Differential high-selectivity antenna with broadband anti-interference characteristic

Abstract

The invention belongs to the field of wireless communication, and particularly relates to a differential high-selectivity antenna with a broadband anti-interference characteristic, which comprises an upper-layer metal radiating surface, an upper-layer dielectric substrate, a middle-layer metal radiating surface, a middle-layer dielectric substrate, a metal floor, a bottom-layer dielectric substrate, a metal micro-strip feeder line layer and an SMA feeder. The metal micro-strip feeder line layer is composed of two pairs of differential micro-strip feeder lines, and each micro-strip feeder line comprises a first rectangular micro-strip feeder line, a second rectangular micro-strip feeder line and a U-shaped micro-strip feeder line. And an L-shaped open-circuit branch loaded on one side of the second rectangular microstrip feeder and a concave groove part etched in the upper-layer metal radiating surface respectively form a radiation zero point at a high frequency and a low frequency in a differential feed mode, so that the high-selectivity characteristic of the antenna is realized. A first rectangular open-circuit branch knot and a second rectangular open-circuit branch knot are loaded on the other side of the second rectangular microstrip feeder line so as to restrain additional interference generated by loading a structure meeting the high-selectivity characteristic of the antenna, and therefore the broadband anti-interference characteristic is achieved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of wireless communication, and particularly relates to a differential high-selectivity antenna with wideband anti-interference characteristics. BACKGROUND

[0002] Traditional filtering antennas need additional suppression circuits to solve the problem of harmful harmonic interference, but this is not conducive to system high integration. Now, with the rapid development of the fifth generation (5G) and future wireless communication technology, the radio frequency front-end system is evolving towards high integration, high spectral efficiency and low power consumption. Under this trend, filtering antennas that integrate filtering and radiation functions have become a research hotspot.

[0003] In addition, traditional single-feed single-polarized antennas often have poor port isolation and poor cross-polarization performance when facing multi-band and multi-port integrated applications, which can easily introduce inter-channel coupling and harmonic interference, thereby limiting the overall performance of the system. Differential feed technology can effectively suppress common-mode noise and improve signal-to-noise ratio and port isolation by introducing a pair of equal and opposite signals, so differential dual-polarized antennas are considered as one of the ideal choices for high-integration high-selectivity antenna systems.

[0004] However, the design of deeply integrating differential feed, dual polarization and filtering functions still faces severe challenges. On the one hand, traditional designs usually introduce filtering circuits in the feed network or load resonant structures to produce radiation zeros, thereby achieving filtering response. For example, Chinese patent CN109728429B shows a differential dual-polarized filtering antenna that realizes second harmonic suppression by loading a quarter-wavelength and half-wavelength branch on the lower surface of the dielectric substrate, combined with a radiation patch ring slot. However, the harmonic suppression effect produced by such methods is usually limited to specific, isolated frequency points, i.e. "point suppression", which has limited suppression bandwidth. On the other hand, more difficultly, in the process of pursuing steep filtering characteristics at the passband edge, the introduced filtering structure itself may excite new, unexpected high-order harmonic resonances. These "self-generated extra harmonics" will limit the out-of-band suppression level of the antenna in the actual system, resulting in insufficient overall harmonic suppression bandwidth, making it difficult to meet the increasingly stringent requirements of modern communication systems for spectral purity.

[0005] Therefore, the existing differential dual-polarized filtering antennas still lack effective solutions on how to achieve the leap from narrow "point suppression" to wide "band suppression" without introducing additional circuit complexity. Developing a high-selectivity filtering antenna that can effectively suppress extra harmonics generated by its own structure, while having a symmetric structure to ensure high isolation between ports, has become a technical problem that needs to be solved in the current wireless communication field. SUMMARY

[0006] Therefore, the present application aims to overcome the problem of insufficient harmonic suppression bandwidth and additional harmonics generated by the existing differential dual-polarized filter antenna after introducing the filter structure, and to provide a differential high-selectivity antenna with wideband anti-interference characteristics to achieve a wider harmonic suppression bandwidth.

[0007] To achieve the above-mentioned purpose, the present application provides the following technical solutions: The present application provides a differential high-selectivity antenna with wideband anti-interference characteristics, which comprises an upper metal radiation surface, an upper dielectric substrate, a middle metal radiation surface, a middle dielectric substrate, a metal ground plate, a bottom dielectric substrate, a metal microstrip feed line layer, an SMA feeder, and a metal column.

[0008] The upper dielectric substrate, the middle dielectric substrate, and the bottom dielectric substrate each have an upper surface and a lower surface; the upper metal radiation surface is arranged on the upper surface of the upper dielectric substrate and has a concave groove inside; the middle metal radiation surface is arranged on the upper surface of the middle dielectric substrate; the metal ground plate is arranged on the lower surface of the middle dielectric substrate and is located between the middle dielectric substrate and the bottom dielectric substrate; and the metal microstrip feed line layer is arranged on the lower surface of the bottom dielectric substrate.

[0009] The metal microstrip feed line layer comprises two pairs of metal microstrip feed lines, each of which comprises a first rectangular microstrip feed line, a second rectangular microstrip feed line, and a "H" shaped microstrip feed line connected in sequence, and each of which is loaded with an "L" shaped open stub, a first rectangular open stub, and a second rectangular open stub; and each metal microstrip feed line is connected to a feeding point and the metal column.

[0010] The "H" shaped microstrip feed line is connected to the middle metal radiation surface through the metal column; one end of the first rectangular microstrip feed line is connected to the SMA feeder, and the other end is connected to the second rectangular microstrip feed line; the "L" shaped open stub is loaded on one side of the second rectangular microstrip feed line to form a low-frequency radiation zero point; and the first rectangular open stub and the second rectangular open stub are loaded on the other side to suppress the additional harmonics generated by the high-selectivity structure, thereby improving the anti-interference capability. The upper metal radiation surface is in a square structure; a concave groove is formed inside the upper metal radiation surface, and the concave groove is in a square structure and symmetrically etched inside the upper metal radiation surface; and the middle metal radiation surface is in a square structure with a side length smaller than that of the upper metal radiation surface.

[0011] Further, the upper dielectric substrate, the middle dielectric substrate, the bottom dielectric substrate, and the metal ground plate have the same size.

[0012] Further, each pair of metal microstrip feed lines and the stub structure loaded thereon are strictly symmetrical in the vertical direction of their excitation.

[0013] Further, the width of the second rectangular microstrip feed line is greater than the width of the first rectangular microstrip feed line, and the width of the first rectangular microstrip feed line is greater than the width of the "H" shaped microstrip feed line; the lengths of the "L" shaped open-circuit stub, the first rectangular open-circuit stub and the second rectangular open-circuit stub are different but the widths are the same, and the "L" shaped open-circuit stub is bent along the direction of the SMA feeder.

[0014] Further, one end of the metal column is connected to the "H" shaped microstrip feed line, and the other end is connected to the intermediate layer metal radiation surface; the metal column penetrates the intermediate layer dielectric substrate, the metal ground plate and the bottom layer dielectric substrate.

[0015] Further, the two pairs of metal microstrip feed lines include eight feed points, corresponding to eight metal columns; each metal microstrip feed line is connected to two feed points through the "H" shaped microstrip feed line.

[0016] Further, the relative dielectric constant of the upper layer dielectric substrate, the intermediate layer dielectric substrate and the bottom layer dielectric substrate ranges from 4 to 5, and the loss tangent ranges from 0.01 to 0.03. Further, the distance between the upper layer dielectric substrate and the intermediate layer dielectric substrate ranges from 7 to 8 mm.

[0017] Further, the length of the upper layer dielectric substrate, the intermediate layer dielectric substrate and the bottom layer dielectric substrate ranges from 49 to 51 mm, the width ranges from 49 to 51 mm, and the thickness ranges from 0.3 to 1.3 mm.

[0018] Further, the thickness of the metal microstrip feed layer and the metal radiation surface ranges from 0.010 to 0.025 mm, the length of the first rectangular microstrip feed line ranges from 2.33 to 3.33 mm, and the width ranges from 1.02 to 2.02 mm, the length of the second rectangular microstrip line ranges from 3.7 to 4.7 mm, and the width ranges from 1.75 to 2.75 mm, and the length of the "H" shaped microstrip feed line ranges from 21.65 to 22.65 mm, and the width ranges from 0.2 to 1.2 mm.

[0019] Further, the diameter of the metal column ranges from 0.25 to 0.35 mm, and the height ranges from 1.135 to 2.135 mm; the total length of the "L" shaped open-circuit stub ranges from 15 to 16 mm, the length of the first rectangular open-circuit stub ranges from 5.45 to 6.45 mm, the length of the second rectangular open-circuit stub ranges from 3 to 4 mm, and the width of the "L" shaped open-circuit stub, the first rectangular open-circuit stub and the second rectangular open-circuit stub ranges from 0.2 to 1.2 mm.

[0020] Furthermore, the side length of the upper metal radiating surface ranges from 25 to 26 mm, the length of its internal concave groove ranges from 11 to 12 mm, and the width ranges from 0.25 to 1.25 mm, while the side length of the middle metal radiating surface ranges from 19.85 to 20.85 mm.

[0021] Furthermore, the SMA feeder includes an inner core wire, an insulation layer, an outer conductor, and a sheath, wherein the inner core wire is connected to a first rectangular microstrip feeder wire of a metal microstrip feeder wire.

[0022] The beneficial effects of this invention are as follows: (1) This invention changes the traditional single-ended feeding structure to a dual-port differential feeding structure. While introducing dual polarization technology, it suppresses high-frequency interference and highly integrates the differential circuit and system. By integrating functionally distinct "L"-shaped open-circuit stubs and two rectangular open-circuit stubs on the same microstrip feed line, a collaborative working mechanism of "main filtering-auxiliary harmonic suppression" is constructed. Specifically, the length of the "L"-shaped open-circuit stub loaded on the microstrip feed line is changed to allow it to be connected in parallel with a low-impedance stub, generating a radiation null at low frequencies. A square concave groove is etched on the upper metal radiating surface to reverse the current and generate radiation cancellation, generating another radiation null at high frequencies, thus enhancing the antenna's high selectivity.

[0023] (2) This invention loads two rectangular open-circuit stubs of different lengths onto the metal microstrip feed line, suppressing the additional harmonics generated after loading to achieve a high-selectivity structure. This allows the antenna's harmonic suppression capability to leap from suppressing isolated frequency points in traditional designs to suppressing a wide frequency band, achieving a qualitative leap in harmonic suppression from "point" to "band". The antenna operates at a frequency of 3.28 GHz, has an impedance bandwidth of 14.3% (3.05-3.52 GHz), and can achieve a peak gain of 6.1 dBi.

[0024] (3) While achieving high performance, this invention also ensures the antenna's high selective filtering response. Based on a rigorous symmetrical differential feed design, this invention achieves port isolation greater than 35dB in both polarization directions, effectively reducing inter-channel interference. This antenna features excellent performance, compact structure, and ease of integration, meeting the current demands of highly integrated RF front-end systems in wireless communication.

[0025] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0026] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be described in preferred detail below in conjunction with the accompanying drawings, where: Figure 1 It is a schematic diagram of the overall structure of the differential high-selectivity antenna with broadband anti-interference characteristics according to the present invention; Figure 2 It is a schematic diagram of the dimensions of the differential high-selectivity antenna with broadband anti-interference characteristics according to the present invention; Figure 3 It is a graph of the relationship between frequency and reflection coefficient |S dd11 |, port isolation |S dd21 | and achievable gain of the differential high-selectivity antenna with broadband anti-interference characteristics according to the present invention under the excitation of a pair of differential signals in the Y direction; Figure 4 It is the achievable gain two-dimensional radiation pattern of the differential high-selectivity antenna with broadband anti-interference characteristics according to the present invention when the operating frequency is 3.28 GHz; Reference numerals: 0 - upper dielectric substrate, 1 - upper metal radiation surface, 2 - intermediate metal radiation surface, 3 - intermediate dielectric substrate, 4 - bottom dielectric substrate, 5 - metal floor, 6 - concave groove, 7 - first rectangular microstrip feeder, 8 - second rectangular microstrip feeder, 9 - "C"-shaped microstrip feeder, 10 - "L"-shaped open stub, 11 - first rectangular open stub, 12 - second rectangular open stub, 13 - metal column, 14 - SMA feeder. Specific embodiments

[0027] The following illustrates the embodiments of the present invention through specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the drawings provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0028] Among them, the drawings are only for illustrative purposes, showing only schematic diagrams, not physical diagrams, and should not be construed as a limitation to the present invention; to better illustrate the embodiments of the present invention, some components in the drawings will be omitted, enlarged or reduced, and do not represent the dimensions of actual products; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0029] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present invention. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0030] See appendix Figure 1 The present invention provides a differential high-selectivity antenna with wideband anti-interference characteristics. The antenna includes: an upper dielectric substrate 0, an upper metal radiating surface 1, an intermediate metal radiating surface 2, an intermediate dielectric substrate 3, a bottom dielectric substrate 4, a metal ground plane 5, a concave groove 6, a metal pillar 13, an SMA feeder 14, and a metal microstrip feeder layer.

[0031] The metal microstrip feed line layer includes two pairs of metal microstrip feed lines. Each metal microstrip feed line includes a first rectangular microstrip feed line 7, a second rectangular microstrip feed line 8, and a "U"-shaped microstrip feed line 9 connected in sequence. Each metal microstrip feed line is loaded with an "L"-shaped open-circuit stub 10, a first rectangular open-circuit stub 11, and a second rectangular open-circuit stub 12. Each metal microstrip feed line is also connected to a metal pillar 13 and a feed point. The metal pillar 13 passes through the bottom dielectric substrate 4, the metal ground plane 5, and the intermediate dielectric substrate 3 along the metal microstrip feed line.

[0032] One end of the first rectangular microstrip feeder 7 is connected to the SMA feeder 14, and the other end is connected to the second rectangular microstrip feeder 8; one side of the second rectangular microstrip feeder 8 is loaded with an "L"-shaped open stub 10 to form a low-frequency radiation null point, and the other side is loaded with a first rectangular open stub 11 and a second rectangular open stub 12 to suppress additional harmonics generated by loading to achieve a high-selectivity structure; the "U"-shaped microstrip feeder 9 is connected to the intermediate layer metal radiating surface 2 through a metal pillar 13.

[0033] The upper dielectric substrate 0, the middle dielectric substrate 3, and the bottom dielectric substrate 4 all have an upper surface and a lower surface; the upper surface of the upper dielectric substrate 0 is provided with an upper metal radiation surface 1; the upper surface of the middle dielectric substrate 3 is provided with an middle metal radiation surface 2; the lower surface of the middle dielectric substrate is provided with a metal ground plane 5, which is located between the middle dielectric substrate 3 and the bottom dielectric substrate 4; the lower surface of the bottom dielectric substrate 4 is provided with a metal microstrip feed line.

[0034] A square concave groove 6 is etched on the upper metal radiation surface 1, and the middle metal radiation surface 2 is designed as a symmetric square.

[0035] The upper dielectric substrate 0, the middle dielectric substrate 3, the bottom dielectric substrate 4 and the metal floor 5 have the same size, with a length of 50 mm and a width of 50 mm. The side length of the upper metal radiation surface is 25.5 mm, the side length of the middle metal radiation surface is 20.35 mm, the length of the first rectangular microstrip feeder is 2.83 mm and the width is 1.52 mm, the length of the second rectangular microstrip feeder is 4.2 mm and the width is 2.25 mm, and the length of the "C" - shaped microstrip feeder is 22.15 mm and the width is 0.7 mm. The length of the "L" - shaped open - circuit stub is 15.5 mm, the length of the first rectangular open - circuit stub is 5.95 mm, the length of the second rectangular open - circuit stub is 3.5 mm, and the width of all stubs is 0.7 mm. The diameter of the metal column is 0.3 mm and the height is 1.635 mm, the interval between the upper dielectric substrate and the middle dielectric substrate is 7.5 mm, the thicknesses of the metal floor and the metal radiation surface are both 0.017 mm, and the thicknesses of the three dielectric substrates are all 0.8 mm.

[0036] The material of the dielectric substrate is FR4, with a relative dielectric constant of 4.4 and a loss tangent of 0.02.

[0037] The differential high - selectivity antenna with broadband anti - interference characteristics is simulated using the high - frequency electromagnetic simulation software HFSS2022, and the simulation parameters are set as shown in Table 1 (unit: mm).

[0038]

[0039] Table 1 Among them, L is the side length of the dielectric substrate, L1 is the side length of the upper metal radiation surface, L2 and L3 are respectively the outer side length and the inner side length of the concave groove, L4 is the side length of the middle metal radiation surface, L5 and L6 are respectively the bending length and the vertical length of the "L" - shaped open - circuit stub, L7 and W1 are the length and width of the first rectangular microstrip feeder, L8 and W3 are the length and width of the second rectangular microstrip feeder; L9 and W2 are half of the length and the width of the "C" - shaped microstrip feeder, L 11 is the length of the first rectangular open - circuit stub, L 10 is the length of the second rectangular open - circuit stub, W4 is the width of all open - circuit stubs, d1 is the diameter of the circular metal microstrip under the metal column, d2 is the diameter of the metal column, and the schematic diagram of the dimensions of each parameter of the antenna can be seen in Figure 2 .

[0040] Figure 3 For the |S dd11 |, |S dd21| and the curve showing the gain versus frequency. As shown in the figure, from the simulation results |S dd11 The antenna exhibits an impedance bandwidth of 14.3% below -10dB, a center frequency of 3.28GHz, and an operating frequency range of 3.05-3.52GHz. The achievable gain curve shows an achievable peak gain of 6.1dBi within the band, with a flat response in the passband and a radiation null at both the upper and lower edges, enhancing the antenna's high selectivity. Simulation results |S dd21 This indicates that the port isolation parameter values ​​are all less than -35dB. Figure 4 (a) and (b) show the simulated antenna radiation patterns in the E and H planes at a center frequency of 3.28 GHz, respectively, both exhibiting low levels of cross-polarization.

[0041] Wideband anti-interference antennas ensure normal operation within the passband while preventing harmonic interference in the upper stopband. On one hand, differential feeding technology feeds two equal-amplitude, out-of-phase signals into the two ports of the antenna. Compared to traditional single-ended feeding, differential feeding significantly suppresses high-frequency harmonic interference and improves port isolation, enhancing the antenna's anti-interference capability and signal-to-noise ratio, and is more suitable for highly integrated RF front-ends. On the other hand, the "L"-shaped open-circuit stubs and two rectangular open-circuit stubs of different lengths loaded on the metal microstrip feed line enhance the antenna's high selectivity and effectively suppress additional harmonics generated by the high-selectivity structure, transforming harmonic suppression from traditional "point suppression" to "band suppression," and from isolated frequency suppression to wideband suppression. This design effectively reduces system complexity and cost while improving the system's anti-interference performance and stability.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A differential high-selectivity antenna with wideband anti-interference characteristics, characterized in that, Comprising: An upper dielectric substrate (0) having an upper surface and a lower surface; An upper metal radiation surface (1) disposed on the upper surface of the upper dielectric substrate (0), the upper metal radiation surface (1) being a square structure with a concave groove (6) formed therein; An intermediate dielectric substrate (3) having an upper surface and a lower surface; An intermediate metal radiation surface (2) disposed on the upper surface of the intermediate dielectric substrate (3), the intermediate metal radiation surface (2) being a square structure with a side length smaller than that of the upper metal radiation surface (1); A metal floor (5) disposed on the lower surface of the intermediate dielectric substrate (3); A lower dielectric substrate (4) having an upper surface and a lower surface, the metal floor (5) being located between the intermediate dielectric substrate (3) and the lower dielectric substrate (4); A metal microstrip feeder layer disposed on the lower surface of the lower dielectric substrate (4), including two pairs of metal microstrip feeders, each metal microstrip feeder including a first rectangular microstrip feeder (7), a second rectangular microstrip feeder (8) and a "C"-shaped microstrip feeder (9) connected in sequence; A metal post (13), the "C"-shaped microstrip feeder (9) being connected to the intermediate metal radiation surface (2) through the metal post (13); An SMA feeder (14), each SMA feeder (14) being connected to one end of the first rectangular microstrip feeder (7); Wherein, one end of the first rectangular microstrip feeder (7) is connected to the SMA feeder (14), and the other end is connected to the second rectangular microstrip feeder (8); a "L"-shaped open stub (10) is loaded on one side of the second rectangular microstrip feeder (8) for forming a low-frequency radiation null point; a first rectangular open stub (11) and a second rectangular open stub (12) are loaded on the other side for suppressing harmonic interference.

2. A differential high-selectivity antenna with wideband anti-interference characteristics according to claim 1, characterized in that, Each pair of the metal microstrip feeders and the stub structures loaded thereon are strictly symmetric in the vertical direction of excitation.

3. A differential high-selectivity antenna with wideband anti-interference characteristics according to claim 1 or 2, characterized in that, The width of the second rectangular microstrip feeder (8) is greater than the width of the first rectangular microstrip feeder (7), and the width of the first rectangular microstrip feeder (7) is greater than the width of the "C"-shaped microstrip feeder (9); the lengths of the "L"-shaped open stub (10), the first rectangular open stub (11) and the second rectangular open stub (12) are different but the widths are the same, and the "L"-shaped open stub (10) is bent along the direction of the SMA feeder (14).

4. A differential high-selectivity antenna with wideband anti-interference characteristics according to claim 1, characterized in that, One end of the metal post (13) is connected to the "C"-shaped microstrip feeder (9), and the other end is connected to the intermediate metal radiation surface (2), and the metal post (13) penetrates through the intermediate dielectric substrate (3), the metal floor (5) and the lower dielectric substrate (4).

5. A differential high-selectivity antenna with wideband anti-interference characteristics according to claim 1, characterized in that, The two pairs of metal microstrip feeders include eight feeding points corresponding to eight metal posts (13); each metal microstrip feeder is connected to two feeding points through the "C"-shaped microstrip feeder (9).

6. A differential high-selectivity antenna with wideband anti-interference characteristics according to claim 1, characterized in that, The relative dielectric constant value ranges of the upper dielectric substrate (0), the middle dielectric substrate (3), and the bottom dielectric substrate (4) are 4 to 5, and the tangent value of the loss angle ranges are 0.01 to 0.

03.

7. A differential high-selectivity antenna with wideband anti-interference characteristics according to claim 1, characterized in that, The length value ranges of the upper dielectric substrate (0), the middle dielectric substrate (3), the metal floor (5), and the bottom dielectric substrate (4) are 49 to 51 mm, the width value ranges are 49 to 51 mm, and the thickness value ranges are 0.3 to 1.3 mm. The length value range of the first rectangular microstrip feeder (7) is 2.33 to 3.33 mm, the width value range is 1.02 to 2.02 mm. The length value range of the second rectangular microstrip feeder (8) is 3.7 to 4.7 mm, the width value range is 1.75 to 2.75 mm. The length value range of the "C"-shaped microstrip feeder (9) is 21.65 to 22.65 mm, and the width value range is 0.2 to 1.2 mm.

8. A differential high-selectivity antenna with broadband anti-interference characteristics according to claim 1, wherein The diameter range of the metal column (13) is 0.25 to 0.35 mm, the height value range is 1.135 to 2.135 mm. The vertical length value range of the "L"-shaped open stub (10) is 9.25 to 9.75 mm, the bending length value range is 9. A differential high-selectivity antenna with wideband anti-interference characteristics according to claim 3, characterized in that, ​ 10. A differential high-selectivity antenna with wideband anti-interference characteristics according to claim 1 or 9, characterized in that: ​

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