Dual-frequency broadband microwave and millimeter wave common-aperture antenna

Abstract

The invention discloses a dual-frequency broadband microwave and millimeter wave common-aperture antenna, particularly relates to the technical field of microwave and millimeter wave communication, and solves the technical problem that the performance of a microwave and millimeter wave common-aperture antenna in the prior art is deteriorated due to the fact that mutual restraint between antennas is difficult to overcome. According to the technical scheme, a microwave magnetoelectric dipole antenna and a millimeter wave phase control patch antenna array are integrated; according to the invention, the problems of performance deterioration, incapability of scanning and the like of a sub-antenna under common-caliber integration are avoided, and based on a partial structure multiplexing design strategy, the broadband millimeter wave patch antenna array is multiplexed as a parasitic radiation patch of the microwave antenna to expand the microwave frequency band bandwidth, the microwave antenna bandwidth improvement target is additionally achieved, and the dual-frequency broadband effect is realized.

Description

Technical Field

[0001] The present invention relates to the field of microwave and millimeter wave communications, and in particular to a dual-frequency, broadband microwave and millimeter wave common-aperture antenna. Background Art

[0002] Compared with 4G mobile networks, 5G and 6G systems not only add multiple Sub-6 GHz frequency bands, but also introduce millimeter wave frequency bands unprecedentedly, in order to achieve stable and high-speed communication in different scenarios. Therefore, the collaborative work of microwave and millimeter wave technology is an inevitable trend in emerging wireless communications. As for application-oriented terminal antennas, at least the following two most critical requirements must be met: First, the newly added millimeter wave frequency band antenna must be a phased antenna array with beam scanning capability to overcome transmission loss and meet the requirements of dealing with multi-directional waves; second, microwave and millimeter wave antennas should cover one or more widely used important commercial frequency bands, such as microwave Sub-6 GHz n78 (3.3-3.8GHz), n79 (4.4-5GHz), millimeter wave n257 (26.5-29.5GHz) bands, etc. The above two requirements require that the design of the multi-antenna system retains sufficient allocable space to layout arrays and larger broadband antennas. However, the trend of miniaturization and thinness of terminal equipment constantly requires that the space occupied by its internal components be reduced, which undoubtedly makes the antenna system design face the trade-off between performance and size. The introduction of microwave and millimeter wave co-aperture antennas provides a solution to the above problem. By integrating antennas of two frequency bands into the same physical aperture, the actual "footprint" of the antenna to be integrated can be reduced, thereby effectively alleviating the pressure of internal device layout.

[0003] Microwave millimeter wave common aperture antennas can be roughly divided into four implementation forms: stacked structure, embedded structure, mode composite transmission line structure and partial structure multiplexing scheme. The stacked structure is easy to implement, and the high and low frequency antennas are designed independently. However, in order to avoid the antennas covering each other, this structure often requires an additional air layer, which makes the profile too high and difficult to apply to most terminal devices. The advantage of the embedded structure is that the antenna of each frequency band can be designed separately, but the millimeter wave antenna usually destroys the microwave antenna structure in the form of occupation, causing the original radiation mode of the microwave antenna to shift, be missing or distorted, and further deteriorate the already limited performance of the small-size microwave antenna. Under the mode composite transmission line structure, the radiation apertures of the microwave and millimeter wave antennas are highly overlapped, and the metal structure parts of the dual antennas are tightly combined. It is impossible to build a symmetrical antenna structure and introduce multiple independent feeding ports, so it is difficult to achieve beam scanning in the millimeter wave frequency band. Partial structural reuse schemes usually have high space utilization, but in existing reuse schemes, microwave and millimeter wave antennas are highly constrained in structure and have weak independent design capabilities, especially in the millimeter wave frequency band, because it is difficult to achieve flexible changes and independent feeding control of each antenna unit, which limits its ability to achieve phased beam scanning. Therefore, existing microwave millimeter wave co-aperture antennas are difficult to overcome the problem of performance deterioration caused by mutual restraint between antennas. Summary of the invention

[0004] Therefore, the present invention solves the technical problem in the prior art that microwave millimeter wave co-aperture antennas are difficult to overcome the performance deterioration caused by mutual restraint between antennas; the dual-band broadband microwave millimeter wave co-aperture antenna provided by the present invention realizes the integrated integration of microwave magneto-electric dipole antenna and millimeter wave phased patch antenna array, which not only avoids the problems of sub-antenna performance deterioration and inability to scan under co-aperture integration, but also based on the design strategy of partial structure reuse, reuses the broadband millimeter wave patch antenna array as a parasitic radiation patch of the microwave antenna to expand the microwave frequency band bandwidth, and additionally achieves the goal of improving the microwave antenna bandwidth, realizing the dual-band broadband effect.

[0005] The invention provides a dual-frequency broadband microwave millimeter wave common aperture antenna, comprising a top metal structure, a first dielectric substrate, a metal ground, a second dielectric substrate and a feeding metal layer which are sequentially arranged from top to bottom.

[0006] Furthermore, the top metal structure includes four square patches, which are arranged in a field shape in the central area of ​​the upper surface of the first dielectric substrate; each of the square patches has three first metallized vias evenly distributed outward from a corner close to the center of the upper surface of the first dielectric substrate, and the square patch is connected to the metal ground through the first metal vias.

[0007] Furthermore, gaps are left between the four square patches, and long metal strips are arranged at the horizontal gaps, one end of which is connected to the feeding metal layer through a second metallized via.

[0008] Furthermore, four-unit millimeter wave antenna structure arrays are arranged on both sides of the top metal structure.

[0009] Furthermore, each unit millimeter wave antenna structure includes two square metal patches and two third metallized vias respectively opened on the two square metal patches, and the square metal patches are connected to the metal ground through the third metallized vias.

[0010] Furthermore, the third metallized via hole passes through the first dielectric substrate.

[0011] Furthermore, a short groove is provided in the metal ground in an area corresponding to the gap between the two square metal patches.

[0012] Furthermore, the two square metal patches and the two third metalized vias of each millimeter wave antenna unit structure are respectively fed with signals from independent ports and then excited by signal coupling via the short slot located in the metal ground.

[0013] Furthermore, the length of each of the four central square patches is 0.48λ g -0.52λ g ,λ g is the wavelength of the waveguide corresponding to the center frequency of the microwave band, and the width is 0.45λ g -0.48λ g , the spacing between each two square patches is 0.1λ g -0.15λ g , the length of the long metal strip located in the middle of the four square patches is 0.4λ g -0.45λ g ; Located in the mushroom-shaped structures on both sides, the square metal patch in each mushroom-shaped structure is 0.2λ long in the horizontal direction g -0.25λ g , width is 0.1λ g -0.13λ g , the diameter of the third metallized via is 0.02λ g -0.04λ g The distance between each two mushroom-shaped structures is 0.025λ g -0.028λ g The spacing between the microwave antenna structure composed of the mushroom-shaped structure groups on both sides and the four square patches in the center is 0.07λ g -0.09λ g .

[0014] Furthermore, the four-unit millimeter-wave antenna array is excited by feeding signals through the slot coupling ports located between every two mushroom-shaped structures, and radiation phase control is achieved through independent feeding ports.

[0015] Furthermore, for this common aperture antenna structure, in the millimeter wave frequency band, each antenna unit achieves a radiation effect similar to that of a traditional patch antenna in the radiation frequency band through the two patches on the top, with a total of two modes, namely TM 01 Mode and InversionTM 02 The four millimeter-wave antenna units are respectively fed with signals through the slot coupling port located between each two mushroom-shaped structures to achieve excitation, and the radiation phase is controlled based on this independent feeding port to obtain the array beamforming capability.

[0016] Furthermore, for the microwave frequency band, before the introduction of the four-element millimeter wave antenna array, the magneto-electric dipole antenna has two modes, namely the electric dipole radiation mode dominated by four square patches and the magnetic dipole radiation mode dominated by the metallized via structure group. In the electric dipole mode, there is a strong current amplitude on the square patches in the horizontal and vertical directions, and in the magnetic dipole mode, the current intensity is concentrated on the inner side of the metallized via.

[0017] Furthermore, after the four-element millimeter-wave antenna array is loaded, the electrical length of the central square main radiation surface is extended in the horizontal direction, that is, the parasitic radiation surface of the central patch, so the third resonant mode, the parasitic mode, is introduced. In this mode, the current is coupled from the boundary of the central magnetoelectric dipole patch to the parasitic mushroom-shaped structures on both sides, and the central original magnetoelectric dipole antenna and the parasitic structure radiate together. The introduction of the parasitic mode can significantly expand the original microwave frequency band, such as Figure 3 shown.

[0018] Furthermore, the operating frequency of the millimeter wave antenna in the present invention can be adjusted by controlling the size of the square metal patch in the mushroom-shaped structure along the vertical direction and the distance between the two mushroom-shaped structures that constitute the unit. The center frequency and the first two resonant mode positions of the microwave antenna in the present invention can be adjusted mainly by adjusting the corresponding structure of the central magnetoelectric dipole, such as the size of the square patch, the size and position of the metallized via, etc. Furthermore, adjusting the size of the square metal patch in the mushroom-shaped structure along the horizontal direction can achieve the third resonant mode adjustment, and can achieve comprehensive control of the overall matching bandwidth level.

[0019] In the above technical solution, the technical effects and advantages provided by the present invention are:

[0020] 1. The dual-band broadband microwave millimeter wave co-aperture antenna provided by the present invention, under the design premise of the microwave millimeter wave co-aperture antenna, reuses the radiation surface of the four-unit broadband millimeter wave phased array antenna as the parasitic radiation structure of the microwave magnetic tape dipole antenna, realizes the co-aperture integration of the broadband microwave antenna and the broadband millimeter wave phased array, and makes the two antennas have no negative performance loss in a high-integration environment compared to a separate working environment, and has the characteristics of broadband, compact structure, easy integration, etc.

[0021] 2. The dual-band broadband microwave millimeter wave common aperture antenna provided by the present invention, the millimeter wave antenna unit is composed of a pair of mushroom-shaped structures (square patches and ground vias), polarized in the vertical direction; four millimeter wave antenna units, that is, eight mushroom-shaped structures are combined to form a longitudinal four-unit antenna array, and the array elements are respectively fed with signals through slot coupling to achieve phased scanning. The array operating frequency is controlled by the vertical direction related structural dimensions of the mushroom-shaped structure.

[0022] 3. The dual-band broadband microwave millimeter wave common-aperture antenna provided by the present invention, the radiation array surface of the millimeter wave antenna array constitutes a parasitic radiation surface of a microwave magneto-electric dipole antenna, which introduces an additional resonant mode for the microwave antenna, and the newly added mode can be controlled by adjusting the horizontal related dimensions of the mushroom-shaped structure (i.e., the millimeter wave antenna unit) and the diameter of the center ground via.

[0023] 4. The dual-band broadband microwave millimeter wave co-aperture antenna provided by the present invention, the microwave magnetoelectric dipole antenna and the two millimeter wave antenna arrays are arranged at intervals in the horizontal direction, the polarization directions of the dual antennas are orthogonal, and the feeding paths are independent, ensuring excellent isolation of the dual antenna ports, and independent designs can be realized respectively. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0025] Figure 1a A top view of the overall structure of the antenna of the present invention;

[0026] Figure 1b A top view of a single unit in the millimeter wave antenna array of the present invention;

[0027] Figure 1c It is a side view of the overall structure of the antenna of the present invention;

[0028] Figure 2 The microwave frequency band reflection coefficient and antenna gain diagram of the dual-band broadband microwave and millimeter-wave common-aperture antenna of the present invention;

[0029] Figure 3 a is a simulated directional diagram of the first resonant frequency point of the microwave antenna loaded with a parasitic structure (i.e., a millimeter wave antenna) of the present invention;

[0030] Figure 3 b is a simulated directional diagram of the second resonant frequency point of the microwave antenna loaded with a parasitic structure (i.e., a millimeter wave antenna) of the present invention;

[0031] Figure 3c is a simulated radiation pattern of the third resonant frequency point of the microwave antenna loaded with a parasitic structure (i.e., a millimeter wave antenna) of the present invention;

[0032] Figure 4 The millimeter wave frequency band reflection coefficient and antenna gain diagram of the dual-band broadband microwave millimeter wave common aperture antenna of the present invention;

[0033] Figure 5 a is a simulated radiation pattern of the first resonant frequency point of the millimeter wave antenna array of the present invention;

[0034] Figure 5 b is a simulated radiation pattern of the second resonant frequency point of the millimeter wave antenna array of the present invention;

[0035] Figure 6 The simulated directional pattern of the millimeter wave antenna array of the present invention at 28 GHz beam scanning;

[0036] Figure 7 This is a diagram of the port isolation level in the microwave / millimeter wave frequency band of the present invention.

[0037] Description of reference numerals:

[0038] 1. Top metal structure; 1-1. Square patch; 1-2. First metalized via; 1-3. Long metal strip; 1-4. Second metalized via; 1-5. Four-unit millimeter-wave antenna array; 1-5-1. Square metal patch; 1-5-2. Short slot; 1-5-4. Third metalized via; 2. First dielectric substrate; 3. Metal ground; 4. Second dielectric substrate; 5. Feed metal layer. DETAILED DESCRIPTION

[0039] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0040] The present invention provides a dual-band broadband microwave millimeter wave co-aperture antenna, and a schematic diagram of its case structure is shown in Figure 1. It is mainly composed of a top metal structure 1, a first dielectric substrate 2, a metal ground 3, a second dielectric substrate 4 and a feeding metal layer 6. In the top metal structure 1, there are four larger square patches 1-1 at the center, and each square patch has three first metalized vias 1-2 evenly distributed from one corner to the outside, forming the radiation structure of the microwave magnetoelectric dipole antenna. At the horizontal center of the top metal structure 1, there is a long metal strip 1-3, one end of which is connected to the feeding metal layer 5 through the second metal via 1-4 to realize the feeding signal access of the microwave magnetoelectric dipole antenna. The feeding metal layer 5 is provided with an independent port and port 1. On both sides of the top metal structure 1, there is a four-unit millimeter wave antenna array 1-5 composed of eight mushroom-shaped structures, wherein each millimeter wave antenna unit structure includes two square metal patches 1-5-1 and two third metalized vias 1-5-4, which are fed with signals from independent ports and then coupled with signals through short slots 1-5-2 located in the metal ground 3. In this common aperture antenna, the length of each of the four central square patches is 0.48λ g -0.52λ g (λ g is the wavelength of the waveguide corresponding to the center frequency of the microwave frequency band), and the width is 0.45λ g -0.48λ g , the spacing between patches is 0.1λ g -0.15λ g , the length of the long metal strip located in the middle of the four square patches is 0.4λ g -0.45λ g ; In the mushroom-shaped structure groups (i.e., four-unit millimeter wave antenna arrays) located on both sides, the square metal patch 1-5-1 in each mushroom-shaped structure is 0.2λ long in the horizontal direction g -0.25λ g , width is 0.1λ g -0.13λ g , the diameter of the third metallized via 1-5-4 is 0.02λ g -0.04λ g The distance between each two mushroom-shaped structures is 0.025λ g -0.028λ g The spacing between the microwave antenna structure composed of the mushroom-shaped structure groups on both sides and the four square patches 1-1 in the center is 0.07λ g -0.09λ g .

[0041] According to the above principle analysis and design method, a design case of the present invention is provided below. The structure of the dual-band broadband microwave millimeter wave common aperture antenna is shown in Figure 1. In the design case, the first dielectric substrate 2 and the second dielectric substrate 4 used are both FR4 plates. The matching and gain simulation results of the antenna proposed in the present invention in the microwave frequency band are shown in Figure 1. Figure 2 As shown. The 10-dB impedance matching frequency band of the microwave band covers 4.38GHz-6.11GHz, with a relative bandwidth of 33%, while the operating frequency band of the traditional non-co-aperture magneto-electric dipole antenna (i.e., the millimeter-wave antenna is not loaded as a parasitic structure) is 4.62GHz-5.75GHz, with a relative bandwidth of 21.8%. Therefore, in the co-aperture integrated environment, the antenna proposed in the present invention achieves a microwave bandwidth expansion of more than one third, and obtains a significant bandwidth enhancement. Figure 3 The simulated radiation patterns of the microwave antenna at three resonant frequency points in this case are shown, and better radiation effects are achieved at the three resonant points.

[0042] The simulation results of the independent port reflection coefficient and array gain of the common aperture antenna proposed in the present invention in the millimeter wave frequency band are as follows: Figure 4 The millimeter wave frequency band bandwidth ranges from 25.7GHz to 30GHz, completely covering the 5G millimeter wave n257 frequency band (i.e. 26.5GHz to 29.5GHz), and the gain within the frequency band is above 11dBi. Figure 5 The radiation patterns of the antenna at 26.5 GHz and 28.5 GHz are given. The radiation patterns of the antenna are symmetrical, the front-to-back ratio is greater than 10, and the cross-polarization is better than 15 dB. In addition, since each millimeter-wave antenna unit can be fed independently, the millimeter-wave antenna array beam pointing can be controlled by controlling the feeding phase difference of each unit. Figure 6 As shown, in this case, the millimeter wave antenna array can support ±40° beam scanning.

[0043] Figure 7 The simulation results of isolation between the microwave band feeding port and the millimeter wave band port of the co-aperture antenna in this case are shown. The dual-band port isolation is greater than 55dB in the microwave band and greater than 20dB in the millimeter wave band. This result shows that the microwave and millimeter wave antennas work independently and have weak mutual interference.

[0044] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A dual-band broadband microwave and millimeter wave common aperture antenna, characterized in that: It comprises a top metal structure (1), a first dielectric substrate (2), a metal ground (3), a second dielectric substrate (4) and a feeding metal layer (5) which are arranged in sequence from top to bottom.

2. The dual-band broadband microwave and millimeter wave common aperture antenna according to claim 1, characterized in that: The top metal structure (1) comprises four square patches (1-1) arranged in a field shape in the central area of ​​the upper surface of the first dielectric substrate (2); three first metallized vias (1-2) are evenly distributed outwards from the center of the upper surface of the first dielectric substrate (2) on each of the square patches (1-1), forming a radiation structure of a microwave magnetoelectric dipole antenna.

3. The dual-band, broadband microwave and millimeter-wave common-aperture antenna according to claim 2, characterized in that: A gap is left between the four square patches (1-1), a long metal strip (1-3) is arranged at the horizontal center of the gap, a second metal via hole (1-4) is arranged at one end of the long metal strip (1-3), and one end of the long metal strip (1-3) is connected to the feeding metal layer (5) through the second metal via hole (1-4), so as to realize the feeding signal access of the microwave magnetoelectric dipole antenna.

4. The dual-band broadband microwave and millimeter wave common aperture antenna according to claim 1, characterized in that: On both sides of the top metal structure (1), there is a row of four-unit millimeter wave antenna arrays (1-5) composed of eight mushroom-shaped structures.

5. The dual-band broadband microwave and millimeter wave common aperture antenna according to claim 4, characterized in that: Each unit millimeter wave antenna structure comprises two square metal patches (1-5-1) and two third metalized vias (1-5-4) respectively opened on the two square metal patches (1-5-1).

6. The dual-band broadband microwave and millimeter wave common aperture antenna according to claim 5, characterized in that: The third metallized via (1-5-4) passes through the first dielectric substrate (2).

7. The dual-band, broadband microwave and millimeter-wave common-aperture antenna according to claim 6, characterized in that: The metal ground (3) is provided with a short groove (1-5-2) in an area corresponding to the gap between the two square metal patches (1-5-1).

8. The dual-band broadband microwave and millimeter wave common aperture antenna according to claim 7, characterized in that: Each millimeter wave antenna unit structure includes two square metal patches (1-5-1) and two third metalized vias (1-5-4), which are respectively fed with signals from independent ports and then coupled with signal excitation via a short slot (1-5-2) located in the metal ground (3).

9. The dual-band broadband microwave and millimeter wave common aperture antenna according to claim 6, characterized in that: The length of each of the four central square patches (1-1) is 0.48λ g -0.52λ g ,λ g is the wavelength of the waveguide corresponding to the center frequency of the microwave frequency band, and the width is 0.45λ g -0.48λ g , the spacing between each two square patches (1-1) is 0.1λ g -0.15λ g , the long metal strip (1-3) located in the middle of the four square patches (1-1) has a length of 0.4λ g -0.45λ g ; Located in the mushroom-shaped structures on both sides, the square metal patch (1-5-1) in each mushroom-shaped structure is 0.2λ long in the horizontal direction g -0.25λ g , width is 0.1λ g -0.13λ g , the diameter of the third metallized via (1-5-4) is 0.02λ g -0.04λ g The distance between each two mushroom-shaped structures is 0.025λ g -0.028λ g The spacing between the microwave antenna structure composed of the mushroom-shaped structure groups on both sides and the four square patches (1-1) in the center is 0.07λ g -0.09λ g .

10. The dual-band broadband microwave and millimeter wave common aperture antenna according to claim 6, characterized in that: The four-unit millimeter wave antenna array (1-5) is respectively fed with signals through the slot coupling ports located between each two mushroom-shaped structures to achieve excitation, and radiation phase regulation is achieved through independent ports.

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