CN114784502A

CN114784502A - Millimeter wave quadrupole electromagnetic dipole antenna

Info

Publication number: CN114784502A
Application number: CN202210707792.0A
Authority: CN
Inventors: 孙瑶; 肖亮; 唐金; 魏伟; 钮浪; 陈斯; 陶林
Original assignee: Chengdu Space Matrix Technology Co ltd
Current assignee: Chengdu Space Matrix Technology Co ltd
Priority date: 2022-06-22
Filing date: 2022-06-22
Publication date: 2022-07-22
Anticipated expiration: 2042-06-22
Also published as: CN114784502B

Abstract

The invention provides a millimeter wave quadrupole electromagnetic dipole antenna, which is characterized in that: the metal floor comprises a first dielectric layer, a metal floor layer and a second dielectric layer, wherein a feed structure consisting of a high-impedance line and a differential microstrip line is arranged on the outer surface of the first dielectric layer; the outer surface of the second medium layer is provided with four folding metal patches, the metal floor layer is arranged between the first medium layer and the second medium layer, a cross-shaped gap is formed in the metal floor layer, and the four folding metal patches are respectively communicated with the metal floor layer through metal through holes and form a radiation structure with the cross-shaped gap. The effect is as follows: the feed structure with the high-impedance line and the microstrip line fused is provided, and 4 polarization modes can be realized on the basis of keeping the gap coupling advantage of the traditional microstrip line; the broadband antenna has wide bandwidth, stable gain, directional diagram and low cross polarization in a working frequency band, can be processed by adopting a PCB (printed Circuit Board) process in the whole structure, has low cost and is convenient to realize miniaturization and integrated design.

Description

Millimeter wave quadrupole electromagnetic dipole antenna

Technical Field

The invention relates to the technical field of antennas, in particular to a millimeter wave quadrupole electromagnetic dipole antenna.

Background

The millimeter wave frequency band has the advantages of wide bandwidth, small influence by climate, narrow antenna beam, small size of the antenna and the system and the like. In 5G mobile communication, millimeter wave satellite communication and automotive radar, millimeter wave technology has gained wide attention and application. The applications are all concentrated in the frequency band of 22GHz-33 GHz, so that the frequency band has wide market prospect.

The development of millimeter wave technology has put new requirements on antennas, such as broadband, high gain, low cross polarization, multi-polarization, and the like. The electromagnetic dipole antenna has the characteristics of wide band, unidirectional radiation, symmetrical directional diagram, stable gain, low cross polarization, simple design and the like, and has great advantages in millimeter wave frequency bands. In addition, the multi-polarization antenna can enhance the capacity of the system.

Conventional electromagnetic dipole antennas employ either probe direct feed or Substrate Integrated Waveguide (SIW) slot coupling. For example, the cross-shaped high-gain broadband dielectric dual-polarized electromagnetic dipole antenna disclosed in chinese patent 202111266978.9 adopts a probe coupling manner, and is complex in design, difficult to process, and difficult to implement in a millimeter wave frequency band. For example, the millimeter wave differential feeding dual-polarized electromagnetic dipole antenna disclosed in chinese patent 201810308995.6, the SIW feeding mode results in a larger size of the antenna, increases the cost of the antenna, is difficult to integrate with other parts of the system, reduces the integration level and compactness of the system, and furthermore, the SIW feeding electromagnetic dipole bandwidth is limited.

Disclosure of Invention

Based on the above problems, the present invention is directed to a millimeter wave quadrupole electromagnetic dipole antenna, which adopts microstrip line differential feeding and cross-shaped slot coupling structures, so as to have the advantages of wide bandwidth, stable and symmetrical directional diagram, low cross polarization, simple structure, and the like.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

the utility model provides a millimeter wave quadrupole electromagnetic dipole antenna which the key lies in: the metal floor comprises a first medium layer, a metal floor layer and a second medium layer, wherein a feed structure consisting of a high-impedance line and a differential microstrip line is arranged on the outer surface of the first medium layer; the outer surface of the second medium layer is provided with four folding metal patches, the metal floor layer is arranged between the first medium layer and the second medium layer, cross-shaped gaps are formed in the metal floor layer, and the four folding metal patches are respectively communicated with the metal floor layer through metal through holes and form a radiation structure with the cross-shaped gaps.

Optionally, the high impedance lines are distributed in a shape of a Chinese character mi, two ends in the horizontal direction and the vertical direction are respectively provided with a section of microstrip line, and different polarization modes of the antenna can be realized through different settings of feed signals of the ends in the horizontal direction and the vertical direction.

Optionally, the four-direction slits of the cross-shaped slit are overlapped with the four ends of the high-impedance line, which are not connected with the microstrip line.

Optionally, a folded metal patch is arranged on the second dielectric layer corresponding to the region between two adjacent cross-shaped gaps, and a gap corresponding to the cross-shaped gap is reserved between the two adjacent folded metal patches.

Optionally, each of the folded metal patches is in conduction with the metal floor layer through two metal through holes.

Optionally, the first dielectric layer is connected and fixed with the metal floor layer through an adhesive layer.

Optionally, the first dielectric layer, the metal floor layer, and the second dielectric layer are all arranged in a rectangular or circular shape.

Optionally, four folded metal patches are symmetrically arranged in the horizontal direction and the vertical direction at the same time.

Optionally, each of the folded metal patches includes a segment of arc patch and a segment of linear patch, and the four folded metal patches have the same shape and size and serve as an electric dipole; the sizes of the gaps in four directions of the cross-shaped gap are the same and the cross-shaped gap is used as a magnetic dipole.

Optionally, a limiting sheet for clamping the first dielectric layer is respectively convexly arranged on four edges of the metal floor layer.

The invention has the following effects:

(1) the feed structure with the high-impedance line and the microstrip line fused together provided by the invention can realize 4 polarization modes by utilizing the polarization synthesis technology on the basis of keeping the gap coupling advantage of the traditional microstrip line;

(2) the differential feed mode is adopted, the bandwidth is wide, and stable gain, directional diagram and low cross polarization are realized in the working frequency band;

(3) the whole structure can be processed by adopting a PCB process, the cost is lower, the size of the antenna is smaller, and the antenna is easy to integrate with other parts of the system.

Drawings

In order to more clearly illustrate the detailed description of the invention or the technical solutions in the prior art, the drawings that are needed in the detailed description of the invention or the prior art will be briefly described below.

Fig. 1 is a front exploded view of an antenna structure according to an embodiment of the present invention;

fig. 2 is a bottom exploded view of an antenna structure according to an embodiment of the present invention;

fig. 3 is a front perspective view of an antenna structure according to an embodiment of the present invention;

FIG. 4 is a bottom perspective view of an antenna structure according to an embodiment of the present invention;

fig. 5 is a schematic front plan view of an antenna structure according to an embodiment of the present invention;

FIG. 6 is a bottom plan view of an antenna structure according to an embodiment of the present invention;

fig. 7 is a schematic diagram of the distribution of the slot electric field under different port feeding conditions, wherein: fig. 7 (a) shows the electric field distribution state in the cross-shaped gap when port 1 and port 2 are fed with equal amplitude and opposite phase, and port 3 and port 4 are not fed with power; FIG. 7 (b) shows the electric field distribution state in the cross-shaped slot when the port 3 and the port 4 are fed and the port 1 and the port 2 are not fed;

fig. 8 is a schematic diagram of electric field synthesis in different polarization modes, wherein: FIG. 8 (a) is a diagram showing the effect of the x-direction linear polarization electric field; FIG. 8 (b) is a diagram showing the effect of the synthesis of linearly polarized electric field in the y-direction; FIG. 8 (c) is a left-hand circularly polarized electric field synthesis effect diagram; FIG. 8 (d) is a diagram illustrating the effect of right-hand circularly polarized electric field synthesis;

FIG. 9 is a schematic structural view of a cross-shaped slit;

FIG. 10 is a diagram illustrating S-parameter simulation effects according to an embodiment of the present invention;

FIG. 11 is a diagram illustrating the simulation effect of the antenna in x-direction linear polarization according to an embodiment of the present invention;

FIG. 12 is a diagram illustrating simulation effects of the antenna when linearly polarized in the y-direction according to the embodiment of the present invention;

fig. 13 is a diagram illustrating simulation effects of the left-handed circular polarized antenna according to the embodiment of the present invention;

FIG. 14 is a diagram illustrating simulation effects of right-hand circularly polarized antenna in an embodiment of the present invention;

FIG. 15 is a graph of gain frequency for an antenna in 4 polarizations;

fig. 16 is a graph of axial ratio frequency for two circular polarizations for the antenna.

Reference numerals are as follows: 10-a first dielectric layer, 20-a metal floor layer, 30-a second dielectric layer, 40-an adhesive layer, 11-a high-impedance line, 12-a differential microstrip line, 21-a cross-shaped gap, 22-a limiting sheet, 31-a folded metal patch and 32-a metal through hole.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and therefore are only examples, and the protection scope of the present invention is not limited thereby.

It is to be noted that, unless otherwise specified, technical or scientific terms used herein shall have the ordinary meaning as understood by those skilled in the art to which the invention pertains.

As shown in fig. 1, 2, 3, and 4, the present embodiment provides a millimeter wave quadrupole electromagnetic dipole antenna, which includes a first dielectric layer 10, a metal floor layer 20, and a second dielectric layer 30, wherein the metal floor layer 20 is disposed between the first dielectric layer 10 and the second dielectric layer 30, the metal floor layer 20 and the second dielectric layer 30 may be integrated by a PCB process, the first dielectric layer 10 may be connected and fixed by an adhesive layer 40, and specifically, the metal floor layer 20 is further provided with a limiting sheet 22 protruding from four edges thereof for clamping the first dielectric layer 10.

A feed structure consisting of a high-impedance line 11 and a differential microstrip line 12 is arranged on the outer surface of the first medium layer 10; as can be seen from fig. 2, 4 and 6, the high impedance lines 11 are distributed in a shape of a Chinese character mi, and two ends in the horizontal direction and the vertical direction are respectively provided with a section of microstrip line, and in specific implementation, the microstrip lines in all directions have the same size.

As can be seen from fig. 1, 3 and 5, four folded metal patches 31 are disposed on the outer surface of the second dielectric layer 30, the four folded metal patches 31 are symmetrically disposed in the horizontal direction and the vertical direction, each folded metal patch 31 includes a segment of arc patch and a segment of linear patch, and two metal through holes 32 connected to the arc patch are communicated with the metal floor layer 20, so that multiple polarizations can be implemented.

As can be seen from fig. 1 and 2, a cross-shaped gap 21 is formed in the metal floor layer 20, a folded metal patch 31 is disposed on the second medium layer 30 corresponding to an area between two adjacent gaps of the cross-shaped gap 21, a gap corresponding to the cross-shaped gap 21 is reserved between two adjacent folded metal patches 31, the four folded metal patches 31 have the same shape and size and are used as electric dipoles, and the gaps of the cross-shaped gap 21 in four directions have the same size and are used as magnetic dipoles, so that the radiation structure of the antenna is integrally formed.

As can also be seen from fig. 1 and fig. 2, in practical implementation, the slits in four directions of the cross-shaped slit 21 coincide with the directions of the four ends of the unconnected microstrip lines in the high impedance line 11. The first dielectric layer 10, the metal floor layer 20 and the second dielectric layer 30 are all arranged in a rectangular or circular shape.

As shown in fig. 6, 7 and 8, by designing the cross slot structure, when the port 1 and the port 2 are fed with equal amplitude in opposite phase and the port 3 and the port 4 are not fed with power, two 45-degree electric fields E1 and E2 shown in fig. 7 (a) are generated in the slot, so that the x-direction electric field shown in fig. 8 (a) can be synthesized, and the antenna operates in the x-direction linear polarization; when the port 3 and the port 4 are fed and the port 1 and the port 2 are not fed, two 45-degree-direction electric fields E3 and E4 shown in fig. 7 (b) are generated in the slot, so that an electric field in the y direction shown in fig. 8 (b) can be synthesized, and the antenna operates in linear polarization in the y direction. When the port 1 and the port 2 have equal amplitude and opposite phase, the port 3 and the port 4 have equal amplitude and opposite phase, and the port 1 and the port 3 have equal amplitude and 90 degrees phase difference, the antenna can work in left-hand circular polarization as shown in fig. 8 (c); when port 1 and port 2 are in equal amplitude and opposite phase, port 3 and port 4 are in equal amplitude and opposite phase, and port 1 and port 3 are in equal amplitude and opposite phase by-90 degrees, the antenna can operate in right hand circular polarization as shown in fig. 8 (d).

To further verify the performance of the antenna structure, simulation was performed according to the specific parameter settings shown in table 1, and the simulation results are shown in fig. 10-14.

TABLE 1 simulation data of antenna size parameters

L1

W1

L2

W2

L3

W3

W4

D2

D1

2.07mm

0.5mm

1.26mm

0.2mm

2.57mm

0.5mm

11mm

5mm

4.3mm

As can be seen from the positions of the parameters marked in fig. 5, 6, and 9, L1 represents the length of the slit in each direction of the cross-shaped slit, W1 represents the width of the slit in each direction of the cross-shaped slit, L2 represents the length of the high-impedance line 11 in each direction of the shape of the Chinese character 'mi', W2 represents the width of the high-impedance line 11 in each direction of the shape of the Chinese character 'mi', L3 represents the length of the straight-line-shaped patch section of the folded metal patch 31, W3 represents the width of the straight-line-shaped patch section of the folded metal patch 31, W4 is the side length of the first dielectric layer 10, the metal floor layer 20, and the second dielectric layer 30 when all of them are arranged in a square shape, D2 represents the outer diameter of the arc-shaped patch section of the folded metal patch 31, and D1 represents the inner diameter of the arc-shaped patch section of the folded metal patch 31.

As can be seen from fig. 10: the S11 corresponding to the antenna port 1 and the S33 corresponding to the port 3 are smaller than-10 dB in the frequency range of 22 GHz-34 GHz, and the relative bandwidth of-10 dB is larger than 42%. The matching characteristics of the 4 polarizations are good, and the application requirements are met.

As can be seen from fig. 11: at the central frequency of 28GHz, the E surface and the H surface of the x-direction linear polarization directional diagram of the antenna are symmetrical, the cross polarization is lower than-40 dB, and the front-to-back ratio is lower than 15 dB.

As can be seen from fig. 12: at the center frequency of 28GHz, the E surface and the H surface of a y-direction linear polarization directional diagram of the antenna are symmetrical, the cross polarization is lower than-35 dB, and the front-to-back ratio is lower than 15 dB.

As can be seen from fig. 13: at the center frequency of 28GHz, the E surface and the H surface of a left-handed circularly polarized directional diagram of the antenna are symmetrical, the cross polarization is lower than-35 dB, and the front-to-back ratio is lower than 15 dB.

As can be seen from fig. 14: at the central frequency of 28GHz, the E surface and the H surface of a right-hand circularly polarized directional diagram of the antenna are symmetrical, the cross polarization is lower than-50 dB, and the front-to-back ratio is lower than 15 dB.

As can be seen from fig. 15: the gain of 4 polarizations of the antenna has the same trend with frequency. At 22GHz, the antenna gain is maximum, 6.45 dBi. In the frequency range of 22 GHz-32 GHz, the gain change of the antenna is less than 2 dBi.

As can be seen from fig. 16: the axial ratio of the two circularly polarized states of the antenna is less than 0.25dB in the range of 22 GHz-32 GHz, and the relative bandwidth of the axial ratio is more than 42%.

In conclusion, the millimeter wave quadrupole electromagnetic dipole antenna provided by the invention adopts a microstrip line differential feed and cross-shaped gap coupling structure, has the advantages of stable and symmetrical broadband and directional diagram, low cross polarization, simple structure and the like, can stably realize various polarization modes, and is small in size, low in cost and easy to integrate.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the embodiments of the present invention, and such changes are intended to be covered by the appended claims and their equivalents.

Claims

1. A millimeter wave quadrupole electromagnetic dipole antenna is characterized in that: the metal floor comprises a first dielectric layer (10), a metal floor layer (20) and a second dielectric layer (30), wherein a feed structure consisting of a high-impedance line (11) and a differential microstrip line (12) is arranged on the outer surface of the first dielectric layer (10); the radiating structure is characterized in that four folding metal patches (31) are arranged on the outer surface of the second medium layer (30), the metal floor layer (20) is arranged between the first medium layer (10) and the second medium layer (30), a cross-shaped gap (21) is formed in the metal floor layer (20), the four folding metal patches (31) are respectively communicated with the metal floor layer (20) through metal through holes (32), and the four folding metal patches and the cross-shaped gap (21) form a radiating structure.

2. The millimeter wave quadrupolar electromagnetic dipole antenna according to claim 1, wherein: the high-impedance lines (11) are distributed in a shape of Chinese character 'mi', and two end parts in the horizontal direction and the vertical direction are respectively provided with a section of microstrip line.

3. The millimeter wave quadrupolar electromagnetic dipole antenna according to claim 2, wherein: gaps in four directions of the cross-shaped gap (21) are overlapped with four end heads of the high-impedance line (11) which are not connected with the microstrip line in directions.

4. The millimeter wave quadrupolar electromagnetic dipole antenna according to claim 1, wherein: and arranging a folding metal patch (31) on the second medium layer (30) corresponding to the area between two adjacent cross-shaped gaps (21), wherein a gap corresponding to the cross-shaped gap (21) is reserved between the two adjacent folding metal patches (31).

5. The millimeter wave quadrupolar electromagnetic dipole antenna according to claim 4, wherein: each folded metal patch (31) is communicated with the metal floor layer (20) through two metal through holes (32).

6. The millimeter wave quadrupolar electromagnetic dipole antenna according to any one of claims 1 to 5, wherein: the first dielectric layer (10) and the metal floor layer (20) are fixedly connected through an adhesive layer (40).

7. The millimeter wave quadrupolar electromagnetic dipole antenna according to claim 6, wherein: the first dielectric layer (10), the metal floor layer (20) and the second dielectric layer (30) are all arranged in a rectangular or circular shape.

8. The millimeter wave quadrupolar electromagnetic dipole antenna according to claim 6, wherein: the four folded metal patches (31) are symmetrically arranged in the horizontal direction and the vertical direction at the same time.

9. The millimeter wave quadrupolar electromagnetic dipole antenna according to claim 8, wherein: each folding metal patch (31) comprises an arc patch and a straight line patch, and the four folding metal patches (31) have the same shape and size and are used as electric dipoles; the cross-shaped slits (21) have the same slit size in four directions and are used as magnetic dipoles.

10. The millimeter wave quadrupolar electromagnetic dipole antenna according to claim 6, wherein: and limiting sheets (22) used for clamping the first dielectric layer (10) are respectively arranged on four edges of the metal floor layer (20) in a protruding mode.