Dual-frequency antenna

Abstract

The utility model discloses a dual-frequency antenna, and relates to the technical field of antennas. The antenna comprises a first layer of copper sheet, a first substrate, a second layer of copper sheet, a second substrate and a third layer of copper sheet. First through holes penetrating through the first substrate are formed in the periphery of the first layer of copper sheet; a first groove is formed around the center of the first layer of copper sheet, so that a first copper block is formed in the center of the first layer of copper sheet; a second groove is formed in the diagonal line of the first layer of copper sheet, and a second copper block is formed in the center of the second groove; diagonal angles of the first layer of copper sheet, the first groove, the first copper block, the second groove and the second copper block are all provided with chamfers, the chamfers of the first groove and the chamfers of the first copper block are located on the same diagonal line, and the chamfers of the second groove and the chamfers of the second copper block are located on the same diagonal line; second through holes penetrating through the first substrate are formed in the periphery of the first copper block; and a first feed point is arranged on the second copper block. The antenna provided by the utility model can work in a C wave band and an X wave band at the same time, and realizes circular polarization.

Description

Technical Field

[0001] This utility model belongs to the field of antenna technology, and in particular relates to a C-band and X-band dual-frequency antenna. Background Technology

[0002] Current weather radars mainly focus on C-band and X-band. With the rapid development of wireless technology, miniaturization and multi-band operation have become research hotspots. Traditionally, radar systems superimposed with C-band and X-band systems result in excessively large RF front-end and antenna sizes. Circularly polarized antennas have significant advantages in suppressing multipath effects and reducing channel polarization mismatch. However, most research on circularly polarized antennas focuses on single-frequency antennas, while dual-frequency antennas are mainly concentrated in areas such as dual-band Wi-Fi and millimeter-wave, primarily using linear polarization.

[0003] Therefore, there is an urgent need to study a dual-band antenna that can operate in both C-band and X-band to adapt to the miniaturization and multi-band applications of radar. Utility Model Content

[0004] The purpose of this invention is to provide a dual-band antenna to solve the problem of excessively large size of the radio frequency front-end and antenna system caused by directly superimposing C-band and X-band antennas on a radar.

[0005] The present invention solves the above-mentioned technical problems through the following technical solution: a dual-frequency antenna, comprising a first copper layer, a first substrate, a second copper layer, a second substrate, and a third copper layer stacked from top to bottom;

[0006] Multiple first through holes are formed around the first copper layer and the first through holes penetrate the first substrate; a first groove is formed around the center of the first copper layer, so that a first copper block is formed at the center of the first copper layer; a second groove is formed on the diagonal of the first copper layer and a second copper block is formed at the center of the second groove; a second through hole is formed around the first copper block and the second through hole penetrates the first substrate; a first feed point is provided on the second copper block;

[0007] A second feed point is provided on the second copper layer, and the second feed point is located in the cavity surrounded by the first through hole; two third through holes are provided on the diagonal of the second copper layer, and both third through holes penetrate the second substrate and the third copper layer, and the position of one of the third through holes corresponds to the position of the first feed point and is used to nest the first probe.

[0008] A fourth through hole is provided on the third copper layer, the position of which corresponds to the position of the second feed point and is used to nest the second probe; the first probe and the second probe are provided with anti-soldering pads at their entrances on the third copper layer.

[0009] A C-band dielectric integrated waveguide slot antenna is formed by combining a first slot, a first layer of copper foil, a first copper block, a first substrate, a first through hole, and a second through hole, with the first slot serving as the independent and primary C-band antenna radiator. An X-band antenna is formed by combining a second slot, a second copper block, a first layer of copper foil, and a first substrate, with the second copper block separated by the second slot serving as the independent X-band antenna radiator. The overall antenna size is similar to that of a traditional patch C-band antenna, and it can operate simultaneously in both the C-band and X-band. This invention has a high aperture reuse rate and a compact structure.

[0010] Furthermore, two fifth through holes are formed on the central axis of the first copper layer, and two sixth through holes are formed on the diagonal of the first copper layer. Both the fifth and sixth through holes penetrate the first substrate.

[0011] Furthermore, the two sixth through holes are located on different diagonals from the second copper block and the second groove.

[0012] Furthermore, the chamfers of the first copper layer, the first groove, the first copper block, the second groove, and the second copper block are all located on the same diagonal.

[0013] Furthermore, the first pair of opposite corners of the first copper layer, the first pair of opposite corners of the first groove, the first pair of opposite corners of the first copper block, the first pair of opposite corners of the second groove, and the first pair of opposite corners of the second copper block all have chamfered angles. The chamfered angle of the first groove and the chamfered angle of the first copper block are located on the same diagonal line, and the chamfered angle of the second groove and the chamfered angle of the second copper block are located on the same diagonal line.

[0014] The first pair of opposite corners of the second copper layer has chamfered edges.

[0015] This invention achieves circular polarization through chamfering. By changing the chamfer position of the first copper layer, the antenna can be flexibly adjusted to right-hand or left-hand circular polarization. The principle of circular polarization is simple.

[0016] Furthermore, two seventh through holes are formed on the diagonal of the second copper layer, and both seventh through holes penetrate the second substrate and the third copper layer. The two seventh through holes and the two third through holes are located on different diagonals.

[0017] Furthermore, the second feed point is located on the central axis of the second copper layer.

[0018] Furthermore, insulating rings are fitted onto the first and second probes.

[0019] Furthermore, the insulating ring is made of polytetrafluoroethylene (PTFE).

[0020] Furthermore, the first copper layer has the same dimensions as the second copper layer, and the third copper layer has the same dimensions as the first substrate and the second substrate.

[0021] Beneficial effects

[0022] Compared with the prior art, the advantages of this utility model are:

[0023] The dual-band antenna provided by this utility model can operate simultaneously in the C-band and X-band. The C-band antenna and the X-band antenna are highly integrated, sharing part of the reference ground and short-circuit via without adding extra size. It has a high aperture reuse rate and a compact structure, making it very suitable for narrowband systems such as weather radar.

[0024] This invention achieves circular polarization through chamfering. The principle of circular polarization is simple. At the same time, by changing the chamfer position of the first copper layer, the antenna can be flexibly adjusted to either right-hand or left-hand circular polarization, thus improving the flexibility of circular polarization. Attached Figure Description

[0025] To more clearly illustrate the technical solution of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only one embodiment of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is an exploded view of the dual-frequency antenna in an embodiment of this utility model;

[0027] Figure 2 This is a schematic diagram of the first copper layer in an embodiment of this utility model;

[0028] Figure 3 This is a schematic diagram of the second copper layer in an embodiment of this utility model;

[0029] Figure 4 This is a schematic diagram of the third copper layer in an embodiment of this utility model;

[0030] Figure 5 These are the S11 and S21 parameter curves of the dual-frequency antenna in this embodiment of the present invention;

[0031] Figure 6 These are the S12 and S22 parameter curves of the dual-frequency antenna in this embodiment of the present invention.

[0032] Explanation of reference numerals in the attached diagram: 1-First copper layer, 10-First groove, 101-Chamfer of the first groove, 11-First copper block, 111-Chamfer of the first copper block, 112-Second through hole, 12-Second groove, 121-Chamfer of the second groove, 13-Second copper block, 131-Chamfer of the second copper block, 132-First feed point, 14-First through hole, 15-Chamfer of the first copper layer, 16-Fifth through hole, 17-Sixth through hole, 2-First substrate, 3-Second copper layer, 31-Seventh through hole, 32-Second feed point, 33-Third through hole, 34-First probe, 35-Chamfer of the second copper layer, 4-Second substrate, 5-Third copper layer, 51-Fourth through hole, 52-Insulating ring, 53-Second probe, 54-Reverse pad. Detailed Implementation

[0033] The technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0034] The technical solutions of this application will be described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0035] like Figure 1 As shown in the figure, the dual-band antenna provided in this embodiment of the present invention includes a first copper layer 1, a first substrate 2, a second copper layer 3, a second substrate 4, and a third copper layer 5 stacked from top to bottom. The dielectric constants of the first substrate 2 and the second substrate 4 are between 2 and 4. The thicknesses of the first copper layer 1, the second copper layer 3, and the third copper layer 5 are 18 μm. The first copper layer 1 is the antenna radiator and is used to radiate electromagnetic waves into space. The first substrate 2 and the second substrate 4 serve as electromagnetic wave transmission carriers. The second copper layer 3 and the third copper layer 5 serve as a reference ground plane and are used for feed network design. In this embodiment, the first copper layer 1, the first substrate 2, the second copper layer 3, the second substrate 4, and the third copper layer 5 are all rectangular.

[0036] like Figure 2As shown, multiple first through holes 14 are formed around the first copper layer 1, and the first through holes 14 penetrate the first substrate 2; a first groove 10 is formed around the center of the first copper layer 1, so that a first copper block 11 is formed at the center of the first copper layer 1; a second groove 12 is formed on the diagonal of the first copper layer 1, and a second copper block 13 is formed at the center of the second groove 12; the first pair of opposite corners of the first copper layer 1 (i.e., the upper left corner and the lower right corner), the first pair of opposite corners of the first groove 10 (i.e., the upper left corner and the lower right corner), the first pair of opposite corners of the first copper block 11 (i.e., the upper left corner and the lower right corner), and the first pair of opposite corners of the second groove 12 (i.e., the upper left corner and the lower right corner) are shown. The first copper block 11 has chamfered corners at the bottom corner and the first pair of diagonals (i.e., the upper left corner and the lower right corner). The chamfered corner 101 of the first slot and the chamfered corner 111 of the first copper block are located on the same diagonal line. The chamfered corner 121 of the second slot and the chamfered corner 131 of the second copper block are located on the same diagonal line. A second through hole 112 is provided around the first copper block 11 and the second through hole 112 penetrates the first substrate 2. A first feed point 132 (i.e., the feed point of the X-band antenna) is provided on the second copper block 13. The first feed point 132 passes through the first substrate 2, the second copper layer 3, the second substrate 4 and the third copper layer 5 in sequence, and is fed from the back of the third copper layer 5.

[0037] The first through-hole 14 is used to connect the first copper layer 1 and the second copper layer 3. The current in the first copper layer 1 can directly reach the second copper layer 3 through the first through-hole 14. The first copper layer 1 has a pair of diagonal chamfers to achieve circular polarization. After chamfering, two degenerate modes with equal amplitude and orthogonal polarization can operate simultaneously. Circular polarization radiation is achieved when one degenerate mode leads the other by 45° and the other lags by 45°. Circular polarization is divided into left-handed and right-handed circular polarization. Circular polarization conforming to the left-handed spiral rule in the direction of propagation is called left-handed circular polarization, and conforming to the right-handed spiral rule is called right-handed circular polarization. In this embodiment, when the chamfers of the first copper layer 1 are located at the upper left and lower right corners, the antenna is left-handed circularly polarized; when the chamfers of the first copper layer 1 are located at the upper right and lower left corners, the antenna is right-handed circularly polarized.

[0038] The first copper layer 1, the first groove 10 and the first copper block 11, the second groove 12 and the second copper block 13 are independent of each other. Therefore, the chamfer 15 of the first copper layer, the chamfer 101 / 111 of the first groove and the first copper block, and the chamfer 121 / 131 of the second groove and the second copper block can be located on the same diagonal or on different diagonals. In this embodiment, the second groove 12 and the second copper block 13 are located at the lower right corner of the first groove 10 and the first copper block 11. The second groove 12 and the second copper block 13 can also be located at the upper left, upper right, or lower left corner of the first groove 10 and the first copper block 11.

[0039] The first slot 10 separates the first copper layer 1 from the first copper block 11, allowing the first copper layer 1, the first slot 10, and the first copper block 11 to form an independent C-band antenna radiator. The second slot 12 separates the first copper layer 1 from the second copper block 13, allowing the second copper block 13 to form an independent X-band antenna radiator. The first slot 10, the first copper layer 1, the first copper block 11, the first substrate 2, the first through-hole 14, and the second through-hole 112 are combined to form a C-band dielectric integrated waveguide slot antenna, with the first slot 10 serving as the main C-band antenna radiator, radiating electromagnetic waves into space through the first slot 10. The second slot 12, the second copper block 13, the first copper layer 1, and the first substrate 2 are combined to form an X-band antenna, with the second copper block 13 serving as the X-band antenna radiator, radiating electromagnetic waves into space through the second copper block 13. The second slot 12 acts as an isolation element. This invention integrates a C-band antenna and an X-band antenna together, reducing the antenna size and isolating the C-band antenna from the X-band antenna.

[0040] like Figure 3 As shown, the first pair of diagonals of the second copper layer 3 have chamfered angles 35; a second feed point 32 (i.e., the feed point of the C-band antenna) is provided on the second copper layer 3, and the second feed point 32 is located in the cavity enclosed by the first through hole 14; two third through holes 33 are provided on the diagonal of the second copper layer 3, and both third through holes 33 penetrate the second substrate 4 and the third copper layer 5, and the position of one of the third through holes 33 corresponds to the position of the first feed point 132 and is used to nest the first probe 34. In this embodiment, the second feed point 32 is located on the central axis of the second copper layer 3, which improves the impedance matching of the antenna.

[0041] The second copper layer 3 serves as a reference ground plane. The third through hole 33 is used to connect the second copper layer 3 and the third copper layer 5. One of the third through holes 33 contains a first probe 34 (i.e., the probe of the X-band antenna). Therefore, the third through hole 33 indirectly serves as a shield, increasing the isolation between the C-band and X-band antennas.

[0042] like Figure 4 As shown, a fourth through hole 51 is provided on the third copper layer 5. The position of the fourth through hole 51 corresponds to the position of the second feed point 32 and is used to nest the second probe 53. In order to prevent short circuit between the probe and the third copper layer 5, the first probe 34 and the second probe 53 are cut at the entrance of the third copper layer 5 to form a reverse solder pad 54.

[0043] In a specific embodiment of this utility model, such as Figure 2 As shown, two fifth through holes 16 are opened on the central axis of the first copper layer 1, and two sixth through holes 17 are opened on the diagonal of the first copper layer 1. Both the fifth through holes 16 and the sixth through holes 17 penetrate the first substrate 2.

[0044] A pair of through-holes (i.e., the fifth through-hole 16 and the sixth through-hole 17) are introduced on both the central axis and the diagonal. These two types of through-holes are disturbance vias, and impedance matching can be adjusted by changing the position of the disturbance vias. The two fifth through-holes 16 are located on the central axis of the first copper layer 1, and the two sixth through-holes 17 are located on the diagonal of the first copper layer 1, which improves the impedance matching of the antenna.

[0045] In this embodiment, the two sixth through holes 17 are located on different diagonals from the second copper block 13 and the second groove 12.

[0046] In a specific embodiment of this utility model, such as Figure 3 As shown, two seventh through holes 31 are formed on the diagonal of the second copper layer 3, and both seventh through holes 31 penetrate the second substrate 4 and the third copper layer 5. The two seventh through holes 31 and the two third through holes 33 are located on different diagonals. The seventh through holes 31 are used to connect the second copper layer 3 and the third copper layer 5.

[0047] In a specific embodiment of this utility model, such as Figure 4 As shown, an insulating ring 52 is fitted onto the first probe 34 and the second probe 53 to provide insulation. In this embodiment, the insulating ring 52 is made of polytetrafluoroethylene (PTFE).

[0048] In a specific embodiment of this utility model, such as Figure 1 As shown, the first copper layer 1 and the second copper layer 3 have the same dimensions, and the third copper layer 5 has the same dimensions as the first substrate 2 and the second substrate 4.

[0049] Compared with traditional patch C-band antennas, the antenna of this invention has a comparable size and can operate in both C-band and X-band simultaneously. It can flexibly adjust the right-hand circular polarization or left-hand circular polarization of the antenna, and the circular polarization principle is simple. The C-band antenna and X-band antenna are highly integrated, sharing part of the reference ground and short-circuit via, without adding extra size, and have a high aperture reuse rate and compact structure.

[0050] To demonstrate the good isolation between the C-band and X-band antennas of this invention, simulations were performed on the antenna to obtain its S-parameter curves, as shown below. Figure 5 and Figure 6As shown. S-parameters (i.e., scattering parameters) are used to describe the input-output characteristics of a microwave network. For a two-port network (i.e., with two ports, usually labeled port 1 and port 2), the S-parameters include S11, S12, S21, and S22. S11 represents the reflection coefficient of port 1, which is the ratio of the signal reflected back to port 1 from the signal input to port 1 to the input signal; S21 represents the forward transmission coefficient, which is the ratio of the signal transmitted from the signal input to port 1 to port 2 to the input signal; S22 represents the reflection coefficient of port 2, which is the ratio of the signal reflected back to port 2 from the signal input to port 2 to the input signal; and S12 represents the reverse transmission coefficient, which is the ratio of the signal transmitted from the signal input to port 2 to port 1 to the input signal.

[0051] Figure 5 and Figure 6 In the diagram, port 1 is the C-band antenna port, and port 2 is the X-band antenna port. According to... Figure 5 It can be seen that at 5.4 to 5.6 GHz, S11 is below -10 dB, indicating that in this frequency band, more than 90% of the antenna's energy is radiated out, and less than 10% of the energy is reflected back, indicating that the antenna of this invention has good matching. In this frequency band, S21 is below -20 dB, indicating that less than 10% of the C-band antenna energy is transferred to the X-band antenna, indicating that the C-band antenna and X-band antenna of this invention have good isolation and do not affect each other.

[0052] according to Figure 6 It can be seen that in the 9.3-10GHz range, S22 is below -10dB, indicating that in this frequency band, more than 90% of the antenna's energy is radiated out, and less than 10% of the energy is reflected back, indicating that the antenna of this invention has good matching. In this frequency band, S12 is below -20dB, indicating that less than 10% of the X-band antenna energy is transferred to the C-band antenna, indicating that the C-band antenna and X-band antenna of this invention have good isolation and do not affect each other.

[0053] The above description only discloses specific embodiments of the present utility model, but the protection scope of the present utility model is not limited thereto. Any changes or modifications that can be easily conceived by those skilled in the art within the technical scope disclosed in the present utility model should be included within the protection scope of the present utility model.

Claims

1. A dual-band antenna, characterized in that, The antenna comprises a first copper layer, a first substrate, a second copper layer, a second substrate, and a third copper layer stacked from top to bottom; Multiple first through holes are formed around the first copper layer and the first through holes penetrate the first substrate; a first groove is formed around the center of the first copper layer, so that a first copper block is formed at the center of the first copper layer; a second groove is formed on the diagonal of the first copper layer and a second copper block is formed at the center of the second groove; a second through hole is formed around the first copper block and the second through hole penetrates the first substrate; a first feed point is provided on the second copper block; A second feed point is provided on the second copper layer, and the second feed point is located in the cavity surrounded by the first through hole; two third through holes are provided on the diagonal of the second copper layer, and both third through holes penetrate the second substrate and the third copper layer, and the position of one of the third through holes corresponds to the position of the first feed point and is used to nest the first probe. A fourth through hole is provided on the third copper layer, the position of which corresponds to the position of the second feed point and is used to nest the second probe; the first probe and the second probe are provided with anti-soldering pads at their entrances on the third copper layer.

2. The dual-band antenna according to claim 1, characterized in that, Two fifth through holes are formed on the central axis of the first copper layer, and two sixth through holes are formed on the diagonal of the first copper layer. Both the fifth and sixth through holes penetrate the first substrate.

3. The dual-frequency antenna according to claim 2, characterized in that, The two sixth through holes are located on different diagonals from the second copper block and the second groove.

4. The dual-band antenna according to claim 1, characterized in that, The first pair of opposite corners of the first layer of copper foil, the first pair of opposite corners of the first groove, the first pair of opposite corners of the first copper block, the first pair of opposite corners of the second groove, and the first pair of opposite corners of the second copper block all have chamfered corners. The chamfered corner of the first groove and the chamfered corner of the first copper block are located on the same diagonal line, and the chamfered corner of the second groove and the chamfered corner of the second copper block are located on the same diagonal line. The first pair of opposite corners of the second copper layer has chamfered edges.

5. The dual-frequency antenna according to claim 4, characterized in that, The chamfers of the first copper layer, the first groove, the first copper block, the second groove, and the second copper block are all located on the same diagonal.

6. The dual-band antenna according to claim 1, characterized in that, Two seventh through holes are formed on the diagonal of the second copper layer, and both seventh through holes penetrate the second substrate and the third copper layer. The two seventh through holes and the two third through holes are located on different diagonals.

7. The dual-band antenna according to claim 1, characterized in that, The second feed point is located on the central axis of the second copper layer.

8. The dual-band antenna according to claim 1, characterized in that, An insulating ring is fitted onto the first probe and the second probe.

9. The dual-frequency antenna according to claim 8, characterized in that, The insulating ring is made of polytetrafluoroethylene.

10. The dual-frequency antenna according to any one of claims 1 to 9, characterized in that, The first copper layer has the same dimensions as the second copper layer, and the third copper layer has the same dimensions as the first substrate and the second substrate.

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