A millimeter wave packaged antenna suitable for radar sensing

Abstract

The present invention discloses a millimeter wave packaged antenna suitable for radar sensing, comprising: a first dielectric substrate, a first metal floor, a second dielectric substrate and a second metal floor stacked in sequence; an antenna layer is arranged on the upper side of the first dielectric substrate, a gap and a plurality of short-circuit metal columns are arranged on the second metal floor, two ends of the short-circuit metal columns are respectively connected to the coplanar waveguide transmission lines of the first metal floor and the second metal floor, and three groups of coplanar waveguide transmission lines are arranged on one side of the second dielectric substrate close to the second metal floor; the antenna layer comprises an H-shaped decoupling structure and three radiation patches, the H-shaped decoupling structure has two opposite openings, two radiation patches are arranged corresponding to the openings of the H-shaped decoupling structure and are surrounded by the opening part of the H-shaped decoupling structure, and the three radiation patches all work in fundamental mode TM 01 In this invention, an H-shaped decoupling structure is provided to suppress the propagation of surface waves, increase the complementary characteristics of the radiation pattern, and improve the isolation between the two radiation patches.

Description

Technical Field

[0001] The present invention relates to the technical field of antennas, circuits and systems, and in particular to a millimeter wave packaged antenna suitable for radar sensing. Background Art

[0002] With the rapid development of the fifth generation of mobile communication technology, millimeter wave antennas are widely used in various wireless communication systems and radar sensors due to their advantages of low latency, high transmission rate and high access density. In the traditional millimeter wave radar sensor design, the antenna and chip are set on the same plane, and the interconnection between the chip and the circuit is achieved through jumpers or longer planar transmission lines, which will increase the lateral size of the front-end module of the communication system and the link RF loss, and the system integration is low.

[0003] The packaged antenna technology based on multi-layer interconnected transmission lines can effectively solve these technical problems. The packaged antenna technology flips the chip on the back of the antenna and interconnected circuit. The antenna and circuit are interconnected through multi-layer transmission lines, avoiding the use of jumpers or longer planar transmission lines. It can effectively reduce the RF loss in the millimeter wave frequency band and reduce the lateral size of the antenna module.

[0004] However, for packaged antennas or arrays with multiple radiating elements, the reduction in circuit board area will increase the mutual coupling between antenna elements, resulting in deteriorated isolation between antenna elements and reduced anti-interference capability of the antenna module. In order to achieve the system application requirements of precise positioning, the isolation between the transmitting antenna and the receiving antenna or between any two antenna radiating elements is often required to be greater than 20dB. Therefore, how to improve the isolation between antenna elements in a limited space without sacrificing the antenna radiation performance has become one of the key issues that need to be urgently solved in the field of packaged antenna technology. Summary of the invention

[0005] The main purpose of the present invention is to provide a millimeter-wave packaged antenna suitable for radar sensing, and to provide a feasible technical solution for achieving high isolation between multiple units of the packaged antenna and compact integration of the millimeter-wave front-end transceiver module.

[0006] To achieve the above object, the present invention provides a millimeter wave packaged antenna suitable for radar sensing, characterized in that it comprises: a first dielectric substrate, a first metal floor, a second dielectric substrate and a second metal floor stacked in sequence. An antenna layer is provided on the upper side of the first dielectric substrate, a gap is provided on the second metal floor, and a plurality of short-circuit metal columns are arranged around the gap, the two ends of the short-circuit metal columns are respectively connected to the coplanar waveguide transmission lines of the first metal floor and the second metal floor, and three groups of the coplanar waveguide transmission lines are provided on the side of the second dielectric substrate close to the second metal floor.

[0007] The antenna layer includes an H-shaped decoupling structure connected to the first metal floor, and three radiating patches correspondingly connected to the three coplanar waveguide transmission lines, the H-shaped decoupling structure has two opposite openings, the two radiating patches are symmetrically arranged corresponding to the openings of the H-shaped decoupling structure and are surrounded by the openings of the H-shaped decoupling structure, and the three radiating patches all work in the fundamental mode TM 01 mode.

[0008] It also includes a first probe for feeding power from the coplanar waveguide transmission line to the radiation patch, and two ends of the first probe are respectively connected to the antenna layer and the coplanar waveguide transmission line.

[0009] Wherein, the distance between adjacent short-circuit metal pillars is less than one quarter of the wavelength corresponding to the operating frequency of the antenna.

[0010] It also includes a plurality of short-circuit metal connecting columns penetrating the first dielectric substrate and extending along the length direction of the H-shaped decoupling structure, wherein two ends of the short-circuit metal connecting columns are respectively connected to the H-shaped decoupling structure and the first metal floor.

[0011] The slot includes three sections of stepped slots connected in sequence, and is matched with three sections of stepped metal guide strips connected in sequence to form the coplanar waveguide transmission line.

[0012] Wherein, the first metal floor is provided with a circular ring groove, and the circular ring groove is symmetrically arranged around the first probe.

[0013] Wherein, it also includes a dielectric bonding layer located between the first metal floor and the second dielectric substrate, and the dielectric bonding layer is used to bond the first metal floor and the second dielectric substrate.

[0014] Among them, the H-shaped decoupling structure includes two short-circuited metal long strips and a short-circuited metal short strip connecting the two short-circuited metal long strips, the electrical length of the short-circuited metal long strips is 0.4-0.6 times the wavelength corresponding to the antenna operating frequency, the electrical length of the short-circuited metal short strips is 0.3-0.5 times the wavelength corresponding to the antenna operating frequency, and the spacing between the H-shaped decoupling structure and the adjacent radiation patch is 0.024-0.028 times the wavelength corresponding to the antenna operating frequency.

[0015] The present invention arranges an H-shaped decoupling structure between the two radiation patches, suppresses the propagation of surface waves, and increases the complementary characteristics of the radiation pattern, thereby improving the isolation between the two radiation patches. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the prior art solutions, the following briefly introduces the drawings used in the embodiments or the prior art solutions. The drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0017] Figure 1 A top view of a millimeter wave packaged antenna suitable for radar sensing provided by an embodiment of the present invention;

[0018] Figure 2 A side view of a millimeter wave packaged antenna suitable for radar sensing provided by an embodiment of the present invention;

[0019] Figure 3 A schematic diagram of the structure of a first metal floor in a millimeter wave packaged antenna suitable for radar sensing provided by an embodiment of the present invention;

[0020] Figure 4 A bottom view of a millimeter wave packaged antenna suitable for radar sensing provided by an embodiment of the present invention;

[0021] Figure 5 A simulated reflection coefficient curve diagram of a millimeter wave packaged antenna suitable for radar sensing provided in an embodiment of the present invention;

[0022] Figure 6 A transmission coefficient curve diagram of a simulation of a millimeter wave packaged antenna suitable for radar sensing provided in an embodiment of the present invention;

[0023] Figure 7 A simulated E-plane and H-plane side-radiation pattern of a first radiation patch of a millimeter-wave packaged antenna suitable for radar sensing at a frequency of 24 GHz provided in an embodiment of the present invention;

[0024] Figure 8 The simulated E-plane and H-plane radiation patterns of the second radiation patch of a millimeter-wave packaged antenna suitable for radar sensing at a frequency of 24 GHz provided in an embodiment of the present invention;

[0025] Fig. 9 A simulated E-plane and H-plane side-radiation pattern of a third radiation patch of a millimeter-wave packaged antenna suitable for radar sensing at a frequency of 24 GHz provided in an embodiment of the present invention;

[0026] Fig.10 A simulated radiation efficiency curve diagram of a millimeter wave packaged antenna suitable for radar sensing provided in an embodiment of the present invention, wherein antennas 1, 2, and 3 correspond to radiation patches 1a, 1b, and 1c, respectively;

[0027] Fig.11A simulated gain curve diagram of a millimeter-wave packaged antenna suitable for radar sensing provided in an embodiment of the present invention, wherein antennas 1, 2, and 3 correspond to radiation patches 1a, 1b, and 1c, respectively.

[0028] The implementation, functional features and advantages of the present invention will be further described in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0029] The following is a complete description of the technical solutions of the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. The described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0030] It should be noted that the descriptions of "first", "second", etc. involved in the present invention are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the definition of "first", "second", etc. features may explicitly or implicitly include at least one of the features.

[0031] A millimeter wave packaged antenna suitable for radar sensing provided in an embodiment of the present invention is now described.

[0032] In one embodiment provided by the present invention, please refer to Figures 1 to 4 , Figure 1 A top view of a millimeter wave packaged antenna suitable for radar sensing provided by an embodiment of the present invention, Figure 2 A side view of a millimeter wave packaged antenna suitable for radar sensing provided by an embodiment of the present invention, Figure 3 A schematic diagram of the structure of a first metal floor in a millimeter wave packaged antenna suitable for radar sensing provided by an embodiment of the present invention, Figure 4A bottom view of a millimeter wave packaged antenna suitable for radar sensing provided in an embodiment of the present invention. The millimeter wave packaged antenna suitable for radar sensing is applied to a wireless transceiver module, and the millimeter wave packaged antenna comprises: a first dielectric substrate 2, a first metal floor 5a, a second dielectric substrate 4 and a second metal floor 5b stacked in sequence. An antenna layer is provided on the upper side of the first dielectric substrate 2, the second metal floor 5b is provided with a gap, and a plurality of short-circuit metal columns 3d are arranged around the gap, and the two ends of the short-circuit metal columns 3d are respectively connected to the coplanar waveguide transmission lines 6 of the first metal floor 5a and the second metal floor 5b, and three groups of the coplanar waveguide transmission lines 6 are provided on the side of the second dielectric substrate 4 close to the second metal floor 5b. The antenna layer comprises an H-shaped decoupling structure 1d connected to the first metal floor 5a, and three radiation patches (1a, 1b, 1c) connected to the three groups of coplanar waveguide transmission lines 6, wherein the H-shaped decoupling structure 1d has two opposite openings, and the two radiation patches (1a, 1b) are symmetrically arranged corresponding to the openings of the H-shaped decoupling structure 1d and are surrounded by the openings of the H-shaped decoupling structure 1d, and the three radiation patches (1a, 1b, 1c) all work in the fundamental mode TM 01 In the mode, the first radiation patch 1a and the second radiation patch 1b are used to receive signals, and the third radiation patch 1c is used to transmit signals. The H-shaped decoupling structure 1d is arranged between the two radiation patches (1a, 1b), which can suppress the propagation of surface waves, increase the complementary characteristics of the radiation pattern, and achieve the purpose of improving the isolation between the two radiation patches (1a, 1b). The first dielectric substrate 2 and the first metal floor 5a belong to one layer of printed circuit board, and the second dielectric substrate 4 and the second metal floor 5b belong to another layer of printed circuit board. A plurality of short-circuit metal posts 3d are arranged so that the floor (second metal floor 5b) of the coplanar waveguide transmission line 6 is connected to the first metal floor 5a, further constraining the electromagnetic energy to be transmitted on the coplanar waveguide transmission line 6, preventing the electromagnetic energy from being transmitted between the floors and leaking, and the spacing between adjacent short-circuit metal posts 3d is less than one-fourth of the wavelength corresponding to the antenna operating frequency.

[0033] The millimeter wave packaged antenna also includes a first probe (2a, 2b, 2c) for feeding power from the coplanar waveguide transmission line 6 to the radiation patch (1a, 1b, 1c); the first probe (2a, 2b, 2c) is sequentially passed through the first dielectric substrate 2, the first metal floor 5a and the second dielectric substrate 4, and the two ends of the first probe (2a, 2b, 2c) are respectively connected to the radiation patch (1a, 1b, 1c) and the coplanar waveguide transmission line 6.

[0034] The millimeter wave packaged antenna also includes a plurality of short-circuit metal connecting columns 2d penetrating the first dielectric substrate 2 and extending along the length direction of the H-shaped decoupling structure 1d, and two ends of the short-circuit metal connecting columns 2d are respectively connected to the H-shaped decoupling structure 1d and the first metal floor 5a.

[0035] The second metal floor 5b is provided with three sequentially connected stepped gaps, and is adapted to the three sequentially connected stepped metal guide strips to form the coplanar waveguide transmission line 6. The coplanar waveguide transmission line 6 is stepped, and a broadband transition from the first probe (2a, 2b, 2c) to the feeding port of the coplanar waveguide transmission line 6 is achieved.

[0036] Furthermore, three annular grooves are provided on the first metal floor 5a, so that the first probes (2a, 2b, 2c) can pass through the first metal floor 5a to achieve interconnection, and the annular grooves are symmetrically arranged around the first probes (2a, 2b, 2c), and the outer radius of the annular grooves is greater than the radius of the first probes (2a, 2b, 2c).

[0037] The millimeter wave packaged antenna further includes a dielectric bonding layer 3 located between the first metal floor 5 a and the second dielectric substrate 4 , and the dielectric bonding layer 3 is used to bond the first metal floor 5 a and the second dielectric substrate 4 .

[0038] The H-shaped decoupling structure 1d of the millimeter wave packaged antenna includes two short-circuited metal long strips and a short-circuited metal short strip connecting the two short-circuited metal long strips, the electrical length of the short-circuited metal long strip is 0.4-0.6 times the wavelength corresponding to the antenna operating frequency, and the electrical length of the short-circuited metal short strip is 0.3-0.5 times the wavelength corresponding to the antenna operating frequency. The spacing between the H-shaped decoupling structure 1d and the adjacent radiation patch (1a, 1b) is 0.024-0.028 times the wavelength corresponding to the antenna operating frequency.

[0039] Please refer to Figure 5 , Figure 5 A simulated reflection coefficient curve diagram of a millimeter wave packaged antenna suitable for radar sensing provided by an embodiment of the present invention. Figure 5 It can be seen that the operating frequency of the three radiating patches (1a, 1b, 1c) is 24 GHz, and the -10-dB bandwidth is about 1 GHz. Figure 5 It shows that the antenna can achieve good impedance matching under this feeding scheme.

[0040] Please refer to Figure 6 , Figure 6 The transmission coefficient curve diagram of a simulation of a millimeter wave packaged antenna suitable for radar sensing provided by an embodiment of the present invention. Figure 6It can be seen that after adding the H-shaped decoupling structure 1d, the port isolation of the first radiation patch 1a and the third radiation patch 1c, and the second radiation patch 1b and the third radiation patch 1c are all greater than 20dB, indicating that the antenna layout can achieve high isolation performance and fully meet the actual application requirements.

[0041] Please refer to Figures 7 to 11 , Figure 7 The simulated E-plane and H-plane radiation patterns of the first radiation patch of a millimeter-wave packaged antenna suitable for radar sensing at a frequency of 24 GHz provided in an embodiment of the present invention, Figure 8 The simulated E-plane and H-plane radiation patterns of the second radiation patch of a millimeter-wave packaged antenna suitable for radar sensing at a frequency of 24 GHz provided in an embodiment of the present invention, Fig. 9 The simulated E-plane and H-plane radiation patterns of the third radiation patch of a millimeter-wave packaged antenna suitable for radar sensing at a frequency of 24 GHz provided in an embodiment of the present invention, Fig.10 A simulated radiation efficiency curve diagram of a millimeter wave packaged antenna suitable for radar sensing provided in an embodiment of the present invention, wherein antennas 1, 2, and 3 correspond to radiation patches 1a, 1b, and 1c, respectively. Fig.11 A simulated gain curve diagram of a millimeter-wave packaged antenna suitable for radar sensing provided in an embodiment of the present invention, wherein antennas 1, 2, and 3 correspond to radiation patches 1a, 1b, and 1c, respectively. As can be seen from the figure, at 24GHz, the simulated gains of the three radiation patches (1a, 1b, 1c) are all greater than 5dBi, the 3-dB beam width is greater than 60°, and the simulated antenna radiation efficiency is above 86%. In the working frequency band, the simulated gains of the three radiation patches (1a, 1b, 1c) are all better than 4.25dBi, meeting the actual application requirements of radar sensors.

[0042] The above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any equivalent structural transformation made by using the contents of the present invention specification and drawings under the technical solution of the present invention, or the direct / indirect application of the technical solution in other related technical fields, is included in the protection scope of the present invention.

Claims

1. A millimeter wave packaged antenna suitable for radar sensing, characterized in that: include: A first dielectric substrate, a first metal floor, a second dielectric substrate and a second metal floor stacked in sequence; An antenna layer is provided on the upper side of the first dielectric substrate, a gap is provided on the second metal floor, and a plurality of short-circuit metal pillars are arranged around the gap, two ends of the short-circuit metal pillars are respectively connected to the coplanar waveguide transmission lines of the first metal floor and the second metal floor, and three groups of the coplanar waveguide transmission lines are provided on a side of the second dielectric substrate close to the second metal floor; The antenna layer includes an H-shaped decoupling structure connected to the first metal floor, and three radiating patches correspondingly connected to the three groups of coplanar waveguide transmission lines, the H-shaped decoupling structure has two opposite openings, the two radiating patches are symmetrically arranged corresponding to the openings of the H-shaped decoupling structure and are surrounded by the openings of the H-shaped decoupling structure, and the three radiating patches all work in the fundamental mode TM 01 Mode; It also includes a first probe for feeding power from the coplanar waveguide transmission line to the radiation patch; the first probe passes through the first dielectric substrate, the first metal floor and the second dielectric substrate in sequence, and the two ends of the first probe are respectively connected to the radiation patch and the coplanar waveguide transmission line.

2. The millimeter wave packaged antenna suitable for radar sensing as claimed in claim 1, characterized in that: The distance between adjacent short-circuit metal pillars is less than a quarter of the wavelength corresponding to the operating frequency of the antenna.

3. The millimeter wave packaged antenna suitable for radar sensing as claimed in claim 1, characterized in that: It also includes a plurality of short-circuit metal connecting columns penetrating the first dielectric substrate and extending along the length direction of the H-shaped decoupling structure, wherein two ends of the short-circuit metal connecting columns are respectively connected to the H-shaped decoupling structure and the first metal floor.

4. The millimeter wave packaged antenna suitable for radar sensing as claimed in claim 1, characterized in that: The slot includes three sections of stepped slots connected in sequence, and is matched with three sections of stepped metal guide strips connected in sequence to form the coplanar waveguide transmission line.

5. The millimeter wave packaged antenna suitable for radar sensing as claimed in claim 1, characterized in that: The first metal floor is provided with an annular groove, and the annular groove is symmetrically arranged around the first probe.

6. The millimeter wave packaged antenna suitable for radar sensing as claimed in claim 1, characterized in that: It also includes a dielectric bonding layer located between the first metal floor and the second dielectric substrate, and the dielectric bonding layer is used to bond the first metal floor and the second dielectric substrate.

7. The millimeter wave packaged antenna suitable for radar sensing as claimed in claim 1, characterized in that: The H-shaped decoupling structure includes two short-circuited metal long strips and a short-circuited metal short strip connecting the two short-circuited metal long strips. The electrical length of the short-circuited metal long strip is 0.4-0.6 times the wavelength corresponding to the antenna operating frequency, the electrical length of the short-circuited metal short strip is 0.3-0.5 times the wavelength corresponding to the antenna operating frequency, and the spacing between the H-shaped decoupling structure and the adjacent radiation patch is 0.024-0.028 times the wavelength corresponding to the antenna operating frequency.

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