Low-frequency antenna, antenna array, and electronic device

Abstract

The application provides a low-frequency antenna, an antenna array and an electronic device. The low-frequency antenna comprises a dielectric substrate and a plurality of radiation units arranged on the dielectric substrate. Each radiation unit comprises a ring-shaped radiation element and a frequency selective surface arranged in the ring-shaped radiation element, and the frequency selective surface and the ring-shaped radiation element are insulated from each other. Each ring-shaped radiation element is provided with a gap. The low-frequency antenna provided by the application has a relatively wide wave transmission characteristic, and can realize relatively independent regulation and control.

Description

Technical Field

[0001] This application relates to the field of wireless communication technology, and in particular to a low-frequency antenna, antenna array, and electronic device. Background Technology

[0002] With the development of communication systems, more and more frequency bands are being used. Meanwhile, miniaturized antennas not only significantly save rooftop resources and reduce antenna system redundancy, but also effectively lower antenna construction costs. Therefore, miniaturized multi-band base station antennas have significant research and application value. For example, for 5G base station antennas, miniaturized multi-band base station antennas are an inevitable development trend to ensure compatibility with previous generations of communication systems and reduce antenna manufacturing costs. Among these, multi-band common-aperture base station antennas with interleaved arrangements are an effective miniaturized antenna solution. However, with interleaved arrangements, the low-frequency antenna blocks the high-frequency antenna. On the one hand, the scattering interference generated by the low-frequency antenna causes severe distortion of the high-frequency antenna's radiation pattern; on the other hand, the high-frequency antenna also generates common-mode interference to the low-frequency antenna, deteriorating the radiation performance of the low-frequency antenna.

[0003] In related technologies, low-frequency antenna designs based on Frequency Selective Surface (FSS) or filter stubs are commonly used to form staggered, multi-band, common-aperture antennas. FSS-based low-frequency antenna designs allow for independent control of the transmission frequency and the antenna's own operating performance (operating frequency, impedance characteristics, etc.), offering convenient and flexible design. However, a drawback is that it often only has one low point in the normalized radar cross section (RCS) (transmission frequency), resulting in narrow-band transmission characteristics. Filter stub-based low-frequency antenna designs offer stronger transmission frequency control. However, a disadvantage is that the filter stubs affect the antenna's own operating performance (operating frequency, impedance characteristics, etc.), causing the transmission frequency and the antenna's own operating performance to influence each other, making independent control difficult and complicating the design.

[0004] Therefore, how to provide a low-frequency antenna with a wide transmission range and relatively independent control has become a technical problem that urgently needs to be solved. Summary of the Invention

[0005] In view of the above, it is necessary to provide a low-frequency antenna with a wide transmission range and the ability to achieve relatively independent control.

[0006] The first aspect of this application provides a low-frequency antenna, including: a dielectric substrate; and a plurality of radiating elements disposed on the dielectric substrate, each radiating element including a ring radiating element and a frequency selective surface disposed in the ring radiating element, wherein the frequency selective surface is insulated from the ring radiating element, and each ring radiating element has a slit.

[0007] A second aspect of this application provides an antenna array including a ground surface, at least one high-frequency antenna, and at least one low-frequency antenna as described above. Both the low-frequency antenna and the high-frequency antenna are disposed on one side of the ground surface. The distance between the low-frequency antenna and the ground surface is greater than the distance between the high-frequency antenna and the ground surface, and the projected area of ​​the dielectric substrate of the low-frequency antenna on the ground surface partially covers the projected area of ​​the high-frequency antenna on the ground surface.

[0008] A third aspect of this application provides an electronic device, including a low-frequency antenna as described above or an antenna array as described above.

[0009] The low-frequency antenna provided in this application includes a dielectric substrate and a plurality of radiating elements disposed on the dielectric substrate. Each radiating element includes a ring radiating element and a frequency selective surface disposed within the ring radiating element, wherein the frequency selective surface is insulated from the ring radiating element, and each ring radiating element has a slot. In this way, by providing a frequency selective surface in the low-frequency antenna and creating a slot in the ring radiating element, the low-frequency antenna can provide two transmission bands within the normalized radar cross section (RCS) in the high-frequency band through the frequency selective surface and the slot, respectively. Simultaneously, the ring radiating element can excite the operating frequency band within the low-frequency band. Therefore, compared to low-frequency antennas in related technologies, this application can achieve dual-band transmission characteristics, effectively widening the radiation frequency band of the antenna array equipped with the low-frequency antenna. Furthermore, the low-frequency antenna provided in this application allows for adjustment of its transmission frequency band in the high-frequency band by adjusting the size and position of the frequency selection surface, and / or the width, size, and position of the slot. Simultaneously, the operating frequency band of the low-frequency antenna in the low-frequency band can be adjusted by adjusting the size, width, and length of the ring radiating element, or the feeding structure. Therefore, the low-frequency antenna provided in this application can achieve relatively independent control of the high-frequency transmission frequency band and the low-frequency operating frequency band, making the low-frequency antenna more flexible and valuable for engineering applications. Attached Figure Description

[0010] The present application will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0011] Figure 1 This is a plan view of an antenna array provided in one embodiment of this application.

[0012] Figure 2This is a plan view of several radiating units on a dielectric substrate in one embodiment of this application.

[0013] Figure 3 This is a schematic diagram of a gap in one embodiment of this application.

[0014] Figure 4 for Figure 1 A partial structural diagram of a low-frequency antenna.

[0015] Figure 5 This is a schematic diagram of the surface current distribution of the radiating element in the high-frequency band in the -45° polarization direction in one embodiment of this application.

[0016] Figure 6A This is a surface schematic diagram of an antenna in the related art, and the antenna is related to... Figure 1 The difference between the antenna arrays shown is that... Figure 6A The antenna shown does not include a low-frequency antenna.

[0017] Figure 6B This is a surface schematic diagram of an antenna in the related art, and the antenna is related to... Figure 1 The difference between the antenna arrays shown is that... Figure 6B The low-frequency antenna in the design does not have a frequency selectable surface or slots.

[0018] Figure 6C This is a surface schematic diagram of an antenna in the related art, and the antenna is related to... Figure 1 The difference between the antenna arrays shown is that... Figure 6C The low-frequency antenna in the middle does not have any gaps.

[0019] Figure 7 for Figure 6B , Figure 6C and Figure 1 The diagram shows the normalized RCS numerical curve of the antenna.

[0020] Figure 8A for Figure 6A , Figure 6B , Figure 6C and Figure 1 The diagram shows the half-power beamwidth of the antenna in the first polarization direction.

[0021] Figure 8B for Figure 6A , Figure 6B , Figure 6C and Figure 1 The diagram shows the half-power beamwidth of the antenna in the second polarization direction.

[0022] Figure 9A For individual ring radiating elements, adding FSS structures to ring radiating elements and Figure 1The S11 curves of the three low-frequency antennas in the low-frequency band.

[0023] Figure 9B For individual ring radiating elements, adding FSS structures to ring radiating elements and Figure 1 The S21 curves of the three low-frequency antennas in the low-frequency band.

[0024] Figure 10 For individual ring radiating elements, adding FSS structures to ring radiating elements and Figure 1 The antenna gain of the three low-frequency antennas in the low-frequency band.

[0025] Figure 11 This is a schematic block diagram of an electronic device provided in an embodiment of this application. Detailed Implementation

[0026] The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0027] It is understood that the connection relationships described in this application refer to direct or indirect connections. For example, the connection between A and B can be a direct connection between A and B, or an indirect connection between A and B through one or more other electrical components. For example, A can be directly connected to C, and C can be directly connected to B, thus achieving a connection between A and B through C. It is also understood that the "A connects to B" described in this application can be a direct connection between A and B, or an indirect connection between A and B through one or more other electrical components.

[0028] In the description of this application, unless otherwise stated, " / " means "or". For example, A / B can mean A or B. The "and / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A exists alone, A and B exist simultaneously, and B exists alone.

[0029] In the description of this application, the words "first," "second," etc., are used only to distinguish different objects and do not limit the quantity or order of execution, nor do they imply that they must be different. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0031] Some embodiments will now be described with reference to the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0032] With the development of communication systems, more and more frequency bands are being used. Meanwhile, miniaturized antennas not only significantly save rooftop resources and reduce antenna system redundancy, but also effectively lower antenna construction costs. Therefore, miniaturized multi-band base station antennas have significant research and application value. For example, for 5G base station antennas, miniaturized multi-band base station antennas are an inevitable development trend to ensure compatibility with previous generations of communication systems and reduce antenna manufacturing costs. Among these, multi-band common-aperture base station antennas with interleaved arrangements are an effective miniaturized antenna solution. However, with interleaved arrangements, the low-frequency antenna blocks the high-frequency antenna. On the one hand, the scattering interference generated by the low-frequency antenna causes severe distortion of the high-frequency antenna's radiation pattern; on the other hand, the high-frequency antenna also generates common-mode interference to the low-frequency antenna, deteriorating the radiation performance of the low-frequency antenna.

[0033] In related technologies, low-frequency antenna designs based on Frequency Selective Surface (FSS) or filter stubs are commonly used to form staggered, multi-band, common-aperture antennas. FSS-based low-frequency antenna designs allow for independent control of the transmission frequency and the antenna's own operating performance (operating frequency, impedance characteristics, etc.), offering convenient and flexible design. However, a drawback is that it often only has one low point in the normalized radar cross section (RCS) (transmission frequency), resulting in narrow-band transmission characteristics. Filter stub-based low-frequency antenna designs offer stronger transmission frequency control. However, a disadvantage is that the filter stubs affect the antenna's own operating performance (operating frequency, impedance characteristics, etc.), causing the transmission frequency and the antenna's own operating performance to influence each other, making independent control difficult and complicating the design.

[0034] Based on this, this application provides a low-frequency antenna, antenna array, and electronic device with a wide transparency characteristic and the ability to achieve relatively independent control, in order to solve at least one of the above-mentioned technical problems.

[0035] First, please refer to Figure 1 , Figure 1This is a plan view of an antenna array 100 provided in an embodiment of this application. The antenna array 100 includes at least one high-frequency antenna 10, at least one low-frequency antenna 20, and a ground surface 30. Both the high-frequency antenna 10 and the low-frequency antenna 20 are disposed on one side of the ground surface 30, with the short distance between the low-frequency antenna 20 and the ground surface 30 being greater than the distance between the high-frequency antenna 10 and the ground surface 30. That is, with the ground surface 30 as the bottom layer, the low-frequency antenna 20 is disposed above the high-frequency antenna 10. Furthermore, the projected area of ​​the low-frequency antenna 20 along the direction of gravity on the ground surface 30 partially covers the projected area of ​​the high-frequency antenna 10 along the direction of gravity on the ground surface 30. Thus, the high-frequency antenna 10 and the low-frequency antenna 20 are arranged in an alternating manner.

[0036] The low-frequency antenna 20 includes a dielectric substrate 21 and a plurality of radiating elements 22 disposed on the dielectric substrate 21. Please continue reading. Figure 2 Each radiating element 22 includes a ring radiating element 221 and a frequency selective surface 222 disposed within the ring radiating element 221. The frequency selective surface 222 is insulated from the ring radiating element 221. The ring radiating element 221 also has a slot 223, which can serve as a slot-shaped resonator. Thus, in the low-frequency antenna 20, two transmission bands can be provided within the normalized radar cross section (RCS) in the high-frequency band through the frequency selective surface 222 and the slot 223, while the ring radiating element 221 can excite the operating frequency band in the low-frequency band. Therefore, compared to low-frequency antennas in related technologies, this application can achieve dual-band transmission characteristics, effectively widening the radiation frequency band of the antenna array 100. Furthermore, the low-frequency antenna 20 provided in this application can adjust its transmission frequency band in the high-frequency band by adjusting the size and position of the frequency selection surface 222, and / or adjusting the width, size, and position of the slot 223. Simultaneously, the operating frequency band of the low-frequency antenna 20 in the low-frequency band can be adjusted by adjusting the size, width, length, or feeding structure of the ring radiating element 221. Therefore, the low-frequency antenna 20 provided in this application can achieve relatively independent control of the high-frequency transmission frequency band and the low-frequency operating frequency band, making the low-frequency antenna 20 more flexible and valuable for engineering applications.

[0037] Please refer to the following: Figure 2 In some embodiments, the frequency selection surface 222 includes a plurality of spaced-apart sheet conductors 2221, and the plurality of sheet conductors 2221 are arranged in an array structure. For example, please refer to Figure 1The frequency selective surface 222 may include four sheet conductors 2221, and the four sheet conductors 2221 are arranged in a 2×2 array structure. The sheet conductors 2221 may be made of metals with good conductivity, such as copper, or other conductive materials. This application does not limit the manufacturing material, shape, or number of the sheet conductors 2221 in the frequency selective surface 222.

[0038] In some embodiments, the annular radiating element 221 is generally square-shaped. The slit 223 does not obstruct the annular radiating element 221. That is, when the slit 223 is disposed on the annular radiating element 221, the slit 223 communicates with at most one of the inner or outer sides of the annular radiating element 221. The inner side refers to the side where the center O of the annular radiating element 221 is located, and the outer side refers to the side of the annular radiating element 221 away from the center O. Thus, since the slit 223 does not obstruct the annular radiating element 221, the current fed into the annular radiating element 221 can bypass the slit 223 and flow through the annular radiating element 221, thereby reducing the influence of the slit 223 on the low-frequency operating band excited by the annular radiating element 221 itself. In some embodiments, the annular radiating element 221 can also be a annular dipole.

[0039] Please see Figure 3 In some embodiments, the slit 223 is a continuous, bent slit, and after extending a first distance from the starting point a in a first direction (e.g., the X direction shown in the figure) on the annular radiating element 221, the slit 223 bends and extends a second distance in the opposite second direction (e.g., the -X direction shown in the figure), the bend continues to bend a third distance in the first direction, and then bends and extends a fourth distance in the second direction until the endpoint b. In some embodiments, the slit 223 is also symmetrical about the centerline L, and the straight line e between the starting point a and the endpoint b is perpendicular to the centerline L. Understandably, Figure 3 The X and -X directions shown are only used for the bending changes of the gap 223, and are not used to restrict the gap 223.

[0040] For example, the gap 223 may include a first slit 241, a second slit 242, a third slit 243, a fourth slit 244, a fifth slit 245, a sixth slit 246, and a seventh slit 247 connected sequentially. The first slit 241 and the seventh slit 247 are arranged adjacent to each other at intervals, with one end of the first slit 241 and the seventh slit 247 close to the fourth slit 244. The end of the first slit 241 close to the fourth slit 244 is the starting point a, and the end of the seventh slit 247 close to the fourth slit 244 is the ending point b. It is understood that this application does not limit the specific shape of the gap 223, and in other embodiments, the gap 223 may also be of other shapes.

[0041] Please refer to it again. Figure 2 In some embodiments, the annular radiating element 221 has two slits 223, and the two slits 223 are symmetrical about one of the diagonals of the annular radiating element 221.

[0042] Please refer to the following: Figure 4 The following content will further introduce the specific structure of the low-frequency antenna 20.

[0043] In one embodiment, the dielectric substrate 21 includes a first surface 211 and a second surface 212 that are opposite to each other. The first surface 211 is located on the side of the dielectric substrate 21 away from the high-frequency antenna 10. The annular radiating element 221 and the frequency selective surface 222 are disposed on the second surface 212 insulated from each other.

[0044] Furthermore, the low-frequency antenna 20 also includes a support member 25, a coaxial feed line 26, and a power supply unit 27. The support member 25 connects the ground surface 30 and the dielectric substrate 21, supporting the dielectric substrate 21 disposed on one side of the ground surface 30. The support member 25 may be made of an insulating material, such as plastic.

[0045] A coaxial feed line 26 is connected to a power supply unit 27 and is used to feed a power supply signal into the power supply unit 27. The power supply unit 27 is used to feed energy into the ring radiating element 221. The coaxial feed line 26 is disposed on the side of the dielectric substrate 21 near the second surface 212, and the power supply unit 27 is disposed on the first surface 211 of the dielectric substrate 21. In some embodiments, the power supply unit 27 may be a Y-type power supply structure used to power each radiating element 22, for example, it may be a ring radiating element 221 that couples current into the radiating element 22. Understandably, in some embodiments, the ground surface 30 may be disposed on the base plate 31. The coaxial feed line 26 receives the power supply signal via a power supply interface on the underside of the base plate 31. The base plate 31 and the dielectric substrate 21 may be made of FR4 PCB board with a dielectric constant of 4.7 and a loss tangent of 0.02. This application does not limit the specific parameters of the base plate and the dielectric substrate 21.

[0046] Understandably, the high-frequency antenna 10 is also provided with a corresponding feeding unit. Since the high-frequency antenna 10 is not the focus of this application, this application does not limit the specific structure of the high-frequency antenna 10, and will not elaborate on it here.

[0047] Please refer to it again. Figure 1In one embodiment of this application, the antenna array 100 may include four high-frequency antennas 10 and one low-frequency antenna 20. The low-frequency antenna 20 has four radiating elements 22 disposed on its dielectric substrate 21. The four radiating elements 22 form a 2×2 structure first array Array1. Two radiating elements 22 disposed along the first diagonal c of the first array Array1 form a first polarization unit, and the other two radiating elements 22 disposed along the second diagonal d of the first array Array1 form a second polarization unit. Each annular radiating element 221 has two slots 223, and the two slots 223 on each annular radiating element 221 in the first polarization unit are symmetrical along the first diagonal c, and the two slots 223 on each annular radiating element 221 in the second polarization unit are symmetrical along the second diagonal d. Two of the four high-frequency antennas 10 are disposed close to their corresponding two radiating elements 22 along the first diagonal c; the other two of the four high-frequency antennas 10 are disposed close to their corresponding other two radiating elements 22 along the second diagonal d. This allows the first array Array1 to form a ±45° dual-polarized radiation array, which is beneficial for improving the capacity of the wireless system and synthesizing high-gain directional beams.

[0048] Corresponding to the first array Array1, the feeding unit 27 can be a Y-type feeding structure, and two feeding units 27 are disposed on the first surface 211 of the dielectric substrate 21. The two feeding units 27 respectively couple and feed the corresponding first polarization unit and second polarization unit.

[0049] Thus, when current is fed into the antenna array 100 through the feeding unit 27, it is used to excite the first operating frequency band, the second operating frequency band, and the third operating frequency band. The first and second operating frequency bands are high-frequency bands; for example, the first and second operating frequency bands can be any two frequency bands in the range of 1710MHz to 2170MHz or higher. The third operating frequency band is a low-frequency band; for example, the third operating frequency band can be any frequency band in the range of 600MHz to 960MHz. This application does not limit the specific frequency range of the first, second, and third operating frequency bands.

[0050] In one embodiment, the slit 223 is disposed at a first position on the annular radiating element 221, and the position where the surface current distribution of the annular radiating element 221 is maximum at high frequencies at least partially overlaps with the first position. This facilitates resonance of the slit 223 at high frequencies, thereby providing a corresponding high-frequency transmission band. For example, please refer to [further details omitted]. Figure 5 , Figure 5 This is a schematic diagram of the surface current distribution of each annular radiating element 221 in the low-frequency antenna 20 of one embodiment of this application in the mid-to-high frequency band along the -45° polarization direction. (Combined with...) Figure 1 and Figure 5 It can be seen that, Figure 1 In the first array Array1, the first position P of the slot 223 in the annular radiating element 221 located at the upper left and lower right corners is... Figure 5 The locations of maximum surface current distribution in the low-frequency antenna 20 at least partially overlap. Similarly, the surface current distribution diagram of each annular radiating element 221 in the low-frequency antenna 20 in the high-frequency band along the +45° polarization direction can be used to determine the location of maximum surface current distribution. Figure 1 In the first array Array1, the first position P where the slit 223 is located in the annular radiating element 221 at the upper right and lower left corners is... Figure 5 The locations of the maximum surface current distribution in the ring radiating elements 221 at least partially overlap. This application does not show a schematic diagram of the surface current distribution in the high-frequency band of each annular radiating element 221 in the +45° polarization direction.

[0051] Please continue reading. Figures 6A to 6C , Figure 6A This is a surface schematic diagram of an antenna in related technologies, and Figure 6A The antenna 100A shown is consistent with that in this application. Figure 1 The difference in the antenna array 100 shown is that, Figure 6A The low-frequency antenna 20 is not included in the antenna 100A shown. Figure 6B The antenna 100B shown is in Figure 6A The antenna shown is obtained by adding a low-frequency antenna to the antenna 100A. Figure 6B The antenna 100B shown is... Figure 1 The difference between the antenna array 100 shown is that... Figure 6B The low-frequency antenna in the middle does not have a frequency selection surface 222 and a slot 223. Figure 6C The antenna 100C shown is in Figure 6B The antenna 100B shown is obtained by setting a frequency selective surface on a low-frequency antenna. Figure 6C The antenna 100C shown is Figure 1 The difference between the antenna array 100 shown is that... Figure 6C The low-frequency antenna in the middle does not have a gap 223.

[0052] Please see Figure 7 , Figure 7 for Figure 6B , Figure 6C and Figure 1The diagram shows a schematic of the normalized RCS value of the antenna. Understandably, measuring the radar cross section (RCS) is an important method for studying the electromagnetic scattering characteristics of a target. It represents the target's ability to reflect radar signals in the radar receiving direction. The RCS of a target is equal to the ratio of the power reflected by the target per unit solid angle in the direction of the radar receiving antenna to the power density incident on the target. Those skilled in the art generally consider an antenna with a normalized RCS value ≤ -8 dB to have good wave transmission performance. Figure 7 As shown in the normalized RCS numerical curves, the antenna array 100 provided in this application, through the addition of the FSS structure, enables the low-frequency antenna 20 to have one frequency point within the high-frequency RCS range (e.g., 2100MHz~2170MHz). Furthermore, with the etched slot 223 within the ring radiating element 221, the low-frequency antenna 20 has another frequency point within the high-frequency RCS range (e.g., 1900MHz~2000MHz), and the overall RCS is also improved. Clearly, the antenna array 100 provided in this application possesses dual-band transparency characteristics.

[0053] Please see Figure 8A and Figure 8B , Figure 8A This is a schematic diagram of the half-power beamwidth of antennas 100A, 100B, 100C and antenna array 100 in the first polarization direction of the high-frequency band. Figure 8B This diagram illustrates the half-power beamwidth in the second polarization direction of antennas 100A, 100B, 100C, and antenna array 100. Half-power beamwidth (HPBW) is an important concept in antenna design. In an antenna pattern, the main lobe is the region where radiated energy is most concentrated. HPBW refers to the angle between two points on the main lobe where the power drops to half the peak power (i.e., a 3dB decrease), describing the degree of energy concentration in space. Figure 8A and Figure 8B As shown, with antenna 100A operating alone as a reference, antenna 100B itself does not play a role in repairing the half-power beamwidth of the high-frequency antenna. After the FSS structure is introduced into antenna 100C, the transmission performance of the high-frequency antenna is improved to a certain extent. The hybrid scheme proposed in this application, which is based on the FSS structure and simultaneously etches a slot 223 on the ring radiating element 221 of the low-frequency antenna, has a better effect on the transmission performance of the high-frequency antenna in both the first polarization direction and the second polarization direction.

[0054] Please refer to the following: Figures 9A to 10 , Figure 9AThe S11 curves of a single ring radiating element, a ring radiating element with an added FSS structure, and the low-frequency antenna 20 of this application are shown in the low-frequency band. Figure 9B The S21 curves of a single ring radiating element, a ring radiating element with an added FSS structure, and the low-frequency antenna 20 of this application are shown in the low-frequency band. Figure 10 The diagram shows the antenna gain curves in the low-frequency band for a single ring radiating element, a ring radiating element with an added FSS structure, and the low-frequency antenna 20 of this application. From... Figure 9A , Figure 9B and Figure 10 It can be seen that the low-frequency antenna 20 can still excite the operating frequency band in the low-frequency band, indicating that the frequency selection surface 222 and etching gap 223 set in the low-frequency antenna 20 in this application will not affect the performance of the low-frequency antenna 20 in the low-frequency band. Thus, the low-frequency antenna 20 proposed in this application also has better impedance characteristics and antenna gain in the low-frequency band. Moreover, the low-frequency antenna 20 proposed in this application can achieve independent control of the transmission frequency and the operating performance (operating frequency, impedance characteristics, etc.) of the low-frequency antenna 20 itself.

[0055] Understandable. Figure 1 The antenna array 100 shown is only one of all embodiments involved in this application. This application does not limit the number or arrangement of the high-frequency antennas 10 and low-frequency antennas 20 in the antenna array 100. In some embodiments, the antenna array 100 can serve as a base station antenna.

[0056] Please see Figure 11 This application also provides an electronic device 300, including the low-frequency antenna 20 or antenna array 100 as provided in any of the above embodiments. The electronic device 300 may be, for example, a satellite communication device, a gateway device, etc., and this application does not limit the specific type of the electronic device 300.

[0057] In summary, compared to related technologies where antennas based on the FSS structure have only one frequency point in their normalized radar cross section (RCS) within the frequency band, the low-frequency antenna 20 provided in this application overcomes the limitation of the traditional FSS structure's single tuning scheme by creating a slot 223 on the vibrator arm (i.e., the ring radiating element 221) as a slot-type resonator. This allows the frequency selection surface 222 to provide one transmission frequency point, while the slot 223 provides another, thus achieving broadband or dual-band transmission characteristics. Simultaneously, etching the slot 223 on the ring radiating element 221 allows current to still flow through the metal surface beside the slot 223, reducing the impact on the operating performance of the ring radiating element 221 itself. Therefore, the hybrid scheme based on FSS and slot resonator adopted in this application can not only generate two RCS frequency points in the mid-to-high frequency band (e.g., 1710 MHz ~ 2170 MHz), but also achieve independent control of the transmission frequency and the low-frequency antenna's own operating performance (operating frequency, impedance characteristics, etc.) on this basis, which has very important engineering application value.

[0058] Those skilled in the art will understand that, without conflict, the technical features of this embodiment and implementation scheme can be combined arbitrarily.

[0059] This application is not limited to the specific embodiments described above. Those skilled in the art will readily understand that many alternative solutions exist for the test fixture without departing from the principles and scope of this application. The scope of protection of this application is determined by the claims.

Claims

1. A low-frequency antenna, characterized in that: include: Dielectric substrate; A plurality of radiating units are disposed on the dielectric substrate. Each radiating unit includes an annular radiating element and a frequency selective surface disposed in the annular radiating element. The frequency selective surface is insulated from the annular radiating element. Each annular radiating element has a slit, which serves as a slit-shaped resonator. The slit does not block the annular radiating element and is not connected to the inner or outer side of the annular radiating element. The gap is located at a first position on the annular radiating element, and the position where the surface current distribution of the annular radiating element is maximum in the high-frequency band at least partially overlaps with the first position. The frequency selection surface includes a plurality of sheet-like conductors spaced apart, and the plurality of sheet-like conductors are arranged in an array structure.

2. The low-frequency antenna according to claim 1, characterized in that: The slit extends a first distance in a first direction from the starting point on the annular radiating element, then bends and extends a second distance in the opposite second direction, then bends a third distance in the first direction, and then bends a fourth distance in the second direction until the end point.

3. The low-frequency antenna according to claim 2, characterized in that: The gaps are symmetrical about the center line, and the straight line between the starting point and the ending point is perpendicular to the center line.

4. The low-frequency antenna according to claim 2, characterized in that: The gap includes a first slit to a seventh slit connected in sequence. The first slit and the seventh slit are arranged adjacent to each other at intervals. One end of the first slit and the seventh slit are close to a fourth slit. The end of the first slit close to the fourth slit is the starting point, and the end of the seventh slit close to the fourth slit is the ending point.

5. The low-frequency antenna according to any one of claims 1 to 4, characterized in that: The annular radiating element has two slits, and the two slits are symmetrical about one of the diagonals of the annular radiating element.

6. The low-frequency antenna according to claim 1, characterized in that: The low-frequency antenna further includes a feeding unit. The dielectric substrate includes a first surface and a second surface that are opposite to each other. A plurality of the radiating elements are disposed on the second surface, and the feeding unit is disposed on the first surface. The feeding unit is used to feed each of the radiating elements.

7. The low-frequency antenna according to claim 1, characterized in that: The dielectric substrate is provided with four radiation units, which are arranged in a 2×2 array to form a first array. Two radiation units arranged along the first diagonal of the first array form a first polarization unit, and the other two low-frequency antennas arranged along the second diagonal of the first array form a second polarization unit. Each of the annular radiating elements in the first array has two slots, and the two slots on each of the annular radiating elements in the first polarization unit are symmetrical along the first diagonal, and the two slots on each of the annular radiating elements in the second polarization unit are symmetrical along the second diagonal.

8. An antenna array, characterized in that, The antenna array includes a ground surface, at least one high-frequency antenna, and at least one low-frequency antenna as described in any one of claims 1 to 7. The low-frequency antenna and the high-frequency antenna are both disposed on one side of the ground surface. The distance between the low-frequency antenna and the ground surface is greater than the distance between the high-frequency antenna and the ground surface. The dielectric substrate of the low-frequency antenna partially covers the projected area of ​​the high-frequency antenna on the ground surface.

9. The antenna array according to claim 8, characterized in that: The antenna array includes four high-frequency antennas and one low-frequency antenna. The low-frequency antenna has four radiating elements on its dielectric substrate. The four radiating elements are arranged in a 2×2 array to form a first array. Two of the four high-frequency antennas are arranged along the first diagonal of the first array, and the other two of the four high-frequency antennas are arranged along the second diagonal of the first array.

10. The antenna array according to claim 8, characterized in that: The antenna array is fed current to at least excite a first operating frequency band, a second operating frequency band, and a third operating frequency band, wherein the first and second operating frequency bands are high-frequency bands, and the third operating frequency band is a low-frequency band.

11. An electronic device, characterized in that: The electronic device includes a low-frequency antenna as claimed in any one of claims 1 to 7, or includes an antenna array as claimed in any one of claims 8 to 10.

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