A dual-frequency wideband Vivaldi differential feed filtering antenna

Abstract

The application relates to a dual-frequency wide-band Vivaldi differential feeding filter antenna and belongs to the wireless communication field. The application comprises a dielectric substrate, a metal microstrip feeding line layer, a metal radiation surface and two SMA coaxial feeders. The metal radiation surface is designed with double exponential curve gradually changing grooves, a first rectangular groove and a pair of circular grooves to realize specific radiation characteristics. The metal microstrip feeding line layer is composed of a pair of feeding lines, each of which comprises a rectangular and a sectorial microstrip part and is connected with the SMA feeder. Through the differential feeding mode, the sectorial parts of the two feeding lines generate half-wave length and full-wave length resonances respectively, form two radiation zero points and realize the dual-frequency wide-band characteristics. The application can effectively solve the frequency band adaptation problem under multiple communication protocols, reduce the coupling and interference between antennas and provide a new technical solution for the wireless communication field.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of wireless communication and relates to a dual-frequency wideband Vivaldi differential feed filtering antenna. BACKGROUND

[0002] In today's rapidly evolving wireless communication technology, the performance of antennas, as the core components of wireless communication systems, directly affects the overall quality and transmission efficiency of communication systems. With the continuous progress of wireless communication technology, various communication protocols and standards have emerged, including but not limited to Wi-Fi, Bluetooth, 4G, and the latest 5G technology. They are each allocated in a specific frequency band to meet the needs of different application scenarios. This diversified communication standard pattern poses unprecedented challenges to antenna design.

[0003] Traditionally, to adapt to these complex and variable communication frequency bands, wireless communication devices often need to integrate multiple antenna systems, each optimized for a specific frequency band. However, this approach not only significantly increases the physical space occupied by the device, but also brings problems of antenna coupling and mutual interference. The coupling effect between antennas can cause loss of signal energy and degradation of signal quality, while interference can cause communication errors, reducing system stability and reliability.

[0004] Although certain progress has been made in the field of antenna technology, research on differential feed filtering antennas that can effectively cover dual or even multiple frequencies and have wideband characteristics is still relatively scarce. Differential feed technology is of great interest due to its ability to effectively suppress common-mode noise and improve signal integrity, but its application in realizing wideband dual-frequency filtering antennas is still immature. Most existing research focuses on the design of single-band or narrow-band dual-frequency antennas, which cannot meet the comprehensive requirements of modern wireless communication systems for high spectral efficiency, low interference, and high stability.

[0005] Therefore, developing a differential feed filtering antenna that can adapt to multiple communication protocols and standards, effectively reduce antenna coupling and interference in a limited space, and achieve dual-frequency wideband characteristics has become a technical problem that needs to be solved in the field of wireless communication. Such antenna design will greatly promote the development of wireless communication technology and improve the overall performance and user experience of communication systems. SUMMARY

[0006] Therefore, the purpose of the present application is to provide a dual-frequency wideband Vivaldi differential feed filtering antenna.

[0007] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0008] The application discloses a dual-frequency broadband Vivaldi differential feed filtering antenna, which comprises a dielectric substrate, a metal microstrip feed line layer, a metal radiation surface and two SMA coaxial feeders, the metal radiation surface is arranged on one surface of the dielectric substrate, the metal microstrip feed line is arranged on the other surface of the dielectric substrate, the metal radiation surface is provided with a double-exponential curve gradually changing groove, a first rectangular groove and a pair of circular grooves, the first rectangular groove is arranged along the width direction of the dielectric substrate, and the two circular grooves are respectively communicated with two ends of the first rectangular groove; the double-exponential curve gradually changing groove has top edges and bottom edges which are parallel to each other and two symmetrically distributed exponential curve shaped side edges, the top edges of the double-exponential curve gradually changing groove are flush with the first rectangular groove, and the bottom edges are flush with the width edges of the dielectric substrate; the metal microstrip feed line layer comprises a pair of metal microstrip feed lines, each metal microstrip feed line comprises a rectangular microstrip feed line and a sector-shaped microstrip feed line which are arranged along the length direction of the dielectric substrate, one end of the rectangular microstrip feed line is short-circuited with the SMA coaxial feeder, the other end is connected with the sector-shaped microstrip feed line, and the intersection of the rectangular microstrip feed line and the sector-shaped microstrip feed line of the two metal microstrip feed lines forms a cross-coupling structure with the first rectangular groove of the metal radiation surface; in the case that the two SMA coaxial feeders supply power to the two metal microstrip feed lines in a differential feeding mode, the sector-shaped microstrip feed lines of the two metal microstrip feed lines generate half-wave length and full-wave length resonances respectively, thereby generating two radiation zeros, and two passbands are obtained.

[0009] Further, according to the double-exponential curve gradually changing groove, two symmetric double-exponential curve contours are formed on the metal radiation surface, and the connection positions of the double-exponential curve contours and the first rectangular groove are perpendicular to each other.

[0010] Further, the metal radiation surface is symmetrically provided with a rectangular groove group and a second rectangular groove on both sides close to the double-exponential curve contours, the rectangular groove group comprises a plurality of rectangular grooves, the lengths of the plurality of rectangular grooves are different but the intervals are the same, the second rectangular groove has a length greater than that of all the rectangular grooves in the rectangular groove group, and all the rectangular grooves in the rectangular groove group and the second rectangular groove are arranged along the width direction of the dielectric substrate.

[0011] Further, the rectangular microstrip feed lines of the two metal microstrip feed lines are provided with short-circuit branches extending to both sides, the short-circuit branches are provided with metal rings at the ends, the dielectric substrate is provided with metalized through holes penetrating the metal rings on both sides, and the metalized through holes communicate the metal rings with the metal radiation surface.

[0012] Further, the thicknesses of the metal radiation surface and the metal microstrip feed line layer are 0.010mm-0.025mm, the material of the metal radiation surface and the metal microstrip feed line layer is copper, the thickness of the dielectric substrate is 1mm-2mm, the dielectric constant of the dielectric substrate is 2.2-3.5, the dielectric loss tangent of the dielectric substrate is 0.001-0.002, the thickness of the SMA coaxial feeder is 0.5mm-1mm, the material of the SMA coaxial feeder is copper, the dielectric constant of the SMA coaxial feeder is 2.2-3.5, and the dielectric loss tangent of the SMA coaxial feeder is 0.001-0.002. e r Between 3 and 4, the loss tangent is 0.003-0.004.

[0013] Further, the length L of the dielectric substrate and the metal radiating surface is 234.1mm~235.1mm, and the width W is 206.5mm~207.5mm;

[0014] The top edge W3 of the double-exponential curve metal groove is 9.39mm~10.39 mm, and the bottom edge is consistent with the width W of the dielectric substrate;

[0015] The distance W1 between the centers of the circular grooves at the two ends of the first rectangular groove is 72.5mm~73.5mm, the radius R1 of the circular groove is 4.1mm~5.1mm, the distance L2 between the center of the circular groove and the width edge of the installed SMA coaxial feeder is 18mm~19mm, the length L7 of the first rectangular groove is the center distance minus twice the radius, that is, L9=W1-2·R1, and the width W7 of the first rectangular groove is 0.18mm~0.28mm.

[0016] Further, the distance W2 between the rectangular microstrip feed lines of the two metal microstrip feed lines is 47.8mm~48.8mm, the length L3 of the rectangular microstrip feed line is 19.2mm~20.2mm, and the width W8 of the rectangular microstrip feed line is 2.7mm~3.7mm;

[0017] The radius R2 of the sector-shaped microstrip feed line is 31.7mm~32.7mm, and the included angle α of the sector-shaped microstrip feed line is 66°~76°.

[0018] Further, the distance L5 from the end of the longest rectangular groove in the rectangular groove group away from the double-exponential curve profile to the symmetric central axis of the metal radiating surface is 17.5mm~18.5mm, the distance L4 from the end of the shortest rectangular groove in the rectangular groove group away from the double-exponential curve profile to the symmetric central axis of the metal radiating surface is 17mm~18mm, the loading interval W5 of the rectangular grooves in the rectangular groove group is 0.65mm~0.75mm, and the width W4 of the rectangular grooves in the rectangular groove group is 0.45mm~0.55mm;

[0019] The distance L6 from the end of the second rectangular groove away from the double-exponential curve profile to the symmetric central axis of the metal radiating surface is 27.1mm~28.1mm, and the width W6 of the second rectangular groove is 0.16mm~0.26mm; the distance L1 from the second rectangular groove to the center of the first rectangular groove and the circular groove is 48.1mm~49.1mm.

[0020] Further, the extension length L7 of the short-circuit stub is 12.9mm~13.9mm, and the width W9 of the short-circuit stub is 0.15mm~0.25mm;

[0021] The outer radius R4 of the metal ring on the short-circuit branch is 0.34mm~0.44mm, and the inner radius R3 of the metalized via on the dielectric substrate is 0.15mm~0.25mm.

[0022] Further, the SMA coaxial feeder comprises an inner core wire, an insulating layer, an outer conductor and a sheath, wherein the inner core wire is connected with the rectangular microstrip feed line of the metal microstrip feed line.

[0023] The present application has the advantages of:

[0024] (1) The present application changes the traditional Vivaldi antenna feed structure, changes the single-port feed into double-port differential feed, which is conducive to integration with common differential circuits and systems; and by changing the length of the microstrip feed line, the part of the microstrip feed line that exceeds the upper surface rectangular slot can produce half-wave and full-wave resonances, two radiation zeros are generated in the original working frequency band, and the traditional single working frequency band Vivaldi antenna is changed into a double-frequency wideband Vivaldi antenna.

[0025] (2) The present application introduces a plurality of slots with different lengths on the inner side of the two radiation arms on the upper surface of the dielectric substrate, wherein the longest slot arranged separately generates a radiation zero point in the middle of the two working frequency bands, and the suppression effect of the middle stop band is enhanced; in addition, the six slots arranged at the same interval generate two radiation zeros outside the high frequency band, and the radiation outside the high frequency band is suppressed to improve the filtering performance.

[0026] (3) The present application introduces a half short-circuit branch on the side of the microstrip feed line, which generates another radiation zero point outside the high frequency band, further enhances the filtering performance, and eliminates the deterioration of the reflection coefficient |S dd11 | The antenna is simple in form, compact in structure and easy to integrate. On the one hand, high gain and wideband characteristics can play an important role in modern communication, radar and other fields, such as application in medical detection by combining antenna with microwave imaging technology; on the other hand, the antenna has filtering function, which can filter and process signals in a specific frequency range while receiving or transmitting signals, effectively suppresses interference signals and improves the overall performance and reliability of the wireless communication system; the double-frequency wideband characteristic enables it to support multiple frequency band communication requirements at the same time, meeting the flexible use of frequency band resources in modern wireless communication systems.

[0027] Other advantages, objects, and features of the present application will be understood in view of the following specification, and will be apparent to those skilled in the art from the teachings of the following specification and the accompanying drawings. The objects and other advantages of the present application can be realized and attained by the embodiments particularly pointed out in the specification. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below with reference to the accompanying drawings, in which:

[0029] Figure 1 1 is an overall schematic diagram of the dual-band broadband Vivaldi differential feed filter antenna of the present invention;

[0030] Figure 2 It is a combined top view and perspective view of the dual-band broadband Vivaldi differential feed filter antenna of the present invention;

[0031] Figure 3 2 is a front view of the dual-band broadband Vivaldi differential feed filter antenna of the present invention;

[0032] Figure 4 The frequency and reflection coefficient of the dual-band broadband Vivaldi differential feed filter antenna under differential signal excitation |S dd11 | and the relationship between achievable gain;

[0033] Figure 5 The achievable gain two-dimensional radiation pattern of the dual-band broadband Vivaldi differentially fed filter antenna of the present invention at 1.5 GHz in the low-frequency passband;

[0034] Figure 6 The present invention provides a two-dimensional radiation pattern of achievable gain at 4 GHz within the high-frequency passband of the dual-band, broadband Vivaldi differentially fed filter antenna.

[0035] Figure numerals: 0-dielectric substrate, 1-metal radiation surface, 2-circular slot, 3-first rectangular slot, 4-double exponential curve profile, 5-rectangular slot group, 6-double exponential curve gradient slot, 7-metal microstrip feed line, 8-short-circuit branch, 9-metallized through hole, 10-SMA coaxial feeder, 11-second rectangular slot. DETAILED DESCRIPTION

[0036] The following describes the embodiments of the present invention by means of specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0037] The drawings are only used for exemplary illustration, and the representation is only a schematic diagram, not a physical diagram, and cannot be understood as a limitation on the present application; in order to better illustrate the embodiments of the present application, some components of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0038] The same or similar reference numerals in the drawings of the embodiments of the present application correspond to the same or similar components; in the description of the present application, it should be understood that if the terms "upper", "lower", "left", "right", "front", "back" and the like indicate the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore the terms describing the positional relationship in the drawings are only used for exemplary illustration, and cannot be understood as a limitation on the present application, for those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0039] Please refer to Figures 1-6 , a dual-frequency wideband Vivaldi differential feed filtering antenna.

[0040] Embodiments

[0041] The embodiment provides a specific configuration mode of a dual-frequency wideband Vivaldi differential feeding filtering antenna, which comprises a dielectric substrate 0, a metal microstrip feeding line layer, a metal radiation surface 1 and two SMA coaxial feeders 10. The metal radiation surface 1 is arranged on one surface of the dielectric substrate 0, and the metal microstrip feeding line layer is arranged on the other surface of the dielectric substrate 0. The metal radiation surface 1 is provided with a double exponential curve gradually changing groove 6, a first rectangular groove 3 and a pair of circular grooves 2. The first rectangular groove 3 is arranged along the width direction of the dielectric substrate 0, and the two circular grooves 2 are respectively connected to the two ends of the first rectangular groove 3. The double exponential curve gradually changing groove 6 has top and bottom edges parallel to each other and two symmetrically distributed exponential curve side edges. The top edge of the double exponential curve gradually changing groove 6 is flush with the first rectangular groove 3, and the bottom edge is flush with the width edge of the dielectric substrate 0. The metal microstrip feeding line layer comprises a pair of metal microstrip feeding lines 7. Each metal microstrip feeding line 7 comprises a rectangular microstrip feeding line and a sector-shaped microstrip feeding line arranged along the length direction of the dielectric substrate 0. One end of the rectangular microstrip feeding line is short-circuited to the SMA coaxial feeder 10, and the other end is connected to the sector-shaped microstrip feeding line. The intersection of the rectangular microstrip feeding line and the sector-shaped microstrip feeding line of the two metal microstrip feeding lines 7 forms a cross-coupling structure with the first rectangular groove 3 of the metal radiation surface 1. In the case that the two SMA coaxial feeders 10 supply power to the two metal microstrip feeding lines 7 in a differential feeding mode, the sector-shaped microstrip feeding lines of the two metal microstrip feeding lines 7 generate half-wave and full-wave resonances respectively, and then generate two radiation zeros, thereby generating two passbands.

[0042] Specifically, the antenna comprises an upper surface Vivaldi metal radiation surface 1, a lower surface metal microstrip feed line 7, a dielectric substrate 0 and an SMA coaxial feeder 10, the upper surface Vivaldi metal radiation surface 1 is mainly formed by an upper surface first rectangular groove 3, a double exponential curve gradual groove 6 and a pair of circular grooves 2, the double exponential curve gradual groove 6 divides the metal radiation surface 1 into two radiation arms, the inner side of the radiation arm is excavated with a rectangular groove group 5 and a second rectangular groove 11, the double exponential curve gradual groove 6 intersects the first rectangular groove 3 perpendicularly, and the two ends of the first rectangular groove 3 are communicated with the circular grooves 2; the lower surface metal microstrip feed line 7 is composed of a pair of rectangular microstrip feed lines and a fan-shaped microstrip feed line, the rectangular microstrip feed line is used for short-circuiting the inner core wire exposed at the upper end of the SMA coaxial feeder 10; the SMA coaxial feeder 10 is powered by a 50Ω coaxial cable, and is excited in a mode of equal amplitude but opposite phase to realize the required differential feeding, the SMA coaxial feeder 10 comprises an inner core wire, an insulating layer, an outer conductor and a sheath; the other end of the rectangular microstrip feed line is connected with the fan-shaped metal microstrip line, the lower surface microstrip feed line 7 and the upper surface first rectangular groove 3 form a cross-coupling structure, the outer side of the lower surface microstrip feed line 7 is provided with a short-circuit stub 8, and the end of the short-circuit stub 8 is a metal ring; a metalized via hole 9 penetrates through the dielectric substrate 0 at the metal ring at the end of the short-circuit stub 8 and is communicated to the upper surface metal radiation surface 1; the dielectric substrate 0 is a single-layer structure.

[0043] In the embodiment, the thicknesses of the upper surface Vivaldi metal radiation surface 1, the lower surface microstrip feed line 7 and the short-circuit stub 8 are all 0.018 mm.

[0044] In the embodiment, the length L of the upper surface Vivaldi metal radiation surface 1 is 234.6 mm, the width W is 207 mm, the longest groove inside the two radiation arms is 48.6 mm away from the center of the circular groove, the distance L2 between the circular groove 2 and the edge of the Vivaldi radiation surface 1 is 18.5 mm, the distance W1 between the centers of the two circular grooves 2 is 73 mm, the radius R1 of the circular groove 2 is 4.6 mm, the width W8 of the first rectangular groove 3 connecting the circular grooves 2 is 3.2 mm, the distance L4 of the shortest groove inside the radiation arm from the center line is 17.5 mm, the distance L5 of the second longest groove from the center line is 18 mm, and the distance L6 of the longest groove from the center line is 27.6 mm; the width W6 of the longest groove is 0.21 mm, the width W4 of the other grooves is 0.5 mm, and the groove loading interval W5 is 0.7 mm.

[0045] In this embodiment, the spacing W2 between the rectangular microstrip feed lines in the lower surface metal microstrip feed line 7 is 48.3 mm, the length L3 of the rectangular microstrip feed line is 19.7 mm, and the width W8 of the rectangular microstrip feed line is 3.2 mm; the radius R2 of the fan-shaped microstrip feed line is 32.2 mm, and the included angle a of the fan-shaped microstrip feed line is 71°; the length L7 of the short-circuit stub 8 on the side of the rectangular microstrip feed line is 13.4 mm, the width W9 of the short-circuit stub 8 is 0.2 mm, the outer radius R4 of the metal ring at the end of the short-circuit stub is 0.39 mm, and the radius R3 of the metalized via 9 is 0.2 mm.

[0046] In this embodiment, the thickness H of the dielectric substrate 0 is 1.524 mm; the relative dielectric constant e r of the dielectric substrate 0 is 3.66, and the loss tangent is about 0.004 mm.

[0047] In a specific implementation, the metal radiation surface of a conventional Vivaldi antenna is modified. The modified upper surface Vivaldi metal radiation surface is mainly formed by the upper surface first rectangular groove 3, the double exponential curve gradual groove 6, and a pair of circular grooves 2. The lower surface microstrip feed line 7 also corresponds to a change from one to two, respectively connecting two SMA coaxial feeders 10 with equal amplitude and opposite differential signals. The microstrip feed line 7 and the upper surface first rectangular groove 3 form a cross-coupled structure. The part of the microstrip feed line 7 beyond the upper surface first rectangular groove 3 can produce half-wave and full-wave resonances, resulting in two radiation zeros, which makes the antenna change from one to two in the working frequency band. The double exponential curve gradual groove 6 divides the radiation surface into two radiation arms. The inner sides of the two radiation arms are loaded with a separately placed rectangular groove and six rectangular grooves with the same spacing. The separately placed rectangular groove serves to strengthen the suppression effect between the two passbands and expand the low-frequency band bandwidth. The six rectangular grooves with the same spacing serve to strengthen the filtering performance outside the high-frequency band. The lower surface microstrip feed line is composed of a rectangular microstrip feed line and a fan-shaped microstrip feed line. A pair of short-circuit half-stubs is introduced on the side of the microstrip line. The short-circuit stubs are connected to the upper surface radiation surface through the metalized via penetrating the substrate. The short-circuit stubs serve to strengthen the filtering performance outside the high-frequency band and eliminate the deterioration of the reflection coefficient |S dd11 | outside the high-frequency band. The configuration of the antenna is completely symmetrical with respect to the X axis. The purpose of this initiative is to enable the antenna to achieve a high common-mode suppression level.

[0048] The dielectric substrate 0 is a RO4350 plate with a thickness of 1.524 mm, a dielectric constant e r = 3.66, and a loss tangent δ= 0.004.

[0049] For reference Figure 4It can be seen that the antenna has a -10dB impedance bandwidth of 1.15-2.48 GHz in the low frequency passband and 3.48-4.92 GHz in the high frequency passband under the excitation of the differential signal, and the gain curve shows that the antenna has good frequency selection characteristics and out-of-band suppression capability, and the peak gain in the passband can reach 10.0dBi.

[0050] Referring to Figures 5-6 It can be seen that the antenna has good and stable radiation performance. It shows low cross-polarization levels in both frequency bands, reaching -26dB and -35dB in the low frequency and high frequency, respectively. It can also be seen that the antenna is an end-fire antenna with front-to-back ratios of 18dB and 19dB in the low frequency and high frequency, respectively. It should be noted that most reported end-fire filter antennas are single-frequency, and it is difficult to achieve high bandwidth in the study of dual-frequency end-fire filter antennas. As can be seen from the above results, the antenna of the present application has good filtering response and excellent bandwidth in two frequency bands. In addition, since the Vivaldi antenna is used, it also has a peak gain of up to 10.0dBi and a low cross-polarization level.

[0051] The dual-band wideband antenna increases one working frequency band on the basis of the previous working frequency band, while ensuring the bandwidth in the working frequency band, so that the antenna can achieve good matching and efficient radiation in a wide frequency band, and can support multiple communication protocols or standards at the same time, greatly improving the flexibility, compatibility and communication quality of communication. The Vivaldi antenna plays an important role in wideband wireless communication systems. It has the characteristics of wide frequency band, symmetrical radiation pattern, low cross-polarization, etc. On the one hand, differential feeding technology is a feeding method that feeds two signals with opposite phases into two ports of the antenna. Compared with traditional single-ended feeding, differential feeding can significantly suppress common-mode noise and interference, improve the anti-interference ability and signal-to-noise ratio of the antenna, and is also easier to integrate with common differential circuits and systems. On the other hand, by introducing filtering function in the antenna design, signal filtering can be realized without adding additional filter components. This design not only helps to reduce the complexity and cost of the system, but also improves the anti-interference ability and stability of the system. In the dual-band antenna, two frequency bands are designed respectively to achieve more accurate filtering effect, thereby further optimizing the signal quality.

[0052] Finally, it should be pointed out that the above embodiments are only used to illustrate the technical solutions of the present application and not to limit it. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the spirit and scope of the present application, and they should be covered in the scope of the claims of the present application.

Claims

1. A dual-band, broadband Vivaldi differential feed filter antenna, characterized by: It at least comprises a dielectric substrate (0), a metal microstrip feed line layer, a metal radiation surface (1), and two SMA coaxial feeders (10), wherein the metal radiation surface (1) is provided on one surface of the dielectric substrate (0), and the metal microstrip feed line layer is provided on the other surface of the dielectric substrate (0), wherein: The metal radiation surface (1) is provided with a double exponential curve gradient groove (6), a first rectangular groove (3), and a pair of circular grooves (2), wherein the first rectangular groove (3) is provided along the width direction of the dielectric substrate (0), and the two circular grooves (2) are respectively connected to the two ends of the first rectangular groove (3); the double exponential curve gradient groove (6) has a top side and a bottom side that are parallel to each other and two symmetrically distributed exponential curve-shaped side sides, the top side of the double exponential curve gradient groove (6) is flush with the first rectangular groove (3), and the bottom side is flush with the width edge of the dielectric substrate (0); The metal microstrip feed line layer includes a pair of metal microstrip feed lines (7), wherein each metal microstrip feed line (7) includes a rectangular microstrip feed line and a fan-shaped microstrip feed line arranged along the length direction of the dielectric substrate (0), one end of the rectangular microstrip feed line is short-circuited with the SMA coaxial feeder (10), and the other end is connected to the fan-shaped microstrip feed line; The intersection of the rectangular microstrip feed lines and the fan-shaped microstrip feed lines of the two metal microstrip feed lines (7) forms a cross-coupling structure with the first rectangular slot (3) of the metal radiation surface (1). When the two SMA coaxial feeders (10) supply power to the two metal microstrip feed lines (7) in a differential feeding manner, the fan-shaped microstrip feed lines of the two metal microstrip feed lines (7) respectively generate half-wavelength and full-wavelength resonances, thereby generating two radiation zero points, thereby obtaining two passbands.

2. The dual-band, broadband Vivaldi differential feed filter antenna according to claim 1, characterized in that: According to the double exponential curve gradient groove (6), two symmetrical double exponential curve profiles (4) are formed on the metal radiation surface (1), and the connection between the double exponential curve profiles (4) and the first rectangular groove (3) is perpendicular to each other.

3. The dual-band, broadband Vivaldi differential feed filter antenna according to claim 2, characterized in that: A rectangular slot group (5) and a second rectangular slot (11) are symmetrically arranged on both sides of the metal radiation surface (1) near the double exponential curve profile (4), wherein the rectangular slot group (5) includes a plurality of rectangular slots, the lengths of the plurality of rectangular slots being different but the spacings being the same, and the length of the second rectangular slot (11) being greater than the lengths of all the rectangular slots in the rectangular slot group (5); and all the rectangular slots in the rectangular slot group (5) and the second rectangular slot (11) are opened along the width direction of the dielectric substrate (0).

4. The dual-band, broadband Vivaldi differential feed filter antenna according to claim 1, characterized in that: The rectangular microstrip feed lines of the two metal microstrip feed lines (7) are provided with short-circuit branches (8) extending to both sides, and the ends of the short-circuit branches (8) are provided with metal rings. The dielectric substrate (0) is provided with penetrating metallized through holes (9) at the metal rings on both sides, and the metallized through holes (9) connect the metal rings with the metal radiation surface (1).

5. The dual-band, broadband Vivaldi differential feed filter antenna according to claim 1, characterized in that: The thickness of the metal radiation surface (1) and the metal microstrip feed line layer are both 0.010mm~0.025mm; The thickness of the dielectric substrate (0) is 1mm~2mm, and the dielectric constant ɛ r Between 3 and 4, the loss tangent is 0.003~0.

004.

6. The dual-band, broadband Vivaldi differential feed filter antenna according to claim 1, characterized in that: The length L of the dielectric substrate (0) and the metal radiation surface (1) is 234.1 mm to 235.1 mm, and the width W is 206.5 mm to 207.5 mm; The top edge W3 of the double exponential curve metal groove is 9.39 mm to 10.39 mm, and the bottom edge is consistent with the width W of the dielectric substrate (0); The center distance W1 between the circular grooves (2) at both ends of the first rectangular groove (3) is 72.5 mm to 73.5 mm, and the radius R1 of the circular groove (2) is 4.1 mm to 5.1 mm; the distance L2 between the center of the circular groove (2) and the width edge of the SMA coaxial feeder (10) is 18 mm to 19 mm; the length L7 of the first rectangular groove (3) is the center distance minus twice the radius, that is, L9=W1-2·R1, and the width W7 of the first rectangular groove (3) is 0.18 mm to 0.28 mm.

7. The dual-band, broadband Vivaldi differential feed filter antenna according to claim 1, characterized in that: The distance W2 between the rectangular microstrip feed lines of the two metal microstrip feed lines (7) is 47.8 mm to 48.8 mm, the length L3 of the rectangular microstrip feed line is 19.2 mm to 20.2 mm, and the width W8 of the rectangular microstrip feed line is 2.7 mm to 3.7 mm; The radius R2 of the fan-shaped microstrip feed line is 31.7 mm to 32.7 mm, and the angle α of the fan-shaped microstrip feed line is 66° to 76°.

8. The dual-band, broadband Vivaldi differential feed filter antenna according to claim 3, characterized in that: The distance L5 between the end of the longest rectangular groove in the rectangular groove group (5) away from the double exponential curve profile (4) and the symmetric center axis of the metal radiation surface (1) is 17.5 mm to 18.5 mm, the distance L4 between the end of the shortest rectangular groove away from the double exponential curve profile (4) and the symmetric center axis of the metal radiation surface (1) is 17 mm to 18 mm, the loading interval W5 of the rectangular grooves in the rectangular groove group (5) is 0.65 mm to 0.75 mm, and the width W4 of the rectangular grooves in the rectangular groove group (5) is 0.45 mm to 0.55 mm; The distance L6 between the end of the second rectangular groove (11) away from the double exponential curve profile (4) and the symmetry center axis of the metal radiation surface (1) is 27.1 mm to 28.1 mm, and the width W6 of the second rectangular groove (11) is 0.16 mm to 0.26 mm; the distance L1 between the second rectangular groove (11) and the center of the first rectangular groove (3) and the circular groove (2) is 48.1 mm to 49.1 mm.

9. The dual-band, broadband Vivaldi differential feed filter antenna according to claim 4, characterized in that: The extension length L7 of the short-circuit branch (8) is 12.9 mm to 13.9 mm, and the width W9 of the short-circuit branch (8) is 0.15 mm to 0.25 mm; The outer radius R4 of the metal ring on the short-circuit branch (8) is 0.34 mm to 0.44 mm, and the inner radius R3 of the metallized through hole (9) on the dielectric substrate (0) is 0.15 mm to 0.25 mm.

10. The dual-band, broadband Vivaldi differential feed filter antenna according to claim 1, characterized in that: The SMA coaxial feeder (10) comprises an inner core wire, an insulating layer, an outer conductor and a sheath, wherein the inner core wire is connected to a rectangular microstrip feeder of a metal microstrip feeder (7).

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