A multi-frequency antenna and a communication device

Abstract

The present application discloses a multi-band antenna and a communication device, relating to the field of communication technologies. The multi-band antenna includes a reflector and a feeding structure. Among them, the reflector is provided with a slot, and the slot defines a strip conductor. At this time, one end of the strip conductor is still connected to other parts of the reflector to realize the grounding setting of the strip conductor. The feeding structure includes a microstrip line for a high-frequency antenna unit in the multi-band antenna. The microstrip line is located on one side of the reflector, and at least part of the projection of the microstrip line on the reflector falls within the contour range of the strip conductor. By using the multi-band antenna of the present application, the common-mode induced current generated on the high-frequency antenna unit can be effectively suppressed, so that the directivity parameters such as the polarization rejection ratio and gain stability of the low-frequency antenna unit are significantly improved. In addition, the impedance of each part of the microstrip line is continuous, which can improve the radiation efficiency and operating stability of the high-frequency antenna unit.

Description

Technical Field

[0001] This application relates to the field of communication technologies, and in particular, to a multi-band antenna and a communication device. Background Art

[0002] In communication devices such as base stations, a high-frequency antenna unit and a low-frequency antenna unit are usually configured at the same time. The high-frequency antenna unit has a large signal transmission capacity, and the low-frequency antenna unit has a strong signal anti-attenuation ability. In order to reduce the volume of the communication device, sometimes it is necessary to configure the high-frequency antenna unit and the low-frequency antenna unit in the same antenna array to form a multi-band antenna.

[0003] In a multi-band antenna, the distance between the high-frequency antenna unit and the low-frequency antenna unit is usually small. In this way, when the electromagnetic wave radiated by the low-frequency antenna unit is coupled to the high-frequency antenna unit, common-mode resonance will be generated in the high-frequency antenna unit, thereby exciting a low-frequency induced current in the radiation part and the reflector of the high-frequency antenna unit, and this induced current will further excite a low-frequency electromagnetic wave. This low-frequency electromagnetic wave will interact with the electromagnetic wave directly radiated by the low-frequency antenna unit, resulting in deterioration of the pattern parameters such as the gain stability and polarization rejection ratio of the low-frequency antenna unit. Summary of the Invention

[0004] This application provides a multi-band antenna and a communication device to improve the directional parameters such as the polarization rejection ratio and gain stability of the low-frequency antenna unit in the multi-band antenna.

[0005] In a first aspect, this application provides a multi-band antenna. The multi-band antenna includes at least one low-frequency antenna unit and at least one high-frequency antenna unit disposed in the same antenna array. There may be a low-frequency antenna unit and a high-frequency antenna unit arranged close to each other, and the maximum distance between the low-frequency antenna unit and the high-frequency antenna unit arranged close to each other is less than 0.5 times the wavelength of the low-frequency antenna unit. This wavelength can be understood as the wavelength at which the low-frequency antenna unit operates in a vacuum. When specifically setting the multi-band antenna, it may include a reflector and a feeding structure. Among them, a slot is provided on the reflector, and the slot defines a strip conductor. The strip conductor is a part of the reflector, and one end of it can be connected to other parts of the reflector to realize the grounding setting of the strip conductor. The feeding structure includes a microstrip line for the high-frequency antenna unit in the multi-band antenna. The microstrip line is located on one side of the reflector, and at least part of the projection of the microstrip line on the reflector falls within the contour range of the strip conductor.

[0006] In the multi - frequency antenna provided by the present application, the strip conductor forms a common - mode suppression inductance structure, which can couple the electromagnetic waves radiated by the low - frequency antenna unit to the high - frequency antenna unit and effectively suppress the common - mode induced current generated on the high - frequency antenna unit, so as to significantly improve the directivity parameters such as the polarization suppression ratio and gain stability of the low - frequency antenna unit. In addition, since the strip conductor is formed by slotting the reflector plate, that is, the strip conductor is part of the reflector plate, its processing technology is simple and no additional structure and assembly process are required, so the manufacturing cost of this multi - frequency antenna is relatively low.

[0007] Moreover, by adopting the technical solution of the present application, the influence of the common - mode suppression inductance structure formed by the strip conductor on the impedance continuity of the microstrip line can be avoided to ensure the impedance continuity at all parts of the microstrip line, thereby improving the radiation efficiency and working stability of the high - frequency antenna unit.

[0008] In a possible implementation manner of the present application, the specific wiring shape of the strip conductor is not limited. Exemplarily, the strip conductor can be wired in a straight - line shape, a serpentine shape or a zigzag shape. No matter what shape the strip conductor is wired in, in the wiring direction of the strip conductor, the length of the strip conductor can be greater than 1 / 20 of the wavelength of the low - frequency antenna unit (this wavelength can be understood as the wavelength when the low - frequency antenna unit operates in a vacuum environment) to effectively suppress the common - mode induced current generated on the high - frequency antenna unit.

[0009] In a possible implementation manner of the present application, in the direction perpendicular to the wiring of the strip conductor, the width of the strip conductor can be 0.2 - 5 times the width of the microstrip line. Exemplarily, in the direction perpendicular to the wiring of the strip conductor, the width of the strip conductor is 0.1 mm - 10 mm. In addition, the ratio of the length of the strip conductor in its wiring direction to the width of the strip conductor in the direction perpendicular to the wiring of the strip conductor can be greater than 5:1. In this way, on the basis of keeping the capacitance between the microstrip line and the strip conductor basically unchanged, the inductance ratio of the common - mode suppression inductance structure formed by the strip conductor can be made relatively large, so as to effectively suppress the common - mode induced current.

[0010] In a possible implementation manner of the present application, when specifically setting the feeding structure, the feeding structure can further include a feeding wire, which is respectively connected to the microstrip line and the strip conductor to feed the radiation part of the high - frequency antenna unit. In a specific embodiment, the feeding wire generally includes a signal conductor and a ground conductor, wherein the signal conductor can be connected to the microstrip line and the ground conductor is connected to the strip conductor.

[0011] In order to realize the connection between the feeding wire and the microstrip line, through - holes can be provided on the strip conductor to enable the feeding wire to pass through the through - holes and be connected to the microstrip line, thereby simplifying the structure of the multi - frequency antenna.

[0012] In addition, the feed structure may further include a feed connector, which may be disposed on the same side of the reflector as the microstrip line, and the microstrip line is connected to the feed connector. Thus, the feed connector may be connected to the feed circuit, and the RF signal may be transmitted to the radiating portion through the feed connector and the microstrip line for emission.

[0013] In one possible implementation of the present application, the slot can be a continuous slot arranged continuously, and the shape formed by the slot has a bottom and an open end. The multi-band antenna can also include a first jumper, which is arranged between the bottom and the open end, and the projection of the first jumper on the reflector divides the slot into two parts. In addition, the strip conductor can be located between the first jumper and the microstrip line, or the microstrip line can be located between the first jumper and the strip conductor, and the two ends of the first jumper are respectively located on the two sides of the slot facing away from the strip conductor, and the two ends of the first jumper are respectively connected to the reflector. In this way, the slot forms a short-circuit structure at the position of the first jumper, which is equivalent to shortening the dimension of the slot along the wiring direction of the strip conductor, thereby effectively reducing the leakage of high-frequency signals from the slot to the back of the reflector, thereby reducing the impact on the directional parameters of the high-frequency antenna unit, such as the front-to-back ratio, polarization suppression ratio, and gain stability.

[0014] In this implementation, the slot can be a first U-shaped slot, and the projection of the microstrip line on the reflector is inserted into the area defined by the first U-shaped slot. This ensures that the impedance of the microstrip line is continuous, thereby improving the radiation efficiency and operating stability of the high-frequency antenna unit.

[0015] Furthermore, to simplify the structure and manufacturing process of the multi-band antenna, the multi-band antenna can be configured based on a PCB structure. Specifically, the first jumper, reflector, and microstrip line can be disposed on different conductor layers of the printed circuit board. In this implementation, the two ends of the first jumper can be connected to the reflector through vias provided on the printed circuit board.

[0016] In another possible implementation of the present application, the slots may be configured as discontinuous slots. For example, the slots include a first slot portion and a second slot portion that are separated from each other. In this case, the strip conductor includes a first conductor portion and a second conductor portion that are connected to each other. In this implementation, the slots define the strip conductor, specifically: the first slot portion defines the first conductor portion, and the second slot portion defines the second conductor portion.

[0017] Among them, the first slotted portion can be a closed annular groove, and the second slotted portion can be a second U-shaped groove with an opening at one end, and the opening of the second U-shaped groove faces away from the annular groove. Since the first slotted portion and the second slotted portion are two non-connected ends, the part of the reflector located on the circumferential side of the slot is short-circuited and connected between the first slotted portion and the second slotted portion, which is equivalent to shortening the size of the slot along the wiring direction of the strip conductor, thereby effectively reducing the leakage of high-frequency signals from the slot to the back of the reflector, so as to reduce the influence on the directional parameters such as the front-to-back ratio, polarization suppression ratio, and gain stability of the high-frequency antenna element.

[0018] In order to realize the connection between the first conductor portion and the second conductor portion, the multi-band antenna can also include a second jumper, and both ends of the second jumper are respectively connected to the first conductor portion and the second conductor portion. In order to reduce the influence on the length of the wiring direction of the strip conductor, the equivalent inductance of the common-mode suppression inductance structure formed by the strip conductor does not change, so as to effectively suppress the common-mode induced current generated on the high-frequency antenna element, so that the directional parameters such as the polarization suppression ratio and gain stability of the low-frequency antenna element are significantly improved.

[0019] In this implementation manner, the multi-band antenna can also be arranged based on the structure of the PCB. Specifically, the reflector and the microstrip line can be respectively arranged on different conductor layers of the printed circuit board, and the second jumper and the microstrip line are located on the same conductor layer of the printed circuit board. In this implementation manner, both ends of the first jumper can be respectively connected to the reflector through vias opened on the printed circuit board. In this way, the number of conductor layers of the PCB can be avoided from increasing, thereby effectively reducing the cost of the multi-band antenna.

[0020] In addition, there can be two second jumpers, and the two jumpers are respectively arranged on both sides of the microstrip line. So that the return current of the microstrip line is continuous, thereby effectively improving the impedance continuity of each part of the microstrip line, and further improving the radiation efficiency and operating stability of the high-frequency antenna element.

[0021] By adjusting the distance between the second jumper and the microstrip line, the impedance of the microstrip line can be controlled. In a possible implementation manner, the distance between the second jumper and the microstrip line can be 0.1 to 10 times the thickness of the dielectric substrate of the PCB.

[0022] In a possible implementation manner of the present application, the reflector can also have a periodically arranged grid structure. At this time, the strip conductor can be arranged between the grid structures. Or, the strip conductor is arranged inside the grid structure. So that the multi-band antenna integrates functions such as directional reflection, spatial filtering, feeding, and common-mode suppression, and realizes the comprehensive optimization of the multi-band antenna.

[0023] In a second aspect, the present application further provides a communication device, which includes the multi-frequency antenna of the first aspect. The communication device may be, but is not limited to, a base station, a radar, or other devices. In this communication device, the common-mode suppression inductance structure formed by the strip conductor can effectively suppress the common-mode induced current generated on the high-frequency antenna unit in the multi-frequency antenna, so as to significantly improve the directivity parameters such as the polarization suppression ratio and gain stability of the low-frequency antenna unit. Moreover, the impedance of each part of the microstrip line is continuous, which can improve the radiation efficiency and operating stability of the high-frequency antenna unit. In addition, the manufacturing cost of this multi-frequency antenna is relatively low, thus effectively reducing the cost of the entire communication device. Description of the Drawings

[0024] Figure 1 Schematic structural diagram of an antenna feeding system provided by an embodiment of the present application;

[0025] Figure 2 Schematic structural diagram of a base station antenna provided by an embodiment of the present application;

[0026] Figure 3 Schematic distribution diagram of a multi-frequency antenna provided by the present application;

[0027] Figure 4a Pattern of the low-frequency antenna unit in the antenna array composed of low-frequency antenna units;

[0028] Figure 4b Pattern of the low-frequency antenna unit in the antenna array composed of low-frequency and high-frequency antenna units;

[0029] Figure 5 Schematic structural diagram of a multi-frequency antenna provided by an embodiment of the present application;

[0030] Figure 6 Schematic partial structural diagram of a multi-frequency antenna provided by an embodiment of the present application;

[0031] Figure 7 Schematic diagram of the equivalent circuit formed at the strip conductor provided by an embodiment of the present application;

[0032] Figure 8 Top view of the reflector provided by an embodiment of the present application;

[0033] Figure 9 Exploded view of a multi-frequency antenna provided by an embodiment of the present application;

[0034] Figure 10 Cross-sectional view of a multi-frequency antenna provided by an embodiment of the present application;

[0035] Figure 11aSchematic diagram of an antenna array composed of two low-frequency antenna elements provided by this application;

[0036] Figure 11b For Figure 11a Cross-sectional view;

[0037] Figure 11c For Figure 11a Pattern of the low-frequency antenna element in the antenna array shown;

[0038] Figure 12a Schematic diagram of an antenna array composed of two low-frequency antenna elements and eight high-frequency antenna elements provided by this application;

[0039] Figure 12b For Figure 12a Cross-sectional view of the antenna array shown;

[0040] Figure 12c For Figure 12a Pattern of the low-frequency antenna element in the antenna array shown;

[0041] Figure 13a Schematic diagram of an antenna array composed of two low-frequency antenna elements and eight high-frequency antenna elements provided by this application;

[0042] Figure 13b For Figure 13a Cross-sectional view of the antenna array shown;

[0043] Figure 13c For Figure 13a Pattern of the low-frequency antenna element in the antenna array shown;

[0044] Figure 14 Partial schematic diagram of a multi-frequency antenna provided by another embodiment of this application;

[0045] Figure 15 Partial schematic diagram of a multi-frequency antenna provided by another embodiment of this application;

[0046] Figure 16 For Figure 15 Cross-sectional view of the partial structure of the multi-frequency antenna provided;

[0047] Figure 17a Schematic diagram of an antenna array composed of eight high-frequency antenna elements provided by this application;

[0048] Figure 17b For Figure 17a Cross-sectional view of the antenna array shown;

[0049] Figure 17c For Figure 17aPattern of the high-frequency antenna element in the antenna array shown

[0050] Figure 18 Pattern of the high-frequency antenna element in another antenna array provided by the present application, which is composed of two low-frequency antenna elements and eight high-frequency antenna elements

[0051] Figure 19a Schematic structural diagram of another antenna array provided by the present application, which is composed of two low-frequency antenna elements and eight high-frequency antenna elements

[0052] Figure 19b For Figure 19a Pattern of the high-frequency antenna element in the antenna array shown

[0053] Figure 20 Exploded view of the partial structure of the multi-frequency antenna provided by another embodiment of the present application

[0054] Figure 21 Schematic diagram of the partial structure of the multi-frequency antenna provided by another embodiment of the present application

[0055] Figure 22 Schematic diagram of the partial structure of the multi-frequency antenna provided by another embodiment of the present application

[0056] Figure 23 Cross-sectional view of the multi-frequency antenna provided by another embodiment of the present application

[0057] Figure 24 Exploded view of the multi-frequency antenna provided by another embodiment of the present application

[0058] Figure 25 Schematic structural diagram of the multi-frequency antenna provided by another embodiment of the present application

[0059] Reference numerals

[0060] 10 - Antenna; 1 - Low-frequency antenna element; 2 - High-frequency antenna element; 101 - Radiation part; 1011 - Radiation surface reference dielectric substrate

[0061] 1012 - First radiation arm; 1013 - Second radiation arm; 1014 - Coupling feeding structure; 102 - Reflector; 1021 - Slot

[0062] 1021a - Bottom; 1021b - Open end; 1021c - First slot part; 1021d - Second slot part; 1022 - Strip conductor

[0063] 1022a - First conductor part; 1022b - Second conductor part; 10221 - Through hole; 1023 - Grid structure; 3 - Feeding structure

[0064] 301 - Transmission component; 302 - Calibration network; 303 - Phase shifter; 304 - Combiner; 305 - Filter; 306 - Microstrip line;

[0065] 307 - Feeder line; 3071 - Inner conductor; 3072 - Outer conductor; 308 - Feeding joint; 309 - Dielectric substrate;

[0066] 4 - First jumper; 5 - Second jumper; 20 - Mast; 30 - Antenna adjustment bracket; 40 - Radome;

[0067] 50 - RF processing unit; 60 - Signal processing unit; 70 - Cable line. Detailed implementation manner

[0068] To make the objectives, technical solutions, and advantages of this application clearer, the following will further describe this application in detail with reference to the accompanying drawings. It should be noted that the term "coupled" hereinafter refers to "directly connected or indirectly connected".

[0069] To facilitate the understanding of the multi - frequency antenna provided in the embodiments of this application, the following describes its application scenario. The multi - frequency antenna provided in the embodiments of this application can be applied to communication devices such as base stations. Refer to Figure 1 , Figure 1 shows a schematic structural diagram of the antenna feeding system of a base station in an embodiment of this application. The antenna feeding system of a base station generally may include structures such as antenna 10, mast 20, and antenna adjustment bracket 30. Among them, the antenna 10 of the base station is usually arranged in the radome 40. The radome 40 has good electromagnetic wave penetration characteristics in terms of electrical performance and can withstand the influence of the external harsh environment in terms of mechanical performance, so as to play a role in protecting the antenna system from the external environment. The radome 40 can be installed on the mast 20 or the iron tower through the antenna adjustment bracket 30 to facilitate the signal reception or transmission of the antenna 10.

[0070] In addition, the base station may also include an RF processing unit 50 and a signal processing unit 60. Among them, the RF processing unit 50 can be used to perform frequency selection, amplification, and down - conversion processing on the wireless signals received by the antenna 10, and convert them into intermediate - frequency signals or base - band signals and send them to the signal processing unit 60. Or it is used to convert the signals of the signal processing unit 60 or intermediate - frequency signals through up - conversion and amplification processing and send them out as electromagnetic waves through the antenna 10. The signal processing unit 60 can be connected to the feeding structure of the antenna 10 through the RF processing unit 50 and is used to process the intermediate - frequency signals or base - band signals sent by the RF processing unit 50.

[0071] In a possible embodiment, the radio frequency processing unit 50 may be integrally provided 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 may also be simultaneously located at the far end of the antenna 10. The radio frequency processing unit 50 and the signal processing unit 60 may be connected by a cable 70.

[0072] More specifically, reference may be made together to Figure 1 and Figure 2 , Figure 2 which is a schematic structural diagram of a base station antenna according to a possible embodiment of the present application. Among them, as Figure 2 shown, the antenna 10 of the base station may include a radiation part 101 and a reflector 102. Among them, the radiation part 101 may also be referred to as an antenna element, an oscillator, etc. The radiation part 101 is a unit that constitutes the basic structure of the antenna array, and it can effectively radiate or receive radio waves. In the antenna 10, the frequencies of the radiation parts 101 may be the same or different. The reflector 102 may also be referred to as a bottom plate, an antenna panel, or a metal reflecting surface, etc. The reflector 102 can improve the receiving sensitivity of the antenna signal and reflect and concentrate the antenna signal at the receiving point; in addition, the reflector 102 can achieve the directional radiation of the antenna signal and improve the radiation performance of the antenna 10. The radiation part 101 is usually placed on one side surface of the reflector 102, which can not only greatly enhance the signal receiving or transmitting ability of the antenna 10, but also play a role in blocking and shielding the interference of other radio waves from the back of the reflector 102 (in the present application, the back of the reflector 102 refers to the side opposite to the side of the reflector 102 for setting the radiation part 101) on signal reception.

[0073] In the antenna 10 of the base station, the radiation parts 101 can receive or transmit radio frequency signals through their respective feeding structures 3. The feeding structure 3 is usually composed of a controlled impedance transmission line. The feeding structure 3 can feed the wireless signal to the radiation part 101 according to a certain amplitude and phase, or send the received wireless signal to the signal processing unit 60 of the base station according to a certain amplitude and phase. In addition, the feeding structure 3 can realize different radiation beam directions through the transmission component 301, or be connected to the calibration network 302 to obtain the calibration signal required by the system. A phase shifter 303 may be included in the feeding structure 3 to be used to change the maximum direction of the antenna signal radiation. A combiner 304 (which can be used to combine signals of different frequencies into one path and transmit them through the antenna 10; or when used in reverse, it can be used to divide the signals received by the antenna 10 into multiple paths according to different frequencies and transmit them to the signal processing unit 50 for processing), a filter 305 (used to filter out interference signals), etc. for expanding performance may also be provided in the feeding structure 3.

[0074] Currently, in base station antennas, a low-frequency antenna unit 1 and a high-frequency antenna unit 2 are usually configured in the same antenna array surface to form a multi-frequency antenna. In various embodiments of the present application, the specific operating frequencies of the low-frequency antenna unit 1 and the high-frequency antenna unit 2 are not limited, but the operating frequency of the high-frequency antenna unit 2 is higher than that of the low-frequency antenna unit 1. Exemplarily, the operating frequency of the high-frequency antenna unit 2 can be 30% higher than that of the low-frequency antenna unit 1.

[0075] Reference can be made to Figure 3 , Figure 3 , which shows a schematic diagram of the distribution of an antenna. This antenna includes a low-frequency antenna unit 1 distributed on a reflector 102 and a plurality of high-frequency antenna units 2 distributed around the low-frequency antenna unit 1. The low-frequency antenna unit 1 and the high-frequency antenna unit 2 share the same antenna array surface (i.e., the area where the reflector 102 is located). The low-frequency antenna unit 1 and the high-frequency antenna unit 2 are arranged close to each other, and the maximum distance between them is sometimes less than 0.5 times the wavelength of the low-frequency antenna unit 1. This wavelength can be understood as the wavelength of the low-frequency antenna unit 1 when it operates in a vacuum environment, so as to form a common-aperture antenna. Through the common-aperture technology, antenna units of two frequency bands or even multiple frequency bands are arranged in the same antenna array surface, which can greatly reduce the external dimensions of the multi-frequency antenna and obtain the application advantages of miniaturization, light weight, and easy deployment.

[0076] However, continuing to refer to Figure 3 , in the common-aperture antenna, due to the small distance between the high-frequency antenna unit 2 and the low-frequency antenna unit 1, when the electromagnetic wave radiated by the low-frequency antenna unit 1 is coupled to the high-frequency antenna unit 2, common-mode resonance will occur in the high-frequency antenna unit 2, thereby exciting low-frequency common-mode induced current in the radiation part and the reflector ground of the high-frequency antenna unit 2, and this common-mode induced current will further excite low-frequency electromagnetic waves. This low-frequency electromagnetic wave will act together with the electromagnetic wave directly radiated by the low-frequency antenna unit 1, resulting in the deterioration of pattern parameters such as the gain stability and polarization rejection ratio of the low-frequency antenna unit 1.

[0077] Specifically, reference can be made to Figure 4a and Figure 4b , Figure 4a is the polarization pattern of the low-frequency antenna unit 1 in the antenna array composed of the low-frequency antenna units 1, Figure 4b is Figure 3 the polarization pattern of the low-frequency antenna unit 1 in the multi-frequency antenna in Figure 4a and Figure 4bshows the co-polarization pattern curves and cross-polarization pattern curves of some equally-spaced frequency points in the operating frequency band of the low-frequency antenna element 1. Among them, each solid line represents the co-polarization pattern curve corresponding to a frequency point in the operating frequency band of the low-frequency antenna element 1, and each dashed line represents the cross-polarization pattern curve corresponding to a frequency point in the operating frequency band of the low-frequency antenna element 1, for reflecting the directivity parameters such as the gain stability and polarization rejection ratio of the low-frequency antenna element 1 within the entire operating frequency band. In addition, in Figure 4a and Figure 4b , the ordinate represents the normalized gain, with the unit of dB (decibel), and the abscissa represents the azimuth angle Phi, with the unit of “°” (i.e., degree, degree). The solid line part represents the co-polarization pattern, and the dashed line part represents the cross-polarization pattern. It can be understood that in the embodiments of the present application, the polarization form of the low-frequency antenna element 1 can be but is not limited to single polarization, dual polarization, or circular polarization, etc., Figure 4a and Figure 4b represent the low-frequency antenna element 1 with the same polarization direction.

[0078] Comparing Figure 4a and Figure 4b it can be seen that Figure 4b the top of the main lobe of the solid line part in Figure 4a shows a downward depression relative to the top of the main lobe of the solid line part in Figure 4a , indicating that after the high-frequency antenna element 2 is set in the array of the low-frequency antenna element 1, the gain stability of the low-frequency antenna element 1 deteriorates, and the gain at some frequency points decreases by more than 6 dB. In addition, Figure 4b the average value of the dashed line part in Figure 4a has a significant increase relative to the average value of the dashed line part in Figure 4a , indicating that after the high-frequency antenna element 2 is set in the array of the low-frequency antenna element 1, the polarization rejection ratio of the low-frequency antenna element 1 deteriorates.

[0079] Based on this, the embodiments of the present application provide a multi-band antenna to improve the directivity parameters such as the polarization rejection ratio and gain stability of the low-frequency antenna element 1 in the multi-band antenna, and at the same time improve the radiation efficiency and operating stability of the high-frequency antenna element 2.

[0080] Referring to Figure 5 , Figure 5Schematic diagram of the structure of a multi - frequency antenna provided by an embodiment of the present application. The multi - frequency antenna includes a reflector 102, and a low - frequency antenna unit 1 and a high - frequency antenna unit 2 distributed on the reflector 102. Among them, the material of the reflector 102 can be, but is not limited to, metals such as gold, silver, copper, iron, and aluminum, or alloys such as stainless steel, aluminum alloy, and nickel alloy. In the embodiment of the present application, the number of the low - frequency antenna units 1 is at least one, and the number of the high - frequency antenna units 2 is at least one. The low - frequency antenna unit 1 is located on the periphery of the high - frequency antenna unit 2, and the low - frequency antenna unit 1 and the high - frequency antenna unit 2 can be, but are not limited to, arranged in an array on the reflector 102.

[0081] Refer to together Figure 5 and Figure 6 , Figure 6 Partial schematic diagram of the structure of a multi - frequency antenna of a possible embodiment of the present application. In the present application, a slot 1021 is provided on the reflector 102, and the slot 1021 defines a strip conductor 1022. Specifically, when implemented, the trend of the slot 1021 can be in the shape of a semi - enclosed shape with one end open, so as to divide a semi - enclosed strip area on the reflector 102, and the above - mentioned strip conductor 1022 is located in the semi - enclosed strip area. In the present application, the specific wiring shape of the strip conductor 1022 is not limited. Exemplarily, the strip conductor 1022 can be wired in a straight line, a serpentine line, or a broken line. No matter what shape the strip conductor 1022 is wired in, in the wiring direction of the strip conductor 1022 (such as Figure 6 the X - direction shown in Figure 6 ), the length of the strip conductor 1022 can be greater than 1 / 20 of the wavelength of the low - frequency antenna unit 1, and this wavelength can be understood as the wavelength when the low - frequency antenna unit 1 operates in a vacuum environment. In addition, in the plane of the reflector, perpendicular to the wiring direction of the strip conductor 1022 (such as Figure 6 the Y - direction in

[0082] ), the width of the strip conductor 1022 can be 0.1 mm to 10 mm. In some embodiments, the ratio of the length of the strip conductor 1022 in its wiring direction to the width of the strip conductor 1022 in the direction perpendicular to the wiring direction of the strip conductor 1022 can also be made greater than 5:1.

[0082] It can be understood that in the present application, one end of the strip conductor 1022 is still connected to other parts of the reflector 102 (the connection method can be direct connection or indirect connection), that is, the strip conductor 1022 is still a part of the reflector 102, so as to realize the grounding setting of the strip conductor 1022. At this time, for the common - mode induced current excited by the above - mentioned high - frequency antenna unit 2, the strip conductor 1022 is equivalent to a common - mode suppression inductance structure, and a region such as Figure 7The shown inductance-capacitance parallel resonant circuit (LC parallel resonant circuit) can thus achieve the purpose of suppressing the common-mode induced current.

[0083] In order to effectively suppress the common-mode induced current generated on the high-frequency antenna element 2, the strip conductor 1022 can be arranged corresponding to the high-frequency antenna element 2. During specific implementation, reference can continue to be made to Figure 6 The multi-band antenna further includes a feeding structure 3. The feeding structure 3 includes a microstrip line 306 for the high-frequency antenna element 2. The microstrip line 306 is located on one side of the reflector 102, and at least part of the projection of the microstrip line 306 on the reflector 102 falls within the contour range of the strip conductor 1022. In some embodiments of the present application, the microstrip line 306 can also be arranged in parallel with the strip conductor 1022, that is, the wiring directions of the microstrip line 306 and the strip conductor 1022 can be the same. In addition, the wiring shape of the microstrip line 306 can be the same as or different from that of the strip conductor 1022, as long as the distances between the two are approximately the same at each place in the thickness direction of the reflector 102. Thus, the impedance continuity of the microstrip line 306 is not affected by the common-mode suppression inductance structure formed by the strip conductor 1022, so as to ensure the impedance continuity of each part of the microstrip line 306, and further improve the radiation efficiency and working stability of the high-frequency antenna element 2.

[0084] In addition, in the direction perpendicular to the wiring of the strip conductor 1022, the width of the strip conductor 1022 can be 0.2 to 5 times the width of the microstrip line 306. In this way, on the basis of keeping the capacitance between the microstrip line 306 and the strip conductor 1022 basically unchanged, the inductance of the common-mode suppression inductance structure formed by the strip conductor 1022 is relatively large, so as to effectively suppress the common-mode induced current.

[0085] In a possible embodiment of the present application, the slot 1021 can be arranged around the microstrip line 306. During specific implementation, reference can be made to Figure 8 . First, the microstrip line 306 is arranged on the reflector 102, and then the slot 1021 is arranged around the microstrip line 306 on the reflector 102 to obtain the strip conductor 1022, which can effectively simplify the processing technology of the multi-band antenna. In this embodiment, the wiring direction of the microstrip line 306 can be the same as that of the strip conductor 1022, and the slot 1021 can be, but is not limited to, a U-shaped slot. From Figure 8As can be seen, in the direction perpendicular to the wiring direction of the strip conductor 1022, the width of the projection of the microstrip line 306 on the reflector 102 can be less than or equal to the width of the strip conductor 1022; in the wiring direction of the strip conductor 1022, the length of the projection of the microstrip line 306 on the reflector 102 is greater than the length of the strip conductor 1022. In this way, a part of the projection of the microstrip line 306 on the reflector 102 is located within the region defined by the U-shaped groove, and the other part extends from the opening of the U-shaped groove to the outside of the above-defined region. It can be understood that the projection of the microstrip line 306 on the reflector 102 is inserted into the region defined by the U-shaped groove, so that the impedance of each part of the microstrip line 306 can be continuous.

[0086] Referring to Figure 9 , Figure 9 shows the setting manner of the high-frequency antenna unit 2 of a possible embodiment of the present application. In this embodiment, the feeding structure 3 further includes a feeding wire 307. The feeding wire 307 is respectively connected to the microstrip line 306 and the strip conductor 1022, and the feeding wire 307 can be used to feed the radiation part 101 of the high-frequency antenna unit 2.

[0087] In a specific embodiment, the radiation part 101 of the high-frequency antenna unit 2 is arranged on the side of the reflector 102 away from the microstrip line 306. The radiation part 101 of the high-frequency antenna unit 2 may include a radiation surface reference dielectric substrate 1011, a first radiation arm 1012, a second radiation arm 1013 and a coupling feeding structure 1014 arranged on the radiation surface reference dielectric substrate 1011. Among them, the first radiation arm 1012 and the second radiation arm 1013 are arranged on the first surface of the radiation surface reference dielectric substrate 1011, and the coupling feeding structure 1014 is arranged on the second surface of the radiation surface reference dielectric substrate 1011. In addition, in Figure 9 the shown embodiment, the feeding wire 307 is a coaxial feeding wire. In some other embodiments of the present application, the feeding wire 307 may also but is not limited to be a microstrip line structure, a strip line or a coplanar waveguide transmission line (CPW), etc. It can be understood that no matter what form the feeding wire 307 is, it is provided with a signal conductor and a ground conductor.

[0088] Reference may be made together to Figure 9 and Figure 10 , Figure 10 shows a schematic structural diagram of the connection between the radiation part 101 of the high-frequency antenna unit 2 and the feeding structure 3 of an embodiment of the present application. In Figure 10In the illustrated embodiment, the feeder line 307 is a coaxial feeder line, which includes an inner conductor 3071 and an outer conductor 3072 arranged coaxially. Usually, an insulating layer can be arranged between the inner conductor 3071 and the outer conductor 3072 to avoid short - circuiting between the inner conductor 3071 and the outer conductor 3072. Among them, the inner conductor 3071 can be used as the signal conductor of the feeder line 307, and the outer conductor 3072 can be used as the grounding conductor of the feeder line 307. Specifically, when connecting the radiation part 101 of the high - frequency antenna unit 2 to the feeding structure 3, one end of the inner conductor 3071 (signal conductor) of the feeder line 307 is connected to the signal conductor of the microstrip line 306, and the other end is fed - connected to the first radiation arm 1012 through the coupling feeding structure 1014; one end of the outer conductor 3072 (grounding conductor) of the feeder line 307 is connected to the strip conductor 1022, and the other end is electrically connected to the second radiation arm 1013.

[0089] In the above - mentioned Figure 9 and Figure 10 illustrated embodiment, the high - frequency antenna unit 2 is a dipole antenna. In some other embodiments of the present application, the high - frequency antenna unit 2 can also but is not limited to be a monopole antenna, an electromagnetic dipole antenna, or a patch antenna, etc. No matter what structure the high - frequency antenna unit 2 adopts, its connection method with the feeder line 307 is similar, and will not be introduced one by one here.

[0090] In addition, since the radiation part 101 of the high - frequency antenna unit 2 and the microstrip line 306 are located on both sides of the reflector 102, in order to facilitate the connection of the signal conductor of the feeder line 307 to both the first radiation arm 1012 and the microstrip line 306, continuing to refer to Figure 9 , a through - hole 10221 can be arranged on the strip conductor 1022, so that the feeder line 307 can pass through the through - hole to be connected to the microstrip line 306.

[0091] Referring together to Figure 9 and Figure 10 , in some embodiments of the present application, the feeding structure 3 can also include a feeding joint 308. The feeding joint 308 and the microstrip line 306 are arranged on the same side of the reflector 102, and the microstrip line 306 is connected to the feeding joint 308. Among them, the feeding joint 308 can be connected to the feeding circuit, and the radio - frequency signal can be transmitted to the radiation part 101 through the feeding joint 308 and the microstrip line 306 for emission.

[0092] In some embodiments of the present application, the multi - frequency antenna can be arranged based on the structure of the PCB. Specifically, during implementation, referring to Figure 10 , since the PCB is usually composed of a conductor layer and a dielectric substrate 309 arranged between two adjacent conductor layers, the reflector 102 and the microstrip line 306 can be arranged on two different conductor layers of the PCB, thereby simplifying the structure and processing technology of the multi - frequency antenna.

[0093] Reference Figure 11a and Figure 11b , Figure 11a shows an antenna array composed of two low-frequency antenna elements 1; Figure 11b is Figure 11a the front view of the antenna array shown. Additionally, reference Figure 11c , Figure 11c is Figure 11a the simulation result of the radiation pattern in the horizontal plane of the above-mentioned

[0094] Reference Figure 12a and Figure 12b , Figure 12a shows a multi-band antenna composed of two low-frequency antenna elements 1 and eight high-frequency antenna elements 2; Figure 12b is Figure 12a the cross-sectional front view of the multi-band antenna shown. Additionally, reference Figure 12c , Figure 12c is Figure 12a the simulation result of the radiation pattern in the horizontal plane of the above-mentioned

[0095] Reference Figure 13a and Figure 13b , Figure 13a is a multi-band antenna provided by an embodiment of the present application, where the multi-band antenna is composed of two low-frequency antenna elements 1 and eight high-frequency antenna elements 2, and a slot is provided at the position of the reflector 102 corresponding to the high-frequency antenna element 2 to form a strip conductor 1022; Figure 13b is Figure 13a the side front view of the multi-band antenna shown. Additionally, reference Figure 13c , Figure 13c is Figure 13a the simulation result of the radiation pattern in the horizontal plane of the above-mentioned

[0096] In Figure 11c , Figure 12c and Figure 13c , the ordinate represents the normalized gain, and the unit is dB (decibel), the abscissa represents the azimuth angle Phi, and the unit is "°" (i.e., degree), the solid line part represents the main polarization radiation pattern, and the dotted line part represents the cross polarization radiation pattern, Figure 11c , Figure 12c and Figure 13c The meaning of the curves in Figure 4a and Figure 4b is similar to that in the above-mentioned

[0097] By comparing Figure 11c andFigure 12c It can be seen that Figure 12c the top of the main lobe of the solid line part in Figure 11c shows a downward depression relative to the top of the main lobe of the solid line part in Figure 12c the average value of the dotted line part of Figure 11c has a significant increase relative to the average value of the dotted line part in Figure 13c and Figure 12c It can be seen that by using the multi - frequency antenna provided in this application, the radiation pattern of the low - frequency antenna unit 1 has been significantly improved. In addition, the minimum gain value has been increased from about 5.2 dB to about 6.8 dB.

[0098] Therefore, by using the multi - frequency antenna provided in this application, the common - mode suppression inductance structure formed by the strip conductor 1022 can effectively suppress the common - mode induced current generated on the high - frequency antenna unit 2, thereby significantly improving the directivity parameters such as the polarization rejection ratio and gain stability of the low - frequency antenna unit 1. In addition, since the strip conductor 1022 is formed by slotting the reflector 102, that is, the strip conductor 1022 is a part of the reflector 102, its processing technology is simple and no additional structure and assembly process are required. Therefore, the manufacturing cost of this multi - frequency antenna is relatively low.

[0099] While significantly improving the directivity parameters such as the polarization rejection ratio and gain stability of the low - frequency antenna unit 1, this application also hopes to further reduce the influence on the directivity parameters such as the front - to - back ratio, polarization rejection ratio, and gain stability of the high - frequency antenna unit 2, thereby improving the radiation performance of the multi - frequency antenna.

[0100] In a possible embodiment of this application, it is possible to consider controlling the length of the slot 1021 along the wiring direction of the strip conductor 1022, but at the same time, the length of the strip conductor 1022 cannot be shortened to avoid reducing the equivalent inductance of the common - mode suppression inductance structure formed by the strip conductor 1022, so as to effectively suppress the common - mode induced current generated on the high - frequency antenna unit 2.

[0101] Referring to Figure 14 , Figure 14A schematic diagram of the reflector structure of a multi-band antenna according to one embodiment of the present application is shown. In this embodiment, the slot 1021 is a continuous slot disposed on the reflector 102, and the shape formed by the slot 1021 has a bottom 1021a and an open end 1021b. The multi-band antenna may also include a first jumper 4, which allows adjustment of the length of the slot 1021 along the routing direction of the strip conductor 1022.

[0102] In a specific implementation, the strip conductor 1022 can be positioned between the first jumper 4 and the microstrip line 306. The two ends of the first jumper 4 are located on either side of the slot 1021 facing away from the strip conductor 1022, and both ends of the first jumper 4 are connected to the reflector 102. Furthermore, the first jumper 4 is positioned between the bottom 1021a and the open end 1021b of the slot 1021. The projection of the first jumper 4 on the reflector 102 divides the slot 1021 into two parts. This creates a short-circuit structure in the slot 1021 at the location of the first jumper 4, effectively shortening the slot 1021's dimension along the strip conductor 1022's routing direction. This effectively reduces high-frequency signal leakage from the slot 1021 to the backside of the reflector 102, thereby minimizing the impact on the high-frequency antenna unit 2's directional parameters, such as the front-to-back ratio, polarization suppression ratio, and gain stability. In some other embodiments of the present application, the microstrip line 306 may be located between the first jumper 4 and the strip conductor 1022 . The specific configuration is similar to that of the above embodiment and will not be described in detail here.

[0103] It can be understood that in the embodiment of the present application, by setting the first jumper 4 on the reflector 102, which does not affect the specific setting of the strip conductor 1022, the equivalent inductance of the common-mode suppression inductor structure formed by the strip conductor 1022 does not change, thereby effectively suppressing the common-mode induced current generated on the high-frequency antenna unit 2, so that the directional parameters such as the polarization suppression ratio and gain stability of the low-frequency antenna unit 1 are significantly improved.

[0104] Reference Figure 15 , Figure 15 This is a schematic diagram of the structure of a reflector in a multi-band antenna according to a possible embodiment of the present application. In this embodiment of the present application, the slot 1021 may be, but is not limited to, a U-shaped slot. In addition, at least a portion of the projection of the microstrip line 306 on the reflector 102 may fall within the area defined by the U-shaped slot. For example, please refer to Figure 15, the routing direction of the microstrip line 306 is the same as that of the strip conductor 1022. In the direction perpendicular to the routing direction of the strip conductor 1022, the width of the projection of the microstrip line 306 on the reflector 102 can be less than or equal to the width of the strip conductor 1022; in the routing direction of the strip conductor 1022, the length of the projection of the microstrip line 306 on the reflector 102 is greater than the length of the strip conductor 1022. In this way, a part of the projection of the microstrip line 306 on the reflector 102 is located within the region defined by the U-shaped groove, and the other part extends from the opening of the U-shaped groove to the outside of the defined region, which can be understood as the projection of the microstrip line 306 on the reflector 102 being inserted into the region defined by the U-shaped groove. This ensures the impedance continuity of each part of the microstrip line 306, thereby improving the radiation efficiency and working stability of the high-frequency antenna unit 2.

[0105] In some embodiments of the present application, the multi-frequency antenna can be arranged based on the structure of the PCB. During specific implementation, reference can be made to Figure 16 , since the PCB is usually composed of a conductor layer and a dielectric substrate 309 disposed between two adjacent conductor layers, in this way, the first jumper 4, the reflector 102, and the microstrip line 306 can be respectively arranged on different conductor layers of the printed circuit board. In this embodiment, both ends of the first jumper 4 can be connected to the reflector 102 through vias opened on the printed circuit board. This can effectively simplify the structure and processing technology of the multi-frequency antenna.

[0106] It can be understood that the other structures of the multi-frequency antenna in this embodiment of the present application can be arranged with reference to the above embodiments, and will not be elaborated here.

[0107] Refer to Figure 17a and Figure 17b , Figure 17a shows an antenna array composed of eight high-frequency antenna units 2; Figure 17b is Figure 17a the front view of the antenna array shown. In addition, refer to Figure 17c , Figure 17c is Figure 17a the simulation result of the horizontal pattern of the high-frequency antenna unit 2 in the above-mentioned antenna array. In this embodiment of the present application, the operating frequency of the high-frequency antenna unit 2 is 1.90 GHz to 2.10 GHz.

[0108] Refer to Figure 18 , Figure 18 is Figure 13a the simulation result of the horizontal pattern of the high-frequency antenna unit 2 in the above-mentioned multi-frequency antenna.

[0109] Refer to Figure 19a and Figure 19b , Figure 19aA multi-frequency antenna provided in one embodiment of the present application, wherein the multi-frequency antenna is composed of two low-frequency antenna units 1 and eight high-frequency antenna units 2, wherein the reflector 102 is provided with a slot at a position corresponding to the high-frequency antenna unit 2, and a first jumper is provided between the bottom and the open end of the slot. Figure 19b , Figure 19b For the above Figure 19a The horizontal plane directional pattern simulation results of the high-frequency antenna unit 2 in the multi-frequency antenna are shown.

[0110] exist Figure 17c 、 Figure 18 and Figure 19b In the figure, the vertical axis represents the normalized gain, and the unit is dB (decibel). The horizontal axis represents the azimuth angle Phi, and the unit is "°" (i.e., degree). The solid line represents the main polarization pattern, and the dotted line represents the cross-polarization pattern. Figure 17c 、 Figure 18 and Figure 19b The meaning of the middle curve is the same as above Figure 4a and Figure 4b The above is similar and will not be described in detail here.

[0111] By comparison Figure 17c and Figure 18 It can be seen that Figure 18 The top of the solid line part of the main lobe is relative to Figure 17c The top of the main lobe of the solid line part in FIG appears to be concave downward, indicating that when the low-frequency antenna unit 1 is set in the array of high-frequency antenna units 2, the gain stability of the high-frequency antenna unit 2 needs to be further improved. In addition, Figure 18 The average value of the dotted part is relative to Figure 17c The average value of the dotted line portion in the figure has a significant improvement, indicating that after the low-frequency antenna unit 1 is set in the array of high-frequency antenna units 2, even if the strip conductor 1022 is set at the position corresponding to the high-frequency antenna unit 2 of the reflector 102, the polarization suppression ratio of the high-frequency antenna unit 2 will deteriorate. Figure 19b and Figure 18 It can be seen that by using the multi-frequency antenna provided in this application, the directional pattern distortion of the high-frequency antenna unit 2 is significantly improved, among which the width of the 3dB beam is improved from 41.8°-77.2° to 66.7°-79°, and the axial cross-suppression ratio is improved by about 11.6dB.

[0112] Therefore, when the multi - frequency antenna provided by this embodiment of the present application is adopted, since the first jumper 4 is disposed between the bottom 1021a and the open end 1021b of the slot 1021, the projection of the first jumper 4 on the reflector 102 divides the slot 1021 into two parts. In this way, a short - circuit structure is formed at the position of the first jumper 4 on the slot 1021, which is equivalent to shortening the size of the slot 1021 along the wiring direction of the strip conductor 1022, thereby effectively reducing the influence on the directivity parameters such as the front - to - back ratio, polarization rejection ratio, and gain stability of the high - frequency antenna unit 2. In addition, by setting the first jumper 4 on the reflector 102, it has no impact on the specific setting of the strip conductor 1022, so the equivalent inductance of the common - mode suppression inductance structure formed by the strip conductor 1022 remains unchanged, thereby effectively suppressing the common - mode induced current generated on the high - frequency antenna unit 2, and significantly improving the directivity parameters such as the polarization rejection ratio and gain stability of the low - frequency antenna unit 1.

[0113] In the present application, in addition to the method of setting the first jumper 4 on the reflector 102 as described above, other methods can also be used to control the length of the slot 1021 along the wiring direction of the strip conductor 1022. Exemplarily, referring to Figure 20 , Figure 20 is a schematic structural diagram of a multi - frequency antenna provided by a possible embodiment of the present application. In this embodiment, the slot 1021 includes a mutually separated first slot portion 1021c and a second slot portion 1021d, and the strip conductor 1022 includes a mutually connected first conductor portion 1022a and a second conductor portion 1022b. Specifically, when implemented, the slot 1021 defines the strip conductor 1022, for example, the first slot portion 1021c defines the first conductor portion 1022a, and the second slot portion 1021d defines the second conductor portion 1022b.

[0114] When specifically setting the slot 1021, continuing to refer to Figure 20 , the first slot portion 1021c can be a closed annular slot, and the shape of the annular slot can be, but is not limited to, "O" - shaped or "D" - shaped, etc. The second slot portion 1021d can be a semi - enclosed semi - closed slot with an opening at one end, and the shape of the semi - closed slot can be, but is not limited to, U - shaped. When the second slot portion 1021d is a U - shaped slot, the opening of the U - shaped slot faces away from the first slot portion 1021c. In this way, on the layer where the reflector 102 is located, the first conductor portion 1022a and the second conductor portion 1022b of the strip conductor 1022 are two non - connected segments, and the second conductor portion 1022b is grounded.

[0115] In the present application, there are many connection methods between the first conductor portion 1022a and the second conductor portion 1022b of the strip conductor 1022. It can be referred to Figure 21 , Figure 21Schematic diagram of the reflector in the multi - frequency antenna according to another possible embodiment of the present application. In this embodiment, the multi - frequency antenna includes a second jumper 5. The two ends of the second jumper 5 are respectively connected to the first conductor part 1022a and the second conductor part 1022b, so that the first conductor part 1022a and the second conductor part 1022b are connected through the second jumper 5.

[0116] It can be understood that in the embodiment of the present application, the part of the reflector 102 located on the periphery of the slot is short - circuited and connected through the second jumper 5 between the first slot part 1021c and the second slot part 1021d. This is equivalent to shortening the size of the slot 1021 along the wiring direction of the strip conductor 1022, so as to effectively reduce the leakage of high - frequency signals from the slot 1021 to the back of the reflector 102, and reduce the influence on the directional parameters such as the front - to - back ratio, polarization rejection ratio and gain stability of the high - frequency antenna unit 2.

[0117] In addition, by connecting the first conductor part 1022a and the second conductor part 1022b through the second jumper 5, it basically has no influence on the length of the strip conductor 1022 in the wiring direction. Then the equivalent inductance of the common - mode suppression inductance structure formed by the strip conductor 1022 does not change, so as to effectively suppress the common - mode induced current generated on the high - frequency antenna unit 2, and significantly improve the directional parameters such as the polarization rejection ratio and gain stability of the low - frequency antenna unit 1.

[0118] Reference can be made to Figure 22 In this embodiment of the present application, the multi - frequency antenna can be set based on the structure of the PCB. Since the PCB is usually composed of a conductor layer and a dielectric substrate 309 disposed between two adjacent conductor layers, in this way, the reflector 102 and the microstrip line 306 can be disposed on different conductor layers of the printed circuit board, and the second jumper (not shown in the figure) and the microstrip line 306 are disposed on the same conductor layer of the printed circuit board. For the multi - frequency antenna adopting this solution, it is possible to avoid increasing the number of conductor layers of the PCB, thus effectively reducing the cost of the multi - frequency antenna. In addition, in this embodiment, the two ends of the second jumper 5 can be respectively connected to the first conductor part 1022a and the second conductor part 1022b through vias opened in the printed circuit board. Thus, the structure and processing technology of the multi - frequency antenna can be effectively simplified.

[0119] In the embodiment of the present application, the number of the second jumpers 5 is not specifically limited. Exemplarily, with reference to Figure 21 and Figure 23 the second jumper 5 can be two, and the two second jumpers 5 are respectively located on both sides of the microstrip line 306. The two ends of the two second jumpers 5 are respectively connected to the first conductor part 1022a and the second conductor part 1022b. Reference can be made to Figure 22, By adopting this solution, the return current of the microstrip line 306 can be ensured to be continuous, thereby effectively improving the impedance continuity at various positions of the microstrip line 306, and further improving the radiation efficiency and working stability of the high-frequency antenna element 2.

[0120] In addition, in this embodiment of the present application, in order to control the impedance of the microstrip line 306, the distance between the microstrip line 306 and the second jumper 5 can be adjusted. Exemplarily, the distance between the second jumper 5 and the microstrip line 306 is 0.1 to 10 times the thickness of the dielectric substrate 309 to achieve the impedance continuity at various positions of the microstrip line 306.

[0121] It can be understood that the other structures of the multi-frequency antenna in this embodiment of the present application can be set with reference to the above embodiments, and will not be elaborated here.

[0122] Considering that the frequency selective surface (FFS) has functions of directional reflection, spatial filtering, feeding, and common-mode suppression, therefore, in order to enable the multi-frequency antenna to integrate more functions, in some embodiments of the present application, with reference to Figure 24 and Figure 25 , the reflector 102 can also have a grid structure 1023 with a periodic arrangement. In this embodiment, the strip conductor 1022 can be disposed in a locally continuous metal surface between the grid structures 1023. Alternatively, the strip conductor 1022 can also be disposed within the interval of a single grid structure 1023 to achieve comprehensive optimization of the performance of the multi-frequency antenna. In addition, in this embodiment, the other structures of the multi-frequency antenna can all be set with reference to any of the above embodiments, and will not be elaborated here.

[0123] The present application also provides a communication device, which includes the multi-frequency antenna of any of the above embodiments. The communication device can be, but is not limited to, a base station, a radar, or other devices. In this communication device, the common-mode suppression inductance structure formed by the strip conductor can effectively suppress the common-mode induced current generated on the high-frequency antenna element, so that the directivity parameters such as the polarization suppression ratio and gain stability of the low-frequency antenna element 1 are significantly improved. Moreover, the impedance of each part of the microstrip line is continuous, which can improve the radiation efficiency and working stability of the high-frequency antenna element. In addition, the manufacturing cost of this multi-frequency antenna is relatively low, thereby effectively reducing the cost of the entire communication device.

[0124] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the protection scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application is also intended to include these changes and modifications.

Claims

1. A multi-frequency antenna, characterized in that, including a reflector and a feeding structure; The reflector is provided with a slot, the slot defining a strip conductor, the strip conductor being a part of the reflector, and one end of the strip conductor being connected to other parts of the reflector; The multi-frequency antenna includes a low-frequency antenna unit and a high-frequency antenna unit distributed on the reflector; The feeding structure includes a microstrip line for the high-frequency antenna unit in the multi-frequency antenna, the microstrip line is located on one side of the reflector, and at least a portion of the projection of the microstrip line on the reflector falls within the contour of the strip conductor; The feeding structure further includes a feeding line, which is used to feed the radiation part of the high-frequency antenna unit; A signal conductor of the feeder line is connected to the microstrip line, and a ground conductor of the feeder line is connected to the strip conductor.

2. The multi-band antenna according to claim 1, wherein The strip conductor has a through hole, and the signal conductor of the feed line passes through the through hole and is connected to the microstrip line.

3. The multi-band antenna according to claim 1 or 2, characterized in that The slot is a continuous slot, the multi-band antenna further includes a first jumper, the shape formed by the slot has a bottom and an open end, and the first jumper is arranged between the bottom and the open end; The strip conductor is located between the first jumper and the microstrip line, or the microstrip line is located between the first jumper and the strip conductor; two ends of the first jumper are respectively located on two sides of the slot away from the strip conductor, and the two ends of the first jumper are respectively connected to the reflector.

4. The multi-band antenna according to claim 3, wherein The slot is a first U-shaped slot, and the projection of the microstrip line on the reflector is inserted into the area defined by the first U-shaped slot.

5. The multi-band antenna according to claim 3, wherein The first jumper, the reflector and the microstrip line are respectively located on different conductor layers of a printed circuit board; the first jumper is connected to the reflector through a via hole provided in the printed circuit board.

6. The multi-band antenna according to claim 1 or 2, wherein The slot includes a first slot portion and a second slot portion separated from each other, and the strip conductor includes a first conductor portion and a second conductor portion connected to each other; The slot defines a strip conductor, including: the first slot portion defines the first conductor portion, and the second slot portion defines the second conductor portion.

7. The multi-band antenna according to claim 6, wherein The first slot portion is an annular slot, the second slot portion is a second U-shaped slot, and the opening of the second U-shaped slot faces a side away from the annular slot.

8. The multi-band antenna according to claim 6, wherein The multi-band antenna further includes a second jumper, and two ends of the second jumper are respectively connected to the first conductor portion and the second conductor portion.

9. The multi-frequency antenna according to claim 8, wherein, The reflector and the microstrip line are located on different conductor layers of a printed circuit board, and the second jumper and the microstrip line are located on the same conductor layer of the printed circuit board; The two ends of the second jumper are respectively connected to the first conductor part and the second conductor part, comprising: the two ends of the second jumper are respectively connected to the first conductor part and the second conductor part through via holes opened on the printed circuit board.

10. The multi-band antenna according to claim 9, characterized in that, There are two second jumpers, and the two second jumpers are respectively arranged on both sides of the microstrip line.

11. The multi-band antenna according to claim 9 or 10, wherein, The printed circuit board includes a dielectric substrate disposed between the reflector and the microstrip line, and the distance between the second jumper and the microstrip line is 0.1 to 10 times the thickness of the dielectric substrate.

12. The multi-band antenna according to claim 1 or 2, characterized in that, The feeding structure further includes a feeding connector, and the feeding connector and the microstrip line are disposed on the same side of the reflector; the microstrip line is connected to the feeding connector.

13. The multi-frequency antenna according to claim 1 or 2, characterized in that, The reflector has a grid structure arranged periodically, and the strip conductor is disposed between the grid structures; or the strip conductor is disposed within the grid structures.

14. The multi-band antenna according to claim 1 or 2, characterized in that, In a direction perpendicular to the wiring direction of the strip conductor, the width of the strip conductor is 0.2 to 5 times the width of the microstrip line.

15. The multi-band antenna according to claim 14, wherein In a direction perpendicular to the wiring direction of the strip conductor, the width of the strip conductor is 0.1 mm to 10 mm.

16. The multi-band antenna according to claim 1 or 2, characterized in that, In the wiring direction of the strip conductor, the length of the strip conductor is greater than 1 / 20 of the wavelength of the low-frequency antenna unit.

17. The multi-band antenna according to claim 1 or 2, characterized in that, The ratio of the length of the strip conductor in the wiring direction to the width of the strip conductor in a direction perpendicular to the wiring direction of the strip conductor is greater than 5:

1.

18. The multi-band antenna according to claim 1 or 2, characterized in that, The maximum distance between the low-frequency antenna unit and the high-frequency antenna unit of the multi-frequency antenna is less than 0.5 times the wavelength of the low-frequency antenna unit.

19. A communication device, characterized in that, Comprising the multi-frequency antenna according to any one of claims 1 to 18.

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