A millimeter wave broadband antenna array of a MEFAB process

Abstract

The application discloses a millimeter wave broadband antenna array of a MEFAB process, which comprises an I-shaped slotted metal floor, two pairs of mutually parallel vertical metal columns, L-shaped metal folded patches, two pairs of rounded rectangular patches and a rectangular coaxial structure; the overall profile height of the antenna is reduced by folding the L-shaped patches and cooperating with the vertical metal columns to change the current path; and a larger space is left between the horizontal rounded rectangular patches and the vertical metal columns to generate a capacitive effect, so that the matching of the antenna is realized; the I-shaped slot gap is slotted and gradually changed, so that the electric dipole and the magnetic dipole are effectively excited; and the maximum gain of the antenna unit is improved through the common radiation of the two pairs of magnetic dipoles and electric dipoles.

Description

Technical Field

[0001] This invention relates to the field of antenna technology, and more specifically to a millimeter-wave broadband antenna array fabricated using the MEFAB process. Background Technology

[0002] In the development of modern wireless communication and mobile communication systems, antennas, as components for transmitting and receiving electromagnetic wave signals, play an irreplaceable role in radio systems. Furthermore, because they directly affect the quality of transmitted and received electromagnetic signals, antenna performance is crucial. Especially with the rapid development of information technology, higher and more demanding requirements have been placed on antenna electrical performance: for example, wide bandwidth to increase system capacity and reduce costs; low cross-polarization and low back radiation to reduce interference; stable radiation pattern and gain within the operating frequency band to improve signal quality; and miniaturization and easy integration to reduce system costs and save space.

[0003] Traditional broadband antennas, such as horn antennas and Vivaldi antennas, have a wide bandwidth, but they are often too large and difficult to integrate in the millimeter-wave band. Microstrip patch antennas are easy to integrate, but their inherent narrow bandwidth, low gain and surface wave loss make them difficult to meet the requirements of broadband millimeter-wave systems. Summary of the Invention

[0004] This invention proposes a millimeter-wave broadband antenna array fabricated using MEFAB technology to solve the technical problems mentioned in the background.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A millimeter-wave broadband antenna array manufactured using MEFAB process of the present invention includes an I-shaped slotted metal ground plate, two pairs of parallel vertical metal pillars, an L-shaped metal folded patch, two pairs of rounded rectangular patches, and a rectangular coaxial structure; the bottom end of the vertical metal pillars is fixedly connected to the I-shaped slotted metal ground plate, the top end of the vertical metal pillars is connected to the L-shaped metal folded patch, and the bottom end of the rounded rectangular patch is connected to the L-shaped metal folded patch; the two pairs of parallel vertical metal pillars, the L-shaped metal folded patch, and the rounded rectangular patch are respectively located on both sides of the slot of the I-shaped slot; the two pairs of rounded rectangular patches are parallel to the I-shaped slotted metal ground plate, and the rounded rectangular patches are spatially orthogonal to the L-shaped metal folded patch;

[0006] A magnetoelectric dipole is formed by a pair of parallel vertical metal pillars symmetrical about the gap, an L-shaped metal folded patch, and a rounded rectangular patch.

[0007] Furthermore, the gap of the I-shaped slot is a gradually changing gap, the four corners of the rounded rectangular patch are rounded, and the thickness of the top part of the inner conductor of the rectangular coaxial structure is twice that of the bottom part.

[0008] Furthermore, the antenna array also includes a power divider and a magnetoelectric dipole antenna array;

[0009] The power divider includes an inner conductor and an outer conductor of a rectangular coaxial structure. The power divider performs Chebyshev impedance transformation through three rectangular coaxial impedance matching lines of second, second, and third order, respectively, to form four output ports of the power divider. The inner conductors at the four output ports of the power divider are connected to the top of the inner conductor of the rectangular coaxial structure at the feed point of the magnetoelectric dipole antenna array. The bottom of the inner conductor of the rectangular coaxial structure is shorted to the outer conductor of the rectangular coaxial structure. The I-shaped slotted metal ground plane is connected to the outer conductor of the rectangular coaxial structure.

[0010] Furthermore, multiple support bars are interspersed between the inner and outer conductors of the rectangular coaxial power divider. The support bars are embedded between the inner and outer conductors of the rectangular coaxial power divider to support the suspended inner conductor.

[0011] Furthermore, the rectangular coaxial inner conductor of the power divider is formed with alternating thicknesses of 0.1 mm and 0.2 mm, and the magnetoelectric dipole antenna array has a thickness of 1.1 mm.

[0012] Furthermore, the inner conductor of the power divider is composed of three Chebyshev impedance transformations; the first segment, from 50 ohms to 32.5 ohms, is achieved using a second-order Chebyshev impedance transformation; the second segment, from 65 ohms to 32.5 ohms, is achieved using a second-order Chebyshev impedance transformation; and the third segment, from 65 ohms to 23.7 ohms, is achieved using a third-order Chebyshev impedance transformation. The connection points of the inner conductors with different impedances are designed with chamfers, and the four output ports are adjacent with a distance of 3.45 mm between each pair.

[0013] Furthermore, the I-shaped slotted metal floor shares a layer with the upper wall of the outer conductor in the power divider.

[0014] Furthermore, the inner conductor portion of the power divider is formed by alternating connections of two inner conductors and one inner conductor; the support bar is embedded between the two inner conductors and supported below the one inner conductor; a protruding cylinder is designed below the one inner conductor for inserting into the support bar to increase the interlocking between the support bar and the inner conductor; the input port of the power divider is connected to the output port of the waveguide structure.

[0015] Furthermore, the antenna array also includes a CNC waveguide structure, which is connected to the ground of the magnetoelectric dipole antenna array to form a waveguide structure for feeding.

[0016] The MEFAB process is formed by stacking layers, one of which is the ground of the magnetoelectric dipole antenna array and is also part of the waveguide structure.

[0017] The CNC waveguide structure has two threaded holes distributed on the left and right sides, which allows the CNC waveguide structure to be fixed on the magnetoelectric dipole antenna array.

[0018] As can be seen from the above technical solution, the present invention provides a millimeter-wave broadband antenna array fabricated using MEFAB technology. Compared with the prior art, the present invention has the following advantages:

[0019] 1. This invention reduces the overall cross-sectional height of the antenna by using vertical metal pillars; it achieves effective excitation of electric and magnetic dipoles through slotted, gradually changing I-shaped gaps; and it increases the maximum gain of the antenna element to 11.25 dBi and the maximum gain of the antenna array to 16.62 dBi through the combined radiation of two pairs of magnetic and electric dipoles.

[0020] 2. This invention reduces the overall profile height of the antenna by changing the current path through a folded L-shaped patch and a vertical metal pillar; and by leaving a large space between the horizontal rounded rectangular patch and the vertical metal pillar to generate a capacitance effect, thus achieving antenna matching. Attached Figure Description

[0021] Figure 1 This is a three-dimensional structural schematic diagram of a millimeter-wave broadband antenna array fabricated using the MEFAB process according to the present invention.

[0022] Figure 2 This is a three-dimensional structural diagram of a millimeter-wave broadband antenna array without CNC structure manufactured using MEFAB process according to the present invention.

[0023] Figure 3 This is a top view of a millimeter-wave broadband antenna array without CNC structure fabricated using MEFAB process according to the present invention.

[0024] Figure 4 This is a top view of the CNC-free structure and rounded rectangular patch of a millimeter-wave broadband antenna array fabricated using MEFAB process according to the present invention.

[0025] Figure 5 This is a schematic diagram of the main view structure of a millimeter-wave broadband antenna array fabricated using MEFAB process according to the present invention.

[0026] Figure 6 This is a simulation diagram of the return loss parameters of a millimeter-wave broadband antenna array fabricated using the MEFAB process of the present invention.

[0027] Figure 7 This is a simulation diagram of the gain of a millimeter-wave broadband antenna array fabricated using the MEFAB process of the present invention.

[0028] Figure 8This is a simulation diagram of the gain as a function of the Theta angle at 70 GHz with Phi=0° in the Phi direction.

[0029] Figure 9 This is a simulation diagram of the gain as a function of the Theta angle at 75 GHz with Phi=0° in the Phi direction.

[0030] Figure 10 This is a simulation diagram of the gain as a function of the Theta angle at 80 GHz with Phi=0° in the Phi direction.

[0031] Figure 11 This is a simulation diagram showing the gain as a function of the Theta angle at 70 GHz with Phi = 90° in the Phi direction.

[0032] Figure 12 This is a simulation diagram showing the gain as a function of the Theta angle at 75 GHz with Phi = 90° in the Phi direction.

[0033] Figure 13 This is a simulation diagram showing the gain variation with the Theta angle at 80 GHz, with Phi = 90° in the Phi direction.

[0034] Figure label:

[0035] 1. CNC waveguide structure; 2. Power divider; 3. Metal ground plane; 4. Magnetoelectric dipole antenna array; 5. Vertical metal column; 6. L-shaped metal folded patch; 7. Rounded rectangular patch; 8. Inner conductor; 9. Outer conductor; 10. Rectangular coaxial impedance matching line; 11. Support bar. Detailed Implementation

[0036] 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 some embodiments of the present invention, but not all embodiments.

[0037] like Figure 1As shown, a millimeter-wave broadband antenna array fabricated using MEFAB process in this embodiment includes an I-shaped slotted metal floor 3, two pairs of parallel vertical metal pillars 5, an L-shaped folded metal patch 6, two pairs of rounded rectangular patches 7, and a rectangular coaxial structure. The bottom end of the vertical metal pillar 5 is fixedly connected to the I-shaped slotted metal floor 3, the top end of the vertical metal pillar 5 is connected to the L-shaped folded metal patch 6, and the bottom end of the rounded rectangular patch 7 is connected to the L-shaped folded metal patch 6. The two pairs of parallel vertical metal pillars 5, the L-shaped folded metal patch 6, and the rounded rectangular patch 7 are respectively located on both sides of the slot of the I-shaped slot. The two pairs of rounded rectangular patches 7 are parallel to the I-shaped slotted metal floor 3, and the rounded rectangular patches 7 are spatially orthogonal to the L-shaped folded metal patch 6.

[0038] Among them, a pair of parallel vertical metal pillars 5, L-shaped metal folded patch 6, and rounded rectangular patch 7, symmetrical about the gap, form a magnetoelectric dipole.

[0039] Specifically, the gaps in the I-shaped slots are gradually changing, the four corners of the rounded rectangular patch 7 are rounded, and the thickness of the top part of the inner conductor 8 in the rectangular coaxial structure is twice that of the bottom part.

[0040] The antenna array also includes a power divider 2 and a magnetoelectric dipole antenna array 4;

[0041] The power divider 2 includes an inner conductor 8 and an outer conductor 9 of a rectangular coaxial structure. The power divider 2 performs Chebyshev impedance transformation through three rectangular coaxial impedance matching lines 10 of second-order, second-order, and third-order quarter-wavelengths, respectively, and forms four output ports of the power divider 2. The inner conductor 8 at the four output ports of the power divider 2 is connected to the top of the inner conductor 8 of the rectangular coaxial structure at the feed point of the magnetoelectric dipole antenna array 4. The bottom of the inner conductor 8 of the rectangular coaxial structure is shorted to the outer conductor 9 of the rectangular coaxial structure. The I-shaped slotted metal ground plate 3 is connected to the outer conductor 9 of the rectangular coaxial structure.

[0042] like Figure 2 As shown, the power divider 2 based on the MEFAB process expands the single input port into two output ports through a second-order Chebyshev impedance transformation. The two output ports are then expanded into four output ports through a second-order Chebyshev impedance transformation. The four output ports are connected to the input ports of the four magnetoelectric dipole antenna arrays 4 through a third-order Chebyshev impedance transformation. The power divider 2 based on the MEFAB process performs power distribution in the form of a rectangular coaxial structure. The rectangular coaxial structure is provided with an inner conductor 8 and an outer conductor 9. The inner conductor 8 is supported by a support bar 11 and is suspended at the central axis of the outer conductor 9.

[0043] like Figure 3 , Figure 4 , Figure 5As shown, the electromagnetic wave energy transmitted by the power divider 2 based on MEFAB process technology is divided into four parts and transmitted to the coaxial input terminals of four magnetoelectric dipole antenna arrays 4. The coaxial input terminals of the magnetoelectric dipole antenna arrays 4 receive the energy and propagate within the rectangular coaxial space. The energy is released from the I-shaped slot in the metal ground plane 3. The released energy simultaneously acts on the vertical metal pillar 5 and the rounded rectangular patch 7. The metal ground plane 3 and the surrounding cavity structure together suppress back radiation and enhance forward radiation. The two pairs of vertical walls of the magnetoelectric dipole unit and the L-shaped metal folded patch 6 are located on both sides of the I-shaped slot and form a magnetic flux loop through the slot. The height of the vertical metal pillar 5 and the height and position of the L-shaped metal folded patch 6 together affect the resonant frequency of the magnetic dipole. The rounded rectangular patch 7 is equivalent to an electric dipole, and its length affects the resonant frequency of the electric dipole. The L-shaped metal folded patch 6 leaves a large space between the vertical metal pillar 5 and the rounded rectangular patch 7, which is equivalent to a capacitance effect, optimizing the antenna matching.

[0044] Between the inner conductor 8 and the outer conductor 9 of the rectangular coaxial power divider 2, multiple support bars 11 are interspersed. The support bars 11 are embedded between the inner conductor 8 and the outer conductor 9 of the rectangular coaxial power divider to support the suspended inner conductor 8.

[0045] The rectangular coaxial inner conductor 8 of the power divider 2 is formed with alternating thicknesses of 0.1 mm and 0.2 mm, and the magnetoelectric dipole antenna array 4 has a thickness of 1.1 mm.

[0046] The inner conductor 8 of the power divider 2 is composed of three Chebyshev impedance transformations; the first segment from 50 ohms to 32.5 ohms is achieved using a second-order Chebyshev impedance transformation, the second segment from 65 ohms to 32.5 ohms is achieved using a second-order Chebyshev impedance transformation, and the third segment from 65 ohms to 23.7 ohms is achieved using a third-order Chebyshev impedance transformation; the connection points of the inner conductors 8 with different impedances adopt a chamfer design, and the four output ports are adjacent with a distance of 3.45 mm between each pair.

[0047] Specifically, in the millimeter-wave broadband antenna array and low-loss feed network based on MEFAB process, the excitation signal is input from the input port of the power divider 2, and transmitted to the magnetoelectric dipole antenna array 4 after two 1-to-2 power distributions, and the energy is radiated outward through the gaps in the metal ground plane 3; the inner conductor 8 based on MEFAB process has chamfered corners at the bends to reduce reflection, and chamfers are designed at the connection parts of the inner conductors 8 with different impedances to make the impedance transition smooth. The single input port of power divider 2 is sequentially transformed to the output port using three impedance transformation lines: a second-order Chebyshev impedance transformation line, a third-order Chebyshev impedance transformation line, and a second-order Chebyshev impedance transformation line. The inner conductor 8 of the first second-order Chebyshev impedance transformation line has a width of 0.202mm (double layer) and 0.279mm (double layer); the inner conductor 8 of the second second-order Chebyshev impedance transformation line has a width of 0.173mm (single layer) and 0.133mm (double layer); and the inner conductor 8 of the third third-order Chebyshev impedance transformation line has a width of 0.253mm (double layer), 0.173mm (single layer), and 0.25mm (double layer). Finally, the inner conductor 8 with a width of 0.25mm (double layer) is connected to the inner conductor 8 of the feed input port of the magnetoelectric dipole antenna array 4.

[0048] The I-shaped slotted metal floor 3 shares a layer with the upper wall of the outer conductor 9 in the power divider 2.

[0049] The inner conductor 8 of the power divider 2 is formed by alternating connections of two inner conductors 8 and one inner conductor 8; the support bar 11 is embedded between the two inner conductors 8 and supported below the one inner conductor 8; a protruding cylinder is designed below the one inner conductor 8 to insert into the support bar 11 and increase the interlocking between the support bar 11 and the inner conductor 8; the input port of the power divider 2 is connected to the output port of the waveguide.

[0050] The antenna array also includes a CNC waveguide structure 1, which is connected to the ground of the magnetoelectric dipole antenna array 4 to form a waveguide structure for feeding.

[0051] Two threaded holes are distributed on the left and right sides of the CNC waveguide structure 1, which allows the CNC waveguide structure 1 to be fixed on the magnetoelectric dipole antenna array 4.

[0052] The specific parameters of each structure in the antenna array are as follows:

[0053] The support bar 11 has a thickness of 0.035 mm, a relative permittivity of 2.85, and a loss tangent of 0.045°. The vertical metal pillar 5 of the magnetoelectric dipole unit has a height of 0.3 mm, a side length of 0.56 mm, and chamfers of 0.26 mm and 0.11 mm respectively; the L-shaped metal folded patch 6 has a height of 0.1 mm, a length of 0.56 mm, and a chamfer of 0.26 mm; the rounded rectangular patch 7 has a length of 1.375 mm and chamfers of 0.265 mm, 0.31 mm, and 0.62 mm respectively. The height of the vertical metal pillar 5 and the L-shaped metal folded patch 6, and the length of the rounded rectangular patch 7 affect the resonant frequency of the magnetoelectric dipole antenna array 4. The opening width of the I-shaped slot shrinks from 0.26 mm towards the center to 0.085 mm; the thickness of the inner conductor 8 of the rectangular coaxial feed structure of the magnetoelectric dipole antenna array 4 is 0.1 mm and 0.2 mm at the port. The rectangular coaxial inner conductor 8 of the power divider 2 is made of alternating layers with thicknesses of 0.2 mm and 0.1 mm.

[0054] Figure 6 The simulation results for the S11 (return loss) parameter of the antenna array in this example show that S11 < -10dB across the entire passband of the antenna (62.47-88.9GHz).

[0055] Figure 7 The simulation results for antenna gain show that the overall gain in the passband is above 14.17 dBi, and the maximum gain can reach 16.62 dBi.

[0056] Figures 8-13 These are radiation patterns of the antenna array at 70 GHz, 75 GHz, and 80 GHz, with Phi=0° and Phi=90°, respectively, showing the broadband radiation characteristics of the antenna array. The antenna's impedance bandwidth is approximately 35%. It features high gain, with a minimum gain of 14.17 dBi and a maximum of 16.62 dBi, while also exhibiting low cross-polarization. In the figures, deg represents the angle, Co-pol represents the main polarization, and Cross-pol represents the cross-polarization.

[0057] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0058] The various embodiments in this specification are described in a related manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0059] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention 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. Such 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 the present invention.

Claims

1. A millimeter-wave broadband antenna array fabricated using MEFAB process, characterized in that, The system includes an I-shaped slotted metal floor (3), two pairs of parallel vertical metal columns (5), an L-shaped metal folding patch (6), two pairs of rounded rectangular patches (7), and a rectangular coaxial structure. The bottom of the vertical metal column (5) is fixedly connected to the I-shaped slotted metal floor (3), the top of the vertical metal column (5) is connected to the L-shaped metal folding patch (6), and the bottom of the rounded rectangular patch (7) is connected to the L-shaped metal folding patch (6). The two pairs of parallel vertical metal columns (5), the L-shaped metal folding patch (6), and the rounded rectangular patch (7) are located on both sides of the gap of the I-shaped slot. The two pairs of rounded rectangular patches (7) are parallel to the I-shaped slotted metal floor (3), and the rounded rectangular patches (7) are orthogonal to the L-shaped metal folding patch (6) in space. The antenna array also includes a power divider (2) and a magnetoelectric dipole antenna array (4). The power divider (2) includes an inner conductor (8) and an outer conductor (9) of a rectangular coaxial structure. The power divider (2) performs Chebyshev impedance transformation through three rectangular coaxial impedance matching lines (10) of second, second and third order, respectively, and forms four output ports of the power divider (2). The inner conductor (8) at the four output ports of the power divider (2) is connected to the top of the inner conductor (8) of the rectangular coaxial structure at the feed point of the magnetoelectric dipole antenna array (4). The bottom of the inner conductor (8) of the rectangular coaxial structure is shorted to the outer conductor (9) of the rectangular coaxial structure. The metal ground plate (3) with an I-shaped slot is connected to the outer conductor (9) of the rectangular coaxial structure.

2. The millimeter-wave broadband antenna array fabricated using MEFAB process according to claim 1, characterized in that: The I-shaped slot has a gradually changing gap, the four corners of the rounded rectangular patch (7) are rounded, and the thickness of the top part of the inner conductor (8) of the rectangular coaxial structure is twice that of the bottom part.

3. A millimeter-wave broadband antenna array fabricated using MEFAB process according to claim 2, characterized in that: Between the inner conductor (8) and outer conductor (9) of the rectangular coaxial power divider (2), there are multiple support bars (11). The support bars (11) are embedded between the inner conductor (8) and outer conductor (9) of the rectangular coaxial power divider (2) to support the suspended inner conductor (8).

4. A millimeter-wave broadband antenna array fabricated using MEFAB process according to claim 1, characterized in that: The rectangular coaxial inner conductor (8) of the power divider (2) is formed with alternating thicknesses of 0.1 mm and 0.2 mm, and the magnetoelectric dipole antenna array (4) has a thickness of 1.1 mm.

5. A millimeter-wave broadband antenna array fabricated using MEFAB process according to claim 1, characterized in that: The inner conductor (8) of the power divider (2) is composed of three Chebyshev impedance transformations. The first segment from 50 ohms to 32.5 ohms is achieved using a second-order Chebyshev impedance transformation, the second segment from 65 ohms to 32.5 ohms is achieved using a second-order Chebyshev impedance transformation, and the third segment from 65 ohms to 23.7 ohms is achieved using a third-order Chebyshev impedance transformation. The connection between the inner conductors (8) with different impedances is designed with a chamfer. The four output ports are adjacent and the distance between each pair of adjacent output ports is 3.45 mm.

6. A millimeter-wave broadband antenna array fabricated using MEFAB process according to claim 1, characterized in that: The I-shaped slotted metal floor (3) shares a layer with the upper wall of the outer conductor (9) in the power divider (2).

7. A millimeter-wave broadband antenna array fabricated using MEFAB process according to claim 4, characterized in that: The inner conductor (8) portion of the power divider (2) is formed by alternating connections of two inner conductors (8) and one inner conductor (8); a support strip (11) is also embedded between the two inner conductors (8).

8. A millimeter-wave broadband antenna array fabricated using MEFAB process according to claim 5, characterized in that: The antenna array also includes a CNC waveguide structure (1), which is combined with the magnetoelectric dipole antenna array (4) to form a waveguide structure for power feeding. The input port of the power divider (2) is connected to the output port of the waveguide structure.

9. A millimeter-wave broadband antenna array fabricated using MEFAB process according to claim 8, characterized in that: The CNC waveguide structure (1) has two threaded holes distributed on the left and right sides, which fixes the CNC waveguide structure (1) onto the magnetoelectric dipole antenna array (4).

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