Millimeter wave broadband laminated patch antenna

Abstract

The invention relates to the technical field of millimeter wave communication, in particular to a millimeter wave broadband laminated patch antenna which is composed of a ceramic substrate, a metal strip, a metal via hole, a rectangular metal patch, a back-to-back E-shaped metal patch, a metal layer and a microstrip line feeder, and the millimeter wave broadband laminated patch antenna is of a five-layer structure arranged from top to bottom; the rotary back-to-back E-type patch antenna is adopted, multiple resonance points are introduced, the antenna bandwidth is improved, the size of the patch antenna is reduced, the problem that the relative bandwidth is low in the prior art is solved, and integration is more convenient.

Description

Technical Field

[0001] The present invention relates to the technical field of millimeter-wave communication, and particularly to a millimeter-wave broadband stacked patch antenna. Background Art

[0002] Millimeter-wave antennas are core components of 5G communication, autonomous driving radar, and satellite communication systems, and their performance directly affects signal transmission rate, coverage range, and system reliability. Patch antennas are widely used due to their advantages such as low profile and easy integration. The bandwidth of traditional single-layer patch antennas is relatively narrow (usually <10%), and to expand the bandwidth, the existing technology mostly adopts a stacked patch structure to broaden the frequency band by superimposing multiple resonance points. The fifth-generation mobile communication technology (5G) as the next-generation wireless broadband technology has unique advantages such as high data transmission rate, low air interface delay, and flexible and elastic air interface configuration, and has been widely promoted and applied. At the same time, in order to take advantage of the rich spectrum of the millimeter-wave band, 5G millimeter-wave technology has emerged, laying a solid foundation for the improvement of data transmission rate and capacity.

[0003] The stacked patch antennas in the prior art are difficult to achieve broadband coverage, and the size of the patch antenna unit is relatively large, making it difficult to meet the requirements of high-density integration. For example, the three-layer patch antenna with two radiation nulls disclosed in the journal article “A High Selectivity and High Efficiency Filtering Antenna With Controllable Radiation Nulls Based on Stacked Patches”

[0004] (Journal name: IEEE Transactions on Antennas and Propagation, pages 708 - 713, No. 1, 2022) is shown as follows. The disclosed stacked patch antenna structure is as Figure 1 shown. The antenna is composed of a driven patch, two parasitic patches, a ground layer, and an L-shaped probe feed. Figure 2 The structure of the driven patch is shown as Figure 3 The structure of parasitic patch 1 is shown as Figure 4 The top structure of parasitic patch 2 is shown as. The antenna is fed by an L-shaped probe to excite the TM10 mode of the driven patch, realizes the coupling between parasitic patch 1 and the driven patch through a slot line, and then uses the slot line on parasitic patch 2 to realize the coupling with parasitic patch 1. Figure 5The full-wave simulation results of the antenna are shown. This technical solution adopts a three-layer patch structure and achieves a relative bandwidth of 16%. This relative bandwidth is relatively narrow and it is difficult to meet the application scenarios with high bandwidth requirements. At the same time, the planar size of this antenna is λ 0 ×λ 0 , where λ 0 represents the wavelength at the center frequency of the antenna impedance bandwidth. This size is relatively large and will occupy too much space in practical applications, which is not conducive to integration with other components and limits its application in systems with high integration requirements.

[0005] Therefore, there is an urgent need for a stacked antenna that can achieve high relative bandwidth and high integration. Summary of the Invention

[0006] In view of this, the present invention discloses a millimeter-wave broadband stacked patch antenna to solve the above problems. The millimeter-wave broadband stacked patch antenna includes five ceramic substrates arranged from top to bottom: The first layer: There is a rectangular opening on the ceramic substrate, and a ring of metal strips is arranged on the upper surface of the ceramic substrate. Metal vias penetrating the ceramic substrate are provided in the first to fourth layers. The metal vias are located below the metal strips, and the positions of the metal vias between layers are aligned; The second layer: The ceramic substrate; The third layer: There is a rectangular metal patch on the ceramic substrate, and a ring of metal strips is arranged on the upper surface of the ceramic substrate; The fourth layer: There are back-to-back E-shaped metal patches on the ceramic substrate, and a ring of metal strips is arranged on the upper surface of the ceramic substrate; The fifth layer: The upper surface of the ceramic substrate is covered with a complete metal layer, an etched slot is provided on the metal layer, and a microstrip line feeder is provided below the ceramic substrate.

[0007] The beneficial effects of the present invention include: By adopting a rotating back-to-back E-shaped patch antenna, multiple resonance points are introduced, which improves the antenna bandwidth; By adopting the method of digging rectangular grooves on the substrate, it is easier to achieve matching of the antenna. The planar size of the present invention is 0.49λ 0 ×0.49λ 0 , where λ 0 represents the wavelength at the center frequency of the antenna impedance bandwidth. Compared with the prior art, the size is reduced by about 75%, which is more conducive to integration. Brief Description of the Drawings

[0008] Figure 1 It is a schematic structural diagram of a three-layer patch antenna with two radiation nulls in the prior art;

[0009] Figure 2 It is a schematic diagram of the driving patch structure of a three-layer patch antenna with two radiation nulls in the prior art;

[0010] Figure 3Schematic diagram of parasitic patch 1 of a three - layer patch antenna with two radiation nulls in the prior art;

[0011] Figure 4 Schematic diagram of parasitic patch 2 of a three - layer patch antenna with two radiation nulls in the prior art;

[0012] Figure 5 Full - wave simulation results of a three - layer patch antenna with two radiation nulls in the prior art;

[0013] Figure 6 Schematic diagram of a millimeter - wave broadband stacked patch antenna in an embodiment of the present invention;

[0014] Figure 7 Schematic diagram of the first layer of a millimeter - wave broadband stacked patch antenna in an embodiment of the present invention;

[0015] Figure 8 Schematic diagram of the third layer of a millimeter - wave broadband stacked patch antenna in an embodiment of the present invention;

[0016] Figure 9 Schematic diagram of the fourth layer of a millimeter - wave broadband stacked patch antenna in an embodiment of the present invention;

[0017] Figure 10 Schematic diagram of the fifth layer of a millimeter - wave broadband stacked patch antenna in an embodiment of the present invention;

[0018] Figure 11 Simulation diagram of S - parameter (scattering parameter) of a millimeter - wave broadband stacked patch antenna in an embodiment of the present invention;

[0019] Reference numerals in the figure: 1 represents a rectangular opening, 2 represents a metal strip, 3 represents a metal via, 4 represents a rectangular metal patch, 5 represents a back - to - back E - type metal patch, 6 represents a metal layer, and 7 represents a microstrip line feeder. Detailed implementation manners

[0020] In order to make the objectives, technical solutions, features, and advantages of the present invention clearer and more understandable, the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] This embodiment includes a millimeter - wave broadband stacked patch antenna, which is applied to the n257 frequency band. As Figure 6 shown, the millimeter - wave broadband stacked patch antenna includes five ceramic substrates arranged from top to bottom:

[0022] The first layer: As Figure 7As shown, a rectangular opening 1 is provided on the ceramic substrate, and a metal strip 2 is provided on the upper surface of the ceramic substrate; metal vias 3 penetrating the ceramic substrate are provided in each of the first to fourth layers, and the metal vias within the layer are aligned with the metal strip, and the positions of the metal vias between layers are aligned.

[0023] Furthermore, the rectangular opening is used to achieve impedance matching; due to the relatively high dielectric constant of the ceramic substrate and the relatively serious surface wave effect, the metal strip is designed on the upper layer of the ceramic substrate to form a cavity structure with the metal vias in the substrate, so as to reduce the influence of the surface wave effect.

[0024] The third layer: As Figure 8 shown, a rectangular metal patch is provided on the ceramic substrate for enhancing the antenna bandwidth, and a metal strip is provided on the upper surface of the ceramic substrate.

[0025] The fourth layer: As Figure 9 shown, back-to-back E-shaped metal patches 5 are provided on the ceramic substrate, and a metal strip is provided on the upper surface of the ceramic substrate.

[0026] Furthermore, the back-to-back E-shaped patch is the main radiation patch, and its slotted structure is used to extend the current path, so that the patch size is reduced and the antenna bandwidth is enhanced at the same frequency.

[0027] Furthermore, when the back-to-back E-shaped patch antenna is rotated, new resonance points will be introduced, thereby enhancing the antenna bandwidth; and when the patch is rotated, the impedance bandwidth of the antenna will shift to the low frequency. By simulating and optimizing the rotation angle, the antenna can completely cover the n257 band of 5G millimeter wave, and the preferred rotation angle is 66°.

[0028] The fifth layer: As Figure 10 shown, the upper surface of the ceramic substrate is covered with a complete metal layer 6, an "I"-shaped etched slot is provided on the metal layer, and a microstrip line feeder 7 is provided below the ceramic substrate.

[0029] Furthermore, an etched slot is made on the metal layer to achieve feeding. The slot is designed as an "I" shape for broadening the bandwidth of the antenna element. The included angle between the middle vertical line of the "I" and one side of the ceramic substrate is 0°, and the included angle with the longitudinal vertical line shared by the two E-shapes in the back-to-back E-shaped metal patch is 66°; the microstrip line feeder is printed under the fifth-layer ceramic substrate. The microstrip line feeder is composed of two sections of stepped microstrip lines, which is used to obtain greater freedom to better achieve impedance matching.

[0030] Furthermore, the first section of the two-section stepped microstrip line is the feeding port, with an impedance of 50Ω in this embodiment. The subsequent processed physical object can be directly connected to a 50Ω connector without an additional matching circuit; the second section of the microstrip line is used to achieve the impedance matching of the antenna, and the impedance matching is regulated by adjusting its size.

[0031] Further, the geometric pattern formed by each of the first to fourth layers is centrosymmetric.

[0032] Further, the thickness ratio of the ceramic substrates of the first to fifth layers is: 3:1:2:3:2.

[0033] Further, the metal material is preferably tungsten. In this embodiment, the thickness of the intermediate metal layer is 0.012 mm, and the total size is 5 mm × 5 mm × 1.182 mm. The simulation effect of the embodiment is as Figure 11 shown. The -10 dB impedance bandwidth is 25.72 GHz - 32.03 GHz, and the relative bandwidth is 21.8%. Compared with the simulation effect of the comparative technical solution "A High Selectivity and High Efficiency Filtering Antenna With Controllable Radiation Nulls Based on Stacked Patches" with a relative bandwidth of 16%, the structure proposed by the present invention has a higher relative bandwidth and a smaller size, which is convenient for integration.

[0034] Finally, it should be noted that the above description only describes some embodiments of the present invention. For those skilled in the art, various changes, modifications, substitutions, and deformations of these embodiments can be conceived without departing from the principle and spirit of the present invention. The protection scope of the present invention is defined by the appended claims and their equivalents, and the above actions should all be covered within the protection scope of the present invention.

Claims

1. A millimeter wave broadband laminated patch antenna, applied to the n257 frequency band, characterized in that: The invention comprises five layers of ceramic substrate arranged from top to bottom: the first layer: a rectangular opening is arranged on the ceramic substrate, a circle of metal strips is arranged on the upper surface of the ceramic substrate, the first to fourth layers are all provided with metal vias penetrating the ceramic substrate, the metal vias are located below the metal strips, and the positions of the metal vias between the layers are aligned; The second layer: ceramic substrate; the third layer: a rectangular metal patch is arranged on the ceramic substrate, and a circle of metal strips is arranged on the upper surface of the ceramic substrate; the fourth layer: back-to-back E-shaped metal patches are arranged on the ceramic substrate, and a circle of metal strips is arranged on the upper surface of the ceramic substrate; the fifth layer: the upper surface of the ceramic substrate is covered with a complete metal layer, the metal layer is provided with etched gaps, and a microstrip line feeder is arranged under the ceramic substrate.

2. The millimeter wave broadband laminated patch antenna according to claim 1, characterized in that: The geometric patterns on the upper surface of each layer from the first layer to the fourth layer are centrally symmetrical.

3. The millimeter wave broadband laminated patch antenna according to claim 1, characterized in that: The thicknesses of different ceramic substrates are different, and the thickness ratio of the first to fifth ceramic substrates is 3:1:2:3:

2.

4. The millimeter wave broadband laminated patch antenna according to claim 1, characterized in that: The etched gap on the metal layer is in the shape of an "I" character, and the angle between the vertical line in the "I" character and one side of the ceramic substrate is 0°, and the angle between the vertical line in the "I" character and the longitudinal vertical line shared by the two E-shaped back-to-back E-shaped metal patches is 66°.

5. The millimeter wave broadband laminated patch antenna according to claim 1, characterized in that: The microstrip feed line consists of two sections of stepped microstrip lines.

6. The millimeter wave broadband laminated patch antenna according to claim 1, characterized in that: The metal strips, metal vias, rectangular metal patches, back-to-back E-shaped metal patches and metal layers are all made of tungsten.

7. The millimeter wave broadband laminated patch antenna according to claim 1, characterized in that: The size of the upper surface of the ceramic substrate is 5 mm×5 mm.

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