Large-frequency-ratio three-frequency antenna for Wi-Fi / WiGig application

Abstract

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

Description

Technical Field

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

[0002] In recent years, with the increasing demand for high-speed, low-latency, and high-capacity communications, millimeter-wave technology has experienced rapid development. WiGig, a landmark millimeter-wave technology, has also garnered widespread attention in the industry. This technology enables high-speed, short-range wireless communications and is often considered an extension of Wi-Fi, achieving transmission rates nearly ten times that of Wi-Fi. In many application scenarios, Wi-Fi and WiGig coexist, complementing each other in functionality to achieve a balance between transmission speed and range. Because these two technologies operate in different frequency bands, the antennas in actual devices must also be capable of multi-band operation. Specifically, Wi-Fi operates in the 2.4 GHz and 5.8 GHz bands, while WiGig operates in the 60 GHz band. In terms of antenna technology, 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 larger antenna system size, making it unsuitable for practical applications.

[0003] In order to solve the problem of miniaturization of multi-frequency antennas, a common solution is to adopt a common aperture antenna design. Specifically, multiple antennas working in different frequency bands can be organically integrated together through structural reuse. Multiple antennas radiate from the same aperture surface, which can well achieve antenna miniaturization and high integration. [1]-[4] In this paper, co-aperture designs for patch antennas / dipole antennas, horn antennas / horn antennas, patch antennas / slot antenna arrays, and PIFA antennas / leaky-wave antenna arrays are proposed. Although these antennas can effectively achieve multi-band functionality, some issues remain that need to be addressed. First, due to the high atmospheric attenuation in the millimeter-wave band, antennas in this band generally require high-gain antenna arrays. However, the feed network in traditional antenna arrays may cause additional feed loss, so how to achieve high-gain radiation with low feed loss in the millimeter-wave band is a problem. Second, the co-aperture antennas proposed in the currently reported literature are mostly dual-band designs. Tri-band co-aperture antennas, especially those for Wi-Fi / WiGig applications, are relatively rare. Furthermore, most of the designs in the reported literature have certain limitations in bandwidth performance. Specifically, the bandwidth within each band is relatively narrow, or the bandwidth of each band varies greatly. Designs that are broadband in all three bands are rare.

[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] In order to solve at least one of the problems existing in the prior art, the present invention provides a high-frequency-ratio triple-band antenna for Wi-Fi / WiGig applications, which realizes microwave / millimeter-wave triple-band radiation through the organic combination of a grid patch antenna, a dipole array antenna, and a reflectarray antenna.

[0009] To achieve the purpose of the present invention, the present invention provides a high frequency ratio triple-band antenna for Wi-Fi / WiGig applications, comprising a first dielectric plate and a second dielectric plate arranged opposite to each other;

[0010] One side of the first dielectric plate is defined as the front side, and the other opposite side is defined as the back side. The front side of the first dielectric plate 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 provided in a blank area of the grid patch, wherein the grid patch and the dipole array are reused as the floor of the reflective array antenna;

[0011] The side of the second dielectric plate 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 bandpass filter, the differential feeding network is connected to the rectangular patch on the first dielectric plate through the first through hole and the metal probe, the bandpass filter is connected to the power divider, and the power divider is connected to the dipole array through the second through hole and the coaxial line.

[0012] In a further improvement to the present invention, the reflection array plane includes a plurality of reflection array units, and each reflection array unit includes four rotationally symmetric bent microstrip lines.

[0013] In a further improvement to the present invention, phase shifting is achieved by extending or shortening the length of the meandering microstrip line.

[0014] In a further improvement to the present invention, the length of the meandering microstrip line of each reflective array unit is determined by the phase shift required by each reflective array unit, and the phase shift value follows the Fermat principle, that is:

[0015]

[0016] in, That is, the phase shift required at point (x, y), where x and y represent the coordinates of a point on the reflector array in the x and y directions, 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. Can be any initial phase.

[0017] A further improvement of the present invention further includes a horn, which is arranged opposite to the first dielectric plate and is provided with a feeding port for feeding the reflection array surface.

[0018] In a further improvement to the present invention, the second dielectric board is provided with a feeding port for the differential feeding network and the bandpass filter.

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

[0020] In a further improvement of the present invention, the dipole array includes four dipoles arranged in a 2×2 pattern, and the four dipoles are disposed in four blank areas of the grid patch.

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

[0022] In a further improvement to the present invention, the power divider is a one-way four-way power divider, the ends of which are respectively connected to four coaxial lines, and the other ends of the four coaxial lines are respectively connected to four dipoles.

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

[0024] (1) In the 2.4 GHz, 5.8 GHz and 60 GHz frequency bands, the antenna of the present invention operates in the form of a grid patch antenna, a dipole array antenna and a reflectarray antenna, respectively. The present invention adopts a space-fed reflectarray antenna as a millimeter wave radiation structure, so that low feeding loss and high gain can be achieved in this frequency band. In addition, the solution of the present invention has a high structural reuse rate, so the overall antenna system size is small. At the same time, the antennas of the three frequency bands operate in a relatively independent manner, so the working performance of each frequency band is good and has the characteristics of three-band broadband.

[0025] (2) The grid patch antenna, dipole array, and reflectarray antenna in the triple-band antenna of the present invention are structurally reused, so triple-band operation can be achieved without adding additional space, further improving the integration of the antenna structure and having the advantage of miniaturization.

[0026] (3) In terms of antenna performance, the present invention has the advantage of broadband in all three frequency bands. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

[0031] Figure 5 2 is a schematic diagram of the back side of the first dielectric plate in an embodiment of the present invention.

[0032] Figure 6 4 is a front view of the second dielectric plate in the embodiment of the present invention.

[0033] Figure 7 2 is a schematic diagram of the back side of the second dielectric plate in an embodiment of the present invention.

[0034] Figure 8 Schematic diagram of the relationship between the reflection coefficient and frequency of the triple-band antenna in different operating frequency bands in an embodiment of the present invention.

[0035] Figure 9 Schematic diagram of the gain characteristics of the tri-band antenna within the working frequency band according to an embodiment of the present invention.

[0036] Figure 10 1 and 2 are the E-plane and H-plane radiation patterns of the triple-band antenna in the embodiment of the present invention when the antenna operates in the 2.4 GHz frequency band.

[0037] Figure 11 1 and 2 are the E-plane and H-plane radiation patterns of the triple-band antenna in the embodiment of the present invention when operating in the 5.8 GHz frequency band.

[0038] Figure 121 and 2 are the E-plane and H-plane radiation patterns of the triple-band antenna in the embodiment of the present invention when the antenna operates in the 60 GHz frequency band.

[0039] Figure 13 1 is a schematic diagram of a port isolation curve of a triple-band antenna in an embodiment of the present invention. DETAILED DESCRIPTION

[0040] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0041] The embodiment of the present invention provides a high frequency ratio tri-band antenna for Wi-Fi / WiGig applications. Figures 1 to 3 They are a full view, a top view and a side view of the antenna structure, respectively. The triple-band antenna includes a horn 11, a first dielectric plate 12, a second dielectric plate 13, two feeding metal probes 14 and four coaxial cables 15. The two metal probes 14 and the four coaxial cables 15 are all arranged between the first dielectric plate 12 and the second dielectric plate 13. Figure 4 The following is a diagram of the antenna's operating principle. In the 2.4 GHz band, the tri-band antenna operates as a grid patch antenna, fed by port 1; in the 5.8 GHz band, it operates as a dipole array antenna, fed by port 2; and in the 60 GHz band, it operates as a reflectarray antenna, fed by port 3. Speaker 11 is located directly above first dielectric plate 12, illuminating the reflectarray antenna vertically. In some embodiments of the present invention, first dielectric plate 12 and second dielectric plate 13 are made of the same dielectric material and thickness: 0.508 mm thick Rogers 5880 sheet material, with a dielectric constant and loss tangent of 2.2 and 0.0009, respectively.

[0042] Figure 5 FIG is a schematic diagram of the back side of the first dielectric plate 12, which is provided with a grid patch 25 and a 2×2 dipole array 26, wherein four dipoles are placed in four blank areas of the grid patch 25. Figure 6 As shown, the front side of the second dielectric plate 13 is a metal floor 61 , which is provided 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 7The back side of the second dielectric plate 13 is provided with a differential feeding network 71, a one-way four-way power splitter 72, and a bandpass filter 73 in some embodiments of the present invention. The differential feeding network 71 is used to feed the grid patch antenna. Electromagnetic energy is fed into port 1, passes through the differential feeding network 71, and reaches the two metal probes 14. The two metal probes 14 are respectively connected to the two rectangular patches 22 to form a "T"-shaped feeding structure, which is then coupled with the grid patch 25 for feeding. The bandpass filter 73 is provided at the front end of the one-way four-way power splitter 72, mainly used to improve the isolation between port 1 and port 2. The one-way four-way power splitter 72 is used to feed the 2×2 dipole array antenna. The electromagnetic energy is fed into port 2, passes through the bandpass filter 73, and then reaches the one-way four-way power splitter 72. The ends of the one-way four-way power splitter 72 are respectively connected to the four coaxial cables 15, and the other ends of the four coaxial cables 15 are respectively connected to the four dipole antennas, thereby feeding the 2×2 dipole array antenna.

[0044] The reflectarray antenna is primarily formed by multiplexing a grid patch antenna and a dipole array antenna. Specifically, the grid patch 25 and the 2×2 dipole array 26 provided on the back of the first dielectric plate 12 serve as the floor of the reflectarray antenna, while the front structure of the reflectarray unit is provided on the front of the first dielectric plate 12. A reflectarray surface 21 is provided on the front of the first dielectric plate 12. In some embodiments of the present invention, the reflectarray surface 21 includes a plurality of reflectarray units. Figure 2 The upper right corner shows a partial enlarged view of the front structure of the reflectarray unit. Each reflectarray unit includes four rotationally symmetrical meandering microstrip lines 23 and a reflectarray antenna floor 24. Phase shifting is achieved by extending or shortening the length of these four meandering microstrip lines 23. In some embodiments of the present invention, the length of the meandering microstrip line 23 of each reflectarray unit is determined by the required phase shift of each reflectarray unit. The specific phase shift value follows Fermat's principle, namely:

[0045]

[0046] in, That is, the phase shift required at point (x, y), where x and y represent the coordinates of a point on the reflector array surface 21 in the x and y directions, 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. Can be any initial phase.

[0047] In terms of working principle, due to the high frequency ratio between microwave and millimeter wave bands, the meandering microstrip line 23 in the reflector array unit can be regarded as a small electrically small structure in the microwave band, and they will not affect the radiation in the microwave band. However, the reflector array antenna floor 24, as a large-area metal structure, cannot be ignored. At the same time, since the reflector array antenna floor 24, 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 cross-sectional height is approximately 0.1λ. f (f is the center frequency of the antenna operating frequency band. The center frequencies of the grid patch antenna, dipole array antenna, and reflectarray antenna are 2.4 GHz, 5.8 GHz, and 60 GHz, respectively.) The cross-sectional height of the dipole antenna is approximately 0.25λ. f , due to 0.1λ f＝2.4GHz ≈0.25λ f＝5.8GHz Therefore, in the embodiment of the present invention, the grid patch antenna and the 2×2 dipole array antenna can share the same metal ground 61. In addition, the length of the grid patch antenna is about 0.5λ f , the total length of the two arms of the dipole antenna is about 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 blank areas of the grid patch antenna, allowing the grid patch 25 and the 2×2 dipole array 26 to be placed on the same surface of the same dielectric board, further improving the antenna's reuse rate. When the grid patch antenna is operating, its current is primarily distributed along the lines of the grid structure, so the dipole array has little impact on the grid patch antenna's radiation. When the dipole array antenna is operating, the grid patch 25 can be considered a parasitic structure.

[0048] In the millimeter wave frequency band, the reflector array 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 unit on the reflector array surface 21 performs phase compensation by extending or shortening the length of the four rotationally symmetric curved microstrip lines 23. The phase shift size of each reflector array unit follows the Fermat principle. Therefore, the reflector array surface 21 can convert the incident spherical wave into the outgoing plane wave, completing the beam focusing and realizing the function of electromagnetic radiation in the millimeter wave frequency band.

[0049] Antenna performance, such as Figure 8 As shown in the figure, the reflection coefficient of the port of the 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 frequency band, the -10dB impedance bandwidth of the two working frequency bands is 25.3% and 37.7% respectively, indicating that the tri-band antenna has good impedance matching within the working frequency band. Figure 9The gain characteristics of the three-band antenna are as follows: the maximum gains in the three working frequency bands are 8.1dBi, 11.9dBi and 23.7dBi respectively; in the microwave band, the antenna gain within the -10dB impedance bandwidth is in the range of 6.8~8.1dBi and 8.9~11.9dBi respectively; in the millimeter wave band, its 3dB gain bandwidth is 23.9%, indicating that the three-band antenna has good gain characteristics within the working frequency band and the gain is stable within the working frequency band.

[0050] Figure 10 The E-plane and H-plane radiation patterns of the antenna at 2.4 GHz are basically consistent with the radiation patterns of traditional grid patch antennas, indicating that the antenna can be equivalent to a grid patch antenna and work normally in this frequency band. Figure 11-12 The E-plane and H-plane radiation patterns of the antenna at 5.8GHz and 60GHz respectively. At this time, the triple-band antenna works as a dipole array antenna and a reflector array antenna respectively. The antenna port isolation curve is shown in Figure 13 As shown, the curves in the three working frequency bands are all less than -20dB, indicating that the antenna port isolation is good and the antennas in the three frequency bands work independently.

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

[0052] The aforementioned embodiments of the present invention organically combine grid patch antennas, dipole array antennas, and reflectarray antennas through structural reuse, proposing a high-frequency-ratio tri-band antenna for Wi-Fi / WiGig applications. This antenna features a simple structure and high structural reuse. In terms of performance, the aforementioned embodiments of the present invention offer the advantages of tri-band broadband, high isolation, and low feed loss in the millimeter-wave band. Because a space-fed reflectarray antenna is used as the radiating structure in the millimeter-wave band, the millimeter-wave band offers the advantages of simple feeding, low feed loss, and high gain.

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

Claims

1. A high frequency ratio tri-band antenna for Wi-Fi / WiGig applications, characterized by: It includes a first dielectric plate and a second dielectric plate that are arranged opposite to each other; One side of the first dielectric plate is defined as the front side, and the other opposite side is defined as the back side. The front side of the first dielectric plate 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 provided in a blank area of the grid patch, wherein the grid patch and the dipole array are reused as the floor of the reflective array antenna; The side of the second dielectric plate 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 bandpass filter, the differential feeding network is connected to the rectangular patch on the first dielectric plate through the first through hole and the metal probe, the bandpass filter is connected to the power divider, and the power divider is connected to the dipole array through the second through hole and the coaxial line.

2. The high frequency ratio tri-band antenna for Wi-Fi / WiGig applications according to claim 1, characterized in that: The reflection array plane includes a plurality of reflection array units, and each reflection array unit includes four rotationally symmetric bent microstrip lines.

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

4. The high frequency ratio tri-band antenna for Wi-Fi / WiGig applications according to claim 3, characterized in that: The length of the meandering microstrip line of each reflector array unit is determined by the phase shift required by each reflector array unit. The phase shift value follows the Fermat principle, that is: in, That is, the phase shift required at point (x, y), where x and y represent the coordinates of a point on the reflector array in the x and y directions, 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. Can be any initial phase.

5. The 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 arranged opposite to the first dielectric plate and has a feeding port for feeding the reflection array surface.

6. The high frequency ratio tri-band antenna for Wi-Fi / WiGig applications according to claim 1, characterized in that: The second dielectric board is provided with a feeding port for the differential feeding network and the bandpass filter.

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

8. A high frequency ratio tri-band antenna for Wi-Fi / WiGig applications according to any one of claims 1 to 7, characterized in that: The dipole array includes four dipoles arranged in a 2×2 pattern, and the four dipoles are arranged in four blank areas of the grid patch.

9. The high frequency ratio tri-band antenna for Wi-Fi / WiGig applications according to claim 8, characterized in that: There are two rectangular patches and two metal probes. The two metal probes are connected to the two rectangular patches respectively to form a "T"-shaped feeding structure.

10. The high frequency ratio tri-band antenna for Wi-Fi / WiGig applications according to claim 9, characterized in that: The power divider is a one-to-four-way power divider, the ends of which are respectively connected to four coaxial lines, and the other ends of the four coaxial lines are respectively connected to four dipoles.

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