The antenna part (1) and the transparent plate (2) are attached to the transparent plate (2). The antenna part (1) includes a vibrator (11) and a ground plane (12). One end of the vibrator (11) and the ground plane (12) together form a coplanar waveguide feeding structure through a first guide strip (14). The vibrator (11) includes a first semi-ellipse (111) and a second semi-ellipse (112) with different structural dimensions. The first semi-ellipse (111) is placed laterally along the polarization direction, and the second semi-ellipse (112) is placed longitudinally along the polarization direction. The minor axis of the second semi-ellipse (112) coincides with the major axis of the first semi-ellipse, and the lengths between the minor axis of the second semi-ellipse (112) and the major axis of the first semi-ellipse are equal.

2. The ultra-wideband low-profile transparent ceiling-mounted antenna according to claim 1, characterized in that, The length of the major axis of the first semi-ellipse (111) is 1 / 4 of the wavelength corresponding to the lowest frequency point of 800MHz in the working frequency band.

3. The ultra-wideband low-profile transparent ceiling-mounted antenna according to claim 1, characterized in that, The axial ratio of the first semiellipse (111) is 3.0-5.

0.

4. The ultra-wideband low-profile transparent ceiling-mounted antenna according to claim 1, characterized in that, The floor (12) has a semi-circular structure.

5. The ultra-wideband low-profile transparent ceiling-mounted antenna according to claim 1, characterized in that, A first groove (13) is provided in the middle of the floor (12), and a first guide strip (14) with metal mesh is provided in the first groove (13), and the first guide strip (14) is connected to the second semi-ellipse (112).

6. The ultra-wideband low-profile transparent ceiling-mounted antenna according to claim 5, characterized in that, The outlet position of the first groove (13) is set to a flared shape.

7. The ultra-wideband low-profile transparent ceiling-mounted antenna according to claim 1, characterized in that, The feed point in the waveguide feed structure is located at the center of the transparent plate (2).

8. The ultra-wideband low-profile transparent ceiling-mounted antenna according to claim 1, characterized in that, It also includes a coupling plate (3), which is coaxially disposed on the floor (12).

9. The ultra-wideband low-profile transparent ceiling-mounted antenna according to claim 8, characterized in that, The coupling plate (3) includes a first coupling plate (31), a second coupling plate (32), and a second guide strip (33). The first coupling plate (31) is disposed on the second coupling plate (32) and the two are connected by a metallized via (35). A second groove is provided at the center of the first coupling plate (31), and a fixing groove is opened on the second coupling plate (32). The center of the fixing groove has a third groove. The second guide strip (33) is disposed in the fixing groove. The second groove and the third groove are positioned to form a guide strip groove (34). One end of the second guide strip (33) is located in the guide strip groove (34). The second coupling plate (32) is located on the floor (12), and the positions of the first guide strip (14) and the second guide strip (33) overlap.

10. The ultra-wideband low-profile transparent ceiling-mounted antenna according to claim 9, characterized in that, A pad (36) is provided on the second guide strip (33), the pad (36) is adjacent to the guide strip groove (34), and the pad (36) is fixedly connected to the feed line (4).

Images