High port isolation filtering antenna unit for dual-frequency dual circular polarization and rotating antenna array composed of the unit

Abstract

The invention belongs to the field of antenna technology, and specifically relates to a high-port isolation filtering antenna unit for dual-frequency dual circular polarization and a rotating antenna array formed by the unit; the invention comprises: a supporting structure is arranged between an upper printed circuit board and a lower printed circuit board; a rectangular patch metal layer is arranged on the upper printed circuit board, and a cross slot is etched on the upper printed circuit board; a metal layer, a low-frequency port and a high-frequency port are arranged on the lower printed circuit board, and a low-frequency feeding slot, a high-frequency feeding slot, a low-frequency feeding network and a high-frequency feeding network are arranged on the metal layer; the invention has many advantages, such as being easy to mass produce, being able to achieve full-duplex performance, being able to effectively suppress mutual interference between low-frequency and high-frequency working frequency bands, being able to improve the circular polarization purity of a sequential rotating array, etc., and when the antenna unit forms an antenna array, it has a good element decoupling effect and good economic benefits.

Description

Technical Field

[0001] The invention belongs to the technical field of antennas, and in particular relates to a high-port isolation filtering antenna unit applied to dual-frequency dual-circular polarization and a rotating antenna array formed by the unit. Background Art

[0002] At present, the research work on satellite communication antennas is mainly focused on improving the electrical performance of antennas, such as high-gain antenna design, wide-band circularly polarized antenna design, high port isolation antenna design, filtering antenna design and antenna decoupling.

[0003] With the rapid development of mobile communications, vehicle communications have gradually attracted attention. Vehicle communications require the establishment of connections between vehicles and multiple devices. Generally, in addition to communicating with base stations and vehicles, vehicles also establish connections with satellites. For vehicle-mounted satellite communications, in order to achieve isolation between uplinks and downlinks, avoid interference between different channels, and reduce polarization mismatch and multipath fading, dual-band dual circularly polarized antennas are highly recommended because of their dual-band dual circularly polarized radiation performance. There are many ideas for the design of dual-band dual circularly polarized antennas. Among them, the most typical method is to use sequential rotation feeding technology. This method requires four identical antenna units, and the antenna units need to have dual-band characteristics. The dual-frequency dual circularly polarized antenna in the prior art has many defects, such as using a single port to achieve dual-frequency characteristics, using sequential rotation feeding technology to obtain an antenna array, and the two frequency bands have the same circular polarization characteristics; the dual-frequency characteristics are achieved by different modes of the excitation patch, and the radiation characteristics of different modes are different, which is not conducive to satellite communication; the dual-frequency characteristics are achieved by dual-port feeding, and the isolation between ports is poor; therefore, there is an urgent need for a dual-frequency dual circularly polarized antenna with good isolation between ports and high circular polarization purity of a sequential rotation array. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention proposes a high port isolation filtering antenna unit for dual-frequency dual circular polarization, the high port isolation filtering antenna unit comprising: an upper printed circuit board 1 and a lower printed circuit board 3; a supporting structure 2 is arranged between the upper printed circuit board 1 and the lower printed circuit board 3, an air layer is formed between the upper printed circuit board 1 and the lower printed circuit board 3 through the supporting structure 2; a rectangular patch metal layer 11 is arranged on the upper printed circuit board 1, and a cross gap is etched on the rectangular patch metal layer 11; a lower printed circuit board 3 is provided with a plurality of support structures, wherein the support structure 2 is provided between the upper printed circuit board 1 and the lower printed circuit board 3; a plurality of support structures are ... A metal layer 31, a low-frequency port 32 and a high-frequency port 33 are provided on the circuit board 3; a low-frequency feeding slot 311 and a high-frequency feeding slot 312 are etched on the metal layer, and the low-frequency feeding slot 311 and the high-frequency feeding slot 312 are perpendicular to each other and do not intersect; a low-frequency feeding network and a high-frequency feeding network are provided on the metal layer 31, one end of the low-frequency feeding network is connected to the low-frequency port 32 on the lower printed circuit board 3, and the other end is connected to the low-frequency feeding slot 311; one end of the high-frequency feeding network is connected to the high-frequency port 33, and the other end is connected to the high-frequency feeding slot 312.

[0005] Preferably, the upper printed circuit board 1 and the lower printed circuit board 3 are both rectangular.

[0006] Preferably, the support structure 2 is a plastic column, one end of the plastic column is arranged on the upper printed circuit board 1, and the other end of the plastic column is arranged on the lower printed circuit board 3.

[0007] Preferably, the area of ​​the rectangular patch metal layer 11 on the upper printed circuit board 1 is smaller than the area of ​​the metal layer 31 on the lower printed circuit board 3 .

[0008] Preferably, the length of the low-frequency feeding slot 311 is smaller than the length of the high-frequency feeding slot 312 .

[0009] Preferably, the low-frequency feeding network includes two microstrip lines and an A ring group, the A ring group includes an inner ring and an outer ring, the inner ring is a closed ring, a gap is left between the inner ring and the outer ring, and openings are provided on both sides of the outer ring to form a first outer semi-circular ring and a second outer semi-circular ring; one end of the first microstrip line is connected to the first outer semi-circular ring of the A ring group, and the other end is connected to the low-frequency feeding gap 311; one end of the second microstrip line is connected to the second outer semi-circular ring of the A ring group, and the other end is connected to the low-frequency port 32; the high-frequency feeding network includes two microstrip lines and a B ring group, and the structure of the B ring group is the same as that of the A ring; one end of the third microstrip line is connected to the first outer semi-circular ring of the B ring group, and the other end is connected to the high-frequency feeding gap 312; one end of the fourth microstrip line is connected to the second outer semi-circular ring of the B ring group, and the other end is connected to the high-frequency port 33.

[0010] Furthermore, the sizes of the inner and outer rings of the B ring group are larger than the sizes of the inner and outer rings of the A ring group.

[0011] A sequential rotation antenna array composed of high-port isolation filtering antenna units comprises: four high-port isolation filtering antenna units, the four high-port isolation filtering antenna units are arrayed by adopting sequential rotation technology, and each high-port isolation filtering antenna unit is connected by a microstrip line to form a dual-frequency dual-circular polarization sequential rotation antenna array.

[0012] Preferably, the sequential rotation technique is: rotating four high port isolation filter antenna units 90 degrees in sequence around a central point.

[0013] The beneficial effects of the present invention are as follows: the present invention adopts a patch antenna to design a high port isolation filtering antenna unit for dual-frequency dual circular polarization, the isolation between ports is greater than 40 dB, and the antenna can be applicable to an X-band dual-frequency dual circular polarization sequential rotation antenna array (impedance bandwidth is 7.26 GHz-7.47 GHz and 8.11 GHz-8.41 GHz; the present invention adopts a traditional patch antenna to achieve low processing cost and is easy to mass produce; the antenna unit port isolation is high and full-duplex performance can be achieved; the low-frequency feeding network and the high-frequency feeding network of the antenna both have a filtering structure, which can effectively suppress the mutual interference between the low-frequency and high-frequency working frequency bands; the circular polarization purity of the sequential rotation array can be improved; when the antenna array is composed, it has a good array element decoupling effect and has good economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the structure of a high port isolation filtering antenna unit applied to dual-frequency dual circular polarization in the present invention;

[0015] Figure 2 It is a side view of a high port isolation filtering antenna unit applied to dual-frequency dual circular polarization in the present invention;

[0016] Figure 3 A top view of a dual-frequency dual-circular polarization sequentially rotating antenna array in the present invention;

[0017] Figure 4 The S parameters of a high port isolation filtering antenna unit applied to dual-frequency dual circular polarization in a preferred embodiment of the present invention;

[0018] Figure 5 A directional diagram of a preferred embodiment of the present invention at an operating frequency of 7.36 GHz;

[0019] Figure 6 A directional diagram of a preferred embodiment of the present invention at an operating frequency of 8.22 GHz;

[0020] Figure 7 The S parameters of the sequentially rotated antenna array in a preferred embodiment of the present invention;

[0021] Figure 8 The directional diagram of the sequentially rotating antenna array in a preferred embodiment of the present invention at an operating frequency of 7.36 GHz in the XOZ plane;

[0022] Fig. 9 A directional diagram of a sequentially rotating antenna array in a preferred embodiment of the present invention with an operating frequency of 8.22 GHz in the XOZ plane;

[0023] In the figure: 1, upper printed circuit board; 11, rectangular patch metal layer; 2, supporting structure; 3, lower printed circuit board; 31, metal layer; 311, low-frequency feeding slot; 312, high-frequency feeding slot; 32, low-frequency port; 33, high-frequency port. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] The present invention proposes a high port isolation filtering antenna unit for dual-frequency dual circular polarization; Figure 1 As shown, the high port isolation filtering antenna unit comprises: an upper printed circuit board 1 and a lower printed circuit board 3; a support structure 2 is arranged between the upper printed circuit board 1 and the lower printed circuit board 3, and an air layer is formed between the upper printed circuit board 1 and the lower printed circuit board 3 through the support structure 2; a rectangular patch metal layer 11 is arranged on the upper printed circuit board 1, and a cross gap is etched on the rectangular patch metal layer 11; a metal layer 31, a low-frequency port 32 and a High-frequency port 33; low-frequency feeding slot 311 and high-frequency feeding slot 312 are etched on the metal layer, and low-frequency feeding slot 311 and high-frequency feeding slot 312 are perpendicular to each other and do not intersect; a low-frequency feeding network and a high-frequency feeding network are arranged on the metal layer 31, one end of the low-frequency feeding network is connected to the low-frequency port 32 on the lower printed circuit board 3, and the other end is connected to the low-frequency feeding slot 311; one end of the high-frequency feeding network is connected to the high-frequency port 33, and the other end is connected to the high-frequency feeding slot 312. Optionally, as Figure 2As shown, the thickness of the upper printed circuit board is 0.505-0.51mm, the thickness of the lower printed circuit board is 0.29-0.31mm, and the thickness of the air layer is 0.95-1.05mm; the length of the rectangular patch metal layer is 12.45-12.55mm, and the width is 7.95-8.05mm; the long gap length of the cross gap is 9.95-10.05mm, and the width is 0.95-1.05mm, and the short gap length of the cross gap is 5.95-6.05mm, and the width is 0.95-1.0 5mm; a preferred embodiment, its related dimensions are: the upper printed circuit board is 0.508mm, the lower printed circuit board is 0.3mm thick, and the air layer is 1mm thick; the length of the rectangular patch metal layer is 12.5mm and the width is 8mm; the long gap of the cross gap is 10mm long and 1mm wide, and the short gap of the cross gap is 6mm long and 1mm wide; the length of the high-frequency feed gap is 8mm and the width is 0.5mm; the length of the low-frequency feed gap is 9mm and the width is 0.5mm.

[0026] Preferably, the upper printed circuit board 1 and the lower printed circuit board 3 are both rectangular.

[0027] Preferably, the supporting structure 2 is a plastic column, one end of which is arranged on the upper printed circuit board 1, and the other end of which is arranged on the lower printed circuit board 3; the supporting structure is not limited to the plastic column, and may be other structures that separate the upper printed circuit board from the lower printed circuit board. Preferably, the supporting structure is a foam board.

[0028] Preferably, the area of ​​the rectangular patch metal layer 11 on the upper printed circuit board 1 is smaller than the area of ​​the metal layer 31 on the lower printed circuit board 3 .

[0029] Preferably, the length of the low-frequency feeding slot 311 is smaller than the length of the high-frequency feeding slot 312; optionally, the length of the high-frequency feeding slot is 7.95-8.05 mm, and the width is 0.48-0.52 mm; the length of the low-frequency feeding slot is 8.95-9.05 mm, and the width is 0.48-0.52 mm; a preferred embodiment, its relevant dimensions are: the length of the high-frequency feeding slot is 8 mm, and the width is 0.5 mm; the length of the low-frequency feeding slot is 9 mm, and the width is 0.5 mm.

[0030] Preferably, the low-frequency feeding network includes two microstrip lines and an A-ring group, the A-ring group includes an inner ring and an outer ring, the inner ring is a closed ring, a gap is left between the inner ring and the outer ring, and openings are provided on both sides of the outer ring to form a first outer semi-circular ring and a second outer semi-circular ring; one end of the first microstrip line is connected to the first outer semi-circular ring of the A-ring group, and the other end is connected to the low-frequency feeding gap 311; one end of the second microstrip line is connected to the second outer semi-circular ring of the A-ring group, and the other end is connected to the low-frequency port 32; the high-frequency feeding network It includes two microstrip lines and a B ring group, the structure of the B ring group is the same as that of the A ring; one end of the third microstrip line is connected to the first outer semi-circle of the B ring group, and the other end is connected to the high-frequency feeding gap 312; one end of the fourth microstrip line is connected to the second outer semi-circle of the B ring group, and the other end is connected to the high-frequency port 33; optionally, the width of the microstrip line of the low-frequency feeding network and the microstrip line of the high-frequency feeding network are both 0.62-0.64mm, and the connection can be a coupled feeding connection or a microstrip forced feeding.

[0031] Further, the inner and outer ring sizes of the B ring group are larger than those of the A ring group. Optionally, the inner ring radius of the A ring group is 2.88-2.92mm, the inner ring radius of the B ring group is 3.38-3.42mm, and the inner and outer ring gaps of the A ring group and the B ring group are both 0.24-0.26mm; in a preferred embodiment, the relevant dimensions are: the inner ring radius of the A ring group is 2.9mm, the inner ring radius of the B ring group is 3.4mm, and the inner and outer ring gaps of the A ring group and the B ring group are both 0.25mm.

[0032] The low-frequency feeding slot 311 is electromagnetically coupled to the rectangular patch metal layer 11, and the high-frequency feeding slot 312 is electromagnetically coupled to the rectangular patch metal layer 11 on the upper surface of the upper printed circuit board 1. When working, the rectangular patch metal layer radiates the electromagnetic energy fed into the low-frequency port into space to obtain a low-frequency working frequency band. The rectangular patch metal layer radiates the electromagnetic energy fed into the high-frequency port into space to obtain a high-frequency working frequency band. The low-frequency working frequency band and the high-frequency working frequency band share the rectangular patch metal layer as a radiator.

[0033] A sequential rotation antenna array composed of high-port isolation filtering antenna units comprises: four high-port isolation filtering antenna units, the four high-port isolation filtering antenna units are arrayed by adopting sequential rotation technology, and each high-port isolation filtering antenna unit is connected by a microstrip line to form a dual-frequency dual-circular polarization sequential rotation antenna array.

[0034] Preferably, the sequential rotation technology is: four high-port isolation filter antenna units are rotated 90° around a center point in sequence; the phases of the four high-port isolation filter antenna units are set to 0°, 90°, 180° and 270° respectively, and when the phase gradually increases in the counterclockwise direction, right-hand circular polarization can be obtained, and when the phase gradually increases in the clockwise direction, left-hand circular polarization can be obtained. A low-frequency power division feeding network is used to connect the low-frequency right-hand circularly polarized sequential rotation antenna array, and a high-frequency power division feeding network is used to connect the high-frequency left-hand circularly polarized sequential rotation antenna array. The phases of the four output ports of the low-frequency power division feeding network are 0°, 90°, 180° and 270° in the counterclockwise direction, and the phases of the four output ports of the high-frequency power division feeding network are 0°, 90°, 180° and 270° in the clockwise direction. Preferably, a 2×2 sequential rotation array formed by an array of high-port isolation filter antenna units applied to dual-frequency dual circular polarization is as follows Figure 3 As shown; optionally, the side length of the array after arraying is 94.5-95.5mm; preferably, the side length of the array after arraying is 95mm. Figure 3 In the scheme, the feeding slot realizes energy transmission through coupling, and the high-frequency sequential rotating feeding network provides 90° phase difference for four high-port isolation filtering antenna units in a clockwise direction to realize left-hand circular polarization radiation. The low-frequency sequential rotating feeding network provides 90° phase difference for four high-port isolation filtering antenna units in a counterclockwise direction to realize right-hand circular polarization radiation. The slot on the patch realizes array decoupling by changing the surface current path of the rectangular patch.

[0035] The present invention has good performance. The working frequency bands of the high port isolation filtering antenna unit applied to dual-frequency dual circular polarization in the present invention are 7.26GHz-7.47GHz and 8.11GHz-8.41GHz. In these two bands, the antenna shows good frequency selectivity, which is attributed to the different resonance characteristics of the two circular ring group filters. In addition, the S parameters of the high port isolation filtering antenna unit applied to dual-frequency dual circular polarization in a preferred embodiment of the present invention are as follows: Figure 4 As shown in the figure, in both frequency bands, the isolation between the two ports is greater than 40dB, indicating good duplex performance. Figure 5 , Figure 6 As shown, the maximum gains of the antenna unit at 7.36 GHz and 8.22 GHz are 8.7 dBi and 9.1 dBi respectively.

[0036] The impedance bandwidth of the dual-frequency dual circular polarization sequential rotation antenna array in the present invention is 7.26GHz-7.46GHz and 8.07GHz-8.36GHz. The sequential rotation array S parameters of the dual-frequency dual circular polarization sequential rotation antenna array in a preferred embodiment are as follows: Figure 7As shown in Figure 1, within the two operating frequency bands, the isolation between the two ports of the array is greater than 30dB, achieving good duplex performance. Figure 8 , Fig. 9 As shown, the gains of a dual-frequency dual circularly polarized sequential rotating antenna array of a preferred embodiment are 11.2dBic and 11.7dBic at 7.36GHz and 8.2GHz respectively, and the axial ratio bandwidths of the antenna array are 360MHz (7.12GHz-7.48GHz) and 360MHz (8GHz-8.36GHz) respectively.

[0037] The invention adopts a patch antenna to design a high port isolation filtering antenna unit for dual-frequency dual circular polarization, the isolation between ports is greater than 40 dB, and the antenna can be applicable to an X-band dual-frequency dual circular polarization sequential rotation antenna array (impedance bandwidth is 7.26 GHz-7.47 GHz and 8.11 GHz-8.41 GHz; the invention adopts a traditional patch antenna to realize, has low processing cost and is easy to mass produce; the antenna unit port isolation is high, and full-duplex performance can be achieved; the low-frequency feeding network and the high-frequency feeding network of the antenna both have filtering structures, and can effectively suppress the mutual interference between the low-frequency and high-frequency working frequency bands; the circular polarization purity of the sequential rotation array can be improved; when the antenna array is formed, it has a good array element decoupling effect and has good economic benefits.

[0038] In the present invention, unless otherwise clearly stipulated and limited, the terms such as "setting" and "connection" 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 a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, ordinary technicians in this field can understand the specific meanings of the above terms in the present invention according to the specific circumstances.

[0039] The above embodiments further illustrate the purpose, technical solutions and advantages of the present invention in detail. It should be understood that the above embodiments are only preferred implementation modes of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made to the present invention within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A high port isolation filtering antenna unit for dual-frequency dual circular polarization, characterized in that: include: An upper printed circuit board (1) and a lower printed circuit board (3); a support structure (2) is arranged between the upper printed circuit board (1) and the lower printed circuit board (3), and an air layer is formed between the upper printed circuit board (1) and the lower printed circuit board (3) through the support structure (2); a rectangular patch metal layer (11) is arranged on the upper printed circuit board (1), and a cross slit is etched on the rectangular patch metal layer (11); a metal layer (31) is arranged on the lower printed circuit board (3), and a low-frequency port (32) and a high-frequency port (33) are arranged on the lower surface of the lower printed circuit board (3); a low-frequency feeding slit (311) and a high-frequency feeding slit (312) are etched on the metal layer (31), and the low-frequency feeding slit (311) and the high-frequency feeding slit (312) are perpendicular to each other and do not intersect; A low-frequency feeding network and a high-frequency feeding network are arranged on the lower surface of the lower printed circuit board (3); one end of the low-frequency feeding network is connected to the low-frequency port (32) on the lower printed circuit board (3), and the other end is connected to the low-frequency feeding slot (311); one end of the high-frequency feeding network is connected to the high-frequency port (33), and the other end is connected to the high-frequency feeding slot (312); the low-frequency feeding network includes two microstrip lines and an A-circular ring group, the A-circular ring group includes an inner ring and an outer ring, the inner ring is a closed ring, a gap is left between the inner ring and the outer ring, and openings are arranged on both sides of the outer ring to form a first outer semicircular ring. A ring and a second outer semi-circular ring; one end of a first microstrip line is connected to the first outer semi-circular ring of the A ring group, and the other end is connected to a low-frequency feeding slot (311); one end of a second microstrip line is connected to the second outer semi-circular ring of the A ring group, and the other end is connected to a low-frequency port (32); a high-frequency feeding network comprises two microstrip lines and a B ring group, and the structure of the B ring group is the same as that of the A ring; one end of a third microstrip line is connected to the first outer semi-circular ring of the B ring group, and the other end is connected to the high-frequency feeding slot (312); one end of a fourth microstrip line is connected to the second outer semi-circular ring of the B ring group, and the other end is connected to a high-frequency port (33).

2. The high port isolation filtering antenna unit for dual-frequency dual circular polarization according to claim 1, characterized in that: The upper printed circuit board (1) and the lower printed circuit board (3) are both rectangular.

3. The high port isolation filtering antenna unit for dual-frequency dual circular polarization according to claim 1, characterized in that: The supporting structure (2) is a plastic column, one end of which is arranged on the upper printed circuit board (1), and the other end of which is arranged on the lower printed circuit board (3).

4. The high port isolation filtering antenna unit for dual-frequency dual circular polarization according to claim 1, characterized in that: The area of ​​the rectangular patch metal layer (11) on the upper printed circuit board (1) is smaller than the area of ​​the metal layer (31) on the lower printed circuit board (3).

5. The high port isolation filtering antenna unit for dual-frequency dual circular polarization according to claim 1, characterized in that: The length of the low-frequency feeding slot (311) is shorter than the length of the high-frequency feeding slot (312).

6. The high port isolation filtering antenna unit for dual-frequency dual circular polarization according to claim 1, characterized in that: The inner and outer ring sizes of the B ring group are larger than those of the A ring group.

7. A sequentially rotating antenna array composed of any one of the high port isolation filtering antenna units according to claims 1 to 6, characterized in that: include: Four high-port isolation filtering antenna units are arrayed using sequential rotation technology, and microstrip lines are used to connect the high-port isolation filtering antenna units to form a dual-frequency dual-circular polarization sequential rotation antenna array.

8. The sequentially rotating antenna array composed of high port isolation filtering antenna units according to claim 7, characterized in that: The sequential rotation technology is: rotating four high port isolation filter antenna units 90 degrees around a center point in sequence.

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