CN210607608U - Radiation unit structure and microstrip array antenna - Google Patents

Abstract

The utility model provides a radiating element structure and microstrip array antenna, this radiating element structure includes: a substrate; a radiation patch disposed over the substrate; a feed structure connected to the radiating patch; the radiation unit is arranged on the radiation patch, wherein the radiation unit is provided with a dielectric material structure body, a first metal surface and a second metal surface which are opposite to each other and arranged on the dielectric material structure body, and the radiation unit is connected with the radiation patch through the first metal surface. The utility model discloses a radiation paster and PCB radiating element compound, constitute new radiating element structure, do benefit to and reduce array antenna area, increase the isolation.

Description

Radiation unit structure and microstrip array antenna

Technical Field

The utility model relates to an array antenna technical field, in particular to radiating element structure and microstrip array antenna.

Background

The microstrip antenna is an antenna formed by attaching a metal thin layer as a grounding plate on one surface of a thin dielectric substrate, manufacturing a metal patch with a certain shape on the other surface by using a photoetching corrosion or printing method, and feeding the patch by using a microstrip line or a coaxial probe. Microstrip antennas are generally classified into two types: one is that the patch shape is an elongated strip called a microstrip element antenna. And the patch is called a microstrip antenna when the patch shape is an area unit. If the ground plate is carved with a gap and the microstrip line is printed on the other side of the medium substrate, the gap feeds to form the microstrip slot antenna.

The microstrip antenna forms an array on a two-dimensional plane, which is called a microstrip plane array antenna. According to different feeding modes, the feeding mode can be divided into series feeding and parallel feeding. The series feed microstrip array antenna is a linear array which is composed of microstrip patches serving as basic array elements and is fed in series by using microstrip lines. The series feed can obviously reduce the complexity of a feed network, shorten the length of a microstrip transmission line in the network, reduce the loss caused by the feed network, and is widely adopted in fixed beam and frequency scanning antennas. Especially, the millimeter wave radar is widely used in automobile millimeter wave radars. Generally, to achieve high gain, array is performed along the X direction to form an area array (series-parallel combination) based on the series fed microstrip array antenna.

The series-fed microstrip array antenna has the characteristics of easiness in manufacturing, compact area, convenience in layout, low cost and the like, and has the characteristics of easiness in reaching a wider horizontal angle, higher gain and the like in the aspect of performance, and is widely used in the automotive millimeter wave anti-collision radar at present, so that the microstrip array antenna has a plurality of related technologies at present.

The prior art about the series feed microstrip array antenna mainly has the following defects and shortcomings: in terms of performance, the area of the series-fed microstrip array antenna needs to be reduced, and the isolation between the antennas needs to be increased. Taking the automotive millimeter wave anti-collision radar as an example, the mainstream scheme at present is to use a 76-81 GHz frequency band as the working frequency band of the automotive millimeter wave anti-collision radar.

In the present millimeter wave radar system, two or more antennas are often used to perform half-wavelength equal-spacing arrangement, so as to form a receiving antenna of the radar, so as to measure the angle of the surrounding object relative to the automobile and to depict the moving direction of the surrounding object. Similarly, after the series-fed microstrip array antenna is arranged at equal intervals of one-half wavelength, the isolation between the antennas is generally less than 15dB, which also limits the performance of the radar.

In MIMO (Multiple-Input Multiple-Output) radar, a plurality of transmitting antennas and a plurality of receiving antennas are often required to be arranged, even though a series-fed array antenna has a compact characteristic, when a plurality of antennas are required, the radar area is larger, and the antenna area is also required to be reduced.

Compared with the series feed array antenna, the parallel feed array antenna is characterized in that array elements are fed in parallel, the parallel feed can form a linear array or form an area array, each unit can be set to be fed independently, and a feed network can be formed by using a multistage power divider or other matrixes for feeding. Similarly, the parallel feed array antenna also needs to improve the isolation between the array elements by technical means, which is beneficial to the suppression of side lobes and other benefits, and the parallel feed array antenna also needs to reduce the antenna area by certain technical means. These problems are the subject of continuous research in the industry, and are the difficulties and bottlenecks in application.

SUMMERY OF THE UTILITY MODEL

The utility model discloses aim at solving one of above-mentioned technical problem at least.

Therefore, an object of the present invention is to provide a radiating element structure, which combines a radiating patch and a PCB radiating element to form a new radiating element structure, thereby reducing the area of the array antenna and increasing the isolation.

Therefore, a second objective of the present invention is to provide a microstrip array antenna.

In order to achieve the above object, the present invention provides in a first aspect a radiating element structure, including: a substrate; a radiation patch disposed over the substrate; a feed structure connected to the radiating patch; the radiation patch comprises a radiation unit arranged on the radiation patch, wherein the radiation unit is provided with a dielectric material structure body, a first metal surface and a second metal surface which are arranged on the dielectric material structure body and are opposite to each other, and the radiation unit is connected with the radiation patch through the first metal surface.

According to the utility model discloses a radiating element structure sets up the radiation paster on the base plate, sets up the radiating element on the radiation paster, and the radiating element has dielectric material structure body, sets up relative first metal covering and second metal covering on dielectric material structure body, and the radiating element links to each other with the radiation paster through first metal covering, adopts radiation paster and PCB radiating element to compound promptly, constitutes new radiating element structure, does benefit to and reduces array antenna area, increases the isolation.

In addition, the above-mentioned radiation unit structure according to the present invention may further have the following additional technical features:

in some examples, the radiating element and the radiating patch are connected by welding.

In some examples, the dielectric constant of the dielectric material structural body is greater than the dielectric constant of the substrate.

In some examples, the dielectric material structural body is rectangular, square, or circular.

In some examples, the feed structure is a feed probe or a feed microstrip line.

In some examples, the dielectric material structural body is ceramic.

In order to achieve the above object, the second aspect of the present invention provides a microstrip array antenna, including the radiating element structure described above.

According to the utility model discloses a microstrip array antenna adopts radiation paster and PCB radiating element to compound, constitutes new radiating element structure, does benefit to and reduces array antenna area, increases the isolation.

In addition, the microstrip array antenna according to the present invention may further have the following additional technical features:

in some examples, further comprising: at least one patch radiating element structure connected in series or in parallel with the radiating element structure.

In some examples, the radiating element structure is a plurality.

In some examples, the dielectric material structure bodies among the plurality of radiating element structures differ in size.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 is a schematic structural view of a radiation unit according to an embodiment of the present invention;

fig. 2 is a schematic structural view of a radiation unit according to another embodiment of the present invention;

fig. 3 is a schematic structural diagram of a radiating element according to an embodiment of the present invention;

fig. 4 is a schematic diagram of a microstrip array antenna constructed by two patch radiating element structures according to an embodiment of the present invention;

fig. 5 is a schematic diagram of an array antenna constructed with a three-patch radiating element structure according to an embodiment of the present invention;

fig. 6 is a schematic diagram of a parallel feed array antenna constructed with multiple patch radiating element structures according to an embodiment of the present invention;

fig. 7 is a schematic diagram of a series-parallel combined (hybrid feed) array antenna constructed from multiple patch radiating element structures according to an embodiment of the present invention;

fig. 8 is a schematic diagram of an array antenna with only one patch radiating element according to an embodiment of the present invention;

FIG. 9 is a schematic diagram of a conventional series-fed array antenna;

fig. 10 is a parametric illustration of the array antenna of fig. 8 in accordance with an embodiment of the present invention;

fig. 11 is a parametric illustration of the array antenna of fig. 9 in accordance with an embodiment of the present invention;

fig. 12 is a schematic diagram of two series fed array antennas spaced one-half wavelength at 77GHz according to an embodiment of the present invention;

FIG. 13 is a parametric illustration of the structure shown in FIG. 12 in accordance with an embodiment of the present invention;

FIG. 14 is a schematic diagram of a spacing between two series-fed array antennas at 76 GHz-77 GHz with an isolation of 18dB or more according to an embodiment of the present invention;

fig. 15 is a parametric illustration of the structure shown in fig. 14 according to an embodiment of the present invention.

Description of the drawings:

1-a substrate; 2-radiation patch; 3-a feed structure; 4-a radiating element; 41-structural body of dielectric material; 42-a first metal face; 43-second metal face.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present invention, and should not be construed as limiting the present invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are used merely for convenience of description and for simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The following describes a radiating element structure and a microstrip array antenna according to embodiments of the present invention with reference to the drawings.

Fig. 1 is a schematic structural diagram of a radiating element structure and a microstrip array antenna according to an embodiment of the present invention. Fig. 2 is a schematic structural diagram of a radiating element structure and a microstrip array antenna according to another embodiment of the present invention. As shown in fig. 1 and fig. 2, the radiation unit structure includes: a substrate 1, a radiating patch 2 (as shown in fig. 2), a feed structure 3 and a radiating element 4.

Specifically, the substrate 1 is made of, for example, a PCB (Printed Circuit Board) material. The radiation patch 2 is arranged on the substrate 1; the feed structure 3 is connected with the radiation patch 2; as shown in fig. 2, the radiation unit 4 is disposed above the radiation patch 2. As shown in fig. 3, the radiation unit 4 has a dielectric material structure body 41, and a first metal surface 42 and a second metal surface 43 which are arranged on the dielectric material structure body 41 and are opposite to each other, and the radiation unit 4 is connected to the radiation patch 2 through the first metal surface 42. That is, the radiation unit 4 is configured as a double-sided metalized radiation unit 4.

In one embodiment of the present invention, first metal face 42 and second metal face 43 are both smooth high conductivity metallized surface layers.

In one embodiment of the present invention, the radiation unit 4 and the radiation patch 2 are connected by welding.

In one embodiment of the present invention, the dielectric constant of the dielectric material structure body 41 is greater than the dielectric constant of the substrate 1. More specifically, the dielectric material structural body 41 is ceramic.

In one embodiment of the present invention, the dielectric material structural body 41 is rectangular, square or circular. The illustrations in fig. 1-3 are all rectangular examples.

In an embodiment of the present invention, the feeding structure 3 is a feeding probe or a feeding microstrip line.

Specifically, the main part of the radiation unit structure comprises: the radiation patch 2 is positioned on the surface of the PCB substrate 1; the radiation unit 4 is welded with the radiation patch 2 on the surface of the PCB substrate 1 in a surface-mounted mode and is metallized on two sides; the radiating element 4 has a certain thickness and a dielectric constant larger than that of the material of the PCB substrate 1. The radiating element 4 is a patch radiating element and can be soldered to the surface of the radiating patch 2 on the PCB substrate 1 by SMT. The upper surface and the bottom surface of the radiation unit 4 are smooth high-conductivity metalized surface layers, that is, the upper and lower surfaces of the dielectric material structure body 41 are smooth metal thin layers formed by a metal material with high conductivity. Therefore, the utility model discloses radiating element 4 is a paster type radiating element, and it is different from general dielectric antenna radiating element, need regard as a whole with radiating element 4 welding back on the PCB base plate 1. Furthermore, a new radiating element composed of the patch radiating element and the radiating element originally positioned on the surface of the PCB substrate is utilized to form a series-fed or parallel-fed array antenna, so that the two difficulties at present, namely the area of the array antenna is reduced, and the isolation between array elements is increased.

To sum up, according to the utility model discloses the radiating element structure sets up the radiation paster on the base plate, sets up the radiating element on the radiation paster, and the radiating element has dielectric material structure body, sets up relative first metal covering and second metal covering on dielectric material structure body, and the radiating element links to each other with the radiation paster through first metal covering, adopts radiation paster and PCB radiating element to carry out the complex promptly, constitutes new radiating element structure, does benefit to and reduces array antenna area, increases the isolation.

The utility model discloses a further embodiment has still provided a microstrip array antenna.

According to the utility model discloses microstrip array antenna, including at least one radiating element structure. The radiation unit structure is, for example, the radiation unit structure described in any of the above embodiments of the present invention.

In an embodiment of the present invention, the microstrip array antenna further includes: at least one patch radiating element structure connected in series or in parallel with the radiating element structure.

In one embodiment of the present invention, the radiating element structure is a plurality of radiating elements.

In an embodiment of the present invention, the sizes of the dielectric material structure bodies in the plurality of radiating element structures are different. I.e. the thickness of the dielectric material structure body is different in different radiating element structures.

In a specific embodiment, the embodiment of the present invention is that the radiating element structure on the patch radiating element structure and the PCB substrate is arrayed to form a series-fed and parallel-fed array antenna, which has a new feature. The patch radiating element structure is characterized in that the number and the positions of the patch radiating element structures can be flexibly configured according to cost requirements, performance requirements, structural requirements and other requirements. For example, as shown in fig. 4, in the design of an eight-element series-fed array antenna, a patch radiating element structure is welded on only two of the eight elements, so that a functional microstrip array antenna is formed. Furthermore, the number of the patch radiating unit structures can be 1-8, and when the number is less than 8, the position distribution of the patch radiating unit structures can be flexibly selected. The flexible mode can enable a designer to achieve the purposes of reducing the area and improving the isolation well while reducing the cost.

As shown in fig. 4, a schematic diagram of a microstrip array antenna composed of two patch radiating element structures is shown. As shown in fig. 5, a schematic diagram of an array antenna composed of a three-patch radiating element structure is shown.

For example, without loss of generality, in this example, because the PCB substrate has eight radiating element structures, 1 to 8 patch radiating element structures can be used if necessary. What and the position arrangement mode of the figure of using paster radiation unit structure all is within the scope of the utility model patent. It should be noted that the same approach can be implemented in parallel-fed or hybrid-fed microstrip array antennas, such as those shown in fig. 6 and 7. As mentioned above, without loss of generality, all the PCB radiating patches in fig. 6 and 7 have patch radiating element structures, and in practical applications, the patch radiating element structures can be flexibly configured.

It should be noted that in the above examples, microstrip line feeding is adopted, and other feeding methods, such as probe feeding, may also be adopted without loss of generality, and these feeding methods will not affect the implementation of the present patent solution.

For ease of understanding, the principle of the embodiments of the present invention to reduce the area of the array antenna and increase the isolation is described below.

Specifically, as described above, a general microstrip planar array antenna is usually manufactured by using a single PCB material or a ceramic substrate, the single PCB material is characterized in that the dielectric constant can be very low, the dielectric constant of the commonly used PCB material is between 3 and 5, the array antenna is manufactured by using the PCB material with the low dielectric constant, and the size of a radiating unit manufactured in a planar manner at the same frequency point is larger due to the low dielectric constant; however, due to the low dielectric constant and the use of the thin PCB, the transmission of surface waves can be suppressed to a certain extent, and the isolation between the antenna radiating elements can be higher compared to a material with a high dielectric constant.

If a ceramic material (such as a low-temperature co-fired ceramic material) is used to manufacture a general microstrip planar array antenna, the ceramic material has a high dielectric constant (generally > 5), so that the antenna radiation unit area can be small at the same frequency point, but the isolation is poor.

The embodiment of the utility model provides a can improve the principle of isolation when reducing the area and lie in: because the utility model discloses the radiating element structure comprises radiating element and extra paster radiating element on the PCB base plate, can bring following two points of benefit like this:

firstly, the dielectric constant of the PCB material is low, but the patch radiating element can be made of a material with a high dielectric constant, and since the patch radiating element is welded on the PCB radiating element finally, the new radiating element is integrated, the lower layer is made of a low dielectric constant material, and the upper layer is made of a high dielectric constant material, the equivalent dielectric constant is higher than that of the original pure PCB material, so that the surface area of the whole radiating element can be reduced. In addition, because the main body material is also a low-dielectric constant PCB material, the isolation between the radiating units also keeps the characteristic of the low-dielectric constant material, and is higher than the isolation between the units made of the high-dielectric constant material.

Secondly, a general microstrip planar array antenna is a planar structure and is difficult to be designed into a three-dimensional structure, and if the microstrip planar array antenna is stacked in a planar manner in a PCB substrate or a ceramic substrate to form the three-dimensional structure, not only the cost is greatly increased, but also the process manufacturing becomes complicated, which is not favorable for increasing the product yield. Therefore, the patch radiating element is welded on the surface of the planar array element, and the method provides an inexpensive manufacturing method of the three-dimensional structure antenna. Because the radiating unit is changed into a three-dimensional structure, the resonance mode of the radiating unit is changed, and because the patch radiating unit with high dielectric constant exists, on one hand, the current path of the radiating unit is lengthened, and the area of the whole radiating unit is reduced; on the other hand, the electric field in the high-dielectric-constant patch radiating unit is concentrated, and the isolation between the radiating units is increased as shown results.

In a specific embodiment, the embodiment of the utility model provides an adopt paster radiating element and PCB radiating element to compound, constitute new radiating element and can reach and reduce the area, increase the purpose of isolation, point out simultaneously that the quantity and the position overall arrangement of paster radiating element can dispose in a flexible way, so, do not lose the generality, use a paster radiating element's series feed array antenna as the embodiment of specific application. In this embodiment, the antenna is a series-fed array antenna applied to a 76GHz automotive millimeter wave collision avoidance radar, wherein the dielectric constant of the PCB board is 3.1, and the loss tangent angle is 0.01. As shown in fig. 9, the antenna operates around 76.4GHz without the patch radiating element, and the parameter results are shown in fig. 11. As shown in fig. 8, after adding a patch radiating element to one of the elements, the antenna operates near 75.4GHz, and the parameter results are shown in fig. 10.

Specifically, in fig. 8, the series-fed array antenna of the embodiment of the present invention is shown, only one patch radiating element is provided, and fig. 9 shows a general series-fed array antenna. In this embodiment, the patch radiating element is a rectangular substrate (with a loss tangent angle of 0.002) made of a ceramic material having a dielectric constant of 7.1, and has smooth high-conductivity metallization layers on the upper and lower surfaces, which are soldered to the PCB radiating patch.

In order to embody the effect of the embodiment of the present invention that can reduce the volume, in this embodiment, the unit on the PCB substrate is kept unchanged, comparing the S11 parameter before and after the radiation patch unit is welded. The comparison result is shown in fig. 10 and fig. 11, where New antenna refers to the S11 parameter of the array antenna shown in fig. 10, in which one patch radiating element is disposed; and Normal antenna refers to the S11 parameter of the conventional series-fed array antenna shown in fig. 11. Wherein, the minimum point of the S11 parameter moves to the low frequency by about 1GHz before and after the patch radiating unit is added, so the area of the radiating patch can be reduced if the minimum point is the same as the original resonance point.

In order to prove that the embodiment of the present invention can increase the isolation between the antennas, two series-fed array antennas are set at a spacing of 77GHz half-wavelength (about 1.95 mm). Similarly, comparing the two conditions, it can be seen that the isolation between the common antennas is less than or equal to 15dB, and after the patch radiation unit is added, the isolation is greater than or equal to 18dB, and at least 3dB is increased. Specifically, as shown in fig. 12, a schematic diagram of a spacing between two series-fed array antennas at a wavelength of one-half 77GHz is shown, and a corresponding parameter result is shown in fig. 13.

Further, fig. 14 shows a schematic diagram of a distance between two series-fed array antennas with an isolation degree of greater than or equal to 18dB between 76GHz and 77GHz, and a corresponding parameter result is shown in fig. 15. However, the isolation between the corresponding common antennas is less than or equal to 15dB between 76GHz and 77 GHz.

It should be noted that the above embodiments of the present invention are described by taking the microstrip series fed array antenna as an example, and the present invention is also effective for the microstrip array antenna of parallel feed without loss of generality.

To sum up, according to the utility model discloses microstrip array antenna adopts radiation paster and PCB radiating element to compound, constitutes new radiating element structure, does benefit to and reduces array antenna area, increases the isolation.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims (10)

1. A radiating element structure, comprising:

a substrate;

a radiation patch disposed over the substrate;

a feed structure connected to the radiating patch;

the radiation patch comprises a radiation unit arranged on the radiation patch, wherein the radiation unit is provided with a dielectric material structure body, a first metal surface and a second metal surface which are arranged on the dielectric material structure body and are opposite to each other, and the radiation unit is connected with the radiation patch through the first metal surface.

2. The radiating element structure of claim 1, wherein the radiating element and the radiating patch are connected by welding.

3. The radiating element structure of claim 1, wherein the dielectric constant of the body of dielectric material structure is greater than the dielectric constant of the substrate.

4. The radiating element structure of claim 1 wherein the dielectric material structural body is rectangular, square or circular.

5. The radiating-element structure of claim 1, wherein the feed structure is a feed probe or a feed microstrip line.

6. The radiating element structure of claim 1 wherein the dielectric material structural body is ceramic.

7. A microstrip array antenna comprising at least one radiating element structure according to any of claims 1 to 6.

8. The microstrip array antenna of claim 7 further comprising:

at least one patch radiating element structure connected in series or in parallel with the radiating element structure.

9. The microstrip array antenna of claim 7 wherein the radiating element structure is plural.

10. The microstrip array antenna of claim 9 wherein the dielectric material structure bodies of the plurality of radiating element structures differ in size.

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