Vehicle-mounted omnidirectional filtering radiator antenna based on gap waveguide

Abstract

The invention discloses a vehicle-mounted omnidirectional filtering radiator antenna based on a gap waveguide, and relates to the technical field of integrated antennae, and the antenna comprises a gap waveguide heat dissipation radiation unit and a dielectric substrate. The gap waveguide heat dissipation radiation unit comprises a metal substrate, a radiator array is arranged on the metal substrate, radiators located at the four corners of the metal substrate are first metal pins, radiators distributed on the metal substrate in a cross mode are second metal pins, and the second metal pins distributed in the cross mode are used for forming four radiation calibers. The first metal pin is longer than the second metal pin. By adopting the vehicle-mounted omnidirectional filtering radiator antenna based on the gap waveguide, vertical polarization omnidirectional radiation is realized by using a gap waveguide technology, a feed structure is optimized by using a transmission line theory to introduce filtering response, and high-gain radiation is realized by means of an active integrated amplification factor; the antenna has the advantages of miniaturization, high integration level, stability, high gain, omni-directional performance and good filtering response.

Description

Technical Field

[0001] The present invention relates to the technical field of integrated antennas, and particularly to an omnidirectional filtering radiator antenna for vehicles based on a slot waveguide. Background Art

[0002] Omnidirectional high-gain antennas are required in many application scenarios such as Wi-Fi antennas and vehicle communications. Taking Vehicle-to-Everything (V2X) communication as an example, this frequency band communication is used to collect, analyze, and share information from different infrastructures. In such a communication system, there are various requirements for antennas. On the one hand, when communicating along the ground, a high-gain omnidirectional radiation pattern with vertical polarization is more needed. On the other hand, due to the requirements in the co-platform loading environment, traditional vertical polarization high-gain omnidirectional antennas are implemented by using high-order mode dipoles, array groups, etc. However, under the constraint of small size, it is difficult for their passive omnidirectional gain to break through the theoretical upper limit. In recent years, the active antenna proposed by the academic community, which can integrate some active components such as low-noise amplifiers and power amplifiers in the antenna to improve the antenna gain under the limited size and then increase the communication distance. Among them, the radiator antenna uses the radiator as the radiator of the antenna and at the same time has the ability to dissipate heat from the active chip or module, which is a popular solution that can meet the compact integration requirements of active antennas.

[0003] However, the current reports on radiator antennas mainly focus on horizontal polarization, directional radiation, gain enhancement, bandwidth expansion, heat dissipation performance improvement, etc. Therefore, there are still the following problems in its application in V2X. First, the size is large, the integration degree is low, and it is not easy to achieve the vertical polarization and omnidirectional characteristics required by V2X in the design of radiator antennas, and there are few reports on small-sized vertical polarization omnidirectional antennas. Second, the research on out-of-band broadband filtering ability is insufficient. Summary of the Invention

[0004] The purpose of the present invention is to provide an omnidirectional filtering radiator antenna for vehicles based on a slot waveguide to solve the above technical problems.

[0005] To achieve the above purpose, the present invention provides an omnidirectional filtering radiator antenna for vehicles based on a slot waveguide, including a slot waveguide heat dissipation radiation unit and a dielectric substrate connected to the slot waveguide heat dissipation radiation unit;

[0006] The slot waveguide heat dissipation radiation unit includes a metal substrate, on which a radiator array is arranged. The radiators at the four corners of the metal substrate are the first metal pins, and the radiators distributed in a cross shape on the metal substrate are the second metal pins. The second metal pins distributed in a cross shape are used to form a four-radiation aperture, and the length of the first metal pin is greater than the length of the second metal pin.

[0007] Preferably, the first metal pin is connected to the dielectric substrate by a screw.

[0008] Preferably, the spacing between each radiator in the x-axis direction is 4 - 6 mm, and the spacing between each radiator in the y-axis direction is 3 - 5 mm.

[0009] Preferably, a filtering feeding structure is provided on the side of the dielectric substrate opposite to the gap waveguide heat dissipation radiation unit. The filtering feeding structure includes three filtering feeding strips arranged in parallel, and the three filtering feeding strips are connected by connecting strip bars.

[0010] Preferably, an active integrated circuit is provided on the side of the dielectric substrate opposite to the gap waveguide heat dissipation radiation unit. The active integrated circuit includes an enclosed filtering feeding structure and an active amplifying circuit, and the active amplifying circuit is disposed on the dielectric substrate within the enclosed filtering feeding structure.

[0011] Preferably, the enclosed filtering feeding structure includes a first filtering feeding strip, a second filtering feeding strip, and a third filtering feeding strip. The first filtering feeding strip, the second filtering feeding strip, and the third filtering feeding strip are connected by connecting strip bars. Both the first filtering feeding strip and the second filtering feeding strip are bent. The first filtering feeding strip and the second filtering feeding strip are oppositely arranged to form an enclosed area, and one end of both the first filtering feeding strip and the second filtering feeding strip is connected to the connecting strip bar. The third filtering feeding strip is L-shaped, and the middle of the third filtering feeding strip is connected to the connecting strip bar.

[0012] Preferably, the second metal pin located at the center of the metal substrate is in contact with the power chip of the active amplifying circuit.

[0013] Therefore, the present invention adopts the above-mentioned vehicle-mounted omnidirectional filtering radiator antenna based on a gap waveguide, and has the following beneficial effects: integrating the filtering feeding structure, the active circuit, and the radiator together, and the radiator also has a heat dissipation function. Using the gap waveguide technology to achieve vertical polarization omnidirectional radiation, using the transmission line theory to optimize the feeding structure to introduce a filtering response, and relying on the active integrated amplification factor to achieve high-gain radiation. It has the advantages of miniaturization, high integration, stable high-gain omnidirectionality, and good filtering response, and can be applied to high-integration and high-performance vehicle-mounted communication systems.

[0014] The technical solution of the present invention will be further described in detail below with reference to the drawings and embodiments. Description of the Drawings

[0015] Figure 1 Schematic diagram of the structure of a vehicle-mounted omnidirectional filtering radiator antenna based on a gap waveguide according to Embodiment 1 of the present invention;

[0016] Figure 2 Schematic diagram of the structure of the gap waveguide heat dissipation radiation unit according to Embodiment 1 of the present invention;

[0017] Figure 3 Schematic diagram of the filtering feed structure of the present invention;

[0018] Figure 4 Curve diagram of reflection coefficient and radiation efficiency of Embodiment 1 of the present invention;

[0019] Figure 5 Vertical plane pattern of Embodiment 1 of the present invention;

[0020] Figure 6 Horizontal plane pattern of Embodiment 1 of the present invention;

[0021] Figure 7 Schematic diagram of an omnidirectional filtering radiator antenna structure for vehicles based on a gap waveguide according to Embodiment 2 of the present invention;

[0022] Figure 8 Schematic diagram of the gap waveguide heat dissipation radiation unit structure according to Embodiment 2 of the present invention;

[0023] Figure 9 Schematic diagram of the active amplification circuit structure according to Embodiment 2 of the present invention;

[0024] Figure 10 Curve diagram of the reflection coefficient and amplification factor of the amplification circuit of the present invention;

[0025] Figure 11 Curve diagram of the comparison between the effective gain and the ideal gain according to Embodiment 2 of the present invention;

[0026] Figure 12 Horizontal plane pattern of Embodiment 2 of the present invention;

[0027] Figure 13 Vertical plane pattern of Embodiment 2 of the present invention;

[0028] Figure 14 Heat dissipation performance comparison diagram.

[0029] Reference numerals

[0030] 1. Gap waveguide heat dissipation radiation unit; 11. Metal substrate; 12. First metal pin; 13. Second metal pin; 2. Dielectric substrate; 3. Filtering feed structure; 31. Filtering feed strip; 4. Active integrated circuit; 41. Enclosed filtering feed structure; 411. First filtering feed strip; 412. Second filtering feed strip; 413. Third filtering feed strip; 414. Enclosed area; 42. Active amplification circuit; 5. Connection strip; 6. Screw. Detailed implementation manners

[0031] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the present invention is usually placed during use. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the present invention. In the description of the present invention, it should also be noted that unless otherwise clearly specified and defined, the terms "set", "installed", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] The following will describe in detail the embodiments of the present invention with reference to the accompanying drawings.

[0033] Table 1 is a table of the optimal dimensions of each parameter. The dimensional data of Example 1 and Example 2 are shown in Table 1.

[0034] Table 1 Table of Optimal Dimensions of Each Parameter

[0035]

[0036]

[0037] Example 1

[0038] As Figure 1 shown, a vehicle-mounted omnidirectional filtering radiator antenna based on a gap waveguide. This embodiment is a passive vehicle-mounted omnidirectional filtering radiator antenna, which includes a gap waveguide heat dissipation radiation unit 1 and a dielectric substrate 2 connected to the gap waveguide heat dissipation radiation unit 1.

[0039] As Figure 2 shown, the gap waveguide heat dissipation radiation unit 1 includes a metal substrate 11 with a size of L×W. An array of radiators (3×3 array) is provided on the metal substrate 11. The cross-sectional size of the radiator is W4×W4. The radiators at the four corners of the metal substrate 11 are the first metal pins 12 with a length of H1. The radiators distributed in a cross shape on the metal substrate 11 are the second metal pins 13 with a length of H. The second metal pins 13 distributed in a cross shape are used to form a four-radiation aperture to achieve omnidirectional radiation of vertical polarization. The length of the first metal pin 12 is greater than the length of the second metal pin 13. The first metal pin 12 is connected to the dielectric substrate 2 through a screw 6 (made of aluminum material). The spacing D2 of each radiator in the x-axis direction is 5 mm, and the spacing D1 of each radiator in the y-axis direction is 4 mm.

[0040] The dielectric substrate 2 is made of F4BM350 material, with a relative dielectric constant of 3.5 and a loss tangent of 0.002. A filtering feeding structure 3 is provided on the opposite side of the dielectric substrate 2 to the gap waveguide heat dissipation radiation unit 1, and a copper plating layer is provided on the other side. As Figure 3 shown, the filtering feeding structure 3 includes three filtering feeding strips 31 arranged in parallel. The sizes from left to right are L1×W3, L2×W2, and L3×W1 respectively, and they are connected by a connecting strip 5 with a length of L4. According to the transmission line principle, the length of the microstrip line is calculated to introduce transmission zeros for high and low frequencies, thereby realizing filtering zeros.

[0041] The overall size of this embodiment is 0.32×0.32×0.25λ 3 , in Figure 4 it, the antenna satisfies the reflection coefficient ≤ -10 dB in the frequency range of 5.8 - 6.15 GHz (percentage bandwidth 6.2%). The 3 dB gain bandwidth of the antenna is 6.8%, and a gain of 18.34 dBi can be achieved. The omnidirectional radiation non-circularity of the passive radiator antenna is within 2.5 dBi. As Figure 5 - Figure 6 shown, the passive radiator antenna exhibits good omnidirectional radiation.

[0042] Embodiment 2

[0043] The difference between this embodiment and Embodiment 1 is that, as Figure 7 - 8 shown, this embodiment is an active vehicle-mounted omnidirectional filtering radiator antenna, and there are also slight differences in size. The size of the metal substrate 11 is L 14 ×W6, the length of the first metal pin 12 is H3, the radiators distributed in a cross shape on the metal substrate 11 are the second metal pins 13 with a length of H2, the distance D4 between each radiator in the x-axis direction is 5 mm, and the distance D3 between each radiator in the y-axis direction is 4.1 mm.

[0044] A filtering feeding structure 3 is provided on the opposite side of the dielectric substrate 2 to the gap waveguide heat dissipation radiation unit 1, and a copper plating layer is provided on the other side. As Figure 9The active amplification circuit 42 shown is disposed on the dielectric substrate 2 within the enclosed filtering feeding structure 41. The feeding method of the input port of the amplification circuit is bottom feeding, and the connection method of the output port is side feeding, which is used to simulate the signal input and output method of the actual processing test model. The DC sources all adopt the bottom feeding method, which is also applicable to simulating the actual power supply method. The second metal pin located in the middle of the metal substrate 2 contacts the power chip of the active amplification circuit 42 to improve the heat dissipation performance. The enclosed filtering feeding structure 41 includes a first filtering feeding strip 411, a second filtering feeding strip 412, and a third filtering feeding strip 413. The first filtering feeding strip 411, the second filtering feeding strip 412, and the third filtering feeding strip 413 are connected by a connecting strip 5. The first filtering feeding strip 411 and the second filtering feeding strip 412 are both bent. The first filtering feeding strip 411 and the second filtering feeding strip 412 are oppositely arranged to form an enclosed area 414, and one end of the first filtering feeding strip 411 and the second filtering feeding strip 412 is connected to the connecting strip. The third filtering feeding strip 413 is L-shaped, and the middle part of the third filtering feeding strip 413 is connected to the connecting strip 5. The integrated design of the passive filtering feeding structure and the active amplification circuit retains the filtering response while ensuring the normal operation of the amplification circuit, and the packaging and distribution of the circuit components do not affect the omnidirectional radiation as much as possible.

[0045] As Figure 10 - Figure 11 shown, the out-of-band rejection of the passive antenna is more than 10 dB. The out-of-band rejection of the active integrated heatsink antenna is more than 10 dB, and the 3 dB gain bandwidth is 5.78 - 6.2 GHz (percentage bandwidth 6.8%). As Figure 12 - Figure 13 shown, the circularity of the active heatsink antenna is within 5.52 dB, and the active heatsink antenna exhibits good omnidirectional radiation.

[0046] To verify the superiority of this embodiment, a comparative analysis was carried out with the prior art. The control group adopted a millimeter-wave heatsink antenna based on gap waveguide technology (Yu Y, Yi D, Tang M C, et al. Vertically Polarized, Electromagnetic Interference Suppressed Millimeter-Wave Active Heatsink Antenna Based on Gap Waveguide Technology[J] IEEE Transactions on Antennas and Propagation, 2024, 72(1): 433 - 444). The comparison results between this embodiment and the control group are shown in Table 2.

[0047] Table 2 Comparison Results between this Embodiment and the Control Group

[0048]

[0049] As can be seen from Table 2, while maintaining the vertically polarized omnidirectional radiation pattern (beam non-circularity < 6 dB), the thermal dissipation efficiency is increased to 75 °C, and the out-of-band rejection level is better than -27 dB. It has the advantages of achieving good vertically polarized omnidirectional radiation, heat dissipation performance, out-of-band filtering function and good environmental compatibility under high integration conditions.

[0050] As a radiator antenna, the antenna radiator not only needs to have a radiation effect, but also needs to provide additional heat dissipation function for the active chip. In order to verify the heat dissipation performance of the radiator metal pins that make up the gap waveguide, the IcePak module of Ansys Corporation is used to simulate the degree of improvement in the heat dissipation performance of the chip by the relevant structure, as Figure 14 shown, where (a), (b) and (c) respectively represent the temperature field diagrams of the structure without heat dissipation, the plate-shaped heat dissipation structure and the structure of this embodiment. Without any treatment, the chip will heat up to about 140 °C, and the heat is concentrated on the chip. When a metal plate is loaded on the chip to cool it down, it can be seen that the heat of the chip is dissipated, but there is still a lot of heat on the circuit and the PCB board, which is restricted between the floor and the metal plate by the metal plate and cannot be dissipated. Such heat as high as 160 °C is concentrated in the circuit, which will significantly affect the circuit operation. Most of the heat concentrated on the chip or hoarded on the PCB board in the technical solution of this embodiment is consumed, and the highest temperature of the entire antenna including the radiator, the PCB board and the chip is only 65 °C. It can be verified that the effective temperature drop is about 75 °C, and the technical solution of this embodiment has excellent heat dissipation performance.

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that they can still modify or equivalently replace the technical solutions of the present invention, and these modifications or equivalent replacements do not make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. An omnidirectional filtering radiator antenna for vehicles based on a gap waveguide, characterized in that: It includes a gap waveguide heat dissipation and radiation unit and a dielectric substrate connected to the gap waveguide heat dissipation and radiation unit; The gap waveguide heat dissipation and radiation unit includes a metal substrate, on which a radiator array is provided. The radiators at the four corners of the metal substrate are first metal pins, and the radiators distributed in a cross shape on the metal substrate are second metal pins. The second metal pins distributed in a cross shape are used to form four radiation apertures, and the length of the first metal pins is greater than that of the second metal pins.

2. The omnidirectional filtering radiator antenna for vehicle based on a gap waveguide according to claim 1, characterized in that: The first metal pins are connected to the dielectric substrate by screws.

3. The omnidirectional filtering radiator antenna for vehicle based on the gap waveguide according to claim 1, wherein: The spacing between each radiator in the x-axis direction is 4 - 6 mm, and the spacing between each radiator in the y-axis direction is 3 - 5 mm.

4. The omnidirectional filtering radiator antenna for vehicle based on the gap waveguide according to claim 1, characterized in that: A filter feeding structure is provided on the side of the dielectric substrate opposite to the gap waveguide heat dissipation and radiation unit. The filter feeding structure includes three filter feeding strips arranged in parallel, and the three filter feeding strips are connected by connecting strip bars.

5. The omnidirectional filtering radiator antenna for vehicle based on the gap waveguide according to claim 1, wherein: An active integrated circuit is provided on the side of the dielectric substrate opposite to the gap waveguide heat dissipation and radiation unit. The active integrated circuit includes an enclosed filter feeding structure and an active amplification circuit, and the active amplification circuit is provided on the dielectric substrate within the enclosed filter feeding structure.

6. The omnidirectional filtering radiator antenna for vehicle based on a gap waveguide according to claim 5, wherein: The enclosed filter feeding structure includes a first filter feeding strip, a second filter feeding strip, and a third filter feeding strip. The first filter feeding strip, the second filter feeding strip, and the third filter feeding strip are connected by connecting strip bars. Both the first filter feeding strip and the second filter feeding strip are bent. The first filter feeding strip and the second filter feeding strip are arranged oppositely to form an enclosed area, and one end of both the first filter feeding strip and the second filter feeding strip is connected to the connecting strip bar. The third filter feeding strip is L-shaped, and the middle part of the third filter feeding strip is connected to the connecting strip bar.

7. The omnidirectional filtering radiator antenna for vehicle based on a gap waveguide according to claim 6, wherein: The second metal pin located at the center of the metal substrate is in contact with the power chip of the active amplification circuit.

Images