A multi-frequency antenna and communication device

Abstract

The application provides a multi-frequency antenna and a communication device. The multi-frequency antenna comprises a reflecting plate, a first radiating unit and a second radiating unit, the first radiating unit and the second radiating unit are arranged on one side of the reflecting plate, and the first radiating unit is located between the reflecting plate and the second radiating unit. The first radiating unit comprises a first radiating part and a metal plate, and the metal plate is located between the first radiating part and the second radiating unit. The second radiating unit comprises a second radiating part and a metal ring, and the metal ring is located between the second radiating part and the metal plate. When the above structure is adopted, the size of the multi-frequency antenna as a whole can be reduced, and the first frequency band and the second frequency band have high isolation, so that the two frequency bands can work independently, the multi-frequency antenna can meet the miniaturization demand of the common antenna surface, the antenna works stably, and the efficiency is high.

Description

Technical Field

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

[0002] The current trend in base station antenna development is towards multi-frequency and multi-polarization to meet the needs of individual operators or the shared needs of multiple operators. However, in practical implementation, conventional multi-frequency antennas typically require large spacing between antennas to meet requirements such as isolation and radiation patterns. If the spacing between antennas is reduced, the mutual interference between frequency bands will increase significantly, leading to a noticeable deterioration in performance.

[0003] Taking dual-band antennas as an example, existing dual-band antennas typically employ a side-by-side (SBS) arrangement. The spacing between the radiating elements of the two bands is usually greater than 0.5 times the wavelength corresponding to the lower band's operating frequency, which satisfies the requirements for isolation and distortion-free radiation patterns between the two bands. However, this also leads to a significant increase in the width of the antenna array. To reduce the size of dual-band antennas, the radiating elements are often designed with broadband bandwidth, using a combiner to isolate the two sub-bands, thus achieving two independent bands at the port. However, due to the introduction of the combiner and its connecting lines, the insertion loss in the signal path increases significantly, and passive intermodulation (PIM) interference is generated in the transmitted signal path, resulting in a decrease in the signal-to-noise ratio of the entire antenna system. Summary of the Invention

[0004] This application provides a multi-frequency antenna and communication device to achieve a co-plane design of adjacent dual-band antennas in a small size.

[0005] In a first aspect, this application provides a multi-frequency antenna, including a reflector, a first radiating element, and a second radiating element. The first and second radiating elements are disposed on one side of the reflector, with the first radiating element located between the reflector and the second radiating element. The first radiating element includes a first radiating portion and a metal plate, with the metal plate located between the first radiating portion and the second radiating element. The second radiating element includes a second radiating portion and a metal ring, with the metal ring located between the second radiating portion and the metal plate.

[0006] The technical solution provided in this application uses a first radiating element as the radiating functional element of a first radiating unit, corresponding to the radiation and reception of a first frequency band, and a second radiating element as the radiating functional element of a second radiating unit, corresponding to the radiation and reception of a second frequency band. The first and second radiating elements are stacked, which can reduce the overall width of the multi-frequency antenna. Furthermore, a metal plate and a metal ring are provided between the first and second radiating elements. The metal plate can generate a resonant standing wave null at the far end of the first frequency band, and the metal ring can generate a resonant standing wave null at the near end of the second frequency band, so that the first and second frequency bands have a high degree of isolation, which meets the isolation requirements between the first and second frequency bands. The mutual interference between the first and second radiating elements is reduced, and the first and second radiating elements can be decoupled, ensuring that the two frequency bands can work independently. Moreover, due to the high degree of isolation between the first and second frequency bands, the distance between the first and second radiating elements can be smaller, that is, the overall height of the multi-frequency antenna can be smaller. Overall, multi-band antennas have a small width and height, a small overall size, and high isolation, enabling decoupling of adjacent frequency bands. They can be used as adjacent dual-band antennas (antenna arrays with isolation bandwidth of less than 5% between the two frequency bands), meeting the miniaturization requirements of dual-band antennas sharing the same sky plane. They are also free from PIM interference, have stable antenna operation, high efficiency, and a relatively simple manufacturing process.

[0007] In one specific implementation, the first radiating element has a first through-hole. The second radiating element further includes a balun, which is disposed on the reflector via the second radiating element. The balun passes through the first radiating element and is connected to the reflector via the first through-hole. The first through-hole allows the first and second radiating elements to be arranged coaxially, reducing the overall size of the multi-band antenna. Furthermore, the presence of the first through-hole can generate a resonant standing wave null at the near end of the first frequency band, improving the isolation between the first and second frequency bands and reducing mutual interference between them.

[0008] In the specific configuration of the first through-hole, the first radiating unit and the second radiating unit are stacked along the first direction, which forms an angle with the reflector. The perimeter of the first through-hole in the cross-section perpendicular to the first direction is greater than 1 / 10 of the wavelength corresponding to the lowest operating frequency of the first radiating unit's radiation band. This allows a resonant standing wave null point to be generated outside the highest frequency point of the first frequency band, i.e., a resonant standing wave null point can be generated near the end of the first frequency band, thus providing a high degree of isolation between the first and second frequency bands.

[0009] In one specific implementation, the sidewall of the metal plate perpendicular to the first direction has a second through hole, through which the balun passes. This allows the metal plate and the second radiating element to be arranged coaxially, thereby enabling both the first radiating element and the metal plate to be arranged coaxially with the second radiating element. This, in turn, allows the first radiating element and the second radiating element to be arranged coaxially, thus reducing the overall size of the multi-frequency antenna.

[0010] In one specific implementation, the side of the metal plate facing the second radiating element has an extension plate. The extension plate increases the reflective area of ​​the metal plate, thereby allowing the metal plate to have a larger reflective area with a smaller space occupation, and can enhance the confinement of the second frequency band electromagnetic waves.

[0011] When specifically setting the metal plate, the height of the extension plate along the first direction is greater than 1 / 12 of the wavelength corresponding to the lowest operating frequency of the first radiating unit's radiation band. This can generate a resonant standing wave null point at the far end of the first frequency band, increasing the isolation bandwidth between the first and second frequency bands.

[0012] In one specific implementation, a metal ring is fitted over the outside of the balun and is fixedly connected to the second radiating part. This facilitates the fixation of the metal ring.

[0013] In one specific implementation, the circumference of the metal ring in the plane perpendicular to the first direction is greater than half the wavelength corresponding to the lowest operating frequency of the second radiating element's radiation band. This creates a resonant standing wave null point near the second band, increasing the isolation bandwidth between the second and first bands, improving the isolation between them, and reducing their mutual interference.

[0014] In one specific implementation, the second radiating unit further includes a mounting plate, with the second radiating part fixedly connected to one side of the mounting plate and the metal ring fixedly connected to the other side of the mounting plate. The mounting plate facilitates the fixing of both the second radiating part and the metal ring.

[0015] In one specific feasible implementation, a feeding pin is provided on the side of the reflector facing the first radiating part, and the feeding pin is electrically connected to the first radiating part. This achieves power supply to the first radiating part and ensures stable operation.

[0016] In one specific implementation scheme, the first direction is perpendicular to the reflector. The first radiating element and the second radiating element are stacked vertically along the reflector, resulting in a compact overall antenna structure with minimal space occupation.

[0017] Secondly, this application provides a communication device, including a radio frequency processing unit and a multi-frequency antenna as described above, wherein the radio frequency processing unit is electrically connected to the multi-frequency antenna.

[0018] The technical solution provided in this application enables a multi-frequency antenna to achieve a co-plane design of adjacent dual-band antennas in a small size. Not only is the overall size of the antenna small, but the two frequency bands can also work independently. The multi-frequency antenna allows the communication equipment to stably achieve wireless communication on two frequency bands. When there are multiple multi-frequency antennas, wireless communication on more than two frequency bands can be stably achieved, resulting in higher working efficiency of the communication equipment. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a system architecture applicable to an embodiment of this application;

[0020] Figure 2 The above figure is a schematic diagram of the antenna feeding system of a base station according to one embodiment.

[0021] Figure 3 This is a schematic diagram of the structure of a base station antenna according to a possible embodiment of this application;

[0022] Figure 4 This is a three-dimensional structural diagram of a multi-frequency antenna according to a possible embodiment of this application;

[0023] Figure 5 This is a front view of a multi-frequency antenna according to a possible embodiment of this application;

[0024] Figure 6 for Figure 4 A structural breakdown diagram;

[0025] Figure 7 This is a schematic diagram of the structure of the second radiating unit in one possible embodiment of this application;

[0026] Figure 8 This is a simulation diagram of a multi-frequency antenna according to a possible embodiment of this application;

[0027] Figure 9 This is a simulation diagram of a multi-frequency antenna according to a possible embodiment of this application;

[0028] Figure 10 This is a schematic diagram illustrating the application of a multi-frequency antenna according to one possible embodiment of this application.

[0029] Figure label:

[0030] 10 - Antenna; 20 - Mount; 30 - Antenna adjustment bracket; 40 - Antenna cover; 50 - RF processing unit; 60 - Signal processing unit;

[0031] 70 - Cable; 12 - Reflector; 3 - Feed network; 31 - Transmission component; 32 - Calibration network; 33 - Shifter;

[0032] 34-Combiner; 35-Filter; 100-First radiating element; 200-Second radiating element; 101-First radiating section;

[0033] 102-Metal plate; 103-First through hole; 104-Second through hole; 105-Feeding pin; 106-Extension plate; 201-Barrel;

[0034] 202 - Second radiating section; 203 - Metal ring; 204 - Mounting plate. Detailed Implementation

[0035] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0036] To facilitate understanding, before introducing the multi-frequency antenna provided in the embodiments of this application, we will first introduce some antenna-related concepts:

[0037] Isolation: The ratio of the power of the signal transmitted by one antenna to the power of the signal received by another antenna. A certain level of isolation must be met between frequency bands (typically greater than 15 dB) for each band to operate independently.

[0038] Isolation bandwidth: The difference between the lowest frequency in the high-frequency band and the highest frequency in the low-frequency band, divided by the center frequency of the spacing band. The smaller the isolation bandwidth between frequency bands, the less isolated the frequency bands are.

[0039] Adjacent frequency dual-band array: an antenna array with an isolation bandwidth of less than 5% between the two frequency bands.

[0040] Figure 1 An exemplary schematic diagram of a system architecture applicable to an embodiment of this application is shown, such as... Figure 1 As shown, the system architecture may include wireless access network communication devices and terminals, such as, but not limited to, wireless access network communication devices and terminals. Figure 1The base station shown is used to enable wireless communication between the communication equipment and the terminal. This communication equipment can be located in a base station bubsystem (BBS), a UMTS terrestrial radio access network (UTRAN), or an evolved universal terrestrial radio access network (E-UTRAN), used for cell coverage of wireless signals to achieve connection between the terminal equipment and the wireless network radio frequency terminal. Specifically, the base station can be a base transceiver station (BTS) in a GSM or CDMA system, a base station (NodeB, NB) in a WCDMA system, an evolved NodeB (eNB or eNodeB) in an LTE system, a radio controller in a cloud radio access network (CRAN) scenario, or it can be a relay station, access point, vehicle-mounted equipment, wearable device, a base station in a 5G network, or a base station in a future evolved PLMN network, etc., for example, a new wireless base station. This application embodiment is not limited to these types of base stations.

[0041] Figure 2 The diagram above illustrates the structure of an antenna feeding system for a base station according to one embodiment. The base station antenna feeding system typically includes an antenna 10, a mast 20, and an antenna adjustment bracket 30. The base station antenna 10 includes an radome 40, which possesses excellent electromagnetic wave penetration characteristics in terms of electrical performance and can withstand the effects of harsh external environments in terms of mechanical performance, thus protecting the antenna system from external environmental influences. The radome 40 can be mounted on the mast 20 or a tower via the antenna adjustment bracket 30 to facilitate signal reception or transmission by the antenna 10.

[0042] Additionally, the base station may include a radio frequency (RF) processing unit 50 and a signal processing unit 60. For example, the RF processing unit 50 can be used to perform frequency selection, amplification, and down-conversion processing on the signal received by the antenna 10, converting it into an intermediate frequency (IF) signal or a baseband signal and sending it to the signal processing unit 60. Alternatively, the RF processing unit 50 can be used to up-convert and amplify the IF signal from the signal processing unit 60 or the IF signal, converting it into electromagnetic waves through the antenna 10 for transmission. The signal processing unit 60 can be connected to the feed structure of the antenna 10 via the RF processing unit 50, and is used to process the IF signal or baseband signal transmitted by the RF processing unit 50.

[0043] In one possible embodiment, such as Figure 2As shown, the radio frequency processing unit 50 can be integrated with the antenna 10, and the signal processing unit 60 is located at the far end of the antenna 10. In some other embodiments, the radio frequency processing unit 50 and the signal processing unit 60 can also be located at the far end of the antenna 10 simultaneously. The radio frequency processing unit 50 and the signal processing unit 60 can be connected via a cable 70.

[0044] More specifically, please refer to the following: Figure 2 and Figure 3 , Figure 3 This is a schematic diagram of the structure of a base station antenna according to a possible embodiment of this application. The base station antenna 10 can be connected to a feed network 3. The feed network 3 is typically composed of controlled impedance transmission lines. The feed network 3 can feed signals to the antenna 10 with a certain amplitude and phase, or send received signals to the base station signal processing unit 60 with a certain amplitude and phase. In addition, the feed network 3 can achieve different radiation beam directions through the transmission component 31, or be connected to the calibration network 32 to obtain the calibration signal required by the system. The feed network 3 may include a phase shifter 33 to change the maximum direction of antenna signal radiation. The feed network 3 may also be equipped with modules such as a combiner 34 (which can be used to combine signals of different frequencies into one path for transmission through the antenna 10; or, in reverse, can be used to divide the signals received by the antenna 10 into multiple paths according to different frequencies for transmission to the signal processing unit 50 for processing), and a filter 35 (used to filter out interference signals) to expand performance.

[0045] Antennas are the core components of base stations used to transmit and receive electromagnetic waves. Currently, the number of antennas on base stations is increasing, while available space is limited. Therefore, multi-band antennas integrating antenna arrays across multiple frequency bands are gradually becoming the mainstream development direction. In existing multi-band antennas, when the radiating elements are arranged side-by-side (SBS), the spacing between radiating elements in adjacent frequency bands needs to be greater than 0.5 times the wavelength corresponding to the lower frequency band's operating frequency to meet the requirements of isolation between adjacent frequency bands and no pattern distortion. This results in a significant increase in the width of the antenna array. While a broadband design for the radiating elements of a multi-band antenna reduces the antenna size, the introduction of combiners and their connecting lines significantly increases insertion loss in the signal path. Furthermore, passive intermodulation (PIM) signals are generated in the transmitted signal path, which interfere with the receiver, leading to a decrease in the signal-to-noise ratio of the entire antenna system.

[0046] Based on this, this application provides a multi-frequency antenna to achieve a co-plane design of adjacent dual-band antennas in a small size.

[0047] You can refer to them together. Figure 4 and Figure 5 , Figure 4 This invention illustrates a three-dimensional structural diagram of a multi-frequency antenna according to a possible embodiment of the present application. Figure 5 A front view of a multi-frequency antenna according to one possible embodiment of this application is shown. Figure 4 and Figure 5 As shown, in one possible embodiment of this application, the multi-frequency antenna includes a reflector 12, a first radiating element 100, and a second radiating element 200. The reflector 12 can also be referred to as a base plate, antenna panel, or metal reflective surface, etc. The reflector 12 can reflect and focus the antenna signal onto the receiving point. The first radiating element 100 and the second radiating element 200 can be disposed on one side of the reflector 12, which can enhance the antenna signal reception and transmission capabilities. Additionally, it can block and shield other electromagnetic waves from the back of the reflector 12 (in this application, the back of the reflector 12 refers to the side of the reflector 12 opposite to the side where the first radiating element 100 and the second radiating element 200 are disposed) from interfering with the antenna signal reception. Specifically, the first radiating element 100 and the second radiating element 200 can be stacked along a first direction to reduce the overall width of the multi-frequency antenna. The first direction can be the vertical direction of the reflector 12, that is, the first radiating element 100 and the second radiating element 200 can be arranged from top to bottom along the vertical direction of the reflector 12. It is understood that the first direction can also be a direction that forms other angles with the reflector 12, such as 80°, 70° or other angles with the reflector 12.

[0048] The first radiating unit 100 may include a first radiating part 101 and a metal plate 102, both of which can be fixedly connected to the reflector 12. Furthermore, the first radiating part 101 and the metal plate 102 may be stacked along a first direction, with the metal plate 102 located between the first radiating part 101 and the second radiating unit 200 in the first direction.

[0049] As one possible embodiment, the first radiating part 101 can be a patch antenna. The patch antenna is a plate-shaped directional antenna that has a radiation function and occupies less space. The patch antenna can be fabricated as a printed circuit board (PCB) structure, specifically including a metal layer and a dielectric layer, wherein the metal layer is fixed on the dielectric layer, and the radiation function is achieved by the metal layer.

[0050] In a specific configuration, the first radiating section 101 can be fed by a feeding pin 105. The feeding pin 105 can be fixed to the side of the reflector 12 facing the first radiating section 101, and the feeding pin 105 is electrically connected to the first radiating section 101. In practical applications, the feeding pin 105 can be an L-shaped feeding pin to achieve single-polarization differential feeding. There can be four feeding pins 105, all feeding the first radiating section 101, achieving four-point feeding and corresponding to two polarizations.

[0051] In addition to feeding the first radiating part 101, the feeding pin 105 also serves to support it. Specifically, the first radiating part 101 can be fixedly connected to the reflector 12 via the feeding pin 105, where direct contact allows for electrical connection. Alternatively, the first radiating part 101 and the feeding pin 105 can be electrically connected via coupling. In this case, the first radiating part 101 and the feeding pin 105 are not in direct contact, but rather have a gap between them. The first radiating part 101 can be fixedly connected to the reflector 12 via other non-conductive structural components.

[0052] refer to Figure 6 , Figure 6 It shows Figure 4 A structural breakdown diagram. (See diagram below.) Figure 6 As shown, in a specific implementation, the first radiating part 101 may have a first through-hole 103, which may be located in the central region of the first radiating part 101. To facilitate the explanation of the function of the first through-hole 103, the basic structure of the second radiating unit and the arrangement relationship between the second radiating unit and the first radiating part 101 will be introduced here: The second radiating unit may include a balun 201 and a second radiating part 202. The second radiating part 202 may be connected to the balun 201. The balun 201 may pass through the first radiating part 101 and be connected to the reflector 12 through the first through-hole 103, thereby connecting the second radiating part 202 to the reflector 12. This arrangement allows the first radiating part 101 and the second radiating part 202 to be arranged coaxially on the basis of the stacked arrangement, thereby further reducing the overall size of the multi-frequency antenna. It should be noted that the coaxial arrangement mentioned here is intended to indicate that the balun 201 connected to the second radiating part 202 passes through the first radiating part 101, and is not limited to the balun 201 having to be connected to the central region of the second radiating part 202, nor is it limited to the balun 201 having to pass through the central region of the first radiating part 101.

[0053] When specifically setting the first through hole 103, the shape of the first through hole 103 can be circular, or it can be various regular or irregular polygons, etc. It can be adapted according to actual needs. This application embodiment does not make specific limitations in this regard.

[0054] The perimeter of the first through-hole 103 in the cross-section perpendicular to the first direction can be greater than 1 / 10λ1, where λ1 is the wavelength corresponding to the lowest operating frequency of the first radiating element 100's radiation band, i.e., the wavelength corresponding to the lowest operating frequency of the first band. This allows a resonant standing wave null point to be generated outside the highest frequency point of the first band, i.e., a resonant standing wave null point can be generated near the end of the first band. The perimeter of the cross-section of the first through-hole 103 is defined as a. In actual settings, optionally, 1 / 10λ1 < a < 2λ1. For example, a can be λ1. The near end mentioned here refers to the section where the two operating frequency bands are close to each other; for the first band, the near end is close to the high-frequency band of the first band. In addition, this application also relates to the near end of the second band, which is close to the low-frequency band of the second band.

[0055] As one possible embodiment, the metal plate 102 can be made of metal. Alternatively, the plate structure of the metal plate 102 can be made of non-metallic material, in which case the outer surface of the plate structure is plated with a metal layer. The metal plate 102 can be fixedly connected to the reflector 12 through a non-conductive structural component.

[0056] In a specific implementation, an extension plate 106 can be provided on the side of the metal plate 102 facing the second radiating part 202, thereby increasing the reflective area of ​​the metal plate 102 and thus achieving a larger reflective area with a smaller space occupation. The metal plate 102 can be arranged perpendicular to the first direction, and the extension direction of the extension plate 106 can be perpendicular to the metal plate 102. Figure 6 The example illustrates that the metal plate 102 and the extension plate 106 are integrally rectangular parallelepiped structures without a top wall in the first direction; that is, the metal plate 102 and the extension plate 106 are integrally rectangular parallelepiped structures with an opening at the top in the first direction. Alternatively, the metal plate 102 and the extension plate 106 can also be integrally cubic or cylindrical structures with an opening at the top, etc. Figure 6As shown, the bottom wall of the metal plate 102 in the first direction may have a second through hole 104. The second through hole 104 may be located in the central region of the bottom wall of the metal plate 102. The balun 201 can pass through the metal plate 102 through the second through hole 104, thereby enabling the metal plate 102 and the second radiating part 202 to be arranged coaxially. In combination with the above, the embodiments of this application can realize that the first radiating part 101 and the metal plate 102 are both arranged coaxially with the second radiating part 202, that is, the first radiating unit 100 and the second radiating unit 200 can be arranged coaxially. Thus, the first radiating unit 100 and the second radiating unit 200 can be stacked and arranged coaxially, and the overall size of the multi-frequency antenna is small. It can be understood that the metal plate 102 may be provided with multiple extension plates 106 along the circumferential direction. Adjacent extension plates 106 can be connected to each other. At this time, the metal plate 102 and the extension plates 106 as a whole can be the above-mentioned cuboid structure without a top wall, or, adjacent extension plates 106 may not be connected to each other. It is understood that the extension plate 106 can be extended to form a small angle or be flush with the metal plate 102. For example, the extension plate 106 can be extended to be flush with the metal plate 102, at which time the metal plate 102 and the extension plate 106 are flat as a whole.

[0057] In practical use, on the one hand, the metal plate 102 can serve as a director for the first radiating section 101. By configuring the dimensions of the metal plate 102 and the extension plate 106, a resonant standing wave null point can be generated at the far end of the first frequency band, increasing the isolation bandwidth between the first and second frequency bands and improving the isolation between them. For example, the height of the extension plate 106 along the first direction can be greater than 1 / 12λ1, that is, the height of the extension plate 106 can be greater than 1 / 12 of the wavelength corresponding to the lowest operating frequency of the first frequency band, thus generating a resonant standing wave null point at the far end of the first frequency band. The height of the extension plate 106 along the first direction is defined as b. In actual settings, optionally, 1 / 12λ1 < b < 1 / 4λ1. For example, b can be 1 / 8λ1. It is understood that, in one embodiment, the height of the extension plate 106 along the first direction can be slightly larger; or, in another embodiment, when the height of the extension plate 106 along the first direction is slightly smaller, the vertical width of the metal plate 102 along the first direction can be appropriately increased to ensure that a resonant standing wave null point can be generated at the far end of the first frequency band, thereby increasing the isolation bandwidth between the first and second frequency bands. The height of the extension plate 106 and the width of the metal plate 102 can be flexibly configured according to simulation or actual test results. On the other hand, the metal plate 102 can also serve as an auxiliary reflector for the second radiating part 202, constraining the electromagnetic wave radiation of the second radiating part 202 from omnidirectional to directional, thereby further improving the isolation between the first and second frequency bands; and the extension plate 106 can also serve as an auxiliary reflector for the second radiating part 202, further strengthening the constraint on the electromagnetic waves of the second radiating part 202.

[0058] Following the basic introduction to the second radiating element above, a detailed description of the second radiating element will be provided below. Please refer to [link / reference needed] again. Figure 4 and Figure 5 The second radiating unit 200 may include a balun 201 and a second radiating section 202, and may also include a metal ring 203. One end of the balun 201 may be fixedly connected to the reflector 12, and the other end of the balun 201 may be fixedly connected to the second radiating section 202. The balun 201 can serve as a power supply structure to transmit electrical signals to the second radiating section 202, and to transmit electrical signals from the second radiating section 202 to back-end equipment. The metal ring 203 is located between the second radiating section 202 and the metal plate 102 in a first direction, and the metal ring 203 may be fixedly connected to either the balun 201 or the second radiating section 202.

[0059] As one possible embodiment, the second radiating part 202 can be a half-wave dipole antenna, which serves as the radiating functional element of the second radiating element 200, corresponding to radiating and receiving the second frequency band. Alternatively, the second radiating part 202 can also be a patch antenna.

[0060] In specific implementations, the metal ring 203 can be made of metal. Alternatively, the annular structure of the metal ring 203 can be made of non-metallic material, in which case the outer surface of the annular structure is plated with a metal layer. The metal ring 203 is fitted onto the outside of the balun 201. The metal ring 203 can be directly connected to the second radiating part 202, or it can be fixedly connected to the second radiating part 202 through a non-conductive structural component. That is, the relative position of the metal ring 203 and the second radiating part 202 can be fixed through a non-conductive structural component. In addition, the metal ring 203 can also be fixedly connected to the balun 201 through a non-conductive structural component, or the metal ring 203 can also be fixedly connected to the reflector 12 through a non-conductive structural component.

[0061] In practical applications, the plane containing the metal ring 203 can be perpendicular to the first direction. The dimensions of the metal ring 203 are adjusted so that its circumference on the plane perpendicular to the first direction is greater than half the wavelength corresponding to the lowest operating frequency of the second radiating unit 200's radiation band. This allows a resonant standing wave null point to be generated near the second frequency band, thereby increasing the isolation bandwidth between the second and first frequency bands, improving their isolation, and reducing their mutual interference. Furthermore, it reduces the mutual interference between the second radiating part 202 and the first radiating part 101, achieving decoupling between them.

[0062] In combination with the structure of the first radiation unit 100 described above, the first radiation unit 100 and the second radiation unit 200 can be stacked along the first direction. The first radiation part 101 and the metal plate 102 of the first radiation unit 100 can be stacked along the first direction, and the metal plate 102 can be located between the first radiation part 101 and the second radiation part 202 of the second radiation unit 200 in the first direction.

[0063] refer to Figure 7 , Figure 7 A schematic diagram of the structure of the second radiating element of a multi-frequency antenna according to a possible embodiment of this application is shown. Figure 7As shown, as a possible embodiment, based on the above embodiments, the second radiating unit may further include a mounting plate 204. The mounting plate 204 may be fixedly connected to the balun 201, and the second radiating part 202 may be fixedly connected to the mounting plate 204, thereby achieving a fixed connection between the second radiating part 202 and the balun 201. Exemplarily, the mounting plate 204 is fixedly connected to the balun 201, and the first side of the mounting plate 204 faces away from the first radiating unit, while the second side of the mounting plate 204 faces the first radiating unit. The second radiating part 202 may be fixedly connected to the first side of the mounting plate 204, and the metal ring 203 may be fixedly connected to the second side of the mounting plate 204.

[0064] In a practical implementation, the mounting plate 204 can be a PCB. The second radiating part 202 is electrically connected to the balun 201 through the mounting plate 204. In actual use, the second radiating part 202 is powered through the balun 201 and the mounting plate 204. In this case, the second radiating part 202 can be integrated onto the mounting plate 204, and the second radiating part 202 is part of the PCB. Similarly, the metal ring 203 can also be integrated onto the mounting plate 204.

[0065] The mounting plate 204 can be rectangular, square, circular, or elliptical, etc., and its specific shape can be adapted to the dimensions of the second radiating section 202. For example, Figure 7 The diagram illustrates a configuration where two second radiating sections 202 are arranged perpendicularly to each other. Each second radiating section 202 may include two mating radiating arms. When the lengths of the two second radiating sections 202 are equal, the mounting plate 204 can be square, and the two second radiating sections 202 can be arranged parallel to two mutually perpendicular sides of the mounting plate 204, or they can be arranged along two diagonals of the mounting plate 204; alternatively, the mounting plate 204 can be circular, and the two second radiating sections 202 can be arranged along two mutually perpendicular diameters of the mounting plate 204. When the lengths of the two second radiating sections 202 are unequal, the mounting plate 204 can be rectangular, and the two second radiating sections 202 can be arranged parallel to two mutually perpendicular sides of the mounting plate 204. Figure 7 This arrangement is shown; alternatively, the mounting plate 204 can be elliptical in shape, and the two second radiating portions 202 can be arranged along two mutually perpendicular axes of the mounting plate 204.

[0066] The shape of the metal ring 203 is not limited to a circular ring; it can also be a non-circular closed-loop structure. For example, the shape of the metal ring 203 can be the same as or similar to the shape of the mounting plate 204. When the mounting plate 204 is square, the metal ring 203 can also be square. Exemplarily, the cross-sectional dimension of the metal ring 203 in the vertical direction in the first direction can be approximately 0.5-1.5 times the cross-sectional dimension of the mounting plate 204 in the vertical direction in the first direction. Figure 7 The shape of the metal ring 203 is the same as that of the mounting plate 204, but the size of the metal ring 203 is slightly smaller than that of the mounting plate 204.

[0067] In conjunction with the above, in the multi-frequency antenna of this application embodiment, the first radiating part serves as the radiating functional element of the first radiating unit, corresponding to radiating and receiving electromagnetic waves of the first frequency band, and the second radiating part serves as the radiating functional element of the second radiating unit, corresponding to radiating and receiving electromagnetic waves of the second frequency band. The first and second radiating parts are stacked, which can reduce the overall width of the multi-frequency antenna, and the coaxial arrangement of the first and second radiating parts can further reduce the overall size of the multi-frequency antenna. Furthermore, a metal plate and a metal ring are disposed between the first and second radiating parts, wherein, for example... Figure 8 As shown in the figure (the horizontal axis represents frequency, and the vertical axis represents decibel value), the metal plate can generate a resonant standing wave null at the far end of the first frequency band, and the metal ring can generate a resonant standing wave null near the near end of the second frequency band. This provides a high degree of isolation between the first and second frequency bands, meeting the isolation requirements. The mutual interference between the first and second radiating parts is reduced, achieving decoupling between them and ensuring that the two frequency bands can operate independently. This allows it to be used as an adjacent-frequency dual-band antenna. Furthermore, the presence of the first through-hole can additionally generate a resonant standing wave null outside the highest frequency point of the first frequency band, i.e., a resonant standing wave null near the near end of the first frequency band. This makes the passband of the first frequency band steeper, further improving the isolation between the first and second frequency bands.

[0068] In this embodiment of the multi-frequency antenna, exemplarily, the first frequency band corresponding to the first radiating element can be 698-803MHz, and the second frequency band corresponding to the second radiating element can be 824-960MHz. The isolation bandwidth between the two frequency bands is less than 5%, meeting the requirements of an adjacent-frequency dual-band array. Furthermore, as... Figure 9As shown in the figure (the horizontal axis represents frequency, and the vertical axis represents decibel value), the arrangement of the metal plate and metal ring can achieve ideal isolation for both co-polarization and hetero-polarization of the two frequency bands. The isolation between the two frequency bands can reach more than 15dB, allowing each frequency band to operate independently. Overall, the multi-frequency antenna of this embodiment has a small size, high isolation, can achieve decoupling of adjacent frequency bands, can meet the miniaturization requirements of multi-frequency antennas sharing a common antenna surface, and has no PIM interference. It also boasts high antenna efficiency, simple manufacturing process, and low cost.

[0069] refer to Figure 10 , Figure 10 A schematic diagram illustrating the application of a multi-frequency antenna according to a possible embodiment of this application is shown. Figure 10 As shown in the embodiments of this application, when the base station includes multiple multi-frequency antennas, the multiple multi-frequency antennas can be arranged in a flat layout. Figure 10 The example illustrates a scenario where two multi-frequency antennas are arranged in a flat configuration. It can be understood that each multi-frequency antenna can have a separate reflector 12, or multiple multi-frequency antennas can share a single reflector 12.

[0070] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A multi-frequency antenna, characterized in that, It includes a reflector, and a first radiation unit and a second radiation unit disposed on one side of the reflector, wherein the first radiation unit is located between the reflector and the second radiation unit, wherein: The first radiating unit includes a first radiating part and a metal plate, wherein the metal plate is located between the first radiating part and the second radiating unit; The second radiating unit includes a second radiating part and a metal ring, wherein the metal ring is located between the second radiating part and the metal plate; The first radiating part has a first through hole; The second radiating unit further includes a balun, and the second radiating part is disposed on the reflector through the balun. The balun passes through the first radiating part and is connected to the reflector through the first through hole. The first radiating unit and the second radiating unit are stacked along a first direction, which is at an angle to the reflector. The perimeter of the first through hole in the cross section perpendicular to the first direction is greater than 1 / 10 of the wavelength corresponding to the lowest operating frequency of the first radiation element; The circumference of the metal ring in a plane perpendicular to the first direction is greater than 1 / 2 of the wavelength corresponding to the lowest operating frequency of the second radiating unit; The metal ring is fitted over the outside of the balun, and the metal ring is fixedly connected to the balun by a non-conductive structural component.

2. The multi-frequency antenna as described in claim 1, characterized in that, The metal plate has a second through hole, through which the balun passes.

3. The multi-frequency antenna as described in claim 2, characterized in that, The metal plate has an extension plate on the side facing the second radiating part.

4. The multi-frequency antenna as described in claim 3, characterized in that, The height of the extension plate along the first direction is greater than 1 / 12 of the wavelength corresponding to the lowest operating frequency of the first radiating unit.

5. The multi-frequency antenna as described in any one of claims 1 to 4, characterized in that, The metal ring is fitted onto the outside of the balun, and the metal ring is fixedly connected to the second radiating part.

6. The multi-frequency antenna according to any one of claims 1 to 4, characterized in that, The second radiating unit further includes a mounting plate, the second radiating part is fixedly connected to one side of the mounting plate, and the metal ring is fixedly connected to the other side of the mounting plate.

7. The multi-frequency antenna as described in any one of claims 1 to 4, characterized in that, A power supply pin is provided on the side of the reflector facing the first radiating part, and the power supply pin is electrically connected to the first radiating part.

8. The multi-frequency antenna according to any one of claims 1 to 4, characterized in that, The first direction is perpendicular to the reflector.

9. A communication device, characterized in that, It includes a radio frequency processing unit and a multi-frequency antenna as described in any one of claims 1 to 8, wherein the radio frequency processing unit is electrically connected to the multi-frequency antenna.

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