A micro-coaxial 3D-printed ultrawideband millimeter-wave antenna

Abstract

This invention discloses a micro-coaxial 3D-printed ultra-wideband millimeter-wave antenna, comprising: a back cavity, an irregularly shaped patch, a parasitic patch, a U-shaped slot, a micro-coaxial transmission line, and a test conductor. One end of the micro-coaxial transmission line is connected to the back cavity, and the other end is connected to the conductor. The irregularly shaped patch is symmetrically positioned along the Y-axis of the back cavity. The structure of the irregularly shaped patch, parasitic patch, and U-shaped slot is used to improve the antenna bandwidth and reduce the antenna's lateral dimensions. The conductor connects the antenna to the test waveguide. This invention effectively improves the antenna bandwidth and reduces the antenna's lateral dimensions.

Description

Technical Field

[0001] This invention relates to a micro-coaxial 3D-printed ultra-wideband millimeter-wave antenna, belonging to the field of spacecraft microwave antennas, and is mainly used in spacecraft ultra-wideband millimeter-wave passive phased array antenna array technology. Background Technology

[0002] With the development of wireless communication engineering, the millimeter-wave band is receiving increasing attention and interest. Millimeter waves lie between the microwave and infrared spectra. Compared to the microwave band, millimeter waves operate at higher frequencies and with shorter wavelengths, resulting in a significant reduction in the size of communication systems. In specific communication systems, given the aperture size, the smaller the operating wavelength, the higher the gain and the narrower the beamwidth. Narrower beamwidths offer several advantages. First, narrow beamwidths effectively reduce ground clutter interference to radar systems, facilitating small-angle detection missions. Second, narrow beamwidths effectively reduce the effects of multipath propagation. Furthermore, because the millimeter-wave band has a wider bandwidth, increasing the operating bandwidth allows communication systems within this band to achieve higher transmission rates and better range resolution.

[0003] 3D printing, as a type of additive manufacturing technology, can fabricate highly complex three-dimensional structures through layer-by-layer stacking under computer program control. Compared with traditional processing technologies, 3D printing offers lower processing costs, shorter manufacturing cycles, and greater flexibility in device structural design. Therefore, it has become increasingly popular in many fields such as biology, mechanics, and electromagnetism in recent years, and is widely used in electromagnetic devices operating in the millimeter-wave frequency band.

[0004] Traditional microwave device fabrication primarily involves printed circuit board (PCB) and computer numerical control (CNC) processes. While some existing fabrication technologies can be directly transferred to the millimeter-wave band, various incompatibilities remain, limiting the types and performance of fabricated devices, or significantly increasing processing costs and time, thus hindering mass production and widespread application. Therefore, finding a suitable process specifically for millimeter-wave / THz device fabrication that allows for controllable costs and time, scalable and commercially viable production, and greater design flexibility and complexity is a crucial issue in the millimeter-wave field. Summary of the Invention

[0005] The technical problem solved by this invention is to overcome the shortcomings of the prior art and provide a micro-coaxial 3D printed ultra-wideband millimeter-wave antenna. The all-metal 3D printing process overcomes the problems of high antenna loss and limited power handling capacity of traditional PCB processes. At the same time, in the millimeter-wave antenna design method, this method can effectively reduce the antenna's electrical size, providing technical support for grating lobe suppression of subsequent passive phased array antennas. Meanwhile, this method significantly improves the antenna bandwidth.

[0006] The technical solution of this invention is:

[0007] This invention discloses a micro-coaxial 3D-printed ultra-wideband millimeter-wave antenna, comprising: a back cavity, an irregularly shaped patch, a parasitic patch, a micro-coaxial outer conductor, and a test conductor. One end of the micro-coaxial transmission line outer conductor is connected to the back cavity, and the other end is connected to the test conductor. The irregularly shaped patch is located on the transverse central axis of the back cavity near the end of the micro-coaxial outer conductor. The irregularly shaped patch has a concave structure with an opening on one side forming a concave space. The parasitic patch is located on the central axis within the concave space of the irregularly shaped patch, forming two U-shaped slots symmetrical to the transverse central axis of the irregularly shaped patch with its inner wall. The U-shaped slots are used to improve the impedance bandwidth of the antenna. The test conductor is used to connect to an external test waveguide.

[0008] The millimeter-wave antenna mentioned above also includes a micro-coaxial inner conductor, which is located inside the micro-coaxial outer conductor.

[0009] The aforementioned millimeter-wave antenna also includes a support column located between the upper end face of the back cavity and the lower end face of the parasitic patch, used to support the irregular patch and the parasitic patch, and to adjust the impedance of the antenna.

[0010] In the millimeter-wave antenna described above, one end of the inner conductor of the micro-coaxial cable is connected to the probe, and the other end is connected to the test conductor.

[0011] The millimeter-wave antenna also includes a metal probe located between the upper end face of one end of the micro-coaxial inner conductor and the lower end face of the irregular patch, for feeding the irregular patch.

[0012] In the millimeter-wave antenna described above, the test conductor is connected to a metallic micro-coaxial outer conductor for connection to an external test waveguide.

[0013] In the millimeter-wave antenna described above, a cut is provided on the transverse axis of the test conductor, and the cut is used to connect to an external test waveguide port.

[0014] The millimeter-wave antenna also includes a rectangular matching patch connected to one end of the inner conductor of the micro-coaxial cable. The rectangular matching patch is used for impedance matching between the antenna and the test waveguide.

[0015] In the millimeter-wave antenna described above, the rectangular matching patch is placed within the cutout of the test conductor.

[0016] In the aforementioned millimeter-wave antenna, the total length C of the U-shaped slot... u =0.5~0.75λ0, where λ0 is the wavelength corresponding to the center frequency of the antenna.

[0017] The advantages of this invention compared to the prior art are as follows:

[0018] (1) The present invention uses a U-shaped slot structure with irregular patch loading to enable the antenna to have multiple resonant modes, thereby effectively widening the antenna's spectrum range and enabling the communication system to have higher communication capacity.

[0019] (2) The irregular patch structure used in this invention significantly reduces the lateral size of the antenna compared to the traditional rectangular patch, which can effectively suppress the grating lobes of the phased array antenna, increase the degree of freedom of the array spacing factor, and enable the array antenna to achieve better radiation characteristics. At the same time, the antenna also has the advantages of planarity, small size, light weight, and easy integration, making it particularly suitable for space applications. Attached Figure Description

[0020] Figure 1 This is a top view of the millimeter-wave antenna structure of the present invention;

[0021] Figure 2 This is a top view detail of the millimeter-wave antenna of the present invention;

[0022] Figure 3 This is a side view of the millimeter-wave antenna structure of the present invention;

[0023] Figure 4 This is a detailed view of the millimeter-wave antenna port of the present invention;

[0024] Figure 5 The return loss (S) of the millimeter-wave antenna of this invention 11 );

[0025] Figure 6 The return loss (E-plane) of the millimeter-wave antenna of this invention;

[0026] Figure 7 This refers to the return loss (H-plane) of the millimeter-wave antenna of this invention. Detailed Implementation

[0027] The present invention will now be described in detail with reference to the accompanying drawings and examples.

[0028] This invention discloses a micro-coaxial 3D-printed ultra-wideband millimeter-wave antenna, comprising: a back cavity 1, a shaped patch 2, a parasitic patch 3, a micro-coaxial outer conductor 7, and a test conductor 9. One end of the micro-coaxial transmission line outer conductor 7 is connected to the back cavity 1, and the other end is connected to the test conductor 9. The shaped patch 2 is located on the transverse central axis of the back cavity 1 near the end of the micro-coaxial outer conductor 7. The shaped patch 2 has a concave structure with an opening on one side forming a concave space. The parasitic patch 3 is located on the central axis within the concave space of the shaped patch 2, forming two U-shaped slots 4 symmetrical to the transverse central axis of the shaped patch 2 with the inner wall of the shaped patch 2. The U-shaped slots are used to improve the impedance bandwidth of the antenna. The test conductor 9 is used for connection to an external test waveguide. It also includes a micro-coaxial inner conductor 6, which is located inside the micro-coaxial outer conductor 7. It also includes a support post 5, located between the upper end face of the back cavity 1 and the lower end face of the parasitic patch 3, used to support the irregular patch 2 and the parasitic patch 3, and to adjust the impedance of the antenna. One end of the inner conductor 6 of the micro-coaxial cable is connected to the probe 8, and the other end is connected to the test conductor 9. It also includes a metal probe 8, located between the upper end face of one end of the inner conductor 6 of the micro-coaxial cable and the lower end face of the irregular patch 2, used to feed the irregular patch 2. The test conductor 9 is connected to the outer conductor 7 of the metal micro-coaxial cable, used to connect to an external test waveguide. A cutout 10 is provided on the transverse axis of the test conductor 9, the cutout being used to connect to the external test waveguide port. It also includes a rectangular matching patch 11, connected to one end of the inner conductor 6 of the micro-coaxial cable, the rectangular matching patch 11 being used for impedance matching between the antenna and the test waveguide.

[0029] The rectangular matching patch 11 is placed inside the cutout 10 of the test conductor 9.

[0030] The antenna includes a rectangular metal cavity 1, with length, width, and height of L respectively. g W g With H g A rectangular metal patch is used. A rectangular cut is made along the -Y direction at the midline of the wider side of the rectangular patch to form a concave metal patch 2. The length and width of this cut are W and W respectively. c With L c The concave metal patch 2 has a rectangular metal patch 3 at the central axis of its cut, the length and width of which are L. d With W d The concave metal patch 2 has a U-shaped slit symmetrical along the Y-axis at its central axis, and the width of the U-shaped slit is W. u Both arms are L in length u The total length C of the U-shaped gap 4 u =2×L u +W u =0.5~0.75λ0, where λ0 is the wavelength corresponding to the center frequency of the antenna.

[0031] The rectangular metal patch 3 has a metal support column 6 with a diameter of 0.1 mm and a height of H0 on its central axis. Its position on the central axis is determined according to the antenna matching. The support column connects the patch to the antenna ground.

[0032] The dimensions of the outer and inner conductors of the rectangular coaxial transmission line 7 are determined by the 50Ω matching of the coaxial line. The outer conductor of this coaxial line is divided by four equally spaced metal walls with a width of 0.1mm. The three transmission line isolation units have the same width, and the inner conductor is only placed inside the outer conductor located at the center position. The other two outer conductors do not have inner conductors. The length, width, and height dimensions of the outer conductor unit are determined by converting the impedance matching value of 50 ohms between the inner and outer conductors.

[0033] The inner conductor of the coaxial transmission line has a radius of R at its end. p Metal probe 8, the height of which is the distance between the upper surface of the inner metal conductor and the lower surface of the concave metal patch.

[0034] The rectangular coaxial transmission line 7 has a length, width, and height of W at the end furthest from the metal cavity. t L t With H g A rectangular through hole 10 is cut out along the central axis of the substrate 9. The length and width of the through hole are consistent with the dimensions of the waveguide port to which the test end is connected.

[0035] The extension of the micro-coaxial inner conductor 6 ends in a section with length and width L respectively. s With W s The substrate patch 11 has a height that matches the inner conductor of the rectangular coaxial transmission line 8.

[0036] The inner conductor 6 of the micro coaxial circuit is supported by dielectric support strips arranged periodically with a spacing of d1. The outer conductor is the same length as the inner conductor, and the outer conductor has release holes with a periodic spacing of d2 to remove photoresist that is not needed in the micro 3D printing process.

[0037] The millimeter-wave antenna is primarily fabricated using UV-LIGA lithography, a three-dimensional metal micromachining process.

[0038] Example:

[0039] like Figure 1 , 2As shown in Figure 3, this invention discloses a micro-coaxial 3D-printed ultra-wideband millimeter-wave antenna, comprising: a back cavity 1, an irregular patch 2, a parasitic patch 3, a U-shaped slot 4, a micro-coaxial inner conductor 6, a micro-coaxial outer conductor 7, and a test conductor 9. One end of the micro-coaxial transmission line outer conductor 7 is connected to the back cavity (1), and the other end is connected to the test conductor 9. The irregular patch 2 is located on the central axis of the cavity, the parasitic patch (3) is located on the central axis within the notch of the irregular patch (2), and the U-shaped slot (3) is symmetrical to the central axis of the irregular patch, used to improve the impedance bandwidth of the antenna. The test conductor (9) is used to connect the antenna and the test waveguide. The test conductor 9 has a cuboid structure, and its length, width, and height are W... t L t With H g The length of the dorsal cavity 1 is L. g Width is W g This is used to suppress back radiation of the antenna and reduce the back lobe level of the antenna radiation pattern. The irregularly shaped patch 2 has dimensions L... p With W p It is confirmed that the length of the parasitic patch is W. m The width is L m The length of the U-shaped gap is L u Width is W u .

[0040] like Figure 2 As shown, this invention discloses a micro-coaxial 3D-printed ultra-wideband millimeter-wave antenna, employing a back cavity height H g Based on the micro 3D printing process, this example uses a 9-layer micro 3D printing process, namely H... g The total height is 900 micrometers (the height of a single layer in this process is 100 micrometers);

[0041] like Figure 1 As shown, this invention discloses a micro-coaxial 3D-printed ultra-wideband millimeter-wave antenna, wherein one end of the micro-coaxial outer conductor 7 is connected to the back cavity 1, and the inner conductor 6 is located inside the micro-coaxial 7. The other end of the micro-coaxial outer conductor is connected to the test conductor.

[0042] like Figure 1 , 4 As shown, the present invention discloses a micro-coaxial 3D printed ultra-wideband millimeter-wave antenna, wherein the micro-coaxial inner conductor 6 is located inside the micro-coaxial outer conductor 7, one end of the inner conductor 6 is connected to the feed probe 8, and the other end is connected to the matching patch 11. The inner and outer conductors together form a micro-coaxial structure that transmits microwave signals to the radiating patch of the antenna.

[0043] like Figure 4As shown, this invention discloses a micro-coaxial 3D-printed ultra-wideband millimeter-wave antenna. Its cylindrical metal support 5 is located on the central axis of the irregular patch 2. Its upper surface is connected to the lower end face of the irregular patch 2, and its lower surface is connected to the upper end face of the metal cavity. The metal support is used to support the irregular patch 2. At the same time, by adjusting the position of the metal support 5 on the central axis of the irregular patch, the impedance matching of the antenna as a whole and the current distribution on the patch surface can be adjusted. The diameter of the metal support is 0.1 mm.

[0044] like Figure 4 As shown, this invention discloses a micro-coaxial 3D-printed ultra-wideband millimeter-wave antenna with a cylindrical metal feed 8 having a radius of R0 and a height equal to the distance between the lower surface of the irregular patch 2 and the upper surface of the micro-coaxial inner conductor 6. This feed is used to transmit the electromagnetic signal transmitted by the micro-coaxial antenna to the radiating patch 2.

[0045] like Figure 1 As shown, this invention discloses a micro-coaxial 3D-printed ultra-wideband millimeter-wave antenna, the length of which is W. s The width is L s This rectangular patch is used for impedance matching between the antenna and the test system.

[0046] In summary, the proposed antenna design method can achieve a relative impedance bandwidth of over 40%, an antenna gain of over 8 dBi, and a significant reduction in antenna size, with a lateral dimension of only 0.286λ (λ being the wavelength corresponding to the antenna center frequency) and a longitudinal dimension of only 0.309λ0 (λ0 being the wavelength corresponding to the antenna center frequency). This provides strong technical support for the subsequent low-grid-lobe phased array antenna array layout.

[0047] This embodiment provides an example of an antenna design with a center frequency of 60GHz-90GHz. This antenna can achieve a relative impedance bandwidth of more than 40%, such as... Figure 5 As shown, the maximum gain within the antenna bandwidth is 9 dBi. Figure 6 , Figure 7 As shown in Table 1, the parameter values ​​for each antenna example are presented.

[0048] Table 1. Antenna example parameter values ​​(unit: mm)

[0049] 1.2 1.3 0.8 0.65 0.6 <![CDATA[L m ]]> <![CDATA[L u ]]> <![CDATA[W u ]]> <![CDATA[W s ]]> <![CDATA[L s ]]> 0.3 1.07 1.02 0.75 0.47 <![CDATA[W t ]]> <![CDATA[L t ]]> <![CDATA[H g ]]> 10 6 0.9

[0050] The above embodiments are merely explanations of the present invention and should not be construed as limiting the present invention. Therefore, any implementation methods similar to the present invention or implementation methods used in other similar structures but with similar concepts to the present invention are within the protection scope of the present invention.

[0051] The above description is only the best specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the protection scope of the present invention.

[0052] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A micro-coaxial 3D-printed ultrawideband millimeter-wave antenna, characterized in that, include: The back cavity (1), the irregular patch (2), the parasitic patch (3), the micro-coaxial external conductor (7), and the test conductor (9) are configured such that one end of the micro-coaxial transmission line external conductor (7) is connected to the back cavity (1) and the other end is connected to the test conductor (9); the irregular patch (2) is located on the transverse central axis of the back cavity (1) near the end of the micro-coaxial external conductor (7); the irregular patch (2) has a concave structure with an opening on one side forming a concave space, and the parasitic patch (3) is located on the central axis within the concave space of the irregular patch (2). On the upper part, two U-shaped slots (4) are formed with the inner wall of the irregular patch (2) and are symmetrical about the transverse central axis of the irregular patch (2). The U-shaped slots are used to improve the impedance bandwidth of the antenna. The test conductor (9) is used to connect to the external test waveguide. It also includes a rectangular matching patch (11) connected to one end of the micro coaxial inner conductor (6). The rectangular matching patch (11) is used for impedance matching between the antenna and the test waveguide. The rectangular matching patch (11) is placed in the cut (10) of the test conductor (9).

2. The micro-coaxial 3D-printed ultra-wideband millimeter-wave antenna according to claim 1, characterized in that: It also includes a micro-coaxial inner conductor (6), which is located inside the micro-coaxial outer conductor (7).

3. The micro-coaxial 3D-printed ultra-wideband millimeter-wave antenna according to claim 1, characterized in that: It also includes a support column (5), located between the upper end face of the back cavity (1) and the lower end face of the parasitic patch (3), for supporting the irregular patch (2) and the parasitic patch (3) and adjusting the impedance of the antenna.

4. The micro-coaxial 3D-printed ultra-wideband millimeter-wave antenna according to claim 1, characterized in that: One end of the micro-coaxial inner conductor (6) is connected to the metal probe (8), and the other end is connected to the test conductor (9).

5. A micro-coaxial 3D-printed ultra-wideband millimeter-wave antenna according to claim 1 or 2, characterized in that: It also includes a metal probe (8), which is located between the upper end face of one end of the micro coaxial inner conductor (6) and the lower end face of the irregular patch (2), and is used to feed the irregular patch (2).

6. The micro-coaxial 3D-printed ultra-wideband millimeter-wave antenna according to claim 1, characterized in that: The test conductor (9) is connected to the metal micro-coaxial outer conductor (7) for connection to an external test waveguide.

7. The micro-coaxial 3D-printed ultra-wideband millimeter-wave antenna according to claim 1, characterized in that: A cut (10) is provided on the transverse axis of the test conductor (9), and the cut is used to connect to the external test waveguide port.

8. The micro-coaxial 3D-printed ultra-wideband millimeter-wave antenna according to claim 1, characterized in that: The total length C of the U-shaped gap (4) u =0.5~0.75λ0, where λ0 is the wavelength corresponding to the center frequency of the antenna.

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