Double-frequency broadband Vivaldi differential feed filtering antenna

Abstract

The invention relates to a dual-frequency broadband Vivaldi differential feed filtering antenna, and belongs to the field of wireless communication. The antenna comprises a dielectric substrate, a metal microstrip feeder line layer, a metal radiating surface and two SMA coaxial feeders. The metal radiating surface is provided with a double-index curve gradual change groove, a first rectangular groove and a pair of circular grooves, so that specific radiation characteristics are realized. The metal micro-strip feeder line layer is composed of a pair of feeder lines, and each feeder line comprises a rectangular micro-strip part and a fan-shaped micro-strip part and is connected with the SMA feeder. Through a differential feed mode, the fan-shaped parts of the two feed lines respectively generate half-wavelength and full-wavelength resonance to form two radiation zero points, so that the dual-frequency broadband characteristic is realized. According to the invention, the problem of frequency band adaptation under multiple communication protocols can be effectively solved, coupling and interference between antennas are reduced, and a new technical solution is provided for the field of wireless communication.

Description

Technical Field

[0001] The invention belongs to the field of wireless communications and relates to a dual-band broadband Vivaldi differential feeding filter antenna. Background Art

[0002] As wireless communication technology is changing with each passing day, antennas are the core components of wireless communication systems, and their performance is directly related to the overall quality and transmission efficiency of the communication system. With the continuous advancement of wireless communication technology, various communication protocols and standards have sprung up, including but not limited to Wi-Fi, Bluetooth, 4G and the latest 5G technology, each of which is allocated to operate in a specific frequency band to meet the needs of different application scenarios. This diversified communication standard landscape poses unprecedented challenges to antenna design.

[0003] Traditionally, in order to adapt to these complex and changing communication frequency bands, wireless communication devices often need to integrate multiple antenna systems, each of which is optimized for a specific frequency band. However, this approach not only significantly increases the physical footprint of the device, but also brings problems of coupling and mutual interference between antennas. The coupling effect between antennas will lead to loss of signal energy and degradation of signal quality, while interference may cause communication errors and reduce the stability and reliability of the system.

[0004] Although some progress has been made in the field of antenna technology, research on differentially fed filter antennas that can effectively cover dual-band or even multi-band and have broadband characteristics is still relatively scarce. Differential feeding technology has attracted much attention because it can effectively suppress common-mode noise and improve signal integrity, but its application in realizing broadband dual-band filter antennas is still immature. Most existing research focuses on the design of single-band or narrow-band dual-band antennas, which is difficult to meet the comprehensive requirements of modern wireless communication systems for high spectrum utilization, low interference and high stability.

[0005] Therefore, developing a differentially fed filter antenna that can adapt to multiple communication protocols and standards, effectively reduce antenna coupling and interference in a limited space, and achieve dual-band broadband characteristics has become a technical problem that needs to be solved in the current wireless communication field. Such an antenna design will greatly promote the development of wireless communication technology and improve the overall performance of the communication system and user experience. Summary of the invention

[0006] In view of this, an object of the present invention is to provide a dual-band broadband Vivaldi differential feeding filter antenna.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] A dual-band wideband Vivaldi differential feeding filter antenna, which at least comprises a dielectric substrate, a metal microstrip feeding line layer, a metal radiating surface and two SMA coaxial feeders, wherein the metal radiating surface is arranged on one surface of the dielectric substrate, and the metal microstrip feeding line is arranged on the other surface of the dielectric substrate, wherein the metal radiating surface is provided with a double exponential curve gradient groove, a first rectangular groove and a pair of circular grooves, wherein the first rectangular groove is opened along the width direction of the dielectric substrate, and the two circular grooves are respectively connected to the two ends of the first rectangular groove; the double exponential curve gradient groove has a top edge and a bottom edge parallel to each other and two exponential curve side edges symmetrically distributed, the top edge of the double exponential curve gradient groove is flush with the first rectangular groove, and the bottom edge is flush with the width edge of the dielectric substrate The metal microstrip feed line layer includes a pair of metal microstrip feed lines, wherein each metal microstrip feed line includes a rectangular microstrip feed line and a fan-shaped microstrip feed line 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, and the other end is connected to the fan-shaped microstrip feed line; the intersection of the rectangular microstrip feed line and the fan-shaped microstrip feed line of the two metal microstrip feed lines forms a cross-coupling structure with the first rectangular slot of the metal radiation surface, and when the two SMA coaxial feeders use a differential feeding method to supply power to the two metal microstrip feed lines, the fan-shaped microstrip feed lines of the two metal microstrip feed lines respectively generate half-wavelength and full-wavelength resonances, thereby generating two radiation zero points, thereby obtaining two passbands.

[0009] Furthermore, according to the double exponential curve gradient groove, two symmetrical double exponential curve contours are formed on the metal radiation surface, and the connection between the double exponential curve contour and the first rectangular groove is perpendicular to each other.

[0010] Furthermore, a rectangular groove group and a second rectangular groove are symmetrically arranged on both sides of the metal radiation surface near the double exponential curve contour, wherein the rectangular groove group includes a plurality of rectangular grooves, the lengths of the plurality of rectangular grooves are different but the spacings thereof are the same, and the length of the second rectangular groove is greater than the lengths 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 opened along the width direction of the dielectric substrate.

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

[0012] Furthermore, the thickness of the metal radiation surface and the metal microstrip feed line layer is 0.010 mm to 0.025 mm, and the material of the metal radiation surface and the metal microstrip feed line layer is metal copper; the thickness of the dielectric substrate is 1 mm to 2 mm, and the dielectric constant ε r Between 3 and 4, the loss tangent is 0.03 to 0.04.

[0013] Furthermore, the length L of the dielectric substrate and the metal radiation surface is 234.1 mm to 235.1 mm, and the width W is 206.5 mm to 207.5 mm;

[0014] 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;

[0015] The center distance W1 between the circular grooves at both ends of the first rectangular groove is 72.5mm~73.5mm, and the radius R1 of the circular groove is 4.1mm~5.1mm; the distance L2 from the center of the circular groove to the width edge of the 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 spacing W2 between the rectangular microstrip feed lines of the two metal microstrip feed lines 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;

[0017] 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°.

[0018] Furthermore, the distance L5 between the end of the longest rectangular groove in the rectangular groove group away from the double exponential curve profile and the symmetric central axis of the metal radiation surface 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 and the symmetric central axis of the metal radiation surface is 17 mm to 18 mm, the loading interval W5 of the rectangular grooves in the rectangular groove group is 0.65 mm to 0.75 mm, and the width W4 of the rectangular grooves in the rectangular groove group is 0.45 mm to 0.55 mm;

[0019] The distance L6 between the end of the second rectangular groove away from the double exponential curve profile and the symmetry center axis of the metal radiation surface is 27.1mm~28.1mm, and the width W6 of the second rectangular groove is 0.16mm~0.26mm; the distance L1 between the second rectangular groove and 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 branch is 12.9 mm to 13.9 mm, and the width W9 of the short-circuit branch is 0.15 mm to 0.25 mm;

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

[0022] Furthermore, 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 to a rectangular microstrip feed line of a metal microstrip feed line.

[0023] The beneficial effects of the present invention are:

[0024] (1) The present invention changes the feeding structure of the traditional Vivaldi antenna, converting the single-port feeding into a dual-port differential feeding, which is conducive to integration with commonly used differential circuits and systems; and by changing the length of the microstrip feeding line, the part that exceeds the rectangular slot on the upper surface can produce half-wavelength and full-wavelength resonance, thereby generating two radiation zero points in the original working frequency band, thereby converting the traditional single-band Vivaldi antenna into a dual-band broadband Vivaldi antenna.

[0025] (2) The present invention introduces multiple slots of different lengths on the inner side of the two radiating arms on the upper surface of the dielectric substrate, among which the longest slot, which is independently arranged, generates a radiation zero point in the middle of the two working frequency bands, thereby enhancing the suppression effect of the intermediate stop band; the other six slots arranged at the same intervals generate two radiation zero points outside the high frequency band, thereby suppressing the radiation outside the high frequency band and improving the filtering performance.

[0026] (3) The present invention introduces a half short-circuit branch on the side of the microstrip feed line to generate another radiation zero point outside the high-frequency band, further enhancing the filtering performance while eliminating the reflection coefficient |S dd11 | deterioration. The antenna is simple in form, compact in structure and easy to integrate. On the one hand, the high gain and broadband characteristics can play an important role in modern communications, radar and other fields. For example, it can be used in medical testing after combining the antenna with microwave imaging technology; on the other hand, the antenna has a filtering function, which can filter the signals within a specific frequency range while receiving or transmitting signals, effectively suppress interference signals, and improve the overall performance and reliability of the wireless communication system; its dual-band broadband characteristics enable it to support the communication needs of multiple frequency bands at the same time, meeting the flexible use of frequency band resources by modern wireless communication systems.

[0027] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE 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 in conjunction with the accompanying drawings, wherein:

[0029] Figure 1 It 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 It 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 |S of the dual-band broadband Vivaldi differential feed filter antenna under differential signal excitation of the present invention dd11 | and the relationship between achievable gain;

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

[0034] Figure 6 It is a two-dimensional radiation pattern of gain that can be achieved at 4 GHz in the high frequency passband of the dual-band broadband Vivaldi differential feed filter antenna described in the present invention.

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

[0036] The following describes the embodiments of the present invention by 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 only illustrate the basic concept of the present invention in a schematic manner, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0037] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size 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.

[0038] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "rear", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0039] See also Figure 1 to Figure 6 , which is a dual-band broadband Vivaldi differentially fed filter antenna.

[0040] Example

[0041] The present embodiment provides a specific configuration method of a dual-band broadband Vivaldi differential feeding filter antenna, which at least includes a dielectric substrate 0, a metal microstrip feeding line layer, a metal radiating surface 1 and two SMA coaxial feeders 10, wherein the metal radiating 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, wherein the metal radiating 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 parallel to each other and two exponential curve side sides symmetrically distributed, the top side of the double exponential curve gradient groove 6 is flush with the first rectangular groove 3, and the bottom side 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 line and the fan-shaped microstrip feed line 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, and when the two SMA coaxial feeders 10 use a differential feeding method to supply power to the two metal microstrip feed lines 7, 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 generating two passbands.

[0042] Specifically, the antenna includes a Vivaldi metal radiating surface 1 on the upper surface, a metal microstrip feed line 7 on the lower surface, a dielectric substrate 0 and an SMA coaxial feeder 10. The Vivaldi metal radiating surface 1 on the upper surface is mainly formed by digging a first rectangular groove 3, a double exponential curve gradient groove 6 and a pair of circular grooves 2 from the upper surface. The double exponential curve gradient groove 6 divides the metal radiating surface 1 into two radiating arms. A rectangular groove group 5 and a second rectangular groove 11 are dug on the inner side of the radiating arm. The double exponential curve gradient groove 6 intersects the first rectangular groove 3 perpendicularly, and the two ends of the first rectangular groove 3 are connected to the circular groove 2. The metal microstrip feed line 7 on the lower surface is composed of a pair of rectangular microstrip feed lines and a fan-shaped microstrip feed line. The rectangular microstrip feed line is used to The exposed inner core wire at the upper end of the SMA coaxial feeder 10 is short-circuited; the SMA coaxial feeder 10 is powered by a 50Ω coaxial cable and excited in an equal amplitude but opposite phase manner to achieve 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 feeder is connected to a fan-shaped metal microstrip line, the lower surface microstrip feeder 7 and the upper surface first rectangular slot 3 form a cross-coupling structure, and a short-circuit branch 8 is provided on the outer side of the lower surface microstrip feeder 7, and the end of the short-circuit branch 8 is a metal ring; the metallized through hole 9 penetrates the dielectric substrate 0 at the metal ring at the end of the short-circuit branch 8 and is connected to the metal radiation surface 1 on the upper surface; the dielectric substrate 0 is a single-layer structure;

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

[0044] In this embodiment, the length L of the Vivaldi metal radiation surface 1 on the upper surface is 234.6 mm, the width W is 207 mm, the distance L1 between the longest grooves on the inner side of the two radiation arms and the center of the circular groove is 48.6 mm, and 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, and 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 on the inner side of the radiation arm from the center line loading is 17.5 mm, the distance L5 of the second longest groove from the center line loading is 18 mm, and the distance L6 of the longest groove from the center line loading 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 loading interval W5 of these grooves is 0.7 mm.

[0045] In this embodiment, in the metal microstrip feed line 7 on the lower surface, the spacing W2 between the rectangular microstrip feed lines 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 angle α of the fan-shaped microstrip feed line is 71°; the length L7 of the short-circuit branch 8 on the side of the rectangular microstrip feed line is 13.4 mm, the width W9 of the short-circuit branch 8 is 0.2 mm, the outer radius R4 of the metal ring at the end of the short-circuit branch is 0.39 mm, and the radius R3 of the metallized through hole 9 is 0.2 mm.

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

[0047] In a specific implementation, the metal radiation surface of the traditional Vivaldi antenna is modified. The modified upper surface Vivaldi metal radiation surface is mainly formed by digging out the first rectangular groove 3, the double exponential curve gradient groove 6 and a pair of circular grooves 2 on the upper surface. The microstrip feed line 7 on the lower surface is also changed from one to two, respectively connected to two SMA coaxial feeders 10 with equal amplitude and opposite phase differential signals. The microstrip feed line 7 and the first rectangular groove 3 on the upper surface form a cross-coupling structure. The part of the microstrip feed line 7 that exceeds the first rectangular groove 3 on the upper surface can generate half-wavelength and full-wavelength resonances, generating two radiation zero points, so that the working frequency band of the antenna is changed from one to two. The double exponential curve gradient slot 6 divides the radiation surface into two radiation arms. The inner sides of the two radiation arms are loaded with a single rectangular slot and six rectangular slots placed at the same interval. The function of the single rectangular slot is to strengthen the suppression effect between the two passbands and expand the low-frequency bandwidth. The function of the six rectangular slots loaded at the same interval is to strengthen the filtering performance outside the high-frequency band. The microstrip feed line on the lower surface is composed of a rectangular microstrip feed line and a fan-shaped microstrip feed line. A pair of short-circuited half branches are introduced on the side of the microstrip line. The ends of the short-circuited branches are connected to the radiation surface of the upper surface through metalized through holes penetrating the substrate. The function of the short-circuited branches is to strengthen the filtering performance outside the high-frequency band and eliminate the reflection coefficient |S dd11 |Deterioration outside the high frequency band. The antenna configuration is completely symmetrical with respect to the X-axis, which is intended to achieve a high common-mode rejection level.

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

[0049] Reference Figure 4It can be seen that under differential signal excitation, the antenna has a -10dB impedance bandwidth with a low-frequency passband of 1.15-2.48GHz and a high-frequency passband of 3.48-4.92GHz. The gain curve can show that it has good frequency selection characteristics and out-of-band suppression capabilities, and the peak value in the passband can achieve a gain of 10.0dBi.

[0050] Reference Figure 5-6 , it can be seen that the antenna has good and stable radiation performance. Low cross-polarization levels are shown in both frequency bands, and the cross-polarization levels reach -26dB and -35dB at low and high frequencies respectively. It can also be seen that the antenna is an end-fire antenna with a front-to-back ratio of 18dB and 19dB at low and high frequencies respectively. It should be mentioned that most of the reported end-fire filtering antennas are single-frequency, and it is difficult to achieve high bandwidth in the research of dual-frequency end-fire filtering antennas. It can be seen from the above results that the antenna of the present invention has good filtering response and excellent bandwidth in two frequency bands. In addition, due to the use of the Vivaldi antenna, it also has a peak gain of up to 10.0dBi and a low cross-polarization level.

[0051] The dual-band broadband antenna not only adds a working frequency band to the previous working frequency band, but also guarantees the bandwidth within the working frequency band, so that the antenna can achieve good matching and efficient radiation within a wider frequency band, and can support multiple communication protocols or standards at the same time, greatly improving the flexibility, compatibility and communication quality of communication. Vivaldi antenna plays an important role in broadband wireless communication systems. It has the characteristics of wide bandwidth, symmetrical radiation pattern, and low cross-polarization. On the one hand, differential feeding technology is a feeding method that feeds two signals with opposite phases into the two ports of the antenna respectively. 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 easier to integrate with commonly used differential circuits and systems. On the other hand, by introducing filtering functions in the antenna design, signal filtering processing can be achieved 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, the two frequency bands are designed separately to achieve a more accurate filtering effect, thereby further optimizing the signal quality.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. A dual-band broadband Vivaldi differential feed filter antenna, characterized in that: It comprises at least 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 arranged on one surface of the dielectric substrate (0), and the metal microstrip feed line layer is arranged 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 edge and a bottom edge parallel to each other and two symmetrically distributed exponential curve-shaped side edges, the top edge of the double exponential curve gradient 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 feed line layer comprises a pair of metal microstrip feed lines (7), wherein each metal microstrip feed line (7) comprises 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 line and the fan-shaped microstrip feed line 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 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 profile (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 groove group (5) and a second rectangular groove (11) are symmetrically arranged on both sides of a metal radiation surface (1) near a double exponential curve profile (4), wherein the rectangular groove group (5) includes a plurality of rectangular grooves, the plurality of rectangular grooves have different lengths but the same spacing, and the second rectangular groove (11) has a length greater than the length of all the rectangular grooves in the rectangular groove group (5); and all the rectangular grooves in the rectangular groove group (5) and the second rectangular groove (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 0.010 mm to 0.025 mm; The thickness of the dielectric substrate (0) is 1 mm to 2 mm, and the dielectric constant ε r Between 3 and 4, the loss tangent is 0.003 to 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 central 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 central 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).

Images