A multi-band common aperture antenna and communication equipment

Abstract

A multi-band common aperture antenna and communication equipment, the multi-band common aperture antenna comprises a coupling array element, a frequency division and combining unit, a low-frequency feeding unit, and a high-frequency feeding unit; the coupling array element is arranged on a reflector; the frequency division and combining unit is connected to the coupling array element, the frequency division and combining unit comprises a frequency division and combining layer, the frequency division and combining layer comprises a frequency division and combining device, the frequency division and combining device comprises an antenna port, a high-frequency port, and a low-frequency port, when there is one layer, the antenna port is connected to the coupling array element, the low-frequency port is connected to the low-frequency feeding unit, and the high-frequency port is connected to the high-frequency feeding unit; when there are at least two layers, between two adjacent layers, the upper low-frequency port is connected to the lower antenna port, the first antenna port is connected to the coupling array element, the first high-frequency port is connected to the high-frequency feeding unit, the last low-frequency port is connected to the low-frequency feeding unit, and the last high-frequency port is connected to the high-frequency feeding unit. By using the above technical solution, the antenna has multi-frequency expansion capability and has a wide beam scanning capability in each frequency band.

Description

Technical Field

[0001] The present application relates to the technical field of base station antennas, and in particular to a multi-band common aperture antenna and communication equipment. Background Art

[0002] In the evolution of base station antenna networks, the number of antennas is increasing, and the physical space on the tower to arrange the antennas is getting smaller and smaller. The antenna is the platform where the antenna is located. Therefore, multi-frequency base station antennas have become the mainstream of current antenna design. Under limited antenna aperture, increasing the integration of antenna frequencies as much as possible is the development trend of antenna technology. At present, most 4G multi-frequency base station antennas do not have wide-angle beam scanning capabilities, while 5G MIMO (multiple-inmultipleout) array antennas have flexible 3D-M-MIMO beamforming, wide beam scanning capabilities and high spectrum efficiency, which can effectively improve the antenna coverage.

[0003] In multi-frequency array antennas, wide-angle beam scanning is a difficulty and challenge in array antenna design. At present, it is still difficult to design an array antenna that takes into account both cost scanning and multi-frequency coverage, and it is difficult to commercialize on a large scale. Therefore, the phased array antennas and 5G MIMO antennas that can achieve wide-angle beam scanning are still single-frequency, narrowband designs. For the newly established 5G low-frequency band, although it cannot support 5G high speed, it can provide better frequency coverage, so it is also favored by operators. However, the low-frequency band is several octaves away from the high-frequency band, and it is difficult to integrate the low-frequency band on the existing high-frequency antenna. If the base station needs to meet the requirements of the 5G low-frequency band, it is necessary to rearrange the antenna that meets the 5G low-frequency band. However, there is no extra space on the tower to rearrange the new antenna, and rearranging the antenna requires additional costs. Therefore, it is currently difficult to design an array antenna that can achieve wide-angle beam scanning and meet multi-frequency, especially non-integer frequency ratios in multi-frequency. Summary of the invention

[0004] The present application provides a multi-band common-aperture antenna and communication equipment, which are used to enable the antenna array to have good multi-frequency expansion capability and maintain good wide-angle beam scanning capability in different frequency bands.

[0005] In a first aspect, a multi-band common aperture antenna is provided, comprising a plurality of coupled array elements, a frequency division and combining unit, a low-frequency feeding unit, and a high-frequency feeding unit; wherein:

[0006] Each of the coupling array elements is arranged on a reflective plate;

[0007] The frequency division and combining unit is connected to the multiple coupling array elements, the frequency division and combining unit includes at least one frequency division and combining layer, each frequency division and combining layer includes at least one frequency division and combining device, each frequency division and combining device includes an antenna port, at least one high-frequency port and at least one low-frequency port, the multiple high-frequency ports form at least one high-frequency port group, and the multiple low-frequency ports form at least one low-frequency port group; for each layer, the number of the high-frequency port groups is not greater than the number of the frequency division and combining devices, the number of the low-frequency port groups is less than the number of the frequency division and combining devices, and the number of the high-frequency port groups is not less than the number of the low-frequency port groups;

[0008] When the frequency division and combining unit includes one frequency division and combining layer, the antenna port of the frequency division and combining device is connected to the coupling array element, the multiple low-frequency ports are connected to the low-frequency feeding unit, and the multiple high-frequency ports are connected to the high-frequency feeding unit;

[0009] When the frequency division and combining unit includes at least two layers of the frequency division and combining layers, between every two adjacent layers, the multiple low-frequency ports of the upper layer are connected to the antenna ports of the lower layer, the antenna ports of the first-layer frequency division and combining unit are connected to the coupling array element, the multiple high-frequency ports of the first-layer frequency division and combining unit are connected to the high-frequency feeding unit, the multiple low-frequency ports of the last-layer frequency division and combining unit are connected to the low-frequency feeding unit, and the high-frequency port of the last-layer frequency division and combining unit is connected to the high-frequency feeding unit;

[0010] A low-frequency feeding unit, used for providing low-frequency signal feeding;

[0011] The high frequency feeding unit is used to provide at least one frequency signal feeding higher than the low frequency signal.

[0012] In the above scheme, through the combination of different low-frequency ports and high-frequency ports, the antenna has good multi-frequency expansion capability and can maintain good wide-angle beam scanning capability in different frequency bands. Since the reconstruction of the feed unit structure reduces the number of feed ports, the hardware overhead and power consumption are also reduced. Moreover, during the beam scanning process, the appearance of grating lobes can also be avoided. In addition, since the reconstruction of the feed unit structure reduces the number of feed ports, the hardware overhead and power consumption are also reduced.

[0013] In a specific implementation scheme, the coupling array elements are grouped according to different ports to form reconstruction units of different frequency bands, the coupling array elements corresponding to the low-frequency ports in the low-frequency port group together constitute a low-frequency reconstruction unit, and the coupling array elements corresponding to the high-frequency ports in the high-frequency port group together constitute a high-frequency reconstruction unit.

[0014] In the above scheme, the low-frequency port and the high-frequency port are recombined to form units with different physical apertures and the wide-angle beam scanning capability of each frequency band is improved. At the same time, the antenna cost and complexity can be effectively reduced, so that the antenna has good spread spectrum characteristics and has a solution for constructing multi-band co-aperture antennas with integer ratios and non-integer frequency ratios.

[0015] In a specific embodiment, the distance d between the centers of every two adjacent coupling array elements may satisfy:

[0016] n1*d≤0.5λ1;

[0017] Among them, n1 is the number of the high-frequency ports in the high-frequency port group, λ1 is the wavelength corresponding to the high-frequency signal input by the high-frequency feeding unit, and n1 is a positive integer.

[0018] By determining the distance d between the centers of every two adjacent coupled array elements, it can be ensured that the appearance of grating lobes is avoided during the beam scanning process in the high frequency band.

[0019] In a specific implementation, if the maximum scanning angle of the multi-band common aperture antenna is θ max , then the distance d between the centers of every two adjacent coupled array elements can satisfy:

[0020]

[0021] By setting the distance d between the centers of every two adjacent coupled array elements, it is possible to ensure that the grating lobe is avoided while having a good wide-angle beam scanning capability in the high frequency band.

[0022] In a specific implementation, the number n2 of the low-frequency ports in the low-frequency port group may satisfy:

[0023] n2*d≤0.5λ2;

[0024] Wherein, λ2 is the wavelength corresponding to the low-frequency signal input by the low-frequency feeding unit, n2 is a positive integer; and d is the distance between the centers of every two adjacent coupling array elements.

[0025] Since the distance d between the centers of every two adjacent coupling array elements is determined, by setting the number n2 of the low-frequency ports in the low-frequency port group, it can be ensured that the occurrence of grating lobes is avoided during the beam scanning process in the low-frequency band.

[0026] In a specific implementation, if the maximum scanning angle of the multi-band common aperture antenna is θ max , the number n2 of low-frequency ports in the low-frequency port group may satisfy:

[0027]

[0028] By setting the number n2 of the low-frequency ports in the low-frequency port group, it is possible to ensure that the occurrence of grating lobes is avoided while having good wide-angle beam scanning capability in the low-frequency band.

[0029] In a specific implementation scheme, there may also be phase shifting units on the low-frequency feeding unit and the high-frequency feeding unit; each phase shifting unit is used to adjust the phase lag / advance of the electromagnetic waves radiated by the low-frequency feeding unit and the high-frequency feeding unit to a set phase corresponding to the coupling array element, and the phase shifting unit may be any one or more of the following structures: a digital phase shifter, an analog phase shifter, and a hybrid phase shifter.

[0030] By using the above-mentioned various phase shifting units, the phase lag / advance of the electromagnetic waves radiated by the low-frequency feeding unit and the high-frequency feeding unit is adjusted to the set phase corresponding to the coupling array element to form beams in different directions, thereby completing beam scanning.

[0031] In a specific embodiment, the coupling array element includes at least one dipole array element, the dipole array element is parallel to the polarization direction of the coupling array element, and coupling capacitors are present on both sides of the end of the dipole array element. By setting the direction of the dipole array element, the coupling array element can have at least one polarization direction to form more polarization types.

[0032] In a specific embodiment, when the coupling array element includes two dipole array elements, the dipole array elements are arranged orthogonally. By arranging the dipole array elements in an orthogonal manner, the coupling array element can have dual polarization characteristics in different directions such as vertical and horizontal directions and ±45° directions.

[0033] In a specific embodiment, the frequency division combiner may include any one or more of the following structures: a frequency divider, a duplexer, and a filter.

[0034] By setting the number of interfaces of the frequency divider, duplexer, and filter, the number of low-frequency and high-frequency ports of the frequency divider and combiner can be expanded to perform connections in different ways. The frequency divider is not limited to a dual-frequency type, and a triple-frequency or multi-frequency type of frequency divider device can also be used, thereby more effectively reducing the cost and complexity of the antenna and enabling the antenna to have good spread spectrum characteristics.

[0035] In a second aspect, a communication device is provided, which includes a multi-band common aperture antenna according to any of the above items. The above design enables the antenna to have good multi-frequency expansion capability and maintain good wide-angle beam scanning capability in different frequency bands. Moreover, during the beam scanning process, the appearance of grating lobes can also be avoided. In addition, since the reconstruction of the feed unit structure reduces the number of feed ports, the hardware overhead and power consumption can also be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is a structural schematic diagram of a base station;

[0037] Figure 2a and 2b Schematic diagram of a multi-band co-aperture antenna designed in a coaxial manner;

[0038] Figure 2c and 2d Schematic diagram of a multi-band co-aperture antenna designed for a flower arrangement method;

[0039] Figure 2e for Figure 2a to 2d Schematic diagram of the feeding structure corresponding to the structure shown;

[0040] Figure 2f A schematic diagram of a multi-band common aperture antenna designed using reflector separation technology;

[0041] Figure 2g A schematic diagram of a multi-band common aperture antenna designed using broadband unit sharing technology;

[0042] Figure 2h for Figure 2g Schematic diagram of the feeding structure corresponding to the structure shown;

[0043] Figure 2i Schematic diagram of a multi-band co-aperture antenna designed using tightly coupled phased array technology;

[0044] Figure 2j for Figure 2i Schematic diagram of the isolation of the structure shown in different frequency bands;

[0045] Figure 2k for Figure 2i Schematic diagram of the feeding structure corresponding to the structure shown;

[0046] Figure 3a It is a schematic diagram of a multi-band common aperture antenna;

[0047] Figure 3b It is a schematic diagram of the structure of a multi-band common aperture antenna including a phase shifting unit;

[0048] Figure 4a The beamforming principle diagram for simulating phase shifters;

[0049] Figure 4b This is the beamforming principle diagram of the digital phase shifter;

[0050] Figure 4c The beamforming principle diagram of the hybrid phase shifter;

[0051] Figures 5a to 5dis a schematic diagram of a dual-band antenna;

[0052] Figure 6 is a schematic diagram of a three-band antenna;

[0053] Figures 7a to 7i It is a schematic diagram of a planar array type multi-band common aperture antenna;

[0054] Figure 8a A schematic diagram of periodically arranged array elements;

[0055] Figure 8b It is a schematic diagram of a non-periodic arrangement of array elements;

[0056] Figure 8c Schematic diagram of array element arrangement including dummy elements;

[0057] Figure 9a-9b is a schematic diagram of a dual-polarization coupled array element;

[0058] Fig.10 It is a schematic diagram of a quad-band single-polarization planar array;

[0059] Fig.11 is a schematic diagram of a reflect array antenna;

[0060] Fig.12 is a schematic diagram of a smart reflective surface;

[0061] Fig.13 A schematic diagram of a reflection unit. DETAILED DESCRIPTION

[0062] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings.

[0063] The following is an explanation of the terms that this application involves or may involve:

[0064] 1. At least one means one, or more than one, including one, two, three or more;

[0065] 2. Multiple means two or more than two, including two, three, four or more;

[0066] 3. Connect means coupling, including direct connection or indirect connection via other devices to achieve electrical connectivity;

[0067] 4. Grating lobes refer to lobes generated by superposition in multiple directions in addition to the main lobe when the unit spacing of the array antenna is large enough;

[0068] 5. Phased array radar (PAR) refers to the use of a large number of individually controlled small antenna units arranged into an antenna array. Each antenna unit is controlled by an independent phase shift switch. By controlling the phase of each antenna unit, different phase beams can be synthesized. The electromagnetic waves emitted by each antenna unit of the phased array are synthesized into a nearly straight radar main lobe based on the principle of interference;

[0069] 6. Microwave wireless energy transmission technology is a way of energy transmission. It has good application prospects in the fields of satellite energy transmission, directed energy weapons, biomedicine, and power transmission between two places. The receiving antenna and rectifier circuit in microwave wireless energy transmission technology are two key research technical points;

[0070] 7. Directional backtracking antenna is an antenna array, specifically an antenna that preferentially returns power to the source direction when receiving a signal from the incoming wave direction;

[0071] 8. Tightly coupled phased array (TCPA) is an array antenna that uses strong coupling between units to increase the bandwidth of the phased array.

[0072] 9. Co-aperture antenna is a antenna that uses the same aperture to work in different frequency bands. Compared with non-co-aperture antenna, co-aperture antenna can reasonably design multiple antennas with different frequency and polarization characteristics within the same aperture. While maintaining the compact structure of the antenna, it also has the performance of multi-frequency and multi-polarization operation. It is the development trend of future antennas.

[0073] In order to facilitate the understanding of the multi-band co-aperture antenna provided in the embodiment of the present application, its application scenario is first explained. The multi-band co-aperture antenna provided in the embodiment of the present application is suitable for use in a mobile communication system. The mobile communication system here includes but is not limited to: a global system of mobile communication (GSM) system, a code division multiple access (CDMA) system, a wideband code division multiple access (WCDMA) system, a general packet radio service (GPRS), a long term evolution (LTE) system, a LTE frequency division duplex (FDD) system, a LTE time division duplex (TDD), a universal mobile telecommunication system (UMTS), a worldwide interoperability for microwave access (WiMAX) communication system, a fifth generation (5G) system or a new wireless (NR), and a future (6th generation, 6G) system, etc.

[0074] For example, the multi-band co-aperture antenna of the present application can also be applied to the field of phased array radar. Using the multi-band co-aperture antenna as the phased array antenna of the phased array radar can improve the radar scanning angle, improve the scanning flexibility, and make the performance more reliable.

[0075] The multi-band common aperture antenna of the present application can also be applied to the field of microwave wireless energy transmission. The multi-band common aperture antenna is used as a receiving antenna for microwave wireless energy transmission to add a reflector function. By connecting to a microwave rectifier circuit, it receives and converts energy. It can reconstruct the reflection surface characteristics of other frequency bands without affecting the receiving characteristics of the energy transmission frequency band, and take into account the advantages of the reflective reconstruction unit array / reflector antenna while achieving wireless energy transmission.

[0076] The multi-band co-aperture antenna design of the present application can also be applied to the field of directional tracing antennas. The working mode of the directional tracing antenna determines that the array antenna needs to have a wider beam scanning angle and frequency bandwidth. However, based on the traditional directional tracing antenna, due to its huge beam radio frequency transceiver components, the complexity and cost of the system are greatly increased, which limits its application in directional tracing antennas. The present application can be extended to the antenna array of the directional tracing antenna, and the multi-band co-aperture antenna in the above embodiment can be used as an array antenna to realize a multi-band directional tracing antenna and extend the bandwidth; a coupler can also be loaded on the multi-band co-aperture antenna, and the coupled array elements on the multi-band co-aperture antenna can absorb the load, and the interference signal can be automatically tracked and aligned through the coupler calibration, thereby reducing the array RCS (radar cross-section) and improving signal security.

[0077] The multi-band co-aperture antenna provided in the embodiment of the present application can also be applied to a wireless network system, wherein the multi-band co-aperture antenna can be applied to a base station subsystem (base btation bubsystem, BBS), a terrestrial radio access network (UMTS terrestrial radio access network, UTRAN, UMTS, universal mobile telecommunications system, universal mobile telecommunications system) or an evolved terrestrial radio access network (evolved terrestrial radio access, E-UTRAN), and is further used to provide cell coverage for wireless signals to achieve connection between the UE and the radio frequency end of the wireless network.

[0078] The multi-band common aperture antenna involved in this embodiment can also be set in a wireless access network device to realize signal transmission and reception. Specifically, the wireless access network device may include but is not limited to the following: Figure 1The base station 100 shown. The base station 100 can be a base station (base transceiver station, BTS) in a GSM or CDMA system, or a base station (NodeB, NB) in a WCDMA system, or an evolutionary NodeB (eNB or eNodeB) in an LTE system, or a wireless controller in a cloud radio access network (CRAN) scenario, or the base station 100 can be a relay station, an access point, a vehicle-mounted device, a 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 is not limited in the embodiments of the present application. The base station 100 can provide wireless cell signal coverage and serve terminal devices with one or more cells.

[0079] Figure 1 A possible structure of a base station 100, under which the base station 100 may include a base station antenna 101, a transceiver (TRX) 102 and a baseband processing unit 103, wherein the TRX 102 is connected to the antenna port of the base station antenna 101, so that the antenna port can be used to receive a signal to be transmitted sent by the TRX 102 and the radiation unit of the base station antenna 101 radiates the signal to be transmitted, or sends the received signal received by the radiation unit to the TRX 102, wherein the TRX 102 may be a radio remote unit (RRU), and the baseband processing unit 103 may be a baseband unit (BBU).

[0080] The baseband unit can be used to process the baseband optical signal to be transmitted and transmit it to the RRU, or receive the received baseband signal sent by the RRU (that is, the baseband signal obtained by the conversion and processing of the received RF signal received by the base station antenna 101 during the signal reception process by the RRU) and process it; the RRU can convert the baseband optical signal to be transmitted sent by the BBU into the RF signal to be transmitted (including performing necessary signal processing on the baseband signal, such as signal amplification, etc.). Thereafter, the RRU can send the RF signal to be transmitted to the base station antenna 101 through the antenna port, so that the RF signal is radiated through the base station antenna 101, or the RRU can receive the received RF signal sent by the antenna port of the base station antenna 101, convert it into a received baseband signal and send it to the BBU.

[0081] The base station antenna 101 may include an array antenna 1011, a feed network 1012, and an antenna port 1013. The array antenna 1011 may be composed of radiating units arranged according to a certain geometric rule, and is used to receive and / or radiate radio waves. The output end of the feed network 1012 is connected to the array antenna 1011, and is used to feed each radiating unit in the array antenna 1011, so that the array antenna 1011 radiates multiple beams, wherein different beams can cover different ranges. The feed network 1012 may include a phase shifter, which is used to change the phase of the array antenna. Line 1011 radiates the radiation direction of the beam; the feeding network 1012 may include a vertical feeding network and a horizontal feeding network, wherein the vertical feeding network may be used to adjust the beam width and vertical beam direction of the beam, and the horizontal feeding network may be used to perform horizontal beamforming on the transmitted signal, changing the beam width, shape and beam direction of the beam; the input end of the feeding network 1012 is connected to the antenna port 1013 to form a transceiver channel, wherein each antenna port 1013 corresponds to a transceiver channel, and the antenna port 1013 may be connected to the TRX 102.

[0082] In some embodiments, each base station antenna 101 may have multiple antenna ports 1013 and multiple TRXs 102 , wherein each antenna port 1013 is connected to one TRX 102 ; and the baseband processing unit 103 may be connected to one or more TRXs 102 .

[0083] Currently, communication base stations need to achieve full-band coverage of 2G, 3G, 4G, and 5G, which requires antennas to have radiation units that match different frequency bands. Current antennas mainly include but are not limited to the following structures to achieve multi-band beam scanning:

[0084] Structure 1: A multi-band, co-aperture antenna designed using the overlap-coaxial method.

[0085] Figure 2a This is the front view of the multi-band common aperture antenna designed using the coaxial method. Figure 2b The top view of the multi-band common aperture antenna designed using the coaxial method. The low-frequency array element 2011 is a bowl-shaped unit composed of two pairs of dipoles. The middle of the bowl-shaped unit is hollowed out to place the high-frequency array element 2012. Here, the high-frequency array element 2012 in the bowl is called the bowl-inside unit, and the other high-frequency array elements 2012 outside the bowl are called bowl-outside units. The low-frequency array element 2011 has a larger aperture than the high-frequency array element 2012. The high-frequency array elements 2012 inside and outside the bowl use traditional cross dipoles to form dual-polarization units.

[0086] Structure 2: A multi-band common-aperture antenna designed using the overlap-interleave method.

[0087] Figure 2c Front view of the multi-band common aperture antenna designed for the flower arrangement method. Figure 2d A top view of a multi-band common aperture antenna designed for the flower arrangement method. The multi-band antenna is composed of a low-frequency array element 2021 and a high-frequency array element 2022 that are staggered and crossed. Figure 2e As shown, Figure 2a to 2d The base station antenna may include low-frequency array elements and high-frequency array elements. The low-frequency array elements are used to receive the signal f sent by the low-frequency feeding network. L , the high-frequency array element is used to receive the signal f sent by the high-frequency feeding network H .

[0088] Structure three: Multi-band common-aperture antenna designed using reflector separation technology.

[0089] Figure 2f Schematic diagram of a multi-band common aperture antenna designed using reflector separation technology. The multi-band common aperture antenna is composed of a low-frequency array element 2031 and a high-frequency array element 2032. The radiation structure of the low-frequency array element 2031 is transparent to the low-frequency array element 2031, and is used as a part of the low-frequency array element 2031 and as a radiation ground for the high-frequency array element 2032.

[0090] Structure 4: Multi-band common-aperture antenna designed using broadband unit sharing technology.

[0091] Figure 2g Schematic diagram of a multi-band common aperture antenna designed using broadband unit sharing technology. The multi-band common aperture antenna is composed of a broadband antenna unit 2051, and multiple frequency bands share the same broadband antenna unit 2051. Figure 2h As shown, Figure 2g The antenna may include a broadband antenna unit, which is used to receive the signal f sent by the low-frequency feeding network. L and the signal f sent by the high-frequency feeding network H .

[0092] Structure 5: Multi-band co-aperture antenna designed using tightly coupled phased array technology.

[0093] Figure 2i Schematic diagram of a multi-band common aperture antenna designed using tightly coupled phased array technology. The tightly coupled phased array includes multiple tightly coupled units 2061. Usually, the electrical size of each tightly coupled unit 2061 of the tightly coupled phased array is relatively small. In order to achieve separate beamforming for different frequency bands, the input port of each array element will be connected to the output port of the phase shifter of different frequencies through a frequency division network to achieve a common aperture array. Figure 2j As shown, Figure 2iThe isolation diagram of the structure shown in different frequency bands is shown in Figure 2k As shown, Figure 2i The base station antenna may include a tight coupling unit 2061, each of which is used to receive a signal f sent by a low-frequency feeding network. L and the signal f sent by the high-frequency feeding network H .

[0094] Among them, in the above structures one and two, radiation interference will occur between the high-frequency array elements and the low-frequency array elements. Since different types of high-frequency array elements and low-frequency array elements are required, the cost will also increase, and since the high-frequency array elements and low-frequency array elements are arranged, it is difficult to expand other frequency bands; in the above structure three, the high-frequency array elements and the low-frequency array elements are layered three-dimensional structures, which are complex in structure, high in cost, and difficult to apply in practice; in the above structure four, when performing broadband design, it is difficult to achieve large-angle beam scanning in the high-frequency band within the bandwidth; and when performing narrowband design, frequency expansion cannot be performed; in the above structure five, since the size of the tightly coupled unit is smaller than that of the conventional antenna unit, the scale of the feeding port is larger, and the cost increases due to the increase in the number of phase shifters or baseband processing modules. In addition, the isolation in the low frequency band is also relatively poor.

[0095] In summary, it is currently difficult to provide a multi-band common-aperture antenna that can perform multi-band expansion, especially non-integer frequency ratios in multiple frequencies, and achieve large-angle beam scanning without generating grating lobes, while meeting the requirements of low cost and good isolation of each frequency band.

[0096] In view of the above problems, the embodiment of the present application provides a multi-band common aperture antenna, which designs different frequency bands on coupled array elements of the same aperture, so that it has a common aperture structure, so that the antenna has good multi-frequency expansion capability and can maintain good wide-angle beam scanning capability in different frequency bands. Moreover, during the beam scanning process, the appearance of grating lobes can also be avoided. In addition, due to the reconstruction of the feed unit structure, the number of feed ports is reduced, thereby also reducing hardware overhead and power consumption.

[0097] The multi-band common aperture antenna provided in the embodiment of the present application can meet the following conditions: the working bandwidth covers more than 10 times the frequency, and the voltage standing wave ratio of the whole frequency band is less than 2. Figure 3a The structure shown is described in detail. Figure 3a A schematic structural diagram of a multi-band co-aperture antenna is provided for the present application, wherein the multi-band co-aperture antenna 101 may include a plurality of coupling array elements 301, each of the coupling array elements 301 being disposed on a reflector 302;

[0098] The frequency division and combining unit 303 is connected to the multiple coupling array elements 301, and the frequency division and combining unit 303 includes at least one layer of frequency division and combining layer 304, and each layer of the frequency division and combining layer 304 includes at least one frequency division and combining device 305, and each of the frequency division and combining devices 305 includes an antenna port 306, at least one high-frequency port 307 and at least one low-frequency port 308, and the high-frequency ports 307 constitute at least one high-frequency port group, and the low-frequency ports 308 constitute at least one low-frequency port group; for each layer, the number of the high-frequency port groups is not greater than the number of the frequency division and combining devices 305, the number of the low-frequency port groups is less than the number of the frequency division and combining devices 305, and the number of the high-frequency port groups is not less than the number of the low-frequency port groups;

[0099] When the frequency division and combining unit 303 includes a layer of the frequency division and combining layer 304, the antenna port 306 of the frequency division and combining unit 305 is connected to the coupling array element 301, the multiple low-frequency ports 308 are connected to the low-frequency feeding unit 309, and the multiple high-frequency ports 307 are connected to the high-frequency feeding unit 310;

[0100] When the frequency division and combining unit 303 includes at least two layers of the frequency division and combining layers 304, between each two adjacent layers, the low frequency port 308 of the upper layer is connected to the antenna port 306 of the lower layer, the antenna port 306 of the first layer of the frequency division and combining unit 305 is connected to the coupling array element 301, the high frequency port 307 of the first layer of the frequency division and combining unit 305 is connected to the high frequency feeding unit 310, the low frequency port 308 of the last layer of the frequency division and combining unit 305 is connected to the low frequency feeding unit 309, and the high frequency port 307 of the last layer of the frequency division and combining unit 305 is connected to the high frequency feeding unit 310;

[0101] A low frequency feeding unit 309, used for providing low frequency signal feeding;

[0102] The high frequency feeding unit 310 is used to provide at least one frequency signal feeding higher than the low frequency signal.

[0103] In some embodiments, the coupling array elements 301 are grouped according to different ports to form reconstruction units of different frequency bands. The coupling array elements 301 corresponding to the low-frequency ports 308 in the low-frequency port group together constitute a low-frequency reconstruction unit 311, and the coupling array elements 301 corresponding to the high-frequency ports 307 in the high-frequency port group together constitute a high-frequency reconstruction unit 312.

[0104] By using the above method, different frequency bands can be reasonably designed to form a common aperture structure in the same coupling array element 301, and through the flexible reconstruction of the coupling array element 301, units with different physical apertures can be formed, and the wide-angle beam scanning capability of each frequency band can be improved, while effectively reducing the antenna cost and complexity, so that the base station antenna 101 has good spread spectrum characteristics and has a solution for constructing a multi-band common aperture antenna with integer ratio and non-integer frequency ratio. In addition, since the coupling array element 301 is reconstructed, the isolation of the array antenna can meet the requirements, and the number of feeding ports can be reduced when performing beam scanning.

[0105] In some embodiments, the low frequency feeding unit 309 and the high frequency feeding unit 310 further include a phase shifting unit 313;

[0106] See also Figure 3b As shown, it is a schematic diagram of a multi-band co-aperture antenna structure including a phase shifting unit. Each phase shifting unit 313 is used to adjust the phase lag / advance of the electromagnetic waves radiated by the low-frequency feeding unit 309 and the high-frequency feeding unit 310 to the set phase corresponding to the coupled array element, and the phase shifting unit 313 is any one or more of the following structures: a digital phase shifter, an analog phase shifter, and a hybrid phase shifter. By using the above-mentioned various types of phase shifting units, the phase lag / advance of the electromagnetic waves radiated by the low-frequency feeding unit and the high-frequency feeding unit is adjusted to the set phase corresponding to the coupled array element to form beams in different directions, thereby completing beam scanning.

[0107] Specifically, the phase shift unit 313 is used to adjust the weighting coefficient of each antenna unit in the antenna array to generate a directional beam, which is called beamforming. The beamforming technology is mainly based on three technical solutions: analog beamforming (ABF), digital beamforming (DBF), and hybrid-digital precoding beamforming (HBF). In order to simplify the description, the following takes a one-dimensional array for beam scanning to generate beamforming as an example to introduce the above three beamforming methods. It should be noted that the present application is not limited to one-dimensional beam scanning. Through reasonable coupled array element reconstruction and feed unit layout, the antenna array can also perform two-dimensional beam scanning in a two-dimensional plane. By adjusting the weighting coefficient of each unit in the antenna array, a directional beam with directivity can be generated.

[0108] The analog phase shifter corresponds to the analog beamforming technology, see Figure 4aThe figure shows the beamforming principle diagram of the analog phase shifter. The phase shifter principle is mainly divided into a phase shifter that changes the physical length and a phase shifter that changes the dielectric constant. The analog phase shifter part is at the back end of the antenna and is usually continuously adjustable. It applies the weight to the analog signal. At the transmitting end, the digital signal passes through the DAC and is first decomposed into multiple analog signals by the power divider, and then beamformed by the analog phase shifter. At the receiving end, the analog signals received by multiple antennas are combined and enter the DAC through the phase shifter.

[0109] The digital phase shifter corresponds to the digital beamforming technology, see Figure 4b The figure shows the principle diagram of beamforming of digital phase shifter. Digital phase shifter is used to apply amplitude and phase weights to the front end of baseband signal, that is, before entering DAC at the transmitting end and after ADC at the receiving end. The number of antenna arrays corresponds to the radio frequency chain (RF), that is, each RF chain requires an independent set of DAC / ADC, mixer, filter and power amplifier. When the number of ports increases, the number of RF chains also needs to increase.

[0110] The hybrid phase shifter corresponds to the hybrid beamforming technology, see Figure 4c The figure shows the beamforming principle diagram of the hybrid phase shifter. The hybrid phase shifter combines the characteristics of digital and analog phase shifters, achieving a balance between the number of RF channels, cost, performance, and system design complexity. The phase encoding function is achieved through cascade conversion of digital-to-analog converters. The hybrid phase shifter can effectively reduce the number of RF channels while taking into account both cost and beam scanning performance.

[0111] In some embodiments, the frequency division combiner 305 includes any one or more of the following structures: a frequency divider, a duplexer, and a filter.

[0112] Furthermore, the frequency divider is not limited to a dual-frequency type, and a triple-frequency or multi-frequency type frequency divider may also be used;

[0113] That is, the frequency division combiner 305 may have other frequency band ports besides the low frequency port 308 and the high frequency port 307. By setting the number of interfaces of the frequency divider, duplexer, and filter, the number of low frequency and high frequency ports of the frequency division combiner can be expanded, and different modes of connection can be performed to more effectively reduce the cost and complexity of the antenna, so that the antenna has good spread spectrum characteristics. The specific connection mode between the other frequency band ports besides the low frequency port and the high frequency port on the frequency division combiner 305 and the combiner structure should be known to those skilled in the art, and will not be described in detail here.

[0114] In some embodiments, the distance d between the centers of each two adjacent coupling array elements 301 may satisfy: n1*d≤0.5λ1; wherein λ1 is the wavelength corresponding to the high-frequency signal input by the high-frequency feeding unit 310, and n1 is a positive integer. By determining the distance d between the centers of each two adjacent coupling array elements, the occurrence of grating lobes can be avoided during beam scanning in the high-frequency band.

[0115] In some embodiments, if the maximum scanning angle of the multi-band common aperture antenna 101 is θ max , then the distance d between the centers of every two adjacent coupling array elements 301 can satisfy: By setting the distance d between the centers of every two adjacent coupled array elements, the appearance of grating lobes can be avoided while having good wide-angle beam scanning capability in the high-frequency band.

[0116] Specifically, during beam scanning, the spacing between low-frequency or high-frequency reconstruction units satisfies the following formula:

[0117] λ is the wavelength corresponding to the signal, θ max is the maximum scanning angle of the beam scan.

[0118] Therefore, when arranging the coupling elements 301 , it is necessary to set the distance d between the centers of the coupling elements 301 according to the spacing D between the reconstruction units and the number n1 of the high-frequency ports in the high-frequency port group.

[0119] Optionally, if the number of the high-frequency ports in the high-frequency port group is 1, the spacing d1 between the centers of the high-frequency reconstruction units 312 is the same as the distance d between the centers of the coupling array elements 301 .

[0120] If the number of the high frequency ports in the high frequency port group is m, the distance d between the centers of the coupling array elements 301 is equal to the spacing D / m between the high frequency reconstruction units 312 .

[0121] In some other embodiments, the number n2 of the low-frequency ports 308 in the low-frequency port group satisfies:

[0122] n2*d≤0.5λ2;

[0123] Among them, λ2 is the wavelength corresponding to the low-frequency signal input by the low-frequency feeding unit, d is the distance between the centers of each two adjacent coupling array elements, and n2 is a positive integer. Since the distance d between the centers of each two adjacent coupling array elements has been determined, by setting the number n2 of low-frequency ports in the low-frequency port group, it can be ensured that during the beam scanning process in the low-frequency band, the occurrence of grating lobes is avoided.

[0124] In some other embodiments, if the maximum scanning angle of the multi-band common aperture antenna is θ max , the number n2 of low-frequency ports in the low-frequency port group satisfies:

[0125] By setting the number n2 of the low-frequency ports in the low-frequency port group, it is possible to ensure that the occurrence of grating lobes is avoided while having good wide-angle beam scanning capability in the low-frequency band.

[0126] Specifically, after the coupling elements 301 are arranged, the distance d between the centers of each coupling element 301 has been determined, and the spacing d2 between the centers of the low-frequency reconstruction units 311 is determined according to the wavelength λ2 corresponding to the low-frequency signal input by the low-frequency feeding unit 309 and the known d value.

[0127] The number of the low-frequency ports 308 in the low-frequency port group is d2, and the spacing between the centers of the low-frequency reconstruction units 311 is d2. Then the number of the low-frequency ports 308 in the low-frequency port group needs to satisfy:

[0128] The low frequency reconstruction unit 311 satisfies the maximum scanning angle θ max No grating lobe is generated in the case of ).

[0129] In some embodiments of the present application, after reconstruction, the coupling array element 301 on the multi-band co-aperture antenna can satisfy the integer frequency ratio between the high frequency and the low frequency, and the beam scanning of the high frequency and the low frequency has no grating lobes. In the following embodiments, the beam scanning angle of the multi-band co-aperture antenna satisfies the requirement that no grating lobes are generated when scanning at a maximum scanning angle of ±60°.

[0130] See also Figure 5a , which is a schematic diagram of a dual-band antenna. The coupling array element 301 in the figure is used to connect to the antenna port of the frequency division combiner 305, and the high-frequency port of each frequency division combiner 305 is connected to the high-frequency feeding unit 310, and the low-frequency port 308 is connected to the low-frequency feeding unit 309 in groups of two, where the high frequency is f H , low frequency is f L , f H :f L The ratio of the low-frequency reconstruction unit 311 to the high-frequency reconstruction unit 312 is 2:1, the low-frequency reconstruction unit 311 is reconstructed from two coupled array elements 301, and the high-frequency reconstruction unit 312 is composed of one coupled array element 301, so as to realize a dual-band antenna with a frequency ratio of 2:1. The spacing d1 between the centers of the reconstructed high-frequency reconstruction unit 312 and the spacing d2 between the centers of the reconstructed low-frequency reconstruction unit 311 both meet the beam scanning condition of no grating lobe.

[0131] In some embodiments of the present application, after reconstruction, the coupled array element 301 on the multi-band common aperture antenna can also satisfy a non-integer frequency ratio between high frequency and low frequency, and the beam scanning of high frequency and low frequency has no grating lobe.

[0132] Example 1, see Figure 5b , which is a schematic diagram of a dual-band antenna. The low-frequency reconstruction unit 311 is reconstructed from five coupled array elements 301, and the high-frequency reconstruction unit 312 is reconstructed from two coupled array elements 301, so as to realize a dual-band antenna with a frequency ratio of 2.5:1. The spacing d1 between the centers of the reconstructed high-frequency reconstruction unit 312 and the spacing d2 between the centers of the reconstructed low-frequency reconstruction unit 311 both meet the beam scanning no grating lobe condition.

[0133] Example 2, see Figure 5c , which is a schematic diagram of a dual-band antenna. The low-frequency reconstruction unit 311 is reconstructed from three coupled array elements 301, and the high-frequency reconstruction unit 312 is reconstructed from two coupled array elements 301, so as to realize a dual-band antenna with a frequency ratio of 1.5:1. The spacing d1 between the centers of the reconstructed high-frequency reconstruction unit 312 and the spacing d2 between the centers of the reconstructed low-frequency reconstruction unit 311 both meet the beam scanning no grating lobe condition.

[0134] In addition, the coupled array elements can be reconstructed by combining integer ratio and non-integer ratio to realize dual-band antenna. Figure 5d As shown, some low-frequency reconstruction units 311 are reconstructed from 4 coupled array elements 301, other low-frequency reconstruction units 311 are reconstructed from 3 coupled array elements 301, and high-frequency reconstruction units 312 are reconstructed from 2 coupled array elements 301. The spacing d1 between the centers of the reconstructed high-frequency reconstruction units 312 and the spacing d21 (4 coupled array elements) and d22 (3 coupled array elements) between the centers of the reconstructed low-frequency reconstruction units 311 all meet the beam scanning no grating lobe condition.

[0135] As long as the reconstruction of the coupling array element 301 meets the prerequisite of scanning without grating lobes, adjacent coupling array elements can be arbitrarily combined within the spacing range of the beam scanning without grating lobes, and the number of coupling array element reconstructions is not limited within the same frequency. That is, under the premise of satisfying the scanning without grating lobes, the number of low-frequency ports in the low-frequency port group can be arbitrarily combined and set, and there is no limitation here.

[0136] In some embodiments, the high frequency feeding unit 310 is used to provide at least two frequency signals higher than the low frequency signal to the high frequency port group of the frequency division combiner. For example, in this embodiment, the high frequency feeding unit 310 is used to provide two frequency signals higher than the low frequency signal. The highest frequency signal is taken as the high frequency signal f H , the second high frequency signal is the intermediate frequency signal f M, the low frequency signal is f L For example, Figure 6 , which is a schematic diagram of a three-band antenna, wherein the low-frequency reconstruction unit 311 is reconstructed from four coupled array elements 301, the intermediate frequency reconstruction unit 314 is reconstructed from two coupled array elements 301, and the high-frequency reconstruction unit 312 is composed of one coupled array element 301. The spacing d1 between the centers of the reconstructed high-frequency reconstruction units 312, the spacing d2 between the centers of the reconstructed low-frequency reconstruction units 311, and the spacing d3 between the centers of the intermediate frequency reconstruction units 314 all meet the beam scanning no grating lobe condition.

[0137] In addition, similarly, the design of the present application can be extended to a quad-band or even N-band antenna, where N is a positive integer. Multiple bands share a coupling array element 301 to form a common aperture array. Therefore, the direction of each band in the multi-band common aperture antenna is Figure 1 The antenna has good consistency, can realize ultra-wideband flexible reconstruction capability and frequency expansion, and can still meet the scanning grating-free lobe condition at different frequencies, thereby forming a considerable wide-angle beam scanning capability. Through the reconstruction of the coupled array element 301, the array antenna can effectively reduce the number of active channels and reduce the complexity, reduce the complexity of the feed network and the antenna cost, and ultimately improve the comprehensive competitiveness of the antenna.

[0138] In some embodiments, in order to improve the radiation effect of the antenna, the reconstruction method of the array antenna is not limited to the one-dimensional reconstruction and frequency expansion of the coupling array elements 301 described above, but can also be the reconstruction of the two-dimensional plane coupling array elements 301. Figure 7a The figure shows a schematic diagram of a dual-band antenna of a planar array type. In the array antenna, the coupled array elements are usually arranged in a two-dimensional planar array type. Figure 7a The coupling array element 301 is used to connect to the antenna port of the frequency division combiner 305, and the high frequency port of each frequency division combiner 305 is connected to the high frequency feeding unit 310, and the low frequency port 308 is connected to the low frequency feeding unit 309 in groups of four, where the high frequency is f H , low frequency is f L , see Figure 7b FIG. 1 is a schematic diagram of the connection of the low-frequency reconstruction unit. The low-frequency reconstruction unit 311 is reconstructed from 2*2 coupling array elements 301; see Figure 7c As shown, it is a connection diagram of the high-frequency reconstruction unit, and the high-frequency reconstruction unit 312 is composed of one coupling array element 301. The center spacing d1 of the reconstructed high-frequency reconstruction unit 312 and the center spacing d2 of the reconstructed low-frequency reconstruction unit 311 both meet the beam scanning no grating lobe condition. The number of channels of the feeding port is effectively reduced to reduce the cost.

[0139] In addition, the reconstruction method of the above array antenna is not limited to the one-dimensional and two-dimensional reconstruction described above, and can also be a conformal antenna array type, see Figure 7d As shown, this is a schematic diagram of a conformal array type antenna. Figure 7e Schematic diagram of antenna feeding of a conformal array type. The specific reconstruction method of the coupling array elements on the conformal surface is based on the same concept as the above reconstruction method, which will not be repeated here.

[0140] In some embodiments, the single-polarization planar array may be reconfigured, wherein the single-polarization reconfiguration method may include the following methods:

[0141] Method 1: Refer to Figure 7f As shown, it is a schematic diagram of a planar array formed by reconstructing coupling array elements in the horizontal direction. In the left figure, the low-frequency reconstruction unit 311 is horizontally reconstructed from two coupling array elements 301 in the horizontal direction, and the high-frequency reconstruction unit 312 is composed of one coupling array element 301, realizing a dual-band antenna reconstructed in the horizontal direction. In the middle figure, the low-frequency reconstruction unit 311 is vertically reconstructed from two coupling array elements 301 in the horizontal direction, and the high-frequency reconstruction unit 312 is composed of one coupling array element 301, realizing a dual-band antenna reconstructed in the vertical direction. In the right figure, the low-frequency reconstruction unit 311 is vertically and horizontally reconstructed from 2*2 coupling array elements 301 in the horizontal direction, and the high-frequency reconstruction unit 312 is composed of one coupling array element 301, realizing a dual-band antenna reconstructed in the vertical and horizontal directions.

[0142] Method 2: Refer to Figure 7g As shown, it is a schematic diagram of a planar array formed by reconstructing coupled array elements in a vertical direction. In the left figure, the low-frequency reconstruction unit 311 is horizontally reconstructed from two coupled array elements 301 in the vertical direction, and the high-frequency reconstruction unit 312 is composed of one coupled array element 301, realizing a dual-band antenna reconstructed in the horizontal direction. In the middle figure, the low-frequency reconstruction unit 311 is vertically reconstructed from two coupled array elements 301 in the vertical direction, and the high-frequency reconstruction unit 312 is composed of one coupled array element 301, realizing a dual-band antenna reconstructed in the vertical direction. In the right figure, the low-frequency reconstruction unit 311 is vertically and horizontally reconstructed from 2*2 coupled array elements 301 in the vertical direction, and the high-frequency reconstruction unit 312 is composed of one coupled array element 301, realizing a dual-band antenna reconstructed in the vertical and horizontal directions.

[0143] Method 3: Refer to Figure 7h, which is a schematic diagram of a planar array with a non-integer ratio formed by reconstructing the coupling array elements in the horizontal direction. In the left figure, the low-frequency reconstruction unit 311 is horizontally reconstructed from three coupling array elements 301 in the horizontal direction, and the high-frequency reconstruction unit 312 is horizontally reconstructed from two coupling array elements 301 in the horizontal direction, realizing a dual-band antenna reconstructed in the horizontal direction. In the right figure, the low-frequency reconstruction unit 311 is vertically reconstructed from 3*3 coupling array elements 301 in the horizontal direction, and the high-frequency reconstruction unit 312 is vertically reconstructed from 2*2 coupling array elements 301 in the horizontal direction, realizing a dual-band antenna reconstructed in the vertical and horizontal directions.

[0144] Method 4: Refer to Figure 7i As shown, it is a schematic diagram of a three-band planar array formed by reconstructing coupling array elements in the horizontal direction. In the left figure, the low-frequency reconstruction unit 311 is horizontally reconstructed from 4 coupling array elements 301 in the horizontal direction, the intermediate-frequency reconstruction unit 314 is horizontally reconstructed from 2 coupling array elements 301 in the horizontal direction, and the high-frequency reconstruction unit 312 is composed of 1 coupling array element 301 in the horizontal direction, so as to realize a three-band antenna reconstructed in the horizontal direction. In the middle figure, the low-frequency reconstruction unit 311 is horizontally and vertically reconstructed from 2*4 coupling array elements 301 in the horizontal direction, the intermediate-frequency reconstruction unit 314 is horizontally and vertically reconstructed from 2*2 coupling array elements 301 in the horizontal direction, and the high-frequency reconstruction unit 312 is composed of 1 coupling array element 301 in the horizontal direction, so as to realize a three-band antenna reconstructed in the vertical and horizontal directions. In the right figure, the low-frequency reconstruction unit 311 is horizontally and vertically reconstructed from 4*4 horizontally coupled array elements 301, the intermediate-frequency reconstruction unit 314 is horizontally and vertically reconstructed from 2*2 horizontally coupled array elements 301, and the high-frequency reconstruction unit 312 is composed of 1 horizontally coupled array element 301, realizing a three-band antenna with vertical and horizontal reconstruction.

[0145] After the coupling array elements 301 are reconstructed periodically, the reconstructed planar array belongs to a periodic array; while the coupling array elements 301 are reconstructed non-periodically, the reconstructed array is equivalent to a sparse array. Specifically, it can be flexibly arranged according to the needs of the array antenna. Optionally, the coupling array elements 301 can be arranged in a periodic order or in a non-periodic order on the planar array:

[0146] Method 1: Planar array is arranged periodically, see Figure 8a As shown, it is a schematic diagram of periodically arranged array elements. The coupling array element 301 is reconstructed in one of the frequency bands (similar to other frequency bands), and the ports connected to the reconstructed coupling array element 301 can be configured with different excitation values, and finally a directional pattern characteristic of a specific performance is achieved. The left figure is a schematic diagram of the reconstruction of the coupling array element 301, the middle figure is a schematic diagram of the distribution of the equivalent antenna unit after reconstruction, and the right figure is a schematic diagram of the excitation amplitude distribution, with different patterns representing different excitation amplitudes.

[0147] Method 2: Planar array is arranged non-periodically, see Figure 8b As shown, the left figure is a schematic diagram of the reconstruction of the coupling array element 301, the middle figure is a schematic diagram of the distribution of the equivalent antenna units after reconstruction, and the right figure is a schematic diagram of the excitation amplitude distribution.

[0148] Method 3: You can configure dummy regions on a planar array to achieve a sparse array. Figure 8c As shown, each reconstruction unit can be reconstructed by the same number or different numbers of coupled array elements 301, and for sparse array antennas, the array performance can be optimized by algorithm. The left figure is a schematic diagram of the reconstruction of the coupled array element 301. The dummy element shown in the dotted box can be configured in the planar array, and no feeding configuration is performed on the dummy element, thereby realizing an equivalent sparse array. The middle figure is a schematic diagram of the distribution of the equivalent array after reconstruction, and the right figure is a schematic diagram of the amplitude distribution of the equivalent array.

[0149] In some embodiments, the coupling element 301 includes at least one dipole element;

[0150] The polarization directions of the dipole array element and the coupling array element 301 are parallel, and coupling capacitors are present on both sides of the ends of the dipole array element. By setting the direction of the dipole array element, the coupling array element can have at least one polarization direction to form more polarization types.

[0151] In the above-mentioned embodiment, coupling array elements 301 are all provided in a single polarization direction. Optionally, the multi-band common-aperture antenna can also support multiple polarization directions. By arranging the dipole array elements in an orthogonal manner, the coupling array elements can have dual-polarization characteristics in different directions such as vertical and horizontal directions and ±45° directions.

[0152] When the coupling array element 301 is designed with dual polarization, when the coupling array element 301 includes two dipole array elements, the dipole array elements are orthogonally arranged, and the coupling array element 301 includes but is not limited to being orthogonally arranged in the following manner:

[0153] Method 1: Two dipole array elements are designed in a vertical and horizontal direction, see Figure 9aAs shown, in the left figure, the low-frequency reconstruction unit 311 is horizontally reconstructed from two coupled array elements 301 including vertical and horizontal dipole array elements, and the high-frequency reconstruction unit 312 is composed of coupled array elements 301 including vertical and horizontal dipole array elements. In the middle figure, the low-frequency reconstruction unit 311 is vertically reconstructed from two coupled array elements 301 including vertical and horizontal dipole array elements, and the high-frequency reconstruction unit 312 is composed of coupled array elements 301 including vertical and horizontal dipole array elements. In the right figure, the low-frequency reconstruction unit 311 is vertically and horizontally reconstructed from 2*2 coupled array elements 301 including vertical and horizontal dipole array elements, and the high-frequency reconstruction unit 312 is composed of 1 coupled array element 301 of vertical and horizontal dipole array elements.

[0154] Method 2: Two dipole array elements are designed at ±45°. Figure 9b As shown, in the left figure, the low-frequency reconstruction unit 311 is horizontally reconstructed from two coupled array elements 301 including dipole array elements in the direction of ±45°, and the high-frequency reconstruction unit 312 is composed of one coupled array element 301 including dipole array elements in the direction of ±45°. In the middle figure, the low-frequency reconstruction unit 311 is vertically reconstructed from two coupled array elements 301 including dipole array elements in the direction of ±45°, and the high-frequency reconstruction unit 312 is composed of one coupled array element 301 including dipole array elements in the direction of ±45°. In the right figure, the low-frequency reconstruction unit 311 is vertically and horizontally reconstructed from 2*2 coupled array elements 301 including dipole array elements in the direction of ±45°, and the high-frequency reconstruction unit 312 is composed of one coupled array element 301 including dipole array elements in the direction of ±45°.

[0155] In addition, the present application provides an example of a quad-band antenna. Fig.10 It is a schematic diagram of a four-band single-polarization planar array, wherein the figure includes 12*12 coupling array elements 301, and the physical aperture of the coupling array element 301 is 19mm×19mm, and the array element spacing is also 19mm. The common aperture plane array antenna includes Band3, Band41, Band42 and LAA bands. The standing wave bandwidth of the four-band antenna can cover 1.5~6GHz. By using the multi-band common aperture antenna provided by the present application, the physical aperture of each reconstruction unit of the reconstruction band can meet the conditions of ±60° scanning without grating lobes, and the number of feeding ports of the antenna can be reduced, and the isolation of the reconstruction unit can be improved. Ultimately, each frequency band maintains a reasonable number of channels, reducing the number of antenna feeding ports to save costs and improve the overall competitiveness of the antenna. Specifically, according to the array scanning without grating lobe formula, the spacing between the coupling array elements is about 0.5λ LAA , if the spacing of the coupling array element 301 is set to 0.5λ LAA, the highest frequency of the LAA band can be reconstructed without the coupling array element 301. The coupling array element 301 is the antenna unit of the LAA band. 3.5G (Band42) can use up to 4 coupling array elements 301 for reconstruction, 2.6G (Band41) can use up to 9 coupling array elements 301 for reconstruction, and 1.7G (Band3) can use up to 16 coupling array elements 301 for reconstruction. The above antenna structure can reduce the number of feeding ports and reduce costs. Within the maximum range of the number of reconfigurable coupling array elements, reconstruction units of different frequency bands composed of different antenna units can be flexibly configured.

[0156] Optionally, as shown in Table 1 below, the lower the frequency, the more coupling array elements that can be reconstructed, and thus the more flexible the reconstruction method. The dark part in Table 1 is the reconstruction scale of the coupling array elements that can be selected in different frequency bands. When the spacing between the reconstructed antenna units after reconstruction does not exceed about 0.5 times the wavelength of the corresponding frequency band, the beam scanning angle can reach ±60 degrees without grating lobe scanning. In addition, the number of reconstructed antenna units on the array antenna is different due to different reconstruction methods. For the above-mentioned 12*12 scale array antenna, the LAA band reconstructed antenna units can be designed at least 144 on the array antenna, the Band42 band reconstructed antenna units can be designed at least 36 on the array antenna, the Band42 band reconstructed antenna units can be designed at least 16 on the array antenna, and the Band3 band reconstructed antenna units can be designed at least 9 on the array antenna. As shown in Table 2 below, compared with the traditional four-band antenna array, the four-band antenna provided by the present application can save the number of feeding ports and reduce costs in different frequency bands.

[0157] For Band 3, (144-9) feeding ports can be saved, for Band 41, (144-16) feeding ports can be saved, and for Band 42, (144-36) feeding ports can be saved. Therefore, for a quad-band antenna with a 12×12 coupled array element scale, the number of feeding ports is reduced compared to the traditional solution: This effectively reduces the antenna complexity and the number of beamforming feed port channels. By flexibly adjusting the number of coupled array elements in each reconstruction unit, a large-scale sparse antenna array can be reconstructed to achieve an antenna array with higher performance or special requirements.

[0158] Table 1

[0159]

[0160] Table 2

[0161]

[0162] By utilizing the multi-band common aperture antenna provided by the present application, the coupled array elements are reconstructed based on the tightly coupled phased array technology, and the coupled array elements are flexibly reconstructed to the unit physical apertures of different frequency bands, respectively, to realize a multi-band common aperture type antenna array, which can realize common apertures of different frequency ratios and wide-angle beam scanning capabilities of each frequency band, and at the same time can effectively reduce the cost and complexity of the antenna, and have good multi-frequency expansion capabilities, thereby being able to construct integer and non-integer frequency ratio solutions; the port isolation between the reconstructed units after reconstruction is at least 6dB higher than that of the traditional tightly coupled units; since the multi-band common aperture antenna is a common aperture design and shares the same coupled array elements, it has good manufacturability, and the directions of each frequency band are Figure 1 The uniformity is good and the beam scanning angle can be maintained at a comparable level in different frequency bands, solving the problem of grating lobes caused by excessive spacing; the number of feeding ports is further reduced, reducing costs.

[0163] In some embodiments, the multi-band common aperture antenna of the present application can also be applied to the design of reflective array antenna. Fig.11 The figure shows a schematic diagram of a reflector array antenna, which is composed of a feed source 1101 and a reflector surface 1102. The reflector surface 1102 is generally a planar structure. The planar arrangement of units illuminated by the feed source 1101 makes it an antenna with parabolic characteristics. The main principle is to adjust the unit structure size on the reflector surface 1102 at different positions so that the reflector surface 1102 has different phase delays. Through precise design, the beam focusing and pointing of the antenna can be controlled. However, the traditional reflector array antenna has narrowband characteristics; and because the spatial phase delay difference varies with frequency, the bandwidth of the reflector array antenna composed of traditional microstrip patch units is less than 5%. With the same size change, it is difficult to maintain a high gain bandwidth.

[0164] The above-mentioned reflective surface 1102 can be designed as an intelligent reflector surface (IRS), see Fig.12 As shown, the intelligent reflective surface IRS includes:

[0165] IRS controller 1201, used for receiving reflection amplitude / phase shift information; control circuit board 1202, triggered by IRS controller 1201, responsible for adjusting the reflection amplitude / phase shift of each reflection unit 1204; copper plate 1203, used for avoiding signal energy leakage; PIN diodes are embedded in reflection unit 1204, and their bias voltage is controlled via DC feeder, and the PIN diodes are switched between "on" and "off" states, thereby generating a phase difference of π, and in order to effectively control the reflection amplitude, a variable resistance load can be applied in the design of reflection unit 1204, and different parts of the incident signal energy are consumed by changing the resistance value in each reflection unit 1204, so as to achieve controllable reflection amplitude in [0,1]. However, due to the limitation of patch unit form, the bandwidth of the intelligent reflection surface is also relatively narrow. The multi-band common aperture antenna design of the present application is applied to the reflection unit, and each reflection unit 1204 of the reflection surface can be equivalent to a coupled array element. Fig.13 As shown, it is a schematic diagram of a reflection unit, and a diode or a MEMS (micro-electro-mechanical system) switch is loaded on each patch unit to realize the reflected beam control of the working frequency. After the patch unit 1301 is connected to the load and reconstructed, the control diode 1302 is loaded to equivalently expand the unit physical aperture of the reflective array antenna, thereby adding a new frequency on the reflection surface, realizing the multi-frequency shared aperture reflection surface characteristics, and also realizing the bandwidth expansion of the reflective array antenna. Alternatively, an absorption resistor 1303 can also be loaded on the reconstruction unit to generate wave absorption characteristics in a specific frequency band, reduce the radar scattering interface, realize the stealth characteristics of the reflective array, and increase safety.

[0166] In addition, an embodiment of the present application further provides a communication device, which includes any of the multi-band co-aperture antennas described above. The above design enables the communication device including the multi-band co-aperture antenna to have good multi-frequency expansion capabilities and maintain good wide-angle beam scanning capabilities in different frequency bands. Moreover, during the beam scanning process, the appearance of grating lobes can also be avoided. In addition, since the reconstruction of the feed unit structure reduces the number of feed ports, hardware overhead and power consumption can also be reduced.

[0167] In the scheme of the present application, a multi-band common-aperture antenna and communication equipment provided by the present application are adopted, and the coupled array elements are reconstructed based on the tightly coupled phased array technology, and the coupled array elements are flexibly reconstructed to the unit physical apertures of different frequency bands, so as to realize a multi-band common-aperture type antenna array, which can realize common apertures of different frequency ratios and wide-angle beam scanning capabilities of each frequency band, and can effectively reduce the cost and complexity of the antenna, and have good multi-frequency expansion capabilities, so as to construct integer and non-integer frequency ratio schemes; the port isolation between the reconstructed units after reconstruction is at least 6dB higher than that of the traditional tightly coupled units; because the multi-band common-aperture antenna is a common-aperture design and shares the same coupling array elements, it has good manufacturability, and the directions of each frequency band are Figure 1 The uniformity is good and the beam scanning angle can be maintained at a comparable level in different frequency bands, solving the problem of grating lobes caused by excessive spacing; the number of feeding ports is further reduced, reducing costs.

[0168] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0169] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0170] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0171] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0172] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the scope of protection 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 equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A multi-band common aperture antenna, characterized in that: It includes a plurality of coupling array elements, a frequency division and combining unit, a low-frequency feeding unit and a high-frequency feeding unit; wherein: Each of the coupling array elements is arranged on a reflective plate; The frequency division and combining unit is connected to the multiple coupling array elements, the frequency division and combining unit includes at least one frequency division and combining layer, each frequency division and combining layer includes at least one frequency division and combining device, each frequency division and combining device includes an antenna port, multiple high-frequency ports and multiple low-frequency ports, the multiple high-frequency ports constitute at least one high-frequency port group, and the multiple low-frequency ports constitute at least one low-frequency port group; for each layer, the number of the high-frequency port groups is not greater than the number of the frequency division and combining devices, the number of the low-frequency port groups is less than the number of the frequency division and combining devices, and the number of the high-frequency port groups is not less than the number of the low-frequency port groups; When the frequency division and combining unit includes one frequency division and combining layer, the antenna port of the frequency division and combining device is connected to the coupling array element, the multiple low-frequency ports are connected to the low-frequency feeding unit, and the multiple high-frequency ports are connected to the high-frequency feeding unit; When the frequency division and combining unit includes at least two layers of the frequency division and combining layers, between every two adjacent layers, the multiple low-frequency ports of the upper layer are connected to the antenna ports of the lower layer, the antenna ports of the first-layer frequency division and combining unit are connected to the coupling array element, the multiple high-frequency ports of the first-layer frequency division and combining unit are connected to the high-frequency feeding unit, the multiple low-frequency ports of the last-layer frequency division and combining unit are connected to the low-frequency feeding unit, and the high-frequency port of the last-layer frequency division and combining unit is connected to the high-frequency feeding unit; A low-frequency feeding unit, used for providing low-frequency signal feeding; The high frequency feeding unit is used to provide at least one frequency signal feeding higher than the low frequency signal.

2. The multi-band common aperture antenna according to claim 1, characterized in that: The coupling array elements are grouped according to different ports to form reconstruction units of different frequency bands. The coupling array elements corresponding to the low-frequency ports in the low-frequency port group together constitute a low-frequency reconstruction unit, and the coupling array elements corresponding to the high-frequency ports in the high-frequency port group together constitute a high-frequency reconstruction unit.

3. The multi-band common aperture antenna according to claim 1 or 2, characterized in that: The distance d between the centers of every two adjacent coupled array elements satisfies: n1*d≤0.5λ1; Among them, n1 is the number of the high-frequency ports in the high-frequency port group, λ1 is the wavelength corresponding to the high-frequency signal input by the high-frequency feeding unit, and n1 is a positive integer.

4. The multi-band common aperture antenna according to claim 3, characterized in that: If the maximum scanning angle of the multi-band common aperture antenna is θ max , then the distance d between the centers of every two adjacent coupled array elements satisfies:

5. The multi-band common aperture antenna according to any one of claims 1 to 4, characterized in that: The number n2 of low-frequency ports in the low-frequency port group satisfies: n2*d≤0.5λ2; Wherein, λ2 is the wavelength corresponding to the low-frequency signal input by the low-frequency feeding unit, n2 is a positive integer; and d is the distance between the centers of every two adjacent coupling array elements.

6. The multi-band common aperture antenna according to claim 5, characterized in that: If the maximum scanning angle of the multi-band common aperture antenna is θ max , the number n2 of low-frequency ports in the low-frequency port group satisfies:

7. The multi-band common aperture antenna according to any one of claims 1 to 6, characterized in that: A phase shift unit is also provided on the low-frequency feeding unit and the high-frequency feeding unit; Each phase shifting unit is used to adjust the phase lag / advance of the electromagnetic waves radiated by the low-frequency feeding unit and the high-frequency feeding unit to a set phase corresponding to the coupling array element. The phase shifting unit is any one or more of the following structures: a digital phase shifter, an analog phase shifter, and a hybrid phase shifter.

8. The multi-band common aperture antenna according to any one of claims 1 to 7, characterized in that: The coupling array element comprises at least one dipole array element, the polarization direction of the dipole array element is parallel to that of the coupling array element, and coupling capacitors are present at both sides of the end of the dipole array element.

9. The multi-band common aperture antenna according to claim 8, characterized in that: When the coupling array element includes two dipole array elements, the dipole array elements are orthogonally arranged.

10. The multi-band common aperture antenna according to any one of claims 1 to 9, characterized in that: The frequency division combiner includes any one or more of the following structures: a frequency divider, a duplexer, and a filter.

11. A communication device, characterized in that: It comprises the multi-band common aperture antenna as described in any one of claims 1 to 10.

Images