Millimeter-wave metasurface radar receiving antenna, transmitting antenna, and integrated transceiver antenna

Abstract

This invention discloses a millimeter-wave metasurface radar receiving antenna, transmitting antenna, and integrated transceiver antenna. From top to bottom, it comprises an upper dielectric substrate, a first metal plate, a prepreg, a lower dielectric substrate, and a second metal plate. A receiving metasurface structure is formed on the upper surface of the upper dielectric substrate. A receiving feed slot is etched into the first metal plate. A receiving strip feed line is formed between the prepreg and the lower dielectric substrate. Metal vias are formed around the receiving metasurface structure, the receiving feed slot, and the receiving strip feed line on the upper surface of the upper dielectric substrate and between the second metal plate, forming a self-shielding cavity for the receiving antenna. This invention not only features small size, low profile, compact structure, and simple manufacturing, but also ensures high transmit / receive isolation and high-order harmonic suppression for the millimeter-wave radar transceiver antenna.

Description

Technical Field

[0001] This invention relates to the field of millimeter-wave communication, and in particular to a millimeter-wave metasurface radar receiving antenna, transmitting antenna, and transceiver integrated antenna. Background Technology

[0002] With the development of millimeter-wave technology, the unique functions of phased array antennas, such as simultaneous air search, identification, and tracking, as well as their high power, high data transmission capabilities, and resistance to environmental conditions, have greatly promoted the research, design, and equipment of phased array antennas. Currently, commercial applications in vehicle-mounted systems, early warning radar, wireless communication, and radio frequency identification place increasingly higher demands on antennas, especially on the need for flexible control of antenna patterns.

[0003] However, the high cost of phased array antennas severely restricts their application range. Low-cost design methods for active phased array antennas are an important direction for the development of electronically scanned antennas and a crucial prerequisite for the formation of a series of phased array antenna products. Furthermore, the operating frequency band of active phased array antennas is typically from the X-band to the millimeter-wave band. The higher the operating frequency, the smaller the area of ​​each radiating element, and the higher the integration requirements. Traditional design methods that simply assemble individual subsystem modules can no longer meet the requirements for array layout and maintenance. Highly integrated, unified design technology is necessary to achieve the goals of lightweight, scalable, and low-cost active phased array antennas. Summary of the Invention

[0004] To overcome the aforementioned shortcomings and deficiencies of the prior art, the present invention aims to provide a millimeter-wave metasurface radar receiving antenna, transmitting antenna, and integrated transceiver antenna. The present invention not only features small size, low profile, compact structure, and simple fabrication, but also ensures high transmit / receive isolation and high-order harmonic suppression for the millimeter-wave radar transceiver antenna.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] A millimeter-wave metasurface radar receiving antenna comprises, from top to bottom, an upper dielectric substrate, a first metal plate, a prepreg, a lower dielectric substrate, and a second metal plate. A receiving metasurface structure is formed on the upper surface of the upper dielectric substrate. A receiving feed gap is etched on the first metal plate. A receiving strip feed line is formed between the prepreg and the lower dielectric substrate. Metal through-holes are formed around the receiving metasurface structure, the receiving feed gap, and the receiving strip feed line on the upper surface of the upper dielectric substrate and between the second metal plate to form a self-shielding cavity for the receiving antenna.

[0007] Furthermore, the receiving metasurface structure is composed of M×N receiving annular patch units arranged in a centrally symmetrical periodic manner.

[0008] Furthermore, the receiving feed gap is an H-shaped gap, which is excited by the receiving strip feed line, further exciting the upper receiving metasurface structure to generate linearly polarized radiation.

[0009] Furthermore, the receiving strip feed line is a single-ended strip feed line.

[0010] A millimeter-wave metasurface radar transmitting antenna comprises, from top to bottom, an upper dielectric substrate, a first metal plate, a prepreg, a lower dielectric substrate, and a second metal plate. A transmitting metasurface structure is disposed on the upper surface of the upper dielectric substrate. A transmitting feed gap is etched on the first metal plate. A transmitting strip feed line is disposed between the prepreg and the lower dielectric substrate. The transmitting strip feed line also includes open-circuit stubs. Metal through-holes are disposed around the transmitting metasurface structure, the transmitting feed gap, and the transmitting strip feed line between the upper surface of the upper dielectric substrate and the second metal plate to form a self-shielding cavity for the transmitting antenna.

[0011] Furthermore, the emission metasurface structure comprises M×N emission annular patch units arranged in a centrally symmetrical periodic manner, with a square patch disposed within each emission annular patch unit.

[0012] Furthermore, the emitter feed gap is an I-shaped gap, which is excited by the emitter strip feed line, further exciting the emitter metasurface structure to generate linearly polarized radiation.

[0013] Furthermore, the transmitting strip feed line is a double-ended differential feed line.

[0014] Furthermore, the open-circuit stub is a sector of two quarter-wavelengths that suppress the third and fifth harmonic energies.

[0015] Furthermore, a row of metal vias is provided on one side of the square patch, and it is located within the emitting annular patch unit.

[0016] Furthermore, the I-shaped slit is offset from the center of the emitting metasurface structure, thereby suppressing the fifth harmonic energy pair.

[0017] A self-shielded millimeter-wave metasurface radar transceiver integrated antenna includes a receiving antenna and a transmitting antenna, which are symmetrically arranged on both sides of the antenna. The line connecting their centers is perpendicular to the antenna polarization direction. A decoupling structure to suppress energy coupling between the receiving and transmitting antennas is provided at the middle position of the receiving and transmitting antennas. The feed point is concentrated at the center of the bottom of the antenna. Specifically, the receiving antenna is the millimeter-wave metasurface radar receiving antenna according to any one of claims 1-4, and the transmitting antenna is the millimeter-wave metasurface radar transmitting antenna according to any one of claims 5-11.

[0018] Furthermore, the decoupling structure comprises a periodic arrangement of rectangular metal strips, with a grounding metal via disposed within each rectangular metal strip.

[0019] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0020] (1) The present invention symmetrically sets the self-shielded receiving antenna and the self-shielded transmitting antenna on both sides of the antenna body, with the center line connecting the two perpendicular to the antenna polarization direction, and the feed point is concentrated at the center of the bottom of the antenna, thus avoiding the complexity of the feed network and ensuring the easy integration, symmetry and compact structure of the transmitting and receiving antennas.

[0021] (2) This invention adopts a simple four-layer PCB manufacturing process, and by setting a self-shielding cavity, it completely surrounds the metasurface structure, feed gap and strip feed line of the receiving antenna and the transmitting antenna respectively. While suppressing the energy leakage of the strip feed line, it avoids the setting of blind holes and buried holes that are difficult to implement, and realizes the independence of the receiving antenna and the transmitting antenna themselves.

[0022] (3) The present invention uses a ring-shaped metasurface structure as a radiator to reduce the area occupied by the metasurface antenna and the self-shielding cavity.

[0023] (4) The present invention reduces the area occupied by the power supply network and the self-shielding cavity by reducing the routing of the strip feeder and using H-shaped and "I"-shaped power supply gaps.

[0024] (5) The present invention achieves energy suppression of the third and fifth harmonics by setting two quarter-wavelength fan-shaped open stubs on the strip feed line of the self-shielded transmitting antenna.

[0025] (6) The present invention further improves the suppression of the fifth harmonic energy of the transmitting antenna by setting an asymmetric feeding gap off the center of the radiating patch on the first metal plate of the self-shielded transmitting antenna.

[0026] (7) The present invention reduces the cavity size of the feed network by setting two rows of metal vias bridging the upper surface of the upper dielectric substrate and the second metal plate in the annular patch of the self-shielded transmitting antenna, thereby further improving the suppression of the third harmonic energy of the transmitting antenna and improving the impedance matching characteristics of the antenna.

[0027] (8) The present invention improves the impedance matching characteristics of the antenna by setting a square patch inside the square ring patch of the self-shielded transmitting antenna.

[0028] (9) The present invention uses a periodically arranged decoupling structure to achieve high isolation between the single port and differential port of the transmit and receive antennas.

[0029] (10) The present invention has the characteristics of small size, low profile, compact structure, simple processing and low cost, and thus can be mass-produced. Attached Figure Description

[0030] Figure 1 This is a three-dimensional schematic diagram of the structure of the self-shielded millimeter-wave radar transceiver integrated antenna in Embodiment 1 of the present invention;

[0031] Figure 2(a) is a top view of the self-shielded millimeter-wave radar transceiver integrated antenna in Embodiment 1 of the present invention;

[0032] Figure 2(b) is a side view of the self-shielded millimeter-wave radar transceiver integrated antenna in Embodiment 1 of the present invention;

[0033] Figure 3(a) is a top view and dimension diagram of the upper dielectric substrate of the self-shielded millimeter-wave radar transceiver integrated antenna in Embodiment 1 of the present invention;

[0034] Figure 3(b) is a top view and dimension diagram of the first layer metal plate of the self-shielded millimeter-wave radar transceiver integrated antenna in Embodiment 1 of the present invention;

[0035] Figure 3(c) is a schematic diagram of the strip feed line routing and dimensions of the self-shielded millimeter-wave radar transceiver integrated antenna in Embodiment 1 of the present invention;

[0036] Figure 4 This is a result diagram of the S-parameters of the self-shielded millimeter-wave radar transceiver integrated antenna in Embodiment 1 of the present invention;

[0037] Figure 5 This is the radiation pattern of the receiving antenna in Embodiment 1 of the present invention;

[0038] Figure 6 This is the radiation pattern of the transmitting antenna in Embodiment 1 of the present invention;

[0039] Figure 7 This is a graph showing the high-harmonic efficiency of the transmitting antenna in Embodiment 1 of the present invention;

[0040] Figure 8 This is a gain result diagram of the self-shielded millimeter-wave radar transceiver integrated antenna in Embodiment 1 of the present invention. Detailed Implementation

[0041] The present invention will be further described in detail below with reference to the embodiments, but the implementation of the present invention is not limited thereto.

[0042] Example

[0043] like Figure 1 As shown in Figures 2(a) and 2(b), a self-shielded millimeter-wave metasurface radar transceiver integrated antenna is fabricated using a multilayer PCB process, with the entire antenna using Roger 5880 as the dielectric substrate. The dielectric constant ε of the dielectric substrate is... r The thickness is [1, 10.2], and the thickness is [0.01λ, 0.3λ]. The thickness of the metal floor is [0.005λ, 0.1λ], where λ is the free space wavelength.

[0044] Specifically, it includes a self-shielded receiving antenna 6, a self-shielded transmitting antenna 7, and a decoupling structure 16 for suppressing energy coupling between the transmitting and receiving antennas. The self-shielded receiving antenna 6 and the self-shielded transmitting antenna 7 are symmetrically placed on both sides of the antenna assembly, with the line connecting their centers perpendicular to the antenna polarization direction, and the feed point concentrated at the center of the bottom of the antenna. The decoupling structure 16 for suppressing energy coupling between the transmitting and receiving antennas is located at the center of the two antennas.

[0045] The coupling structure consists of square metal patches and grounding metal vias arranged periodically on the upper dielectric substrate 1, which effectively suppresses energy coupling between the single port of the self-shielded receiving antenna 6 and the differential port of the self-shielded transmitting antenna 7.

[0046] In this embodiment, the coupling structure consists of 3*2 square metal patches, each square metal patch having a grounding metal via.

[0047] Further, as shown in Figures 3(a), 3(b), and 3(c), the self-shielded receiving antenna includes, from top to bottom, an upper dielectric substrate 1, a first metal plate 2, a prepreg 3, a lower dielectric substrate 4, and a second metal plate 5. A receiving metasurface structure 8 is provided on the upper surface of the upper dielectric substrate 1. A receiving feed gap 10 is etched on the first metal plate 2. A receiving strip feed line 12 is provided between the prepreg 3 and the lower dielectric substrate 4. Metal through holes are provided around the receiving metasurface structure 8, the receiving feed gap 10, and the receiving strip feed line 12 on the upper surface of the upper dielectric substrate 1 and between the second metal plate 5 to form a self-shielded cavity 14 for the receiving antenna.

[0048] In this embodiment, the receiving metasurface structure is composed of M×N receiving ring patch units arranged in a centrally symmetrical periodic pattern. The ring design increases the surface current path of the metasurface structure and effectively reduces its size. The ring patch units are not limited to square ring structures, but can also be parallelogram, trapezoidal, or rhomboid ring structures.

[0049] Furthermore, in this embodiment, the receiving annular patch unit is a square annular shape, and the receiving metasurface structure includes 2*1 square annular patch units.

[0050] Furthermore, in this embodiment, the receiving feed gap 10 is an H-shaped gap, etched on the first metal plate, and excited by the strip feed line, thereby exciting the annular metasurface structure above to generate linear polarized radiation; the receiving feed gap is a single gap, and the shape of the feed gap is not limited, and can be H-shaped, U-shaped, I-shaped or horizontal, etc.

[0051] The receiving strip feed of the self-shielded receiving antenna 6 is in the form of a strip line, which is a single-ended strip feed line. The strip feed line transitions from the grounded coplanar waveguide 17 located at the bottom of the antenna through a metal via to the strip feed line, and is routed in a straight line, arc or 45-degree angle mode to the H-shaped feed slot and excited. The single-ended strip feed line of the self-shielded receiving antenna achieves impedance matching adjustment through quarter-wavelength impedance transformation.

[0052] In this embodiment, the millimeter-wave metasurface radar receiving antenna adopts a simple four-layer PCB manufacturing process. The self-shielding cavity of the receiving antenna is composed of several metal through holes between the upper surface of the upper dielectric substrate and the second metal plate, which completely surrounds the annular metasurface structure, the feeding gap and the strip feed line. While suppressing energy leakage of the strip feed line, it avoids the setting of blind holes and buried holes that are difficult to implement, and realizes the independence of the receiving antenna itself.

[0053] A self-shielded millimeter-wave metasurface radar transmitting antenna comprises, from top to bottom, an upper dielectric substrate 1, a first metal plate 2, a prepreg 3, a lower dielectric substrate 4, and a second metal plate 5. A transmitting metasurface structure 9 is disposed on the upper surface of the upper dielectric substrate 1. A transmitting feed gap 11 is etched on the first metal plate 2. A transmitting strip feed line 13 is disposed between the prepreg 3 and the lower dielectric substrate 4. Metal through holes are disposed around the transmitting metasurface structure 9, the transmitting feed gap 11, and the transmitting strip feed line 13 on the upper surface of the upper dielectric substrate 1 and between the second metal plate 5 to form a self-shielding cavity 15 for the transmitting antenna.

[0054] Furthermore, in this embodiment, the transmitting metasurface structure includes M×N transmitting ring patch units arranged in a centrally symmetrical periodic manner. Each transmitting ring patch unit contains a square patch, preferably a square ring patch. The ring design increases the surface current path of the metasurface structure and effectively reduces the size of the metasurface structure. The square patch effectively improves the impedance characteristics of the antenna.

[0055] The metal patch is not limited to square shapes; it can also be a miniaturized parallelogram, trapezoid, rhombus, or other shapes.

[0056] Furthermore, the transmitting feed slot 11 is an "I"-shaped feed slot, disposed on the first metal ground plane, to excite the transmitting metasurface structure 9 to generate linearly polarized radiation; the transmitting feed slot is a single slot, and its shape is not limited, and can be I-shaped, H-shaped, U-shaped, or horizontal, etc. In this embodiment 1, an asymmetric "I"-shaped feed slot is etched at a position off-center from the center of the transmitting metasurface structure 9.

[0057] Furthermore, the transmitting feed line is in the form of a strip line, with the feed point being a grounded coplanar waveguide located at the center of the second metal plate. It transitions from the grounded coplanar waveguide to the strip feed line through a metal via, and is routed in straight lines, arcs, or 45-degree angles to a position perpendicular to the feed gap and for excitation. The strip feed line is equipped with two quarter-wavelength fan-shaped open-circuit stubs, which effectively suppress the third and fifth harmonic energy.

[0058] Furthermore, two rows of metal vias 18 are provided within the square ring patch, bridging the upper surface of the upper dielectric substrate and the second metal plate. These metal vias are located on the upper and lower sides of the two square patches, reducing the size of the self-shielding cavity of the transmitting antenna and further suppressing the third harmonic energy.

[0059] The I-shaped power supply gap is etched at a position off-center from the center of the square ring and square patch, further achieving suppression of the fifth harmonic energy pair.

[0060] The transmitting antenna in this embodiment of the invention adopts a simple four-layer PCB manufacturing process. The self-shielding cavity of the transmitting antenna is composed of several metal through holes between the upper surface of the upper dielectric substrate and the second metal plate, which completely surrounds the transmitting metasurface structure, the transmitting feed gap and the transmitting strip feed line. While suppressing energy leakage of the transmitting strip feed line, it avoids the setting of blind holes and buried holes that are difficult to implement, and realizes the independence of the transmitting antenna itself.

[0061] The self-shielded millimeter-wave radar transceiver integrated antenna has the following dimensions:

[0062] For the self-shielded receiving antenna, the height H1 of the ring-shaped metasurface radiating patch is 0.787 mm, the width rw1 of the square ring patch is 2.2 mm, the length rl1 is 1.65 mm, the ring width rw3 is 0.15 mm, rw4 is 0.175 mm, and the edge spacing rg1 of the square ring element is 0.1 mm; the length rl2 and width rw2 of the self-shielded cavity 14 of the receiving antenna are 3.9 mm and 2.7 mm respectively, and its metal via diameter is 0.1 mm. The metal via center spacing is 0.3mm; the length rl3 of the H-shaped feed gap etched on the first metal plate 2 is 2.2mm, rl4 is 1.3mm, and the gap width rg2 is 0.2mm; the step impedance transformation width rw5 of the single-ended strip feed is 0.19mm, rw6 is 0.4mm, rw7 is 0.1mm, rw8 is 0.18mm, and the length rl5 is 0.6mm and rl6 is 0.34mm.

[0063] For the self-shielded transmitting antenna 7, the height H1 of the ring and square metasurface radiating patches is 0.787 mm. Among them, the length tl1 of the square ring patch is 1.66 mm, the width tw1 is 2.17 mm, the ring widths tw4 and tw5 are 0.1 mm, the edge spacing tg1 of the square ring unit is 0.2 mm, the length tl2 of the square patch inside the ring is 1 mm, the width tw2 is 1.77 mm, and the edge spacing tg2 of the square patch and the ring patch is 0.1 mm. The length tl3 and width tw3 of the self-shielded cavity of the transmitting antenna are 3.9 mm and 2 mm, respectively. The metal via diameter is 0.15 mm, and the center-to-center spacing of the metal vias is 0.3 mm. The lengths tl4, tl5, and tl6 of the H-shaped feed gaps 11 etched on the first metal plate 2 are 1.57 mm, 1.37 mm, and 0.8 mm, respectively. The gap width tg6 is 0.1 mm, and the spacing between the two rows of metal vias is 2.95 mm. The step impedance transformation widths tw6 and tw7 of the strip feed line are 0.1 mm and 0.23 mm, respectively. The open stub lengths tl8 and tl9 are 0.46 mm and 0.29 mm, respectively.

[0064] For the decoupling structure 16 that suppresses energy coupling of the transmitting and receiving antennas, the length el of the periodically arranged metal patches is 2.47 mm, the width ew is 0.2 mm, the edge spacing eg1 and eg2 is 0.1 mm, and the diameter of the grounding metal via is 0.1 mm.

[0065] like Figure 4 As shown, the self-shielded millimeter-wave metasurface radar transceiver antenna operates in the 24-26 GHz frequency band. All ports within the band have a reflection coefficient below -14 dB, and the isolation between the single port of the receiving antenna and the differential port of the transmitting antenna is greater than 25 dB. This design ensures high transmit / receive isolation while maintaining a compact structure. Figure 8 As shown, the gains of the self-shielded receiving antenna and the self-shielded transmitting antenna are 5.3-5.6 dBi and 5.0-5.5 dBi, respectively; from Figure 5 and Figure 6 It can be seen that the E-plane radiation patterns of the self-shielded receiving antenna and the self-shielded transmitting antenna are well symmetrical; for example... Figure 7 and Figure 8 As shown, the transmitting antenna suppresses energy by more than 32.5 dB and 12 dB in the third and fifth harmonics, respectively.

[0066] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the embodiments described above. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A millimeter wave metasurface radar transceiver integrated antenna, characterized in that, The receiving antenna and the transmitting antenna are symmetrically arranged on both sides of the antenna, and the center line of the two is perpendicular to the polarization direction of the antenna, the middle position of the receiving antenna and the transmitting antenna is provided with a decoupling structure for suppressing the energy coupling of the receiving antenna and the transmitting antenna, and the feed points are concentrated in the center position of the bottom of the antenna. The receiving antenna is a millimeter wave super surface radar receiving antenna, which comprises, from top to bottom, an upper dielectric substrate, a first metal plate, a prepreg, a lower dielectric substrate and a second metal plate, a receiving super surface structure is arranged on the upper surface of the upper dielectric substrate, a receiving feed gap is etched on the first metal plate, a receiving strip-shaped feed line is arranged between the prepreg and the lower dielectric substrate, and metal through holes are arranged around the receiving super surface structure, the receiving feed gap and the receiving strip-shaped feed line between the upper surface of the upper dielectric substrate and the second metal plate to form a self-shielding cavity of the receiving antenna. The transmitting antenna is a millimeter wave super surface radar transmitting antenna, which comprises, from top to bottom, an upper dielectric substrate, a first metal plate, a prepreg, a lower dielectric substrate and a second metal plate, a transmitting super surface structure is arranged on the upper surface of the upper dielectric substrate, the transmitting super surface structure comprises M×N transmitting ring-shaped patch units arranged in a central symmetric period, and a square patch is arranged in each transmitting ring-shaped patch unit. A transmitting feed gap is etched on the first metal plate, a transmitting strip-shaped feed line is arranged between the prepreg and the lower dielectric substrate, the transmitting strip-shaped feed line further comprises an open stub, and metal through holes are arranged around the transmitting super surface structure, the transmitting feed gap and the transmitting strip-shaped feed line between the upper surface of the upper dielectric substrate and the second metal plate to form a self-shielding cavity of the transmitting antenna. The open stub is two quarter-wavelength fan-shaped structures for suppressing third and fifth harmonic energy. One side of the square patch is provided with a row of metal vias, and the metal vias are located in the transmitting ring-shaped patch unit. The decoupling structure comprises a plurality of rectangular metal strips arranged in a period, and a grounding metal via is arranged in each rectangular metal strip.

2. The millimeter-wave metasurface radar transceiving integrated antenna of claim 1, wherein, The receiving super surface structure comprises M×N receiving ring-shaped patch units arranged in a central symmetric period.

3. The millimeter-wave metasurface radar transceiving integrated antenna of claim 1, wherein, The receiving feed gap is an H-shaped gap, which is excited by the receiving strip-shaped feed line and further excites the upper receiving super surface structure to generate linear polarization radiation.

4. The millimeter-wave metasurface radar transceiving integrated antenna according to any one of claims 1-3, characterized in that, The receiving strip-shaped feed line is a single-ended strip-shaped feed line.

5. The millimeter-wave metasurface radar transceiving integrated antenna of claim 1, wherein, The transmitting feed gap is an I-shaped gap, which is excited by the transmitting strip-shaped feed line and further excites the transmitting super surface structure to generate linear polarization radiation.

6. The millimeter-wave metasurface radar transceiving integrated antenna of claim 1, wherein, The transmitting strip-shaped feed line is a double-ended differential feed line.

7. The millimeter-wave metasurface radar transceiving integrated antenna of claim 5, wherein, The I-shaped gap deviates from the center position of the transmitting super surface structure to achieve fifth harmonic energy suppression.

Images