Broadband beam tapers slot antenna loaded with metallic cavity

Abstract

The application discloses a metal cavity loaded wide-bandwidth wide-beam tapered slot antenna, mainly solves the problems of narrow bandwidth and half-power beam of the existing wide-beam tapered slot antenna, and comprises a radiator (1), a microstrip feed line (2), a dielectric substrate (3) and a metal cavity (4). Two right-angled triangular notches, two inverted L-shaped slots, two Chinese character 'yi' shaped slots, a tapered slot, a transmission slot and an impedance matching circular slot are etched on the radiator. The metal cavity is provided with an H-shaped cutting groove, forming a concave cavity structure. Isolation slots are formed on the upper portions of the two walls of the concave cavity structure, so that each metal wall is divided into upper and lower portions, and a dielectric gasket is arranged and fixed through a screw. U-shaped fixing clamping grooves are formed in the middle and bottom of the two walls of the concave cavity structure, and a feed port isolation hole is formed in the bottom of the concave cavity structure. The dielectric substrate on which the radiator and the microstrip feed line are printed is inserted into the concave cavity. The application expands the frequency band and half-power beam width of the antenna, and can be used in a modern mobile communication system.

Description

Technical Field

[0001] This invention belongs to the field of antenna technology, specifically relating to a wideband beam taper slot antenna that can be used in modern mobile communication systems. Background Technology

[0002] A wide-beam antenna is an antenna whose radiating half-power beamwidth is greater than 110°. A wideband wide-beam antenna is an antenna that has a radiating half-power beamwidth greater than 110° over a wide frequency range.

[0003] Tapered slot antennas are a type of end-fire traveling-wave antenna. This type of antenna has advantages such as wide bandwidth, light weight, simple planar structure, and ease of integration with microwave circuits, and therefore has long been the subject of extensive research and attention. However, existing tapered slot antennas, due to their narrow beamwidth, cannot meet the technical application requirements for wide beam coverage.

[0004] Patent document CN109687136A discloses a "wide-beam tapered slot antenna based on slot loading," which includes a radiator, a microstrip transmission line, and a dielectric substrate. The radiator and the microstrip transmission line are respectively etched on opposite sides of the dielectric substrate. The radiator includes a tapered slot, two beam-expanding slots, a transmission slot line, and a circular aperture impedance matching device. The tapered slot is a bilaterally symmetrical inverted isosceles triangle etched on the dielectric substrate. This invention effectively changes the current distribution on the surface of the tapered slot antenna by loading beam-expanding slots onto the antenna. Although it overcomes the narrow beamwidth characteristic of tapered slot antennas, the bandwidth remains very narrow, only 7.3GHz to 10.8GHz, with a relative bandwidth of 38.7%, which cannot meet the wideband application requirements of modern mobile communication systems.

[0005] Chang Yulin's "Design of Wide-Beam and Cross-Shaped Circularly Polarized Tapered Slot Antenna," published on CNKI, consists of three parts: a metal radiating patch, a feed balun, and a dielectric substrate. The metal radiating patch and the feed balun are printed on opposite sides of the dielectric substrate. The metal radiating patch is etched with six symmetrical slots, two symmetrical semi-elliptical notch slots, six chamfers, and inverted π-shaped groove slots. The dielectric substrate has non-metallic vias. Although this antenna achieves a wide bandwidth by etching slots on the metal radiating patch, the half-power beamwidth is only greater than 100°, which cannot meet the wide-beam coverage requirements of modern mobile communication systems. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of the prior art by proposing a wideband beam taper slot antenna loaded with a metal cavity. This expands the antenna's operating bandwidth, increases the half-power beamwidth, and meets the application requirements of wideband beam coverage in modern mobile communication systems.

[0007] The technical approach to achieving the objective of this invention is as follows:

[0008] By adding slots to the antenna radiator, the current path length on the radiator surface is extended, thereby broadening the low-frequency impedance bandwidth of the antenna. By adding a metal cavity to the antenna radiator, the surface current distribution is improved to a volume current distribution including the metal cavity, thereby further extending the current path length and broadening the low-frequency impedance bandwidth of the antenna, while achieving wide beam characteristics of the antenna.

[0009] According to the above technical concept, the wideband beam tapered slot antenna loaded with a metal cavity of the present invention includes: an antenna radiator, a microstrip feed line, and a dielectric substrate. The antenna radiator and the microstrip feed line are respectively etched on both sides of the dielectric substrate. A tapered slot is etched in the middle of the upper part of the radiator. An etched transmission slot is connected to the lower end of the tapered slot. An etched impedance matching circular slot is connected to the lower end of the transmission slot. The feature is that it also includes a metal cavity.

[0010] The metal cavity has an I-shaped cutting groove to form a concave cavity structure. The upper part of the two walls of the concave cavity has a gap to divide each metal wall into an upper part and a lower part. The gap is equivalent to a magnetic dipole perpendicular to the antenna radiator, which improves the beamwidth of the antenna.

[0011] The radiator has two right-angled triangular notches etched on its upper two sides, and two inverted "L"-shaped notches and two "I"-shaped notches etched on the left and right sides of the transmission slot, respectively, to improve the bandwidth of the low-frequency band of the antenna.

[0012] A dielectric substrate printed with the radiator and microstrip feed line is inserted into a concave cavity of a metal cavity to extend the low-frequency operating bandwidth of the antenna and increase the half-power beamwidth.

[0013] Furthermore, a dielectric pad is placed in the gap of the concave cavity to form the height of the gap. The upper and lower parts of the two walls of the concave cavity are fixed by dielectric screws. U-shaped fixing slots are opened in the middle and bottom of the two walls of the concave cavity, and a feed port isolation hole is opened at the bottom, which is used to fix the feed port of the dielectric substrate and the isolation antenna, respectively.

[0014] Furthermore, the two straight gaps are located directly below the two inverted L-shaped gaps; each inverted L-shaped gap has a horizontal side length of 10.5mm to 11.5mm and a width of 0.4mm to 0.6mm; its vertical side length is 2mm to 3mm and a width of 0.5mm to 0.7mm; each straight gap has a length of 10.5mm to 11.5mm and a width of 0.5mm to 0.7mm.

[0015] Furthermore, the height h of the metal cavity is 12.8mm to 13.2mm, and the diameter φ is 23.6mm to 24.4mm.

[0016] Furthermore, the vertical length and width of the middle section of the I-shaped cutting groove are equal to the diameter φ of the metal cavity. The arc length L of the upper and lower horizontal sides of the I-shaped groove is 20mm to 21mm, and the width w1 is 2.4mm to 2.8mm. After cutting, the two walls form a stepped structure with a width w2 of 1.3mm to 1.7mm and a height H of 11.7mm to 12.1mm.

[0017] Furthermore, the microstrip feed line includes a 50Ω microstrip line, a 71Ω microstrip line, a 100Ω microstrip line, and a fan-shaped matching stub; the 50Ω microstrip line has its starting end located at the bottom of the dielectric substrate and extends vertically upward, with its end connected to the starting end of the 71Ω microstrip line; the 71Ω microstrip line extends upward and to the right, with its end connected to the starting end of the 100Ω microstrip line; the 100Ω microstrip line extends to the right, with its end connected to the starting end of the fan-shaped matching stub, the starting end of which is located at the transmission slot.

[0018] Furthermore, the 50Ω microstrip line is a vertically rectangular copper-clad body of equal width, with a length of 3.5mm to 4.5mm and a width of 1.9mm to 2.5mm; the 71Ω microstrip line is a right-angled rectangular copper-clad body of equal width, with a width of 1mm to 1.5mm; the 100Ω microstrip line is a horizontally rectangular copper-clad body of equal width, with a length of 1.5mm to 2mm and a width of 0.5mm to 0.7mm; and the fan-shaped matching stub is a copper-clad body with a fan-shaped structure and a radius of 3mm to 3.5mm.

[0019] Compared with the prior art, the present invention has the following advantages:

[0020] 1) The present invention has two inverted "L" shaped slots and two "I" shaped slots etched on the left and right sides of the antenna radiator, respectively, and the two "I" shaped slots are located directly below the two inverted "L" shaped slots. This extends the path length of the current on the surface of the antenna radiator, changes the impedance characteristics of the antenna port, and thus expands the impedance bandwidth.

[0021] 2) This invention designs a concave metal cavity structure and inserts a dielectric substrate with a printed radiator into the concave cavity of the metal cavity, thereby further extending the current path length and widening the impedance bandwidth of the antenna in the low-frequency band.

[0022] 3) The present invention has gaps in the upper part of the two walls of the concave cavity. These gaps can be equivalent to two magnetic dipoles perpendicular to the antenna radiator. Since the radiation pattern of the magnetic dipoles on the E-plane of the antenna is omnidirectional, the beamwidth of the radiation pattern on the E-plane of the antenna can be significantly increased, making the radiation pattern on the H-plane, which is orthogonal to the radiation pattern on the E-plane of the antenna, nearly equal, thus increasing the beamwidth of the antenna on both planes.

[0023] 4) This invention designs a microstrip feeder consisting of a 50Ω microstrip line, a 71Ω microstrip line, a 100Ω microstrip line, and a fan-shaped matching stub connected in sequence. This can convert the 100Ω impedance of the transmission slot on the radiator into a 50Ω impedance, thereby achieving impedance matching of the 50Ω connector at the feed port. Attached Figure Description

[0024] Figure 1 This is the front view of the present invention;

[0025] Figure 2 This is a rear view of the present invention;

[0026] Figure 3 This is a side view of the present invention;

[0027] Figure 4 This is a top view of the present invention;

[0028] Figure 5 This is a front view of the radiator in this invention;

[0029] Figure 6 This is a front view of the microstrip feeder in this invention;

[0030] Figure 7 This is a side view of the metal cavity in this invention;

[0031] Figure 8 This is a front view of the metal cavity in this invention;

[0032] Figure 9 This is a top view of the metal cavity in this invention;

[0033] Figure 10 This is a graph showing the voltage standing wave ratio as a function of frequency according to the present invention.

[0034] Figure 11 The radiation patterns of the E and H planes of this invention at a frequency of 4.5 GHz are shown.

[0035] Figure 12 The radiation patterns of the E and H planes of this invention at a frequency of 5.5 GHz are shown.

[0036] Figure 13 The radiation patterns of the E and H planes of this invention at a frequency of 6.5 GHz are shown.

[0037] Figure 14 This is the radiation pattern of the E and H planes of the present invention at a frequency of 7.8 GHz. Detailed Implementation

[0038] The embodiments and effects of the present invention will be further described below with reference to the accompanying drawings.

[0039] Example 1:

[0040] Reference Figures 1-4 The broadband beam-tapered slot antenna with a metal cavity in this example includes a radiator 1, a microstrip feed line 2, a dielectric substrate 3, and a metal cavity 4. The radiator 1 and the microstrip feed line 2 are respectively etched on both sides of the dielectric substrate 3. The dielectric substrate 3, on which the radiator 1 and the microstrip feed line 2 are printed, is inserted into the fixing slot of the concave cavity of the metal cavity 4 to extend the low-frequency operating bandwidth of the antenna and increase the half-power beamwidth.

[0041] Reference Figure 5 The radiator 1 has two right-angled triangular notches 14 etched on its upper sides, a tapered slit 11 etched in the middle, and a transmission slit 12 connected to the lower end of the tapered slit 11. An impedance matching circular slit 13 is also etched to the lower end of the transmission slit 12. Two inverted "L"-shaped slits 15 and two straight "I"-shaped slits 16 are etched on the left and right sides of the transmission slit 12, respectively, with the two straight "I"-shaped slits located directly below the two inverted "L"-shaped slits. By creating the triangular notches and slits on the radiator, the surface current path length can be extended, improving the low-frequency impedance characteristics of the antenna and widening its low-frequency impedance bandwidth. Among them, the tapered gap is an isosceles triangle structure with a vertex angle of 38°; the transmission gap is 8mm long and 0.6mm wide; the impedance matching circular gap has a radius of 2.1mm; the horizontal side of each inverted "L" shaped gap is 11mm long and 0.5mm wide, and its vertical side is 2.5mm long and 0.6mm wide; the vertical side of each "I" shaped gap is 11mm long and 0.6mm wide.

[0042] Reference Figure 6The microstrip feed line 2 includes a 50Ω microstrip line 21, a 71Ω microstrip line 22, a 100Ω microstrip line 23, and a fan-shaped matching stub 24. The 50Ω microstrip line 21 begins at the bottom of the dielectric substrate and extends vertically upwards, its end connecting to the beginning of the 71Ω microstrip line 22. The 71Ω microstrip line 22 extends upwards and to the right, its end connecting to the beginning of the 100Ω microstrip line 23. The 100Ω microstrip line 23 extends to the right, its end connecting to the beginning of the fan-shaped matching stub 24, the beginning of which is located at the transmission slot 12. The microstrip line consists of a 50Ω microstrip line with a vertical rectangular copper strip of equal width, 4mm in length and 2.2mm in width; a 71Ω microstrip line with a right-angled rectangular copper strip of equal width, 1.2mm in width; a 100Ω microstrip line with a horizontal rectangular copper strip of equal width, 1.8mm in length and 0.6mm in width; and a fan-shaped matching stub with a fan-shaped copper strip and a radius of 3.4mm. This microstrip feeder, composed of microstrip lines of different Ω and fan-shaped matching stubs, can convert the 100Ω impedance generated by the transmission gap on the radiator into a 50Ω impedance, achieving impedance matching at the 50Ω connector of the feed port.

[0043] Reference Figures 7-9 The metal cavity 4 has an I-shaped cutting groove 41 to form a concave cavity structure. The upper part of the two walls of the concave cavity has a slit 42 to divide each metal wall into an upper part and a lower part, which is equivalent to a magnetic dipole perpendicular to the antenna radiator 1 and improves the beamwidth of the antenna. A dielectric pad 43 is placed at the slit 42 of the concave cavity to form the height of the slit. The upper and lower parts of the two walls of the concave cavity are fixed by dielectric screws 44. U-shaped fixing slots 45 are opened in the middle and bottom of the two walls of the concave cavity, and a feed port isolation hole 46 is opened at the bottom of the cavity, which is used to fix the dielectric substrate 3 and the feed port of the isolation antenna, respectively. The metal cavity has a height h of 13mm and a diameter φ of 24mm. The vertical length and width of the middle section of the I-shaped cutting groove are the same as the diameter φ of the metal cavity. The arc length L of the upper and lower horizontal sides of the I-shaped groove is 20.5mm, and the width w1 is 2.6mm. The two walls after cutting form a stepped structure with a width w2 of 1.5mm and a height H of 11.9mm.

[0044] The dielectric substrate 3 is made of Arlon AD270 material with a dielectric constant of 2.65 and a loss tangent of 0.0023. Its height is 1.8 times the height of the metal cavity, and its width is 9 / 10 of the diameter of the metal cavity.

[0045] Example 2:

[0046] Reference Figures 1-4 The structure of this example is the same as that of Example 1.

[0047] Reference Figure 5The structure of the radiator 1 is the same as that of Embodiment 1, except that the apex angle of the tapered slit is changed to 35°; the length of the transmission slit is 7.5 mm and the width is 0.5 mm; the radius of the impedance matching circular slit is 2.3 mm; the length of the horizontal side of the inverted "L" shaped slit is 10.5 mm and the width is 0.4 mm, and the length of its vertical side is 2 mm and the width is 0.5 mm; the length of the "I" shaped slit is 10.5 mm and the width is 0.5 mm.

[0048] Reference Figure 6 The structure of the microstrip feeder 2 is the same as that in Embodiment 1, except that the length of the 50Ω microstrip line is set to 3.5mm and the width to 1.9mm; the width of the 71Ω microstrip line is set to 1mm; the length of the 100Ω microstrip line is set to 2mm and the width to 0.7mm; and the radius of the fan-shaped matching branch is set to 3mm.

[0049] Reference Figures 7-9 The structure of the metal cavity 4 is the same as that in Embodiment 1, except that the height h of the metal cavity is 12.8 mm and the diameter φ is 23.6 mm; the arc length L of the two horizontal sides of the I-shaped structure is 20 mm and the width w1 is 2.4 mm. After cutting, the two walls form a stepped structure with a width w2 of 1.3 mm and a height H of 11.7 mm.

[0050] All other structures not mentioned are the same as in Example 1.

[0051] Example 3:

[0052] Reference Figures 1-4 The structure of this example is the same as that of Example 1.

[0053] Reference Figure 5 The structure of the radiator 1 is the same as that of Embodiment 1, except that the apex angle of the tapered slit is 40°; the length of the transmission slit is 8.5 mm and the width is 0.7 mm; the radius of the impedance matching circular slit is 1.9 mm; the length of the horizontal side of the inverted "L" shaped slit is 11.5 mm and the width is 0.6 mm, and the length of its vertical side is 3 mm and the width is 0.7 mm; the length of the "I" shaped slit is 11.5 mm and the width is 0.7 mm.

[0054] Reference Figure 6 The structure of the microstrip feed line 2 is the same as that in Embodiment 1, except that the length of the 50Ω microstrip line is 4.5mm and the width is 2.5mm; the width of the 71Ω microstrip line is 1.5mm; the length of the 100Ω microstrip line is 1.5mm and the width is 0.5mm; and the radius of the fan-shaped matching branch is 3.5mm.

[0055] Reference Figures 7-9The structure of the metal cavity 4 is the same as that in Embodiment 1, except that the height h of the metal cavity is 13.2 mm and the diameter φ is 24.4 mm; the arc length L of the two horizontal sides of the I-shaped structure is 21 mm and the width w1 is 2.8 mm. After cutting, the two walls form a stepped structure with a width w2 of 1.7 mm and a height H of 12.1 mm.

[0056] All other structures not mentioned are the same as in Example 1.

[0057] The effects of this invention can be further illustrated by the following simulation experiments:

[0058] I. Simulation Conditions

[0059] This invention uses ANSYS Electronics Desktop software to perform electrical characteristic simulation analysis on the designed wideband beam taper slot antenna loaded with a metal cavity. The frequency range of the frequency sweep is set to 3GHz to 13GHz, the frequency sweep interval is set to 0.1GHz, the center frequency of the frequency sweep is set to 8GHz, and the maximum number of iterations is 20.

[0060] II. Simulation Content

[0061] Simulation 1: Under the above conditions, the voltage standing wave ratio (VSWR) of Embodiment 1 of the present invention was simulated, and the results are as follows. Figure 10 As shown. From Figure 10 As can be seen, when the voltage standing wave ratio (VSWR) of the present invention is ≤2.0, the operating frequency range of the antenna is 4.0GHz to 11.6GHz, and the relative bandwidth is 96%.

[0062] Simulation 2: Under the above conditions, the radiation patterns of Embodiment 1 of the present invention at different frequencies were simulated, and the results are as follows. Figures 11-14 As shown, where:

[0063] Figure 11 The diagram shows the E-plane and H-plane radiation patterns of the antenna at a frequency of 4.5 GHz. The solid line represents the H-plane radiation pattern, and the dashed line represents the E-plane radiation pattern. Figure 11 As can be seen, at a frequency of 4.5 GHz, the half-power beamwidth of the antenna's E-plane pattern is 112°, the half-power beamwidth of the antenna's H-plane pattern is 148°, and the front-to-back ratio of the antenna pattern is 10.9 dB.

[0064] Figure 12 The diagram shows the E-plane and H-plane radiation patterns of the antenna at a frequency of 5.5 GHz. The solid line represents the H-plane radiation pattern, and the dashed line represents the E-plane radiation pattern. Figure 12 As can be seen, at a frequency of 5.5 GHz, the half-power beamwidth of the antenna's E-plane pattern is 148°, the half-power beamwidth of the antenna's H-plane pattern is 174°, and the front-to-back ratio of the antenna pattern is 10.6 dB.

[0065] Figure 13 The diagram shows the E-plane and H-plane radiation patterns of the antenna at a frequency of 6.5 GHz. The solid line represents the H-plane radiation pattern, and the dashed line represents the E-plane radiation pattern. Figure 13 As can be seen, at a frequency of 6.5 GHz, the half-power beamwidth of the antenna's E-plane pattern is 180°, the half-power beamwidth of the antenna's H-plane pattern is 182°, and the front-to-back ratio of the antenna pattern is 12.7 dB.

[0066] Figure 14 The diagram shows the E-plane and H-plane radiation patterns of the antenna at a frequency of 7.8 GHz. The solid line represents the H-plane radiation pattern, and the dashed line represents the E-plane radiation pattern. Figure 14 As can be seen, at a frequency of 7.8 GHz, the half-power beamwidth of the antenna's E-plane pattern is 110°, the half-power beamwidth of the antenna's H-plane pattern is 168°, and the front-to-back ratio of the antenna pattern is 13.5 dB.

[0067] In summary, within the 4.5GHz to 7.8GHz frequency band, the relative bandwidth is 53.7%, and the antenna's E-plane and H-plane radiation patterns both exhibit wide beam characteristics. Furthermore, the half-power beamwidth is greater than 110°, which can well meet the wide bandwidth beam coverage requirements for mobile communication.

[0068] The above descriptions are merely three specific examples of the present invention and do not constitute any limitation on the present invention. Obviously, those skilled in the art, after understanding the content and principles of the present invention, may make various modifications and changes in form and detail without departing from the principles and structure of the present invention. However, these modifications and changes based on the ideas of the present invention are still within the scope of protection of the claims of the present invention.

Claims

1. A metal cavity loaded wideband wide-beam tapered slot antenna, comprising an antenna radiator (1), a microstrip feed line (2), a dielectric substrate (3), the antenna radiator (1) and the microstrip feed line (2) are respectively etched on two sides of the dielectric substrate (3), a tapered slot (12) is etched in the middle of the upper part of the radiator (1), the lower end of the tapered slot (12) is connected with an etched transmission slot (13), the lower end of the transmission slot (13) is connected with an etched impedance matching circular slot (14), characterized in that: Also include a metal cavity (4); The metal cavity (4) is provided with a H-shaped slot (41), forming a concave cavity structure, the upper part of the two walls of the concave cavity is provided with a slit (42) to divide each metal wall into two parts, the slit is equivalent to a magnetic dipole perpendicular to the antenna radiator (1), which improves the beam width of the antenna; The upper two sides of the radiator (1) are etched with two right triangle notches, the left and right sides of the transmission slot (13) are etched with two inverted "L" type slots (15) and two "I" type slots (16) respectively, to improve the bandwidth of the low frequency band of the antenna; The dielectric substrate (3) printed with the radiator (1) and the microstrip feed line (2) is inserted into the concave cavity of the metal cavity (4) to expand the low frequency working bandwidth of the antenna and increase the half power beam width.

2. The antenna according to claim 1, characterized in that, The slit (42) of the concave cavity is placed with a dielectric pad (43) to form the height of the slit, the upper and lower parts of the two walls of the concave cavity are fixed by dielectric screws (44), the middle and bottom of the two walls of the concave cavity are provided with U-shaped fixing slots (45), and the bottom is provided with a feed port isolation hole (46) for fixing the dielectric substrate (3) and isolating the feed port of the antenna respectively.

3. The antenna according to claim 1, wherein: The two "I" type slots (16) are respectively located directly below the two inverted "L" type slots (15); Each inverted "L" type slot (15) has a length of 10.5mm-11.5mm and a width of 0.4mm-0.6mm; The length of the vertical side is 2mm-3mm, and the width is 0.5mm-0.7mm; Each "I" type slot (16) has a length of 10.5mm-11.5mm and a width of 0.5mm-0.7mm.

4. The antenna of claim 1, wherein, The height h of the metal cavity (4) is 12.8mm-13.2mm, and the diameter φ is 23.6mm-24.4mm.

5. The antenna according to claim 1, wherein, The H-shaped slot (41) has a vertical length of 20mm-21mm in the middle of the H-shaped slot.

6. The antenna according to claim 1, wherein, The microstrip feed line (2) includes a 50Ω microstrip line (21), a 71Ω microstrip line (22), a 100Ω microstrip line (23) and a fan-shaped matching branch (24) to realize impedance matching of the 50Ω connector of the feed port, wherein: The 50Ω microstrip line (21) has its beginning end located at the bottom of the dielectric substrate and extends vertically upward, and its end is connected with the beginning end of the 71Ω microstrip line (22); The 71Ω microstrip line (22) extends upward and rightward, and its end is connected with the beginning end of the 100Ω microstrip line (23); The 100Ω microstrip line (23) extends rightward, and its end is connected with the beginning end of the fan-shaped matching branch (24), which is located at the transmission slot (13).

7. The antenna according to claim 6, wherein: The 50Ω microstrip line (21) is a vertical rectangular copper body with equal width, and has a length of 3.5mm-4.5mm and a width of 1.9mm-2.5mm. The 71Ω microstrip line (22) is a straight rectangular strip copper body with equal width, and the width is 1mm-1.5mm; The 100Ω microstrip line (23) is a horizontal rectangular strip copper body with equal width, and the length is 1.5mm-2mm and the width is 0.5mm-0.7mm; The fan-shaped matching branch (24) is a fan-shaped copper body, and the radius is 3mm-3.5mm.

8. The antenna according to claim 1, wherein, The parameters of the tapered slot (12), the transmission slot (13) and the impedance matching circular slot (14) etched on the radiator (1) are as follows: The tapered slot is an isosceles triangle structure, and the angle of the top angle is 35°-40°; The length of the transmission slot is 7.5mm-8.5mm, and the width is 0.5mm-0.7mm; The radius of the impedance matching circular slot is 1.9mm-2.3mm.

9. The antenna according to claim 1, wherein, The dielectric substrate (3) adopts Arlon AD270 plate material with a dielectric constant of 2.65 and a loss tangent of 0.0023.

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