Butterfly balun-fed dual-polarized cross-dipole antenna

Abstract

The application discloses a butterfly-shaped balun-fed dual-polarized cross-dipole antenna, which comprises a dielectric substrate, a cross-polarized dipole vibrator, a feeding structure and a metal fence, wherein a first slit is formed in the metal radiator and penetrates the metal radiator from top to bottom, so as to increase the capacitance of the equivalent circuit of the butterfly-shaped balun-fed dual-polarized cross-dipole antenna. The antenna greatly improves the performance of the antenna by improving the feeding structure and the metal radiator, has a compact structure, a wide impedance bandwidth of 2.3-6 GHz, and an isolation degree of more than 15 dB. In addition, the E-plane and H-plane radiation patterns are stable in the whole frequency band, the isolation degree between co-polarization and cross-polarization is greater than 15 dB, the high gain of 6dBi in the low frequency band and 7dBi in the high frequency band can be realized, and the application prospect is very wide in the radio communication system such as radar, communication and telemetry remote sensing with limited platform space, especially in the Sub-6GHz 5G application field.

Description

Technical Field

[0001] This invention relates to the field of wireless communication technology, and in particular to a butterfly-shaped balun-fed dual-polarized cross dipole antenna. Background Technology

[0002] Currently, 5G technology research is mainly focused on two frequency bands: Sub-6 GHz and millimeter wave (mmWave). Sub-6 GHz utilizes bandwidth resources below 6 GHz to develop 5G. A core challenge for 5G technology lies in the difficulty of base station coverage, involving not only inter-frequency cooperation between large and small base stations but also considering network mixing and simultaneous construction of different frequency bands in the early stages of 5G. Antennas are indispensable key components of the radio frequency front-end of these communication systems. If antennas with wider operating bandwidth and multi-polarization operating modes can be adopted, multiple antennas can be integrated into a single antenna, saving manufacturing costs, reducing antenna size, and, more importantly, fundamentally solving the problems of electromagnetic compatibility and electromagnetic interference between multiple antennas.

[0003] Existing literature shows that some dual-polarized cross dipole antennas are mainly fed by coaxial lines. This method makes it difficult to simultaneously meet the requirements of high performance and miniaturization over a wider frequency band, thus making it difficult to achieve a compact structure. Other antennas use microstrip baluns for feeding, which limits the antenna's operating frequency band and results in poor isolation between the two ports. Summary of the Invention

[0004] This invention provides a butterfly-shaped balun-fed dual-polarized cross dipole antenna to solve the technical problems of existing dual-polarized cross dipole antennas, such as simple balun structure, non-compact structure, poor impedance transformation, and insufficient operating bandwidth.

[0005] According to one aspect of the present invention, a butterfly-shaped balun-fed dual-polarized crossed dipole antenna is provided, comprising: dielectric substrate, A cross-polarized dipole oscillator is disposed on the upper surface of the dielectric substrate and includes two dipole oscillators. Each dipole oscillator includes two collinearly arranged metallic radiating oscillators, and the gap between two adjacent metallic radiating oscillators is equal. A power supply structure is disposed below the dielectric substrate. The power supply structure includes a metal butterfly balun and a coaxial line. The axis of the coaxial line is perpendicular to the dielectric substrate. The coaxial line includes a coaxially disposed metal conductor inner core and a metal conductor outer core. The metal conductor inner core passes through the metal butterfly balun and is connected to one metal radiating oscillator of the dipole oscillator. The metal conductor outer core is connected to another metal radiating oscillator of the dipole oscillator through the metal butterfly balun. Dielectric filling is disposed between the metal conductor inner core and the metal conductor outer core and / or between the metal conductor inner core and the metal butterfly balun. The metal ground plane is arranged parallel to the dielectric substrate. A metal base is placed on the metal grounding plate and located directly below the metal butterfly-shaped balun. A gap is left between the upper surface of the metal base and the bottom surface of the metal butterfly-shaped balun. Metal fences are vertically arranged on the metal ground plane and centrally symmetrically arranged around the cross-polarized dipole resonator. The orthogonal centers of the cross-polarized dipole resonator are located on the central axis of symmetry of the plurality of metal fences. The metal radiating element has a first slit that runs vertically through it to increase the capacitance of the equivalent circuit of the butterfly balun-fed dual-polarized cross dipole antenna.

[0006] Furthermore, the metal radiating oscillator includes a first metal radiating oscillator, a second metal radiating oscillator, a third metal radiating oscillator, and a fourth metal radiating oscillator. The first metal radiating oscillator and the third metal radiating oscillator constitute a first dipole oscillator arranged collinearly along a first direction, and the second metal radiating oscillator and the fourth metal radiating oscillator constitute a second dipole oscillator arranged collinearly along a second direction. The first direction is perpendicular to the second direction. The first gap is a rectangular gap. The long sides of the rectangular slots on the first and third metal radiating oscillators are arranged along the second direction. The long side of the rectangular slots on the second and fourth metal radiating oscillators is arranged along the first direction.

[0007] Furthermore, the two ends of the rectangular slit are symmetrically provided with second slits that pass through the metal radiating oscillator vertically. The second slits are connected to the short side of the rectangular slit, and the side of the second slit that is connected to the rectangular slit is perpendicular to the long side of the rectangular slit.

[0008] Furthermore, the second gap is fan-shaped or polygonal.

[0009] Furthermore, the metal radiating oscillator is provided with metal feed probes, and the dielectric substrate has through holes for the metal feed probes to pass through. The metal feed probe includes a first metal feed probe, a second metal feed probe, a third metal feed probe, and a fourth metal feed probe. The line connecting the center point of the first metal feed probe and the center point of the third metal feed probe is arranged along a first direction, and the line connecting the center point of the second metal feed probe and the center point of the fourth metal feed probe is arranged along a second direction.

[0010] Furthermore, the metal butterfly balun includes a first metal butterfly balun and a second metal butterfly balun. The first metal butterfly balun includes a first isosceles trapezoidal wing, a second isosceles trapezoidal wing, and a first connecting bridge. The axis of the first connecting bridge is arranged along a first direction, and the two ends of the first connecting bridge are respectively connected to the short side of the first isosceles trapezoidal wing and the short side of the second isosceles trapezoidal wing. The second metal butterfly balun has the same structure as the first metal butterfly balun. The second connecting bridge of the second metal butterfly balun is arranged along the second direction, and the second connecting bridge is perpendicular to the first connecting bridge.

[0011] Furthermore, the coaxial cable includes a first coaxial cable and a second coaxial cable with identical structures. The inner core of the first metal conductor of the first coaxial cable passes through the first isosceles trapezoidal wing and is connected to the first metal feed probe. The outer metal conductor of the first coaxial cable is connected to the third metal feed probe through the second isosceles trapezoidal wing. The inner core of the second metal conductor of the second coaxial line passes through the third isosceles trapezoidal wing of the second metal butterfly balun and is connected to the second metal feed probe. The outer metal conductor of the second coaxial line is connected to the fourth metal feed probe through the fourth isosceles trapezoidal wing of the second metal butterfly balun.

[0012] Furthermore, a first dielectric post is disposed between the first metal feed probe and the first isosceles trapezoidal wing, and the first dielectric post is sleeved on the inner core of the first metal conductor. A second dielectric post is arranged between the second metal feed probe and the third isosceles trapezoidal wing, and the second dielectric post is sleeved on the inner core of the second metal conductor.

[0013] Furthermore, the metal base is provided with a third medium column for abutting the second isosceles trapezoidal wing and a fourth medium column for abutting the fourth isosceles trapezoidal wing.

[0014] Furthermore, the metal fence consists of two rows.

[0015] The present invention has the following beneficial effects: This invention relates to a butterfly balun-fed dual-polarized crossed dipole antenna. Four metal radiating elements are used for polarization. A first gap is created in each metal radiating element, increasing the capacitance of the entire antenna's equivalent circuit. This significantly improves the antenna's radiation performance near the high-frequency band within the operating frequency range. The inner conductor of the coaxial cable directly passes through two metal butterfly baluns. Dielectric filling protects the inner conductor of the coaxial cable from shortening and prevents short circuits. The outer conductors of the two coaxial cables are converted into two baluns located orthogonally. A metal base increases the distance between the metal radiating element plane and the metal ground plane to achieve higher radiation gain in lower operating frequency bands. The gap between the baluns and the metal base effectively chokes the current on the outer conductor of the coaxial cable. The metal fence works in conjunction with the metal ground plane to reflect backward electromagnetic signals. This antenna significantly improves performance through improved feeding structure and metal radiating elements. The dimensions of the butterfly balun-fed dual-polarized crossed dipole antenna are 65×65×18.5mm. 3 With its compact structure and wide impedance bandwidth from 2.3 GHz to 6 GHz, the isolation reaches more than 15 dB. In addition, the E-plane and H-plane radiation patterns are stable throughout the entire frequency band, and the isolation between common polarization and cross polarization is greater than 15 dB, enabling high gain of 6 dBi in the low-frequency band and 7 dBi in the high-frequency band. It has a very broad application prospect in radio communication systems such as radar, communication and telemetry and remote sensing where platform space is limited, especially in the field of Sub-6 GHz 5G applications.

[0016] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0017] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of the structure of a butterfly-shaped balun-fed dual-polarized crossed dipole antenna according to a preferred embodiment of the present invention; Figure 2 This is a side view of a butterfly-shaped balun-fed dual-polarized crossed dipole antenna according to a preferred embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of a metal radiating oscillator according to a preferred embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of a metal butterfly balun according to a preferred embodiment of the present invention; Figure 5This is a schematic diagram of the structure of the first metal butterfly balun according to a preferred embodiment of the present invention; Figure 6 This is a schematic diagram of the structure of the first coaxial cable according to a preferred embodiment of the present invention; Figure 7 This is a schematic diagram of the structure of the second metal butterfly balun according to a preferred embodiment of the present invention; Figure 8 This is a schematic diagram of the structure of the second coaxial line according to a preferred embodiment of the present invention; Figure 9 This is a schematic diagram of the structure of the first metal butterfly balun according to a preferred embodiment of the present invention; Figure 10 yes Figure 9 The AA-direction sectional view shown; Figure 11 yes Figure 9 The BB-direction sectional view shown; Figure 12 yes Figure 9 The sectional view shown in the CC direction; Figure 13 yes Figure 9 The DD-direction sectional view shown; Figure 14 This is a simulation result of the absolute value of the electric field of the patch antenna when there are no gaps on the metal radiating oscillator; Figure 15 This is a simulation result of the radiation pattern of the patch antenna when there are no gaps on the metal radiating oscillator. Figure 16 This is a simulation result of the absolute value of the electric field of the patch antenna when an H-slot is applied to the metal radiating oscillator. Figure 17 This is a simulation result of the radiation pattern of the patch antenna when an H-slot is applied to the metal radiating oscillator; Figure 18 This is a schematic diagram of the dimensions of the metal feed probe; Figure 19 This is a schematic diagram of the dimensions of a metallic radiating oscillator; Figure 20 This is a schematic diagram of the dimensions of a metal butterfly-shaped balun; Figure 21 This is a schematic diagram showing the dimensions of the metal ground plane; Figure 22 These are the simulation and measured results of the antenna port reflection coefficient and isolation coefficient; Figure 23 These are the simulation and measurement results of the antenna gain; Figure 24 This is the measured radiation pattern of the antenna's E-plane. Figure 24 (a) in the figure represents the result at 3 GHz. Figure 24 (b) in the figure represents the result at 4 GHz. Figure 24 (c) represents the result at 5 GHz. Figure 24 (d) in the figure represents the result at 6 GHz; Figure 25 This is the measured radiation pattern of the antenna in the H-plane. Figure 25 (a) in the figure represents the result at 3 GHz. Figure 25 (b) in the figure represents the result at 4 GHz. Figure 25 (c) represents the result at 5 GHz. Figure 25 (d) in the figure represents the result at 6 GHz.

[0018] Legend: 1. Dielectric substrate; 11. Through-hole; 2. Metal radiating oscillator; 201. First slot; 202. Second slot; 21. First metal radiating oscillator; 22. Second metal radiating oscillator; 23. Third metal radiating oscillator; 24. Fourth metal radiating oscillator; 3. Metal feed probe; 31. First metal feed probe; 32. Second metal feed probe; 33. Third metal feed probe; 34. Fourth metal feed probe; 4. Metal butterfly balun; 41. First metal butterfly balun; 411. First isosceles trapezoidal wing; 412. Second isosceles trapezoidal wing; 413. First connecting bridge; 42. Second metal butterfly balun; 421. Third isosceles trapezoidal wing; 422. Fourth isosceles trapezoidal wing; 423. Second connecting bridge; 5. Metal base; 6. Metal ground plane; 7. Coaxial line; 71. First coaxial line; 711. First metal conductor core; 712. Second dielectric filler; 713. First metal outer conductor; 72. Second coaxial line; 721. Second metal conductor core; 722. Second dielectric filler; 723. Second metal outer conductor; 8. Metal fence; 91. First dielectric post; 92. Second dielectric post; 93. Third dielectric post; 94. Fourth dielectric post. Detailed Implementation

[0019] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0020] Please refer to the following: Figures 1 to 13 The butterfly-shaped balun-fed dual-polarized crossed dipole antenna of this embodiment includes: Dielectric substrate 1 is a non-conductive material with a thickness of 0.2~1 mm, a relative permittivity of 2~3, and a dielectric loss angle of 0.0004~0.001. A cross-polarized dipole oscillator is disposed on the upper surface of a dielectric substrate 1 and includes two dipole oscillators. Each dipole oscillator includes two collinearly arranged metal radiating oscillators 2. The gap between two adjacent metal radiating oscillators 2 is equal. The metal radiating oscillators 21 to 24 on the upper surface of the dielectric substrate 1 are made of gold foil, silver foil or copper foil with a thickness of 0.017 to 0.035 mm. The metal radiating oscillators 21 to 24 are approximately quadrilateral and have a length of 30 to 40 mm. A power supply structure is arranged below the dielectric substrate 1. The power supply structure includes a metal butterfly balun 4 and a coaxial line 7. The axis of the coaxial line 7 is perpendicular to the dielectric substrate 1. The coaxial line 7 includes a metal conductor inner core and a metal outer conductor arranged coaxially. The metal conductor inner core passes through the metal butterfly balun 4 and is connected to a metal radiating oscillator 2 of the dipole oscillator. The metal outer conductor is connected to another metal radiating oscillator 2 of the dipole oscillator through the metal butterfly balun 4. Dielectric filling is arranged between the metal conductor inner core and the metal outer conductor and between the metal conductor inner core and the metal butterfly balun 4 to avoid short circuits. The metal ground plane 6 is arranged parallel to the dielectric substrate 1. The projection of the metal ground plane 6 onto the plane of the dielectric substrate 1 is a square with a width of 50~70 mm and a thickness of 1~2 mm. A metal base 5 is disposed on a metal ground plane 6 and located directly below a metal butterfly balun 4. A gap is left between the upper surface of the metal base 5 and the bottom surface of the metal butterfly balun 4. The projection of the metal base 5 onto the plane of the dielectric substrate 1 is a square with a width of 18-25 mm and a height of 3-8 mm. This increases the distance between the plane of the driven metal radiating oscillator 2 and the metal ground plane 6, thereby achieving higher radiation gain in a lower operating frequency band. Metal fences 8 are vertically arranged on the metal ground plane 6 and are centrally symmetrically arranged around the cross-polarized dipole oscillator. The orthogonal centers of the cross-polarized dipole oscillator are located on the central axis of symmetry of the multiple metal fences 8. A first slit 201 is provided on the metal radiating element 2, which runs vertically through the metal radiating element 2, in order to increase the capacitance of the equivalent circuit of the butterfly balun-fed dual-polarized cross dipole antenna.

[0021] In this embodiment, four metal radiating elements 2 are used for polarization. A first slot 201 is opened on the metal radiating elements 2, which increases the capacitance of the entire antenna equivalent circuit, greatly improving the antenna's radiation performance near the high frequency band within the operating frequency band. The internal conductor of the coaxial cable 7 directly passes through two metal butterfly baluns 4. The dielectric filling protects the internal conductor of the coaxial cable 7 from being shortened. The outer conductors of the two coaxial cables 7 are converted into two baluns. These two baluns are located in orthogonal positions. The metal base 5 increases the distance between the plane of the metal radiating elements 2 and the metal ground plane 6 to achieve higher radiation gain in the lower operating frequency band. The gap between the baluns and the metal base 5 can effectively suppress the current on the outer conductor of the coaxial cable. The metal fence 8 works with the metal ground plane 6 to reflect the backward electromagnetic wave signal. This antenna significantly improves its performance by improving the feed structure and the metal radiating elements 2. It has a compact structure, a wide impedance bandwidth from 2.3 GHz to 6 GHz, and an isolation of 15. Above dB; in addition, the E-plane and H-plane radiation patterns are stable throughout the entire frequency band, and the isolation between common polarization and cross polarization is greater than 15 dB, enabling high gains of 6 dBi in the low-frequency band and 7 dBi in the high-frequency band. It has a very broad application prospect in radio communication systems such as radar, communication and telemetry and remote sensing where platform space is limited, especially in the field of Sub-6 GHz 5G applications.

[0022] In this embodiment, the metal radiating oscillator 2 includes a first metal radiating oscillator 21, a second metal radiating oscillator 22, a third metal radiating oscillator 23, and a fourth metal radiating oscillator 24. The first metal radiating oscillator 21 and the third metal radiating oscillator 23 constitute a first dipole vibrator arranged collinearly along a first direction, and the second metal radiating oscillator 22 and the fourth metal radiating oscillator 24 constitute a second dipole vibrator arranged collinearly along a second direction. The first direction is perpendicular to the second direction. The first gap 201 is a rectangular gap. The long sides of the rectangular gaps on the first metal radiating oscillator 21 and the third metal radiating oscillator 23 are arranged along the second direction, and the long sides of the rectangular gaps on the second metal radiating oscillator 22 and the fourth metal radiating oscillator 24 are arranged along the first direction. Figure 3 As shown, the angle between the first direction and the horizontal direction is -45°, and the angle between the second direction and the horizontal direction is 45°.

[0023] In this embodiment, second slits 202, which are vertically connected to the metal radiating oscillator 2, are symmetrically arranged at both ends of the rectangular slit. The second slits 202 are connected to the short side of the rectangular slit, and the side of the second slit 202 that is connected to the rectangular slit is perpendicular to the long side of the rectangular slit, forming an H-shaped slit. Compared with the loading of the straight rectangular slit 201, the capacitance value of the H-shaped slit is larger than that of the straight rectangular slit: C H型缝隙 >>C 矩形缝隙This can significantly improve the antenna's radiation performance in the vicinity of the high-frequency band within the operating frequency band. Optionally, the length of the H-shaped slot is 5-10 mm, and the width is 1-2 mm.

[0024] In this embodiment, the second gap 202 is fan-shaped or polygonal. Optionally, the second gap 202 is fan-shaped, with a smoother transition of the rounded edge, which can improve signal stability.

[0025] In this embodiment, a metal feed probe 3 is arranged on the metal radiating oscillator 2, and a through hole 11 for passing through the metal feed probe 3 is formed on the dielectric substrate 1. The metal feed probe 3 includes a first metal feed probe 31, a second metal feed probe 32, a third metal feed probe 33, and a fourth metal feed probe 34. The first metal feed probe 31, the second metal feed probe 32, the third metal feed probe 33, and the fourth metal feed probe 34 are respectively arranged in a one-to-one correspondence with the first metal radiating oscillator 21, the second metal radiating oscillator 22, the third metal radiating oscillator 23, and the fourth metal radiating oscillator 24. The line connecting the center point of the first metal feed probe 31 and the center point of the third metal feed probe 33 is arranged along a first direction, and the line connecting the center point of the second metal feed probe 32 and the center point of the fourth metal feed probe 34 is arranged along a second direction. The metal feed probe 3 is soldered to the metal radiating oscillator 2. Optionally, the radius of the metal feed probe 3 is 1~2 mm.

[0026] In this embodiment, the metal butterfly balun 4 includes a first metal butterfly balun 41 and a second metal butterfly balun 42. The first metal butterfly balun 41 includes a first isosceles trapezoidal wing 411, a second isosceles trapezoidal wing 412, and a first connecting bridge 413. The axis of the first connecting bridge 413 is arranged along a first direction. The two ends of the first connecting bridge 413 are respectively connected to the short side of the first isosceles trapezoidal wing 411 and the short side of the second isosceles trapezoidal wing 412. The second metal butterfly balun 42 has the same structure as the first metal butterfly balun 41. The second metal butterfly balun 42 includes a third isosceles trapezoidal wing 421, a fourth isosceles trapezoidal wing 422, and a second connecting bridge 423. The second connecting bridge 423 of the second metal butterfly balun 42 is arranged along a second direction, and the second connecting bridge 423 is perpendicular to the first connecting bridge 413. The feeding of this butterfly balun is evolved from the traditional coaxial line and is completely different from the coaxial line or any microstrip feeding balun. Optionally, the width of the metal butterfly balun 4 is 10-15 mm and the height is 8-15 mm.

[0027] In this embodiment, the coaxial line 7 is welded to the metal feed probe. The coaxial line 7 is a standard coaxial line with a characteristic impedance of 50 ohms. The coaxial line 7 includes a first coaxial line 71 and a second coaxial line 72 with identical structures. The first metal conductor core 711 of the first coaxial line 71 passes through the first isosceles trapezoidal wing 411 and is connected to the first metal feed probe 31. The first metal outer conductor 713 of the first coaxial line 71 is connected to the third metal feed probe 33 through the second isosceles trapezoidal wing 412. The first metal conductor core 711 and the first metal outer conductor 713 are connected together. A dielectric filler 712 is arranged between the first isosceles trapezoidal wing 411. The second metal conductor core 721 of the second coaxial line 72 passes through the third isosceles trapezoidal wing 421 of the second metal butterfly balun 42 and is connected to the second metal feed probe 32. The second metal outer conductor 723 of the second coaxial line 72 is connected to the fourth metal feed probe 34 through the fourth isosceles trapezoidal wing 422 of the second metal butterfly balun 42. A dielectric filler 722 is arranged between the second metal conductor core 721 and the second metal outer conductor 723 and between the second metal conductor core 721 and the third isosceles trapezoidal wing 421.

[0028] In this embodiment, a first dielectric post 91 is disposed between the first metal feed probe 31 and the first isosceles trapezoidal wing 411, and the first dielectric post 91 is sleeved on the first metal conductor core 711. A second dielectric post 92 is disposed between the second metal feed probe 32 and the third isosceles trapezoidal wing 421, and the second dielectric post 92 is sleeved on the second metal conductor core 721. This is to avoid short circuits caused by contact between the metal conductor core of the coaxial line 7, the metal feed probe 3, and the metal butterfly balun 4. Optionally, the relative permittivity of the first dielectric post 91 and the second dielectric post 92 are both 2.1~3, and the dielectric loss angle is both 0.0004~0.001.

[0029] In this embodiment, the metal base 5 is provided with a third dielectric post 93 for abutting against the second isosceles trapezoidal wing 412 and a fourth dielectric post 94 for abutting against the fourth isosceles trapezoidal wing 422, so as to maintain the gap between the metal base 5 and the metal butterfly balun 4. Optionally, the gap between the first metal butterfly balun 41 and the second metal butterfly balun 42 and the metal base 5 is 0.5~1.5 mm. Optionally, the relative permittivity of the third dielectric post 93 and the fourth dielectric post 94 are both 2.1~3, and the dielectric loss angle is both 0.0004~0.001.

[0030] In this embodiment, the metal fence 8 is arranged in two rows to reduce electromagnetic wave signal leakage. Optionally, the metal fence 8 consists of forty thin metal strips, with ten strips forming a group, each group consisting of two rows of five strips. Each strip is vertically inserted into a mounting hole on its corresponding metal ground plane 6 and welded to the ground plane 6, thereby surrounding four metal radiating oscillators 2. The metal fence 8 works in conjunction with the ground plane 6 to reflect rearward electromagnetic wave signals. Optionally, the metal strips are cuboids with a height of 10-25 mm, a width of 3-5 mm, and a thickness of 1-2 mm.

[0031] Example 1 A butterfly-shaped balun-fed dual-polarized crossed dipole antenna has the following specific dimensional parameters, all in mm: Figure 18 As shown, the height of the first dielectric column 91 is h. DS =1 mm, the distance between the metal base 5 and the metal butterfly-shaped balun 4 is h slot =1 mm, the diameter of the end where the metal feed probe 3 is connected to the metal radiating oscillator 2 is D p1 =4 mm, the diameter of the other end of the metal feed probe 3 is D p2 =3 mm, the height of the third metal feed probe 3 is h probe =3 mm, the thickness of the first connecting bridge 413 is h bri =1 mm, the length of the first connecting bridge 413 is L bri =1.5 mm, the diameter of the third medium column 93 is D DS3 =3 mm, the height of the third medium column 93 is h DS3 =4.5 mm, the height of the metal butterfly balun 4 is h bb =10 mm, the height of the metal base 5 is h mp =5 mm, the height of metal fence 8 is h fence =15 mm, the height from the bottom surface of the metal grounding plate 6 to the top surface of the metal feed probe 3 is h. ant =18.5 mm; such as Figure 19 As shown, the distance between two adjacent metallic radiating oscillators 2 is g. ant =0.5 mm, and the maximum width of two adjacent metal radiating oscillators 2 is L. ant =36.5 mm, the length of the rectangular slit 201 is L aslot1 =10 mm, the width of the rectangular slit 201 is W aslot1 =3.8 mm, the total length of the H-shaped gap is L aslot2 =14.8 mm, the length of W extending from both ends of the H-shaped gap beyond the rectangular gap 201 is 14.8 mm. aslot2 =3 mm, the distance between the centers of two adjacent metal feed probes 3 is Dprobe =5.3 mm; such as Figure 20 As shown, the gap between the first isosceles trapezoidal wing 411 and the fourth isosceles trapezoidal wing 422 is g. bb =1 mm, the length of the waist of the first isosceles trapezoidal wing 411 is L bb1 =7 mm, the length of the long side of the first isosceles trapezoidal wing 411 is L bb2 =11.5 mm, the length of the first metal butterfly balun 41 is L bb3 =13 mm, the width of the first connecting bridge 413 is W bri =1.5 mm, the length of the first connecting bridge 413 is L bri =3 mm; such as Figure 21 As shown, Figure 19 As shown, the length of the thin metal strips that make up the metal fence 8 is W. fence =5 mm, the width of the metal strip is t fence =1 mm, the center-to-center distance between two adjacent metal strips is dy fence =8 mm, the distance between the thin metal strip and the edge of the metal ground plane 6 is dx fence =5 mm, the spacing between the two rows of metal fences 8 is dx fence =5mm, the length of the metal ground plate 6 is L gnd =65 mm.

[0032] Figure 14 This is a simulation result of the absolute value of the electric field of the patch antenna when there are no gaps on the metal radiating oscillator; Figure 15 This is a simulation result of the radiation pattern of the patch antenna when there are no gaps on the metal radiating oscillator. Figure 16 This is a simulation result of the absolute value of the electric field of the patch antenna when an H-slot is applied to the metal radiating oscillator. Figure 17 This is a simulation result of the radiation pattern of the patch antenna when an H-slot is applied to the metal radiating oscillator. Figure 15 and Figure 17 The antenna shown is a simulation model without a metal ground plane. The simulation radiation pattern shows that the electromagnetic wave signal travels along... The radiation occurs simultaneously in both directions. These two figures are only used to illustrate the difference in radiation performance of the dipole antenna before and after H-slot loading. The actual fabricated cross-polarized dipole antenna that meets practical engineering requirements has a metal ground plane 6, therefore the electromagnetic wave signal only radiates along... For directional propagation, the gain is approximately 3 dBi higher than without a metal ground plane. The electromagnetic performance of the patch antenna at various frequencies is detailed in Table 1.

[0033] Table 1. Comparison of electromagnetic performance of patch antennas at various frequencies.

[0034] In Table 1, ① is a seamless loading antenna and ② is an H-type slot loading antenna. From the data in the table, we can conclude that: (1) The maximum electric field value is 1~2dB (V / m) higher than that of ①. (2) Gain: ① ranges from -0.2057 to 2.775 dBi, ② ranges from -0.434 to 4.174 dBi; (3) Efficiency: ① ranges from -5.102 to -0.4208 dB, ② ranges from -2.497 to -0.3988 dB.

[0035] In summary, the performance of the H-type slot-loaded antenna is significantly improved.

[0036] Figure 22 These are the simulation and measured results of the antenna port reflection coefficient and isolation coefficient; where S 11 S represents the reflection coefficient at the antenna port. 21 This represents the isolation factor between the two ports. As can be seen from the figure, the antenna operates from 2.3 GHz to 6 GHz, and the isolation factor between the two ports is less than -15 dB.

[0037] Figure 23 These are the simulation and measurement results of the antenna gain; at the lower end of the operating frequency band, the antenna gain is approximately 6 dBi; at the higher end of the operating frequency band, its gain is approximately 7 dBi.

[0038] Figure 24 This is the measured radiation pattern of the antenna's E-plane. Figure 24 (a) in the figure represents the result at 3 GHz. Figure 24 (b) in the figure represents the result at 4 GHz. Figure 24 (c) represents the result at 5 GHz. Figure 24 (d) represents the results at 6 GHz; it also includes pattern data under cross-polarization.

[0039] Figure 25 This is the measured radiation pattern of the antenna in the H-plane. Figure 25 (a) in the figure represents the result at 3 GHz. Figure 25 (b) in the figure represents the result at 4 GHz. Figure 25 (c) represents the result at 5 GHz. Figure 25 (d) represents the results at 6 GHz; it also includes pattern data under cross-polarization.

[0040] from Figure 24 and Figure 25 As can be seen, the antenna exhibits stable radiation performance throughout the entire operating frequency band, with a polarization isolation of less than -20 dB.

[0041] This embodiment presents a butterfly-feed dual-polarized cross-dipole antenna. The butterfly balun feeding, evolved from traditional coaxial cables, is completely different from coaxial cables or any microstrip-feed baluns. It achieves high-performance electromagnetic radiation across an ultra-wide bandwidth from 2.3 GHz to 6 GHz, achieving a wide bandwidth of S11 < -10 dB (89% bandwidth) across the entire 2.3-6 GHz band. The E-plane and H-plane radiation patterns are stable, with polarization isolation greater than 15 dB. Furthermore, the E-plane and H-plane radiation patterns are stable throughout the entire band, and the isolation between common polarization and cross-polarization is greater than 15 dB. The proposed antenna can achieve high gain of 6 dBi in the low-frequency band and 7 dBi in the high-frequency band. In wireless communication systems such as radar, communication, and telemetry / remote sensing where platform space is limited, especially in Sub-6 GHz 5G applications, this antenna has a very broad application prospect.

[0042] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A butterfly-shaped balun-fed dual-polarized crossed dipole antenna, characterized in that, include: Dielectric substrate (1). A cross-polarized dipole oscillator is disposed on the upper surface of the dielectric substrate (1) and includes two dipole oscillators. Each dipole oscillator includes two collinearly arranged metal radiating oscillators (2), and the gap between two adjacent metal radiating oscillators (2) is equal. A power supply structure is disposed below the dielectric substrate (1). The power supply structure includes a metal butterfly balun (4) and a coaxial line (7). The axis of the coaxial line (7) is perpendicular to the dielectric substrate (1). The coaxial line (7) includes a coaxially disposed metal conductor core and a metal outer conductor. The metal conductor core passes through the metal butterfly balun (4) and is connected to one metal radiating oscillator (2) of the dipole oscillator. The metal outer conductor is connected to another metal radiating oscillator (2) of the dipole oscillator through the metal butterfly balun (4). Dielectric filling is disposed between the metal conductor core and the metal outer conductor and / or between the metal conductor core and the metal butterfly balun (4). The metal ground plane (6) is arranged parallel to the dielectric substrate (1). A metal base (5) is placed on the metal grounding plate (6) and located directly below the metal butterfly balun (4). A gap is left between the upper surface of the metal base (5) and the bottom surface of the metal butterfly balun (4). Metal fences (8) are vertically arranged on the metal ground plane (6) and are centrally symmetrically arranged around the cross-polarized dipole oscillator. The orthogonal centers of the cross-polarized dipole oscillator are located on the central symmetry axes of the plurality of metal fences (8). The metal radiating vibrator (2) has a first slit (201) that runs vertically through the metal radiating vibrator (2) to increase the capacitance of the equivalent circuit of the butterfly balun-fed dual-polarized cross dipole antenna. The metal radiating oscillator (2) includes a first metal radiating oscillator (21), a second metal radiating oscillator (22), a third metal radiating oscillator (23), and a fourth metal radiating oscillator (24). The first metal radiating oscillator (21) and the third metal radiating oscillator (23) form a first dipole vibrator arranged collinearly along a first direction. The second metal radiating oscillator (22) and the fourth metal radiating oscillator (24) form a second dipole vibrator arranged collinearly along a second direction. The first direction is perpendicular to the second direction. The first gap (201) is a rectangular gap. The long sides of the rectangular slots on the first metal radiating oscillator (21) and the third metal radiating oscillator (23) are arranged along the second direction, and the long sides of the rectangular slots on the second metal radiating oscillator (22) and the fourth metal radiating oscillator (24) are arranged along the first direction. The two ends of the rectangular slots are symmetrically arranged with second slots (202) that pass through the metal radiating oscillator (2) vertically. The second slots (202) are connected to the short sides of the rectangular slots. The side of the second slot (202) that is connected to the rectangular slots is perpendicular to the long side of the rectangular slots. The metal butterfly balun (4) includes a first metal butterfly balun (41) and a second metal butterfly balun (42). The first metal butterfly balun (41) includes a first isosceles trapezoidal wing (411), a second isosceles trapezoidal wing (412), and a first connecting bridge (413). The axis of the first connecting bridge (413) is arranged along a first direction. The two ends of the first connecting bridge (413) are respectively connected to the short side of the first isosceles trapezoidal wing (411) and the short side of the second isosceles trapezoidal wing (412). The second metal butterfly balun (42) has the same structure as the first metal butterfly balun (41). The second connecting bridge (423) of the second metal butterfly balun (42) is arranged along a second direction, and the second connecting bridge (423) is perpendicular to the first connecting bridge (413).

2. The butterfly-shaped balun-fed dual-polarized crossed dipole antenna according to claim 1, characterized in that, The second gap (202) is fan-shaped or polygonal.

3. The butterfly-shaped balun-fed dual-polarized crossed dipole antenna according to claim 1 or 2, characterized in that, The metal radiating oscillator (2) is provided with a metal feed probe (3), and the dielectric substrate (1) is provided with a through hole (11) for passing through the metal feed probe (3). The metal feed probe (3) includes a first metal feed probe (31), a second metal feed probe (32), a third metal feed probe (33) and a fourth metal feed probe (34). The line connecting the center point of the first metal feed probe (31) and the center point of the third metal feed probe (33) is arranged along a first direction, and the line connecting the center point of the second metal feed probe (32) and the center point of the fourth metal feed probe (34) is arranged along a second direction.

4. The butterfly-shaped balun-fed dual-polarized crossed dipole antenna according to claim 3, characterized in that, The coaxial cable (7) includes a first coaxial cable (71) and a second coaxial cable (72) with the same structure. The first metal conductor inner core (711) of the first coaxial line (71) passes through the first isosceles trapezoidal wing (411) and is connected to the first metal feed probe (31). The first metal outer conductor (713) of the first coaxial line (71) is connected to the third metal feed probe (33) through the second isosceles trapezoidal wing (412). The second metal conductor core (721) of the second coaxial line (72) passes through the third isosceles trapezoidal wing (421) of the second metal butterfly balun (42) and is connected to the second metal feed probe (32). The second metal outer conductor (723) of the second coaxial line (72) is connected to the fourth metal feed probe (34) through the fourth isosceles trapezoidal wing (422) of the second metal butterfly balun (42).

5. The butterfly-shaped balun-fed dual-polarized crossed dipole antenna according to claim 4, characterized in that, A first dielectric post (91) is disposed between the first metal feed probe (31) and the first isosceles trapezoidal wing (411), and the first dielectric post (91) is sleeved on the first metal conductor core (711). A second dielectric post (92) is arranged between the second metal feed probe (32) and the third isosceles trapezoidal wing (421), and the second dielectric post (92) is sleeved on the second metal conductor core (721).

6. The butterfly-shaped balun-fed dual-polarized crossed dipole antenna according to claim 5, characterized in that, The metal base (5) is provided with a third medium column (93) for abutting the second isosceles trapezoidal wing (412) and a fourth medium column (94) for abutting the fourth isosceles trapezoidal wing (422).

7. The butterfly-shaped balun-fed dual-polarized crossed dipole antenna according to claim 1, characterized in that, The metal fence (8) consists of two rows.

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