A large frequency ratio three-frequency antenna for wi-fi / wi gig applications

Abstract

The application provides a large-frequency-ratio three-frequency antenna for Wi-Fi / WiGig application, which comprises a first dielectric plate and a second dielectric plate; one side of the first dielectric plate is defined as a front side, and the other side is a back side; the front side of the first dielectric plate is provided with a reflective array surface and a rectangular patch; the back side is provided with a grid patch and a dipole array arranged in a blank area of the grid patch; the grid patch and the dipole array are multiplexed as a floor in the reflective array antenna; one side of the second dielectric plate and opposite to the back side of the first dielectric plate is a metal floor, and the metal floor is provided with a first through hole and a second through hole for feeding the grid patch antenna and the dipole array antenna respectively; the other side of the second dielectric plate is provided with a differential feeding network, a power divider and a band-pass filter; the grid patch antenna, the dipole array and the reflective array antenna in the application have a multiplexing relationship in structure, three-frequency operation can be realized without increasing additional space, and the integration of the antenna structure is improved.

Description

Technical Field

[0001] This invention relates to the field of antenna technology, and in particular to a high frequency ratio tri-band antenna for Wi-Fi / WiGig applications. Background Technology

[0002] In recent years, with the increasing demand for high speed, low latency, and high communication capacity, millimeter-wave technology has developed rapidly. WiGig, as a landmark millimeter-wave technology, has also attracted widespread attention in the industry. This technology can achieve high-speed, short-range wireless communication and is often regarded as an extension of Wi-Fi technology, achieving transmission rates nearly ten times higher than Wi-Fi. In many application scenarios, Wi-Fi and WiGig coexist, complementing each other functionally and achieving a balance between transmission rate and transmission distance. Because these two technologies operate in different frequency bands, the antenna in actual devices also needs to be multi-frequency capable. Specifically, Wi-Fi operates in the 2.4GHz and 5.8GHz bands, while WiGig operates in the 60GHz band. In terms of antenna technology, such a tri-band antenna design can be achieved by simply placing three antennas operating in different frequency bands within the same system. However, this results in a large antenna system size, which is not conducive to practical applications.

[0003] To address the miniaturization challenge of multi-frequency antennas, a common approach is to employ a common-aperture antenna design. Specifically, multiple antennas operating in different frequency bands can be organically integrated through structural reuse, with all antennas radiating from the same aperture surface. This effectively achieves both miniaturization and high integration. In the reported literature... [1]-[4] The paper proposes common-aperture designs for patch antennas / dipole antennas, horn antennas / horn antennas, patch antennas / slot antenna arrays, and PIFA antennas / leakage antenna arrays. While these antennas can effectively achieve multi-frequency functionality, several issues remain: First, due to the high atmospheric attenuation in the millimeter-wave band, antennas in this band typically require high-gain antenna arrays. However, the feed network in traditional antenna arrays can lead to additional feed losses. Therefore, achieving high-gain radiation with low feed losses in the millimeter-wave band is a challenge. Second, most of the common-aperture antennas proposed in the current literature are dual-band designs; tri-band common-aperture antennas, especially those designed for Wi-Fi / WiGig applications, are relatively rare. Furthermore, most of the reported designs have limitations in bandwidth performance, specifically narrow bandwidth across all frequency bands or significant differences in bandwidth between bands. Designs with wide bandwidth across all three frequency bands are rarely proposed.

[0004] [1]Xujun Yang,Lei Ge,Yuan Ji,Xierong Zeng,Yujian Li,Chen Ding,JieSun,Kwai-Man Luk,“An integrated tri-band antenna system with large frequencyratio for WLAN and WiGig applications,”IEEE Transactions on IndustrialElectronics,vol.68,no.5,pp.4529-4540,May2021.

[0005] [2]Junyao Tan,Yujian Li,Lei Ge,Junhong Wang,“A3-D printed lightweightminiaturized dual-band dual-polarized feed module for advanced millimeter-wave and microwave shared-aperture wireless backhaul system applications,”IEEE Transactions on Antennas and Propagation,vol.71,no.4,pp.3050-3060,Apr.2023.

[0006] [3]Zhen-Xing Xia,Kwok Wa Leung,Nan Yang,Kai Lu,“Compact dual-frequency antenna array with large frequency ratio,”IEEE Transactions onAntennas and Propagation,vol.69,no.4,pp.2031-2040,Apr.2021.

[0007] [4] Yan Ran Ding, Yu Jian Cheng, "A tri-band shared-aperture antenna for (2.4,5.2)GHz Wi-Fi application with MIMO function and 60GHz Wi-Gig application with beam-scanning function," IEEE Transactions on Antennas and Propagation, vol.68, no.3, pp.1973-1981, Mar.2020. Summary of the Invention

[0008] To address at least one of the problems existing in the prior art, this invention provides a high frequency ratio tri-band antenna for Wi-Fi / WiGig applications, which achieves microwave / millimeter-wave tri-band radiation through the organic combination of a grid patch antenna, a dipole array antenna, and a reflective array antenna.

[0009] To achieve the objective of this invention, the present invention provides a high frequency ratio tri-band antenna for Wi-Fi / WiGig applications, comprising a first dielectric substrate and a second dielectric substrate disposed opposite to each other.

[0010] One side of the first dielectric substrate is defined as the front side, and the opposite side is defined as the back side. The front side of the first dielectric substrate is provided with a reflective array surface and a rectangular patch, and the back side is provided with a grid patch and a dipole array disposed in the blank area of ​​the grid patch. The grid patch and the dipole array are multiplexed as the ground plane in the reflective array antenna.

[0011] On the second dielectric substrate, one side opposite to the back of the first dielectric substrate is a metal ground plane, and the metal ground plane has a first through hole and a second through hole for feeding the grid patch antenna and the dipole array antenna, respectively. On the other side of the second dielectric substrate, a differential feed network, a power divider and a bandpass filter are provided. The differential feed network is connected to the rectangular patch on the first dielectric substrate through the first through hole and a metal probe. The bandpass filter is connected to the power divider. The power divider is connected to the dipole array through the second through hole and a coaxial line.

[0012] In a further improvement of the present invention, the reflective array surface includes multiple reflective array elements, and each reflective array element includes four rotationally symmetric bent microstrip lines.

[0013] A further improvement to the present invention is to achieve phase shifting by extending or shortening the length of the bent microstrip line.

[0014] A further improvement to the present invention is that the length of the bent microstrip line of each reflector element is determined by the required phase shift of each reflector element, and the phase shift value follows Fermat's principle, i.e.:

[0015]

[0016] in, This refers to the required phase shift at point (x, y), where x and y represent the coordinates of a point on the reflector array in the x and y directions, respectively. F is the focal length of the reflector array antenna, and λ represents the free-space wavelength at the center frequency of 60 GHz in the millimeter-wave band. It can be any initial phase.

[0017] A further improvement to the present invention includes a horn, which is disposed opposite to the first dielectric plate, and the horn is provided with a power supply port for powering the reflector array surface.

[0018] In a further improvement to the present invention, a feed port for supplying power to the differential feed network and the bandpass filter is provided on the second dielectric substrate.

[0019] In a further improvement to the present invention, the first dielectric plate and the second dielectric plate have the same dielectric material and thickness.

[0020] A further improvement to the present invention is that the dipole array includes four dipoles arranged in a 2×2 configuration, with the four dipoles positioned in four blank areas of the grid patch.

[0021] In a further improvement to the present invention, there are two rectangular patches and two metal probes. The two metal probes are respectively connected to the two rectangular patches to form a "T"-shaped power supply structure.

[0022] In a further improvement of the present invention, the power divider is a 1-to-4 power divider, with the ends of the 1-to-4 power divider connected to four coaxial lines respectively, and the other ends of the four coaxial lines connected to four dipoles respectively.

[0023] Compared with the prior art, the present invention can achieve at least the following beneficial effects:

[0024] (1) In the 2.4GHz, 5.8GHz, and 60GHz frequency bands, the antennas of this invention operate as lattice patch antennas, dipole array antennas, and reflector array antennas, respectively. This invention uses a space-fed reflector array antenna as the millimeter-wave radiation structure, thus achieving low feed loss and high gain in this frequency band. Furthermore, the scheme in this invention has a high structural reuse rate, resulting in a smaller overall antenna system size. Simultaneously, the antennas in the three frequency bands operate relatively independently, thus achieving good performance in each frequency band and exhibiting tri-band broadband characteristics.

[0025] (2) The grid patch antenna, dipole array and reflector array antenna in the tri-band antenna of the present invention have a reuse relationship in structure, so tri-band operation can be achieved without adding extra space, which further improves the integration of the antenna structure and has the advantage of miniaturization.

[0026] (3) In terms of antenna performance, the present invention has the advantage of being wideband across all three frequency bands. Attached Figure Description

[0027] Figure 1 This is a full view of a high-frequency ratio tri-band antenna for Wi-Fi / WiGig applications provided in an embodiment of the present invention.

[0028] Figure 2 This is a top view of a high-frequency ratio tri-band antenna for Wi-Fi / WiGig applications provided in an embodiment of the present invention.

[0029] Figure 3 This is a side view of a high-frequency ratio tri-band antenna for Wi-Fi / WiGig applications provided in an embodiment of the present invention.

[0030] Figure 4 This is a schematic diagram of the working principle of a high frequency ratio tri-band antenna for Wi-Fi / WiGig applications provided in an embodiment of the present invention.

[0031] Figure 5 This is a schematic diagram of the back side of the first dielectric plate in an embodiment of the present invention.

[0032] Figure 6 This is a front view of the second dielectric plate in an embodiment of the present invention.

[0033] Figure 7 This is a schematic diagram of the back side of the second dielectric plate in an embodiment of the present invention.

[0034] Figure 8 This is a schematic diagram illustrating the relationship between the reflection coefficient and frequency of a tri-band antenna in different operating frequency bands, as described in this embodiment of the invention.

[0035] Figure 9 This is a schematic diagram of the gain characteristics of the tri-band antenna in the operating frequency band in an embodiment of the present invention.

[0036] Figure 10 This is the E-plane and H-plane radiation pattern of the antenna when the tri-band antenna operates in the 2.4GHz frequency band in this embodiment of the invention.

[0037] Figure 11 This is the E-plane and H-plane radiation pattern of the antenna when the tri-band antenna operates in the 5.8GHz frequency band in this embodiment of the invention.

[0038] Figure 12This is the E-plane and H-plane radiation pattern of the antenna when the tri-band antenna operates in the 60GHz frequency band in this embodiment of the invention.

[0039] Figure 13 This is a schematic diagram of the port isolation curve of the tri-band antenna in an embodiment of the present invention. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] This invention provides a high frequency ratio tri-band antenna for Wi-Fi / WiGig applications. Figures 1 to 3 The images show a full view, a top view, and a side view of the antenna structure. The tri-band antenna includes a horn 11, a first dielectric substrate 12, a second dielectric substrate 13, two feeding metal probes 14, and four coaxial cables 15. The two metal probes 14 and the four coaxial cables 15 are all disposed between the first dielectric substrate 12 and the second dielectric substrate 13. Figure 4 The diagram illustrates the working principle of the antenna. In the 2.4GHz band, the tri-band antenna operates as a grid patch antenna, fed by port 1; in the 5.8GHz band, it operates as a dipole array antenna, fed by port 2; and in the 60GHz band, it operates as a reflector array antenna, fed by port 3. The horn 11 is located directly above the first dielectric substrate 12, perpendicularly illuminating the reflector array antenna. In some embodiments of the invention, the first dielectric substrate 12 and the second dielectric substrate 13 have the same dielectric material and thickness, both being 0.508mm thick Rogers 5880 substrate with dielectric constants and loss tangents of 2.2 and 0.0009, respectively.

[0042] Figure 5 This is a schematic diagram of the back side of the first dielectric substrate 12, which includes a grid patch 25 and a 2×2 dipole array 26, with four dipoles placed in four blank areas of the grid patch 25. Figure 6 As shown, the front side of the second dielectric substrate 13 is a metal ground plane 61, with two first through holes 62 and four second through holes 63, which are used for feeding the grid patch antenna and the 2×2 dipole array antenna, respectively.

[0043] Figure 7On the back side of the second dielectric substrate 13, in some embodiments of the present invention, a differential feed network 71, a 1-to-4 power divider 72, and a bandpass filter 73 are disposed on the back side of the second dielectric substrate 13. The differential feed network 71 is used to feed the grid patch antenna. Electromagnetic energy is fed in through port 1, passes through the differential feed network 71 to two metal probes 14, and the two metal probes 14 are respectively connected to two rectangular patches 22, forming a "T"-shaped feed structure, and then coupled to the grid patch 25 for feeding. The bandpass filter 73 is disposed at the front end of the 1-to-4 power divider 72, mainly used to improve the isolation between port 1 and port 2. The 1-to-4 power divider 72 is used to feed the 2×2 dipole array antenna. Electromagnetic energy is fed in through port 2, passes through the bandpass filter 73, and then reaches the 1-to-4 power divider 72. The ends of the 1-to-4 power divider 72 are connected to four coaxial cables 15, and the other ends of the four coaxial cables 15 are connected to four dipole antennas, thereby feeding the 2×2 dipole array antenna.

[0044] The reflective array antenna is mainly formed by multiplexing a lattice patch antenna and a dipole array antenna. Specifically, the lattice patch 25 and the 2×2 dipole array 26 disposed on the back side of the first dielectric substrate 12 are multiplexed as the ground plane in the reflective array antenna, while the front side of the first dielectric substrate 12 has a front structure of reflective array elements. The front side of the first dielectric substrate 12 has a reflective array surface 21. In some embodiments of the present invention, the reflective array surface 21 includes multiple reflective array elements. Figure 2 The upper right corner shows a partial enlarged view of the front structure of the reflector array element. Each reflector array element includes four rotationally symmetric bent microstrip lines 23 and a ground plane 24 for the reflector array antenna. Phase shifting is achieved by extending or shortening the length of these four bent microstrip lines 23. In some embodiments of the present invention, the length of the bent microstrip lines 23 of each reflector array element is determined by the required phase shift of each reflector array element. The specific phase shift value follows Fermat's principle, i.e.:

[0045]

[0046] in, That is, the required phase shift at point (x, y), where x and y represent the coordinates of a point on the reflector array 21 in the x and y directions, respectively, F is the focal length of the reflector array antenna, and λ represents the free-space wavelength at the center frequency of 60 GHz in the millimeter-wave band. It can be any initial phase.

[0047] In terms of operating principle, due to the high frequency ratio of microwave and millimeter-wave bands, the bent microstrip lines 23 in the reflector array element can be considered as small polarimetric structures in the microwave band, and they will not affect the radiation in the microwave band. However, the ground plane 24 of the reflector array antenna, as a large-area metal structure, cannot be ignored. Furthermore, since the ground plane 24 of the reflector array antenna, the grid patch 25, and the 2×2 dipole array 26 are structurally reused, both the grid patch antenna and the dipole array antenna can operate normally. For the grid patch antenna, its profile height is approximately 0.1λ. f (f is the center frequency of the antenna's operating frequency band; the center frequencies of the lattice patch antenna, dipole array antenna, and reflector antenna are 2.4 GHz, 5.8 GHz, and 60 GHz, respectively), while the profile height of the dipole antenna is approximately 0.25λ. f Due to 0.1λ f＝2.4GHz ≈0.25λ f＝5.8GHz Therefore, in this embodiment of the invention, the lattice patch antenna and the 2×2 dipole array antenna can share the same metal ground plane 61. Additionally, the length of the lattice patch antenna is approximately 0.5λ. f The total length of the two arms of the dipole antenna is approximately 0.5λ. f Due to 0.5λ f＝2.4GHz ≈2×0.5λ f＝5.8GHz Therefore, the 2×2 dipole array can be placed in the four empty areas of the lattice patch antenna, so that the lattice patch 25 and the 2×2 dipole array 26 are placed on the same side of the same dielectric substrate, further improving the antenna's multiplexing efficiency. When the lattice patch antenna is working, its current is mainly distributed along the lines of the lattice structure, so the dipole array has little impact on the radiation of the lattice patch antenna; when the dipole array antenna is working, the lattice patch 25 can be regarded as a parasitic structure.

[0048] In the millimeter-wave band, the reflector antenna is fed by port 3, and the electromagnetic energy is spatially fed to the reflector array surface 21 through the horn 11. At this time, each reflector array element on the reflector array surface 21 performs phase compensation by extending or shortening the length of four rotationally symmetric bent microstrip lines 23, and the phase shift of each reflector array element follows Fermat's principle. Therefore, the reflector array surface 21 can convert the incident spherical wave into the outgoing plane wave, and complete the beam focusing to realize the function of electromagnetic radiation in the millimeter-wave band.

[0049] Regarding antenna performance, such as Figure 8 As shown, the reflection coefficient of the port of this tri-band antenna is less than -10dB in the ranges of 2.1-2.8GHz, 4.79-7.08GHz, and 50-70GHz. In the microwave band, the -10dB impedance bandwidths of the two operating frequency bands are 25.3% and 37.7%, respectively, indicating that the tri-band antenna has good impedance matching in the operating frequency band. Figure 9The gain characteristics of this tri-band antenna are as follows: the highest gains of the three operating frequency bands are 8.1 dBi, 11.9 dBi, and 23.7 dBi, respectively. In the microwave band, the antenna gain is located in the range of 6.8–8.1 dBi and 8.9–11.9 dBi within the -10 dB impedance bandwidth, respectively. In the millimeter-wave band, its 3 dB gain bandwidth is 23.9%, indicating that the tri-band antenna has good gain characteristics within the operating frequency band and the gain is stable within the operating frequency band.

[0050] Figure 10 The images show the E-plane and H-plane radiation patterns of the antenna at 2.4 GHz. These patterns are basically consistent with those of a traditional grid patch antenna, indicating that the antenna can function normally as an equivalent grid patch antenna at this frequency. Figure 11-12 The E-plane and H-plane radiation patterns of the antenna are shown at 5.8 GHz and 60 GHz, respectively. At these frequencies, the tri-band antenna operates as a dipole array antenna and a reflector array antenna, respectively. The port isolation curve of the antenna is shown below. Figure 13 As shown, the curves in all three operating frequency bands are less than -20dB, indicating that the antenna port isolation is good and the antennas in the three frequency bands can operate independently.

[0051] In the tri-band antenna provided in the foregoing embodiments of the present invention, the operating bandwidths of the 2.4GHz, 5.8GHz and 60GHz bands are 25.3%, 37.7% and 23.9%, respectively, and the peak gains are 8.1dBi, 11.9dBi and 23.7dBi, respectively. These performance indicators are superior to the current technical level.

[0052] The foregoing embodiments of this invention organically combine a lattice patch antenna, a dipole array antenna, and a reflector array antenna through structural reuse, proposing a high-ratio tri-band antenna for Wi-Fi / WiGig applications. This achieves the characteristics of simple antenna structure and high structural reuse rate. In terms of performance, the foregoing embodiments of this invention have the advantages of three-band broadband, high isolation, and low feed loss in the millimeter-wave band. Because the millimeter-wave band uses a space-fed reflector array antenna as the radiating structure, it has the advantages of simple feeding, low feed loss, and high gain in the millimeter-wave band.

[0053] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined in this invention may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A high frequency ratio tri-band antenna for Wi-Fi / WiGig applications, characterized in that, Includes a first and a second medium plate that are positioned relative to each other; One side of the first dielectric substrate is defined as the front side, and the opposite side is defined as the back side. The front side of the first dielectric substrate is provided with a reflective array surface and a rectangular patch, and the back side is provided with a grid patch and a dipole array disposed in the blank area of ​​the grid patch. The grid patch and the dipole array are multiplexed as the ground plane in the reflective array antenna. The reflective array surface includes multiple reflective array elements, and each reflective array element includes four rotationally symmetric bent microstrip lines. On the second dielectric substrate, one side opposite to the back of the first dielectric substrate is a metal ground plane, and the metal ground plane has a first through hole and a second through hole for feeding the grid patch antenna and the dipole array antenna, respectively; on the other side of the second dielectric substrate, a differential feed network, a power divider and a bandpass filter are provided. The differential feed network is connected to the rectangular patch on the first dielectric substrate through the first through hole and a metal probe. The bandpass filter is connected to the power divider. The power divider is connected to the dipole array through the second through hole and a coaxial line. The dipole array includes four dipoles arranged in a 2×2 pattern, with the four dipoles positioned in four blank areas of the grid patch. There are two rectangular patches and two metal probes. The two metal probes are connected to the two rectangular patches respectively, forming a "T"-shaped power supply structure. The power divider is a 1-to-4 power divider. The ends of the 1-to-4 power divider are connected to four coaxial cables, and the other ends of the four coaxial cables are connected to four dipoles.

2. The high frequency ratio tri-band antenna for Wi-Fi / WiGig applications according to claim 1, characterized in that, Phase shifting is achieved by extending or shortening the length of the bent microstrip line.

3. A high frequency ratio tri-band antenna for Wi-Fi / WiGig applications according to claim 2, characterized in that, The length of the bent microstrip line in each reflector element is determined by the required phase shift for each element, and the phase shift value follows Fermat's principle, i.e.: in, Immediately The required phase shift size, and This indicates that a point on the surface of the reflection array is in direction and Coordinates in direction λ represents the focal length of the reflector antenna, and λ represents the free-space wavelength at the center frequency of 60 GHz in the millimeter-wave band. It can be any initial phase.

4. A high frequency ratio tri-band antenna for Wi-Fi / WiGig applications according to claim 1, characterized in that, It also includes a horn, which is positioned opposite to the first dielectric plate, and the horn is provided with a power supply port for powering the reflector array surface.

5. A high frequency ratio tri-band antenna for Wi-Fi / WiGig applications according to claim 1, characterized in that, The second dielectric substrate has feed ports for supplying power to the differential feed network and bandpass filter.

6. A high frequency ratio tri-band antenna for Wi-Fi / WiGig applications according to claim 1, characterized in that, The first and second dielectric substrates have the same dielectric material and thickness.

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