Radio frequency apparatus and communication apparatus

Abstract

The present application relates to the technical field of communications. Provided are a radio frequency apparatus and a communication apparatus. Radio frequency signals are converted into optical signals by means of an electro-optical conversion unit; the optical signals are divided into multiple groups of optical signals by means of a wavelength division multiplexing unit, the wavelengths of adjacent optical signals being at equal-cycle intervals; and the multiple groups of optical signals are subjected to grouping delay processing by a beamforming network unit, so as to obtain multiple paths of first beam optical signals. After the multiple paths of first beam optical signals pass through a beam expansion unit, different groups of first beam optical signals are respectively delayed, so as to obtain multiple paths of second beam optical signals; and the second beam optical signals are processed, and are then transmitted by a phased array antenna. The multiple paths of first beam optical signals are subjected to delay processing by the beam expansion unit, and the obtained multiple paths of second beam optical signals may respectively correspond to beams in different directions. Compared with a radio frequency apparatus without a wavelength division multiplexing unit and a beam expansion unit introduced therein, the beams transmitted by the phased array antenna in the present application are more concentrated, thereby meeting access requirements of multiple users.

Description

A radio frequency device and a communication device

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. 202411664184.1, filed on November 18, 2024, entitled "A Radio Frequency Device and Communication Device", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of communication technology, and in particular to a radio frequency device and a communication device. Background Technology

[0004] With the development of wireless communication, the simultaneous access of multiple users through multi-beam generation using massive MIMO antennas has become an inevitable trend. Hybrid beamforming (HBF) architecture can be used to achieve multi-beam generation with massive MIMO antennas. To achieve full-array gain, a fully connected scheme is adopted in the HBF architecture; however, the fully connected scheme requires a large number of phase shifters and is complex and difficult to implement.

[0005] Related technologies propose using an optoelectronic fusion method based on an optical Butler matrix to select the input port and switch the direction of the output beam to solve the above problems. Although the Butler matrix-based optoelectronic fusion method can switch the direction of the output beam by selecting the input port, the antenna array output beam is sparse and the beam coverage area is small, which is not conducive to multi-user access. Summary of the Invention

[0006] This application provides a radio frequency device and a communication device to enable an antenna array to output a dense beam, thereby improving beam coverage and meeting the access needs of multiple users.

[0007] In a first aspect, this application provides a radio frequency (RF) device, including an electro-optic conversion unit, a wavelength grouping and multiplexing unit, a beamforming network unit, and a beam spreading unit. The electro-optic conversion unit is used to modulate multiple RF signals onto optical signals of different wavelengths. The wavelength grouping and multiplexing unit is used to divide optical signals of different wavelengths into multiple groups according to wavelength to obtain multiple groups of optical signals, wherein the wavelengths of adjacent optical signals are periodically spaced, and the multiple groups of optical signals correspond to different output ports of the wavelength grouping and multiplexing unit. The beamforming network unit is used to delay the multiple groups of optical signals to obtain multiple first beam optical signals, wherein the delay amount of the optical signals within a group is the same, and the delay amount of the optical signals in different groups is different. The beam spreading module is used to delay the multiple first beam optical signals to obtain multiple second beam optical signals, wherein the delay amount of the multiple first beam optical signals corresponding to the same group of optical signals is different, the number of multiple second beam optical signals is the same as the number of multiple first beam optical signals, and the multiple second beam optical signals are processed and transmitted through a phased array antenna.

[0008] In this application, the radio frequency signal is converted into an optical signal by an electro-optical conversion unit. The optical signal is then divided into multiple groups of optical signals by a wavelength grouping multiplexing unit. The wavelengths of adjacent optical signals are evenly spaced. After grouping delay processing by a beamforming network unit, multiple first-beam optical signals are obtained. These multiple first-beam optical signals are then processed by a beam spreading unit, where different groups of first-beam optical signals are delayed to obtain multiple second-beam optical signals. These second-beam optical signals are then processed and transmitted via a phased array antenna. Each of the multiple first-beam optical signals can correspond to multiple beams pointing in the same direction. After delay processing by the beam spreading unit, the resulting multiple second-beam optical signals can each correspond to beams pointing in different directions. Compared to radio frequency devices that do not incorporate wavelength grouping multiplexing units and beam spreading units, the phased array antenna in this application transmits a denser beam with a wider beam coverage, meeting the access needs of multiple users.

[0009] In one optional embodiment, the beamforming unit comprises K×N groups of beamforming sub-units. Each group of beamforming sub-units includes a wavelength demultiplexer, M delay units, and a wavelength division multiplexer. The wavelength demultiplexer and wavelength division multiplexer are wavelength periodic. N is the same as the number of input ports of the beamforming network unit. The value of M is related to the number of optical signals in the multiple groups of optical signals. The multiple first beam optical signals are K×N, where K×N is the same as the number of antenna elements of the phased array antenna. K, N, and M are all positive integers. The wavelength demultiplexer is used to demultiplex the K×N first beam optical signals into M sub-channels of first beam optical signals. Each sub-channel of the M first beam optical signals includes N first beam optical signals. The M delay units are used to delay the M sub-channels of first beam optical signals respectively to obtain M sub-channel delayed optical signals. The wavelength division multiplexer is used to converge the M sub-channel delayed optical signals into one second beam optical signal.

[0010] Based on this, the beam spreader can delay different groups of optical signals separately.

[0011] In one alternative approach, the delay values ​​of the first beam optical signals of each sub-path in the first beam optical signal of the M sub-path are not the same. The delay value is related to the period of the carrier of the radio frequency signal, the output port number and input port number of the wavelength division multiplexer in the beam spreading sub-unit, the number of the beam spreading sub-unit, and K×N; or, the delay value is related to the period of the carrier of the radio frequency signal, the number of the beam spreading sub-unit, and the additional phase shift value. The additional phase shift value is related to the angle difference between the corresponding beam of the second beam optical signal and the corresponding beam of the first beam optical signal.

[0012] Based on this, it can be ensured that after the first beam optical signal undergoes delay processing by the beam spreader unit, beams with different directions and uniform distribution are obtained.

[0013] In one alternative approach, the delay values ​​of the M delayers corresponding to the numbers of adjacent beam spreader subunits in different groups of beam spreader subunits are the same.

[0014] Based on this, it can be ensured that the beam corresponding to the second beam optical signal is uniformly distributed.

[0015] In one alternative approach, a wavelength grouping multiplexing unit is used to divide signals of different wavelengths into N groups of optical signals. Each group of optical signals includes M optical signals. The wavelength interval between adjacent optical signals in the M optical signals is a first value, which ensures that the optical signal spectra corresponding to adjacent wavelengths in the M optical signals do not overlap.

[0016] Based on this, it can be ensured that the wavelengths of adjacent optical signals are periodically spaced.

[0017] In one alternative embodiment, the beam spreading unit comprises X×Y groups of beam spreading sub-units, each group of beam spreading sub-units including a beam demultiplexer, M... x ×M y A time delay and a wavelength division multiplexer (WDM), the WDM and WDM having wavelength periodicity; X is K x ×N x Y is K y ×N y N x ×N y M has the same number of input ports as the beamforming network element. x ×M y The value of M is related to the number of optical signals in the multiple sets of optical signals. The multiple first beam optical signals are X×Y channels, where X is the same as the number of antenna elements in the horizontal direction of the phased array antenna, Y is the same as the number of antenna elements in the vertical direction of the phased array antenna, and M...x、 N x M y、 N y K x K y All are positive integers; Wavelength demultiplexer, used to demultiplex the first beam optical signal of the X×Y channel into M... x ×M y Sub-path first beam optical signal, M x ×M y Each sub-path first beam optical signal in the sub-path first beam optical signal includes N x ×N y The first beam optical signal; M x ×M y A delay unit is used for M x ×M y The first beam optical signal of the sub-path is delayed to obtain M. x ×M y Sub-path delay optical signal; wavelength division multiplexer, used to convert M x ×M y The light signals from the secondary path converge into a second beam of light signal.

[0018] Based on this, the beam spreader can delay different groups of optical signals separately.

[0019] In one alternative approach, M x ×M y The delay values ​​of the first beam optical signals of each sub-path in the first beam optical signal are not the same. The delay value is related to the period of the carrier of the radio frequency signal, the output port number and input port number of the wavelength division multiplexer in the beam spreading sub-unit, the number of the beam spreading sub-unit, and X×Y; or, the delay value is related to the period of the carrier of the radio frequency signal, the number of the beam spreading sub-unit, and the additional phase shift value. The additional phase shift value is related to the angle difference between the corresponding beam of the second beam optical signal and the corresponding beam of the first beam optical signal.

[0020] Based on this, it can be ensured that after the first beam optical signal undergoes delay processing by the beam spreader unit, beams with different directions and uniform distribution are obtained.

[0021] In one alternative approach, the M numbers corresponding to adjacent beam spreading subunits in different groups of beam spreading subunits are... x ×M y The delay values ​​of each delay unit have the same difference.

[0022] Based on this, it can be ensured that the beam corresponding to the second beam optical signal is uniformly distributed.

[0023] In one alternative approach, a wavelength group multiplexing unit is used to divide signals of different wavelengths into N.x ×N y Groups of optical signals, each group of optical signals including M x ×M y One optical signal, M x ×M y The wavelength interval between adjacent optical signals in a given optical signal is a second value, which makes M... x ×M y The optical signal spectra corresponding to adjacent wavelengths in an optical signal do not overlap.

[0024] Based on this, it can be ensured that the beam corresponding to the second beam optical signal is uniformly distributed.

[0025] In one alternative embodiment, the system further includes: a photoelectric conversion unit; the photoelectric conversion unit is used to perform photoelectric conversion on the multiple second beam optical signals to obtain multiple electrical signals, the number of which is the same as the number of the multiple second beam optical signals.

[0026] The photoelectric conversion unit can convert the second beam optical signal into an electrical signal.

[0027] In one alternative approach, the electro-optical conversion unit includes multiple light emitting units.

[0028] In one alternative approach, each optical emitting unit outputs optical signals of different wavelengths in a time-division manner.

[0029] Using a smaller number of optical emitting units can generate multiple optical signals of different wavelengths, thereby reducing the number of optical emitting units and lowering equipment costs.

[0030] In one alternative embodiment, the device further includes: an optical switching unit; the optical switching unit is used to input multiple sets of optical signals to the beamforming network unit, wherein the number of input ports of the optical switching unit is less than or equal to the number of output ports of the optical switching unit, and the number of output ports of the optical switching unit is the same as the number of input ports of the beamforming network unit.

[0031] Applications based on optical switching units can input multiple sets of optical signals to different input ports of beamforming network units.

[0032] In one alternative embodiment, the device further includes: a power amplifier, the number of which is the same as the number of photoelectric conversion units; the power amplifier is used to amplify multiple electrical signals to obtain an amplified electrical signal, and transmit the amplified electrical signal to the phased array antenna.

[0033] During signal transmission, signal energy attenuation occurs. The radio frequency device of this application introduces a power amplifier to increase the power of the electrical signal.

[0034] In one alternative approach, the beamforming network unit is an optical Butler matrix unit.

[0035] In this application, optical Butler matrix units are used as beamforming network units, which can reduce the size of the beamforming network units.

[0036] In a second aspect, this application provides a communication device, including the radio frequency device in the first aspect and a phased array antenna; the phased array antenna is used to feed multiple electrical signals into the antenna elements of the phased array antenna to form multiple directional beam signals, the number of the multiple directional beam signals being the same as the number of multiple radio frequency signals.

[0037] In one alternative embodiment, the communication device further includes a baseband processing unit and an intermediate frequency (IF) radio frequency (RF) unit; the baseband processing unit is used to generate an IF signal; and the RF unit is used to convert the IF signal into an RF signal.

[0038] These or other aspects of this application will become more apparent from the description of the following embodiments. Attached Figure Description

[0039] Figure 1 shows a schematic diagram of a communication scenario;

[0040] Figure 2A shows a schematic diagram of the structure of a network device;

[0041] Figure 2B shows a schematic diagram of another network device;

[0042] Figure 3 shows a schematic diagram of a phased array antenna;

[0043] Figure 4A shows a schematic diagram of an optically symmetric Butler matrix unit;

[0044] Figure 4B shows a schematic diagram of an optical asymmetric Butler matrix unit;

[0045] Figure 5 shows a schematic diagram of a beam hole;

[0046] Figure 6 shows a schematic diagram of a radio frequency device provided in an embodiment of this application;

[0047] Figure 7 shows a schematic diagram of an optical emitting unit provided in an embodiment of this application;

[0048] Figure 8A shows a schematic diagram of a wavelength group multiplexing unit provided in an embodiment of this application;

[0049] Figure 8B shows a schematic diagram of another wavelength group multiplexing unit provided in an embodiment of this application;

[0050] Figure 9 shows a beam diagram corresponding to a beam spreader unit provided in an embodiment of this application;

[0051] Figure 10 shows a schematic diagram of the structure of a beam extender unit provided in an embodiment of this application;

[0052] Figure 11 shows a schematic diagram of the structure of a periodic wavelength division multiplexer or a periodic demultiplexer provided in an embodiment of this application;

[0053] Figure 12A shows a schematic diagram of the structure of a beam extender unit provided in this embodiment;

[0054] Figure 12B shows a schematic diagram of a delay amount provided in an embodiment of this application;

[0055] Figure 13A shows a schematic diagram of the structure of a radio frequency device provided in an embodiment of this application;

[0056] Figure 13B shows a schematic diagram of the structure of a radio frequency device provided in an embodiment of this application;

[0057] Figure 14 shows a schematic diagram of a beam corresponding to a Butler matrix unit provided in an embodiment of this application;

[0058] Figure 15 shows a schematic diagram of the structure of a radio frequency device provided in an embodiment of this application;

[0059] Figure 16A shows a schematic diagram of the structure of a radio frequency device provided in an embodiment of this application;

[0060] Figure 16B shows a schematic diagram of a delay amount provided in an embodiment of this application;

[0061] Figure 17 shows a beam comparison schematic diagram provided by an embodiment of this application;

[0062] Figure 18 shows a schematic diagram of the structure of a radio frequency device provided in an embodiment of this application;

[0063] Figure 19 shows a schematic diagram of the structure of a communication device provided in an embodiment of this application;

[0064] Figure 20 shows a schematic diagram of the structure of a communication device provided in an embodiment of this application. Detailed Implementation

[0065] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0066] It should be noted that in the description of the embodiments of this application, "at least one" refers to one or more, where "multiple" refers to two or more. Therefore, in the embodiments of this invention, "multiple" can also be understood as "at least two". "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone. Additionally, the character " / ", unless otherwise specified, generally indicates that the related objects before and after are in an "or" relationship. Furthermore, the character "×", unless otherwise specified, generally indicates that the related objects before and after are in a "multiplicative" relationship. It should also be understood that in the description of this application, terms such as "first" and "second" are used only for descriptive purposes and should not be construed as indicating or implying relative importance or order.

[0067] The technical solutions provided in this application can be applied to 5G systems, or to future communication systems or other similar communication systems. Furthermore, the technical solutions provided in this application can be applied to cellular links, public land mobile networks (PLMNs), machine-to-machine (M2M) networks, Internet of Things (IoT) networks, or other networks. They can also be applied to links between devices, such as device-to-device (D2D) links. D2D links can also be called sidelinks, which are also referred to as secondary links or auxiliary links. In this application, the above terms all refer to links established between devices of the same type, and their meanings are the same. The so-called same type of devices can be links between terminal devices, links between base stations, links between relay nodes, etc., and this application does not limit this. For links between terminal devices, there are D2D links defined in 3GPP Release (Rel) 12 / 13, and V2X links defined by 3GPP for vehicle-to-vehicle, vehicle-to-mobile, or vehicle-to-any-entity communication, including Rel-14 / 15. There are also V2X links based on the new radio (NR) system in Rel-18 and later versions.

[0068] Referring to Figure 1, this illustrates an application scenario or network architecture used in an embodiment of this application. Figure 1 includes network devices and terminal devices. It should be understood that the number of terminal devices in Figure 1 is not specifically limited, and the network architecture may also include other network devices, such as wireless relay devices and wireless backhaul devices, which are not shown in Figure 1. A network device is an access device through which a terminal device wirelessly accesses the network, and can be a base station. The network device corresponds to different devices in different systems; for example, in a 4th-generation (4G) mobile communication system, it may correspond to an evolved Node B (eNB), and in a 5G system, it may correspond to a generation Node B (gNB). The terminal device may be a cellular phone, smartphone, laptop, handheld communication device, handheld computing device, satellite radio device, global positioning system, personal digital assistant (PDA), and / or any other suitable device for communication on a wireless communication system, and all can be connected to the network device.

[0069] This application's embodiments can be applied to uplink signal transmission, downlink signal transmission, and D2D signal transmission. For downlink signal transmission, the transmitting device is a network device, and the corresponding receiving device is a terminal device; for uplink signal transmission, the transmitting device is a terminal device, and the corresponding receiving device is a network device; for D2D signal transmission, both the transmitting and receiving devices are terminal devices. This application's embodiments do not limit the direction of signal transmission.

[0070] Terminal devices can be wireless terminal devices capable of receiving network device scheduling and instruction information. They can be devices providing voice and / or data connectivity to users, handheld devices with wireless connectivity, or other processing devices connected to a wireless modem. Wireless terminal devices can communicate with one or more core networks or the Internet via a radio access network (e.g., radio access network, RAN). They can be mobile terminal devices, such as mobile phones (or "cellular" phones), computers, and data cards. For example, they can be portable, pocket-sized, handheld, computer-embedded, or vehicle-mounted mobile devices that exchange voice and / or data with the radio access network. Examples include personal communication service (PCS) phones, cordless phones, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, PDAs, tablets, and computers with wireless transceiver capabilities. Wireless terminal equipment can also be referred to as a system, subscriber unit, subscriber station, mobile station, mobile station (MS), remote station, access point (AP), remote terminal, access terminal, user terminal, user agent, subscriber station (SS), customer premises equipment (CPE), terminal, UE, mobile terminal (MT), etc. Wireless terminal equipment can also be wearable devices and next-generation communication systems, such as terminal equipment in 5G networks, terminal equipment in future PLMN networks, and terminal equipment in NR communication systems.

[0071] Network equipment is an entity on the network side used to transmit or receive signals, such as a transmission reception point (TRP) or gNB. Network equipment can be used to communicate with mobile devices. Network equipment can be an access point (AP) in a wireless local area network (WLAN), a base transceiver station (BTS) in a global system for mobile communication (GSM) or code division multiple access (CDMA), a base station (NodeB, NB) in wideband code division multiple access (WCDMA), an evolved Node B (eNB or eNodeB) in long term evolution (LTE), a relay station or access point, or network equipment in vehicle-mounted devices, wearable devices, and future 5G networks, or network equipment in future evolved PLMNs, or gNodeB / gNB in ​​NR systems, etc. In some deployments, gNB can include a centralized unit (CU) and a DU. The gNB can also include an active antenna unit (AAU). The CU and DU implement some of the gNB's functions. For example, the CU handles non-real-time protocols and services, such as implementing radio resource control (RRC), service data adaptation protocol (SDAP), and packet data convergence protocol (PDCP) layer functions. The DU handles physical layer protocols and real-time services, such as implementing radio link control (RLC), medium access control (MAC), and physical (PHY) layer functions. The AAU implements some physical layer processing functions, radio frequency processing, and related functions of the active antenna. Since RRC layer information ultimately becomes PHY layer information, or is derived from PHY layer information, in this architecture, higher-layer signaling, such as RRC layer signaling, can also be considered as being sent by the DU, or by both the DU and AAU.It is understood that the network device can be one or more of the following: CU node, DU node, and AAU node. Furthermore, the CU can be classified as a network device in the radio access network (RAN) or in the core network (CN); this application does not limit this. Additionally, in the embodiments of this application, the network device provides services to a cell, and the terminal device communicates with the network device through the transmission resources (e.g., frequency domain resources, or spectrum resources) used by that cell. This cell can be the cell corresponding to the network device (e.g., a base station). The cell can belong to a macro base station or a base station corresponding to a small cell. Small cells can include: metro cells, micro cells, pico cells, femto cells, etc. These small cells have the characteristics of small coverage area and low transmission power, making them suitable for providing high-speed data transmission services. Furthermore, in other possible cases, the network device can be other devices that provide wireless communication functions for the terminal device. The embodiments of this application do not limit the specific technology or device form used by the network device. For ease of description, in the embodiments of this application, the device that provides wireless communication function for the terminal device is referred to as a network device.

[0072] The radio frequency (RF) devices mentioned in this application mainly relate to the internal structure of network equipment. The structure of the RF device is typically configured as an active antenna unit (AAU) as shown in Figure 2A, or a remote radio unit (RRU) as shown in Figure 2B. The RRU can be connected to a phased array antenna to form a communication device. Additionally, the communication device may also include a baseband processing unit and an intermediate radio frequency (IRF) unit connected to the RF device. The indoor baseband unit (BBU) in Figures 2A and 2B corresponds to the baseband processing unit and IRF unit mentioned in this application.

[0073] To facilitate understanding of the embodiments of this application, the terms or processing flows involved in the embodiments of this application will be briefly explained below.

[0074] 1) Phased array antenna

[0075] A phased array antenna is an antenna that changes the beam direction by controlling the feed phase of the radiating elements in the array. A phased array antenna consists of multiple antenna elements. Specifically, phased array antennas are divided into one-dimensional and two-dimensional types. In a one-dimensional phased array antenna, the antenna elements can be horizontal or vertical. A two-dimensional phased array antenna includes both horizontal and vertical antenna elements. As shown in Figure 3, a two-dimensional phased array antenna includes 16 antenna elements, with 4 horizontal and 4 vertical elements.

[0076] 2) Beamforming network unit

[0077] Beamforming network units can assign corresponding weights to input signals to form multiple output signals, which can be transmitted through an antenna to form corresponding beam directions.

[0078] The beamforming network unit may include devices such as phase shifters and couplers. The beamforming network involved in this application is an optical signal beamforming network, which uses an optical delay unit to delay the output signal so that it achieves beam phase shifting after transmission through the antenna. Depending on the specific application, other devices may also be included, but are not specifically limited here.

[0079] For example, beamforming network units can be implemented using either optically symmetric Butler matrix units or optically asymmetric Butler matrix units. The optically symmetric Butler matrix unit has the same number of input ports and output ports. The optically asymmetric Butler matrix unit has fewer input ports than output ports.

[0080] 3) Optical symmetric Butler matrix unit

[0081] An optically symmetric Butler matrix unit (hereinafter referred to as an optically symmetric Butler matrix) modulates a radio frequency (RF) signal onto an optical carrier, converting it into an RF optical signal. The phase shifter in the optically symmetric Butler matrix corresponds to the delay of the optical signal, and the coupler corresponds to the π / 2 coupler for optical delay. The RF optical signal is input from one input port of the optically symmetric Butler matrix, and the RF electrical signals at each output port satisfy the output phase relationship defined by the optically symmetric Butler matrix. After photoelectric signal conversion, the phased array antenna outputs a beam with a single beam direction. Inputting the RF optical signal into different input ports of the optically symmetric Butler matrix can form beams with different directions, achieving beam scanning. Figure 4A illustrates this using an optically symmetric Butler matrix unit with 8 input ports and 8 output ports (hereinafter referred to as an 8×8 optical Butler matrix). The input ports of the 8×8 optical Butler matrix are 1L, 4R, 3L, 2R, 2L, 3R, 4L, and 1R, and the output ports are 1 to 8. The optical signals output from each output port satisfy an arithmetic phase gradient. For example, the beam signal phase corresponding to the optical signal output from output port 1 is 0, and the beam signal phase corresponding to output port 2 is... The phase of the beam signal corresponding to output port 3 is The phase of the beam signal corresponding to output port 4 is The phase of the beam signal corresponding to output port 5 is The beam signal phase corresponding to output port 6 is The phase of the beam signal corresponding to output port 7 is The phase of the beam signal corresponding to output port 8 is Among them, the phase difference between adjacent antenna elements The delay between the optical signal and the signal satisfies the following formula 1:

[0082] Where Δτ indicates the time delay of the optical signal, and ω indicates the angular frequency of the radio frequency signal transmitted by the phased array antenna.

[0083] Phase difference between adjacent antenna elements The beam pointing angle satisfies the following formula 2:

[0084] Where d indicates the distance between adjacent array elements, θ indicates the beam pointing angle, and k = 2π / λ, where λ indicates the wavelength of the radio frequency signal transmitted by the phased array antenna.

[0085] The beam pointing angle satisfies the following formula 3:

[0086] An optically symmetric Butler matrix unit can only achieve one-dimensional beam scanning (i.e., beams in the same plane). To form a two-dimensional beam (i.e., beams in different planes), multiple optically symmetric Butler matrix units need to be combined.

[0087] 4) Optical asymmetric Butler matrix unit

[0088] In the HBF architecture of large-scale antenna arrays, the number of antennas (transmitting antennas or receiving antennas) is greater than the number of analog-to-digital converters (or digital-to-analog converters). Therefore, an optical asymmetric Butler matrix unit with fewer input ports than output ports is more suitable for the application requirements.

[0089] It should be noted that the symmetric or asymmetric optical Butler matrix units in this application are implemented using incoherent light.

[0090] As shown in Figure 4B, a phase-shifting network is added to the output of the 4×4 optical Butler matrix. This allows for a significant increase in the number of output ports through phase expansion. In Figure 4B, φ1 to φ22 are all phase shifters. Based on the use of the phase-shifting network, the 4×4 optical Butler matrix is ​​expanded into a 4×16 optical Butler matrix.

[0091] Related technologies mention using symmetrical Butler matrix units connected to photoelectric conversion units and phased array antennas to output beams with different directions. However, when the number of phased array antennas is greater than that of analog-to-digital converters, the number of input and output ports must be the same as the number of antenna elements in the phased array. The optical symmetrical Butler matrix unit becomes too large and structurally complex. Furthermore, the beams output from the optical symmetrical Butler matrix unit may not be dense enough to meet the access requirements of multiple users.

[0092] When the number of phased array antennas exceeds that of analog-to-digital converters, optical asymmetric Butler matrix units can meet the application requirements. However, after processing by optical asymmetric Butler matrix units, the output beam of the phased array antenna is narrow, and there are large beam holes between adjacent beams, as shown in Figure 5, which is not conducive to multi-user access. Although beam holes can be compensated by introducing multiple optical asymmetric Butler matrix units, this solution has high hardware costs, and the connection between multiple optical asymmetric Butler matrix units is complex and difficult to implement.

[0093] Based on this, this application provides a radio frequency device that, when using an optically symmetric Butler matrix unit to generate a beam, outputs a denser beam from the phased array antenna, meeting the access requirements of multiple users. It also provides a scheme to reduce beam holes when using an optically asymmetric Butler matrix unit to generate the beam.

[0094] As shown in Figure 6, the radio frequency device includes an electro-optic conversion unit, a wavelength block multiplexing unit, a beamforming network unit, and a beam spreader unit. These units are connected sequentially. The number of output ports of the wavelength block multiplexing unit can be the same as the number of input ports of the beamforming network unit, and the number of output ports of the beamforming network unit is typically the same as the number of input ports of the beam spreader unit.

[0095] An electro-optic conversion unit is used to modulate multiple radio frequency (RF) signals onto optical signals of different wavelengths. The RF conversion unit includes multiple optical transmitting units (e.g., optical transmitters), the number of which can be greater than, less than, or equal to the number of antenna elements in a phased array antenna. When the number of optical transmitting units in the RF device is greater than the number of antenna elements in the phased array antenna, the beam generated by the RF device is a encrypted beam. When the number of optical transmitting units in the RF device is less than the number of antenna elements in the phased array antenna, each optical transmitting unit can output optical signals of different wavelengths in a time-division multiplexing manner. By changing the wavelength of the optical signal, beam signals with different directions are generated. Multiple optical signals of different wavelengths can be generated using a smaller number of optical transmitting units, thereby reducing the number of optical transmitting units and lowering equipment costs.

[0096] For example, as shown in Figure 7(a), the number of optical emitting units is the same as the number of antenna elements in the phased array antenna, which is 4. The electro-optical conversion unit receives 4 radio frequency signals. Different optical emitting units can modulate the radio frequency signals to different optical wavelengths to form radio frequency optical signals. For example, optical emitting unit 1 modulates the radio frequency signal to a wavelength of λ. 1,1 The optical signal, optical transmitting unit 2, modulates the radio frequency signal into a wavelength of λ. 2,1 The optical signal, transmitted by optical transmitter 3, modulates the radio frequency signal into a wavelength of λ. 3,1 The optical signal, optical transmitting unit 4, modulates the radio frequency signal to a wavelength of λ. 4,1 The optical signal. As shown in Figure 7(b), the optical transmitting unit modulates the radio frequency signal into a wavelength of λ at different times. 1,1 , λ 2,1 , λ 3,1 , λ 4,1 The optical signals. In Figure 7(a), the four optical emitting units can simultaneously output four different wavelength optical signals. In Figure 7(b), the one optical emitting unit does not output four different wavelength optical signals simultaneously, but only outputs one optical signal at a time. The four different wavelength optical signals are output in a time-division manner.

[0097] In this design, the spectra of optical signals of different wavelengths do not overlap. Based on this, when the optical signals are subsequently processed into beams, beams with different directions can be obtained. Regardless of which optical emitting unit in Figure 7 is used, four beams with different directions can be generated. This is only an example and not a specific limitation.

[0098] A wavelength group multiplexing unit (WBMU) is used to divide optical signals of different wavelengths into multiple groups according to their wavelengths, resulting in multiple groups of optical signals. The wavelengths of adjacent optical signals are periodically spaced, and the multiple groups of optical signals correspond to different output ports of the WBMU. The WBMU can be implemented using a wavelength division multiplexer (WDM).

[0099] Specifically, when the phased array antenna is one-dimensional, the wavelength grouping multiplexing unit is used to divide signals of different wavelengths into N groups of optical signals. Each group of optical signals includes M optical signals. The wavelength interval between adjacent optical signals in the M optical signals is a first value, which ensures that the spectra of optical signals corresponding to adjacent wavelengths in the M optical signals do not overlap. Here, N and M are both positive integers, and N is the same as the number of input ports of the beamforming network unit. As shown in Figure 8A, signals of different wavelengths are divided into N groups of optical signals, each group of optical signals includes M optical signals. The optical signals in the first group are λ... 1,1 , λ 2,1 , …, λ M,1 The optical signals in the second group of optical signals are λ 1,2 , λ 2,2 , …, λ M,2 The optical signals in the Nth group of optical signals are λ, ..., λ. 1,N , λ 2,N , …, λ M,N . λ 1,1 , λ 2,1 , …, λ M,1 The interval between adjacent wavelengths is the first value, λ M,1 With λ 1,2 The wavelength interval between them is also the first value. Figure 8A uses the optical signal λ 1,1 , λ 2,1 , …, λ M,1 The input to the wavelength group multiplexing unit and the output of the first group of optical signals through output port 1 of the wavelength group multiplexing unit are illustrated. The optical signal λ is used as an example. 1,N , λ 2,N , …, λ M,NThe input to the wavelength group multiplexing unit and the output of the Nth group of optical signals through the output port N of the wavelength group multiplexing unit are illustrated. The value of this first value is related to the carrier frequency, bandwidth, and isolation of the radio frequency signal, and is not specifically limited in this application. The isolation of the radio frequency signal refers to the degree of signal leakage between adjacent channels, and is generally measured in decibels (dB). For example, with a carrier frequency of 10 GHz, a bandwidth of 400 MHz, and an isolation of 40 dB, the wavelength spacing (i.e., the first value) in the wavelength division multiplexing system is 100 GHz or 50 GHz.

[0100] Specifically, when the phased array antenna is two-dimensional, the electro-optic conversion unit includes N x ×N y There are 1 light emitting unit, of which N is horizontal. x One, vertical N y Each wavelength group multiplexing unit includes M units. x ×M y There are 1 input port, of which the horizontal M x One, vertical M y There are N wavelength group multiplexing units. x ×N y The number of output ports, horizontally numbered from 1 to N. x The output ports are vertically numbered from 1 to N. y Wavelength group multiplexing units are used to divide signals of different wavelengths into N... x ×N y Groups of optical signals, each group of optical signals including M x ×M y One optical signal, M x ×M y The wavelength interval between adjacent optical signals in a given optical signal is a second value, which makes M... x ×M y The optical spectrum of adjacent wavelengths in the optical signal does not overlap. As shown in Figure 8B, signals of different wavelengths are divided into N... x ×N y Groups of optical signals, each group of optical signals including M x ×M y There are λ optical signals, and the optical signals in the (1,1)th group of optical signals are respectively λ 1,1,1,1 , λ 2,1,1,1 , ..., The optical signals in group (1,2) are λ 1,1,1,2 , λ 2,1,1,2 , ..., …, the (N)th x N y The optical signals in the group of optical signals are respectively λ1,1,1,1 , λ 2,1,1,1 , ..., The wavelength interval is the second value. With λ 1,1,1,2 The wavelength interval between them is also the second value. Figure 8B uses the optical signal λ 1,1,x,y , ..., The input to the wavelength group multiplexing unit and the output of the (x,y) group of optical signals through the output port x,y of the wavelength group multiplexing unit are illustrated. The value of this second value is related to the carrier frequency, bandwidth, and isolation of the radio frequency signal, and is not specifically limited herein. For example, with a carrier frequency of 10 GHz, a bandwidth of 400 MHz, and an isolation of 40 dB, the wavelength spacing (i.e., the second value) in the wavelength division multiplexing system is 100 GHz or 50 GHz.

[0101] A beamforming network unit is used to delay multiple groups of optical signals to obtain multiple first-beam optical signals. The delay amount of the optical signals within a group is the same, while the delay amount of the optical signals in different groups is different. For example, when using a beamforming network unit to generate a one-dimensional beam, in Figure 8A above, the delay amount of the first group of optical signals is the same, but the delay amount of the first group of optical signals is different from that of the second group of optical signals. For example, when using a beamforming network unit to generate a two-dimensional beam, in Figure 8B above, the delay amount of the (1,1) group of optical signals is the same, but the delay amount of the (1,1) group of optical signals is different from that of the (1,2) group of optical signals. In specific applications, the beamforming network unit can be implemented using the aforementioned optical symmetric Butler matrix unit, or it can be implemented using the aforementioned optical asymmetric Butler matrix unit. No specific limitations are specified here.

[0102] The beamforming unit delays multiple first-beam optical signals to obtain multiple second-beam optical signals. The delay amounts of the multiple first-beam optical signals corresponding to the same group of optical signals are not the same. The number of second-beam optical signals is the same as the number of first-beam optical signals. The multiple second-beam optical signals are processed and then transmitted through a phased array antenna. If the multiple first-beam optical signals generated by the beamforming network unit are processed by photoelectric conversion and then transmitted through an array antenna, multiple beams with the same direction are obtained, as illustrated in Figure 9, where the optical signal is λ. 1,1 , λ 2,1 A set of optical signals corresponds to two beams with the same direction, and the optical signal is λ. 1,2 , λ 2,2 One set of optical signals corresponds to two other beams with the same direction, and the optical signals are λ. 1,3 , λ 2,3A group of optical signals corresponds to another two beams with the same direction. After the delay of the beam expansion unit, the first beam optical signal is subjected to photoelectric conversion processing and then transmitted through the array antenna, obtaining six beams with different directions.

[0103] Specifically, when the phased array antenna is one-dimensional, the beam expansion unit includes K×N groups of beam expansion subunits. Each group of beam expansion subunits includes a wavelength division demultiplexer, M delay units (which can also be called optical delay lines), and a wavelength division multiplexer, as shown in FIG. 10. The wavelength division demultiplexer, M delay units, and wavelength division multiplexer can be integrated on one chip. Among them, the wavelength division demultiplexer and wavelength division multiplexer have wavelength periodicity, and the periodic wavelength division multiplexer and periodic demultiplexer can be implemented by using the structure of a cascaded asymmetric Mach–Zehnder interferometer (AMZI). FIG. 11 shows a periodic wavelength division demultiplexer with an input port number of 1 and an output port number of 8 formed by cascading 7 AMZIs. In specific applications, the wavelength division demultiplexer and wavelength division multiplexer can also be implemented based on a periodic filter, which will not be elaborated here. N is the same as the input port number of the beamforming network unit, the multiple first beam optical signals are K×N paths, K×N is the same as the number of antenna elements of the phased array antenna, and both N and K are positive integers; the wavelength division demultiplexer is used to demultiplex the K×N paths of the first beam optical signals into M paths of the first beam optical signals, and each path of the first beam optical signals in the M paths of the first beam optical signals includes N first beam optical signals; the M delay units are used to delay the M paths of the first beam optical signals respectively, obtaining M paths of delayed optical signals. Among them, K is the multiple of the output port number of the beamforming network unit and the input port number of the beamforming network unit. When K>1, the output port number of the beamforming network unit is greater than the input port number, and when K takes the value of 1, the output port number of the beamforming network unit is equal to the input port number. Based on this, it can be ensured that after the delay processing of the first beam optical signal by the beam expansion unit, beams with different directions and uniform distribution are obtained. The wavelength division multiplexer is used to converge the M paths of delayed optical signals into one path of the second beam optical signal. The output ports of the periodic wavelength division demultiplexer can periodically select the output wavelength. The periodic wavelength division multiplexer can multiplex the wavelengths of the input ports of each wavelength division multiplexer to the output ports periodically. A delay unit is provided between the output port of the periodic wavelength division demultiplexer and the input port of the periodic wavelength division multiplexer. The output port number of the periodic wavelength division demultiplexer and the input port number of the periodic wavelength division multiplexer are M, and the wavelength of its corresponding first port is λ 1,Q , where 0<Q≤N, Q is a positive integer, which is the wavelength of serial number 1 in all wavelength groups. The wavelength of the second port is λ 2,Q , which is the wavelength of serial number 2 in all wavelength groups.

[0104] As shown in FIG. 12A, the beam expansion unit includes K×N groups of beam expansion subunits. The optical signals λ 1,Q , λ 2,Q , …, λ M,Q are input to the input port of the demultiplexer of the first group of beam expansion subunits, where 0 < Q ≤ N and Q is a positive integer. The time delay value corresponding to the optical signal λ 2,Q is τ 2,1 , the time delay value corresponding to the optical signal λ 3,Q is τ 3,1 , and the time delay value corresponding to the optical signal λ M,Q is τ M,1 . Among them, the values of τ 2,1 , τ 3,1 , and τ M,1 are different. The demultiplexer output port 1 outputs the optical signals λ 1,1 , λ 1,2 , …, λ 1,N , the demultiplexer output port 2 outputs the optical signals λ 2,1 , λ 2,2 , …, λ 2,N , the demultiplexer output port 3 outputs the optical signals λ 3,1 , λ 3,2 , …, λ 3,N , …, the demultiplexer output port M outputs the optical signals λ M,1 , λ M,2 , …, λ M,N . The wavelength division multiplexer input port 1 inputs the optical signals λ 1,1 , λ 1,2 , …, λ 1,N , the demultiplexer input port 2 inputs the optical signals λ 2,1 , λ 2,2 , …, λ 2,N , the demultiplexer input port 3 inputs the optical signals λ 3,1 , λ 3,2 , …, λ 3,N , …, the demultiplexer input port M inputs the optical signals λ M,1 , λ<​​​​​​​​​​​​​​​​​​​​​​3,Q The corresponding time delay value is τ 3,2 , optical signal λ M,Q The corresponding time delay value is τ M,2 Among them, τ 2,2 τ 3,2 τ M,2 The values ​​are different. The optical signal λ input to the input port of the beam demultiplexer of the third group of beam spreading subunits is... 1,Q , λ 2,Q , …, λ M,Q . Optical signal λ 2,Q The corresponding time delay value is τ 2,3 , optical signal λ 3,Q The corresponding time delay value is τ 3,3 , optical signal λ M,Q The corresponding time delay value is τ M,3 Among them, τ 2,3 τ 3,3 τ M,3 The values ​​are not the same. The optical signal λ input to the input port of the beam demultiplexer of the K×Nth beam spreading subunit is... 1,Q , λ 2,Q , …, λ M,Q . Optical signal λ 2,Q The corresponding time delay value is τ 2,KN , optical signal λ 3,Q The corresponding time delay value is τ 3,KN , optical signal λ M,Q The corresponding time delay value is τ M,KN Among them, τ 2,KN τ 3,KN τ M,KN The values ​​are not the same. The delay values ​​of the M delayers corresponding to adjacent beam spreader subunits in different groups have the same difference. For example, τ 2,2 With τ 2,1 The difference in delay values ​​is equal to τ 2,3 With τ 2,2 The difference in delay values. τ 3,2 With τ 3,1 The difference in delay values ​​is equal to τ 3,3 With τ 3,2 The difference in delay values. This is illustrated by example only.

[0106] In this context, the delay values ​​of the first beam optical signals in each of the M sub-paths are different. These delay values ​​are related to the carrier period of the radio frequency signal, the output port number and input port number of the wavelength division multiplexer in the beam spreader sub-unit, the number of the beam spreader sub-unit, and K×N. For example, among the M delay units, the delay of the first delay unit is based on τ0, and the delay of the other delay units relative to the first delay unit is τ.z,y Where z is the output port number of the periodic wavelength division multiplexer, or the input port number of the periodic wavelength division multiplexer, z = 1,…M; y is the input port number (or output port number) of the beam spreader, y = 1,…K×N. Set τ zy =(z-1)(y-1)T RF / (K×N), where T RF =1 / f RF T RF f is the period of the carrier wave of the radio frequency signal. RF The frequency of the carrier wave for the radio frequency signal.

[0107] In this case, when the beamforming network unit is an optically symmetric Butler matrix unit, the delay value is related to the carrier period of the radio frequency signal, the number of the beam spreading sub-unit, and the additional phase shift value. The additional phase shift value is related to the angle difference between the beam corresponding to the second beam optical signal and the beam corresponding to the first beam optical signal. Based on this, beam encryption can be achieved. For example, in M ​​delay units, the delay of the first delay unit is based on τ0, and the delay of the other delay units relative to the first delay unit is τ. r,y Where r is the r-th delay unit in the beam spreader subunit, r = 1, ..., M. y is the input port number (or output port number) of the beam spreader unit, y = 1, ..., K×N. Settings Among them, T RF =1 / f RF ,T RF f is the period of the carrier wave of the radio frequency signal. RF The frequency of the carrier wave of the radio frequency signal. This is the additional phase shift value. Among them, Satisfy the following formula 4:

[0108] Where d indicates the distance between adjacent antenna elements, k = 2π / λ, where λ indicates the wavelength of the radio frequency signal transmitted by the phased array antenna, θ is the pointing angle of the beam corresponding to the first beam optical signal, and Δθ is the angular difference between the beam corresponding to the second beam optical signal and the beam corresponding to the first beam optical signal. As shown in Figure 12B, the pointing angle of the beam corresponding to the first beam optical signal is θ, and the pointing angle of the beam corresponding to the second beam optical signal is θ + Δθ.

[0109] To better illustrate the scheme of this application, the following description uses an optical asymmetric Butler matrix unit with 4 input ports and 8 output ports as an example. Where N=4, M=2, K=2, and the value of K is the same as M, the corresponding asymmetric Butler matrix unit is shown in Figure 13A. The optical signals in the first group of optical signals are λ... 1,1 , λ2,1 The optical signals in the second group of optical signals are λ 1,2 , λ 2,2 The optical signals in the third group of optical signals are λ 1,3 , λ 2,3 The optical signals in the fourth group of optical signals are λ 1,4 , λ 2,4 . τ 1,1 =τ 1,2 =τ 1,3 =τ 1,4 =τ 1,5 =τ 1,6 =τ 1,7 =τ 1,8 =τ0, meaning the delay amount of the first delay unit between the periodic wavelength division multiplexer and the periodic wavelength demultiplexer in each group of beam spreader subunits is the same. τ 2,1 =0,τ 2,2 =T RF / 8,τ 2,3 =2T RF / 8,τ 2,4 =3T RF / 8,τ 2,5 =4T RF / 8,τ 2,6 =5T RF / 8,τ 2,7 =6T RF / 8,τ 2,8 =7T RF / 8.

[0110] In practical applications, the radio frequency device also includes an optical switching unit. The optical switching unit is used to input multiple sets of optical signals to the beamforming network unit. The number of input ports of the optical switching unit is less than or equal to the number of output ports of the optical switching unit, and the number of output ports of the optical switching unit is the same as the number of input ports of the beamforming network unit. Applications based on the optical switching unit allow multiple sets of optical signals to be input to different input ports of the beamforming network unit.

[0111] Figure 13B illustrates an example of an electro-optical conversion unit for an RF device, comprising 8 optical transmitting units, 4 wavelength group multiplexing units (each wavelength group multiplexing unit has 2 input ports and 1 output port), an optical switching unit with 4 input ports and 4 output ports, an optical asymmetric Butler matrix unit with 4 input ports and 8 output ports, and 8 beamforming subunits (each beamforming subunit includes 2 delay units). The RF optical signals at input ports 1, 3, 5, and 7 of the optical transmitting units are carried at wavelength λ. 1,1 , λ 1,2 , λ 1,3 , λ 1,4In the above configuration, the 4×4 optical switching unit is in a pass-through state. Input ports 1-4 of the optical switching unit are connected to output ports 1-4 respectively. That is, the RF optical signals from input ports 1, 3, 5, and 7 are input to input ports 1-4 of the 4×8 Butler matrix. The Butler matrix performs phase shifting processing corresponding to the four beams. Then, in the beamforming unit, the signal is delayed by the first row of delay units. Since the first row of delay units is of equal length, it does not change the phase shift of the Butler matrix output signal. Therefore, the beam generated by the signal output from the beamforming module is the four beams generated by the 4×8 optical Butler matrix, namely beams 1, 3, 5, and 7 in Figure 14 (equivalent to the beams output by the existing 4×8 Butler matrix). The RF optical signals from input ports 2, 4, 6, and 8 of the optical transmitting unit are carried at wavelength λ. 2,1 , λ 2,2 , λ 2,3 , λ 2,4 The optical path goes up. After the 4×4 optical switching unit and the 4×8 Butler matrix, it enters the beam spreader unit and is delayed by the second row delay unit. Because the second row delay unit adds T... RF The π / 8 arithmetic delay (i.e., π / 8 arithmetic phase shift) causes the generated beams to shift at an angle relative to the original beams, which can fill the beam holes left by the first row of delay beams.

[0112] Figure 15 illustrates an example of an electro-optical conversion unit for an radio frequency (RF) device, comprising 8 optical transmitting units, 4 wavelength group multiplexing units (each with 2 input ports and 1 output port), an optical switching unit with 4 input ports and 4 output ports, an optical symmetric Butler matrix unit with 4 input ports and 4 output ports, and 4 beamforming subunits (each including 2 delay units). The RF optical signals at input ports 1, 3, 5, and 7 of the optical transmitting units are carried at wavelength λ. 1,1 , λ 1,2 , λ 1,3 , λ 1,4 Above. With the 4×4 optical switching unit in a pass-through state, input ports 1-4 of the optical switching unit are connected to output ports 1-4 respectively. That is, the RF optical signals from input ports 1, 3, 5, and 7 are input to input ports 1-4 of the 4×8 Butler matrix. The Butler matrix performs phase shifting processing corresponding to the four beams, followed by a delay from the first row of delay units. Since the first row of delay units is of equal length, it does not change the phase shift of the Butler matrix output signal. Therefore, the beam generated by the signal output from the beam extension module is the four beams generated by the 4×4 optical Butler matrix, namely beams 1, 3, 5, and 7 in Figure 14 (equivalent to the beams output by the existing 4×4 Butler matrix). The RF optical signals from input ports 2, 4, 6, and 8 of the optical transmitting units are carried at wavelength λ. 2,1 , λ2,2 , λ 2,3 , λ 2,4 Above, after the 4×4 optical switching unit and the 4×4 Butler matrix, the light enters the beam spreader unit, and is delayed by the second row delay unit. Because the second row delay unit adds T... RF The equal-arithmetic delay of π / 8 (i.e., π / 8 equal-arithmetic phase shift) causes the generated beams to shift by an angle relative to the original beams, which can achieve beam encryption.

[0113] For example, if the number of optical transmitting units in the radio frequency device is less than the number of array elements in the phased array antenna, and the optical transmitting units cannot achieve optical wavelength extension, when the radio frequency device uses an optically symmetric Butler matrix, partial beam encryption can be achieved, as shown in Figure 14, where only beams 1, 2, 3, 4, 5, and 7 are acquired. When using an optically asymmetric Butler matrix, some gaps can be filled, as shown in Figure 14, where the gaps between beams 1 and 2 are filled, the gap between beams 3 and 5 is filled, and other gaps are not filled.

[0114] Specifically, when the phased array antenna is two-dimensional (or 2D), the beam spreading unit includes X×Y groups of beam spreading sub-units, and each group of beam spreading sub-units includes a beam demultiplexer, M... x ×M y A time delay and a wavelength division multiplexer (WDM), the WDM and WDM having wavelength periodicity; X is K x ×N x Y is K y ×N y N x ×N y Similar to the number of input ports of the beamforming network unit, the multiplexed first beam optical signals are X×Y channels, where X has the same number of antenna elements in the horizontal direction as the phased array antenna, and Y has the same number of antenna elements in the vertical direction as the phased array antenna. A beam demultiplexer is used to demultiplex the X×Y channels of the first beam optical signals into M channels. x ×M y Sub-path first beam optical signal, M x ×M y Each sub-path first beam optical signal in the sub-path first beam optical signal includes N x ×N y The first beam optical signal; M x ×M y A delay unit is used for M x ×M y The first beam optical signal of the sub-path is delayed to obtain M. x ×M y Sub-path delay optical signal; wavelength division multiplexer, used to convert M x ×M yThe delayed optical signals from the secondary path converge into a second beam of optical signal. Among them, K... x K is the multiple of the number of output ports in the horizontal direction of the beamforming network element to the number of input ports in the horizontal direction of the beamforming network element. y K is the multiple of the number of output ports in the vertical direction of the beamforming network element to the number of input ports in the vertical direction of the beamforming network element. x >1, K y When K > 1, the number of output ports in the horizontal direction of the beamforming network unit is greater than the number of input ports in the horizontal direction, and the number of output ports in the vertical direction of the beamforming network unit is greater than the number of input ports in the vertical direction. x and K y When the value is 1, the number of output ports in the horizontal direction of the beamforming network unit is equal to the number of input ports in the horizontal direction of the beamforming network unit, and the number of output ports in the vertical direction of the beamforming network unit is equal to the number of input ports in the vertical direction of the beamforming network unit.

[0115] In a two-dimensional beam spreader unit, the output port of the two-dimensional delayer, with a horizontal position of i and a vertical position of j, is numbered (i,j), and the wavelength output from this port is λ. i,j,x,y Where x ranges from 1 to N. x The value of y ranges from 1 to N. y As shown in Figure 16A. M x ×M y The delay values ​​of the first beam optical signals in each sub-path are different. These delay values ​​are related to the carrier period of the RF signal, the output port number and input port number of the wavelength division multiplexer in the beam spreading sub-unit, the number of the beam spreading sub-unit, and the X×Y coordinates. x ×M y The delay values ​​of the delay units have the same difference. The delay units are connected to the output port of the periodic wavelength division multiplexer and the input port of the periodic wavelength division multiplexer; the delay amount at the corresponding ports is... The output ports (i,j) of the periodic wave demultiplexer and the port numbers (n) of the beam spreader subunit are shown. x ,n y Delay amount Satisfy the following formula 5:

[0116] In this case, when the beamforming network unit is an optically symmetric Butler matrix unit, the delay value is related to the period of the RF signal carrier, the number of the beam spreading subunit, and the additional phase shift value. The additional phase shift value is related to the angular difference between the beam corresponding to the second beam optical signal and the beam corresponding to the first beam optical signal. Based on this, beam encryption can be achieved. For example, the delay unit connects the output port of the periodic wavelength division multiplexer and the input port of the periodic wavelength division multiplexer, and the delay amount at the corresponding port is... The output ports (i,j) of the periodic wave demultiplexer and the port numbers (n) of the beam spreader subunit are shown. x ,n y Delay amount Satisfy the following formula 6:

[0117] in, and This is the additional phase shift value. Among them, and Satisfy the following formula 7

[0118] Where, θ x θ is the horizontal pointing angle of the beam corresponding to the first beam optical signal. y Δθ is the vertical pointing angle of the beam corresponding to the first beam optical signal. x Δθ is the horizontal angular difference between the beam corresponding to the second beam optical signal and the beam corresponding to the first beam optical signal. y Let θ be the vertical angular difference between the beam corresponding to the second beam optical signal and the beam corresponding to the first beam optical signal. As shown in Figure 16B, the pointing angle of the beam corresponding to the first beam optical signal is (θ). x θ y The pointing angle of the second beam optical signal is (θ). x +Δθ x θ y +Δθ y ).

[0119] To better illustrate the scheme of this application, the following description uses a two-dimensional asymmetric Butler matrix unit with 16 input ports and 64 output ports as an example. Wherein, M... x =2, M y =2, K x =2 and K y=2. Figure 17 shows a comparison between the 16 beams output by the existing asymmetric Butler matrix unit with 16 input ports and 64 output ports, and the 64 beams formed by using the beam extender unit of this application. Compared with the prior art, the beam extender unit of this application can expand the beam by 2 times in both the horizontal and vertical directions, thereby forming 64 beams and filling the beam gaps in the existing system.

[0120] The aforementioned multiple second-beam optical signals, after processing, are transmitted via a phased array antenna. This can be understood as the multiple second-beam optical signals undergoing photoelectric conversion and power amplification before being input to the antenna elements of the phased array antenna. To achieve photoelectric conversion, the RF device also includes a photoelectric conversion unit, used to perform photoelectric conversion on the multiple second-beam optical signals to obtain multiple electrical signals, the number of which is the same as the number of the multiple second-beam optical signals. To achieve power amplification, the RF device also includes power amplifiers, the number of which is the same as the number of photoelectric conversion units. The power amplifiers amplify the multiple electrical signals to obtain amplified electrical signals, and then transmit the amplified electrical signals to the phased array antenna. The photoelectric conversion unit can be implemented using a photodetector, and the power amplifier can also be a low-noise amplifier; this is not specifically limited here. As shown in Figure 18, the RF device includes an electro-optical conversion unit, a wavelength grouping and multiplexing unit, an optical switching unit, an optical asymmetric Butler matrix unit, a beam spreading unit, a photoelectric conversion unit, and power amplifiers. The electro-optical conversion unit includes N×M optical emitting units, M wavelength group multiplexing units, N input ports and N output ports for the optical switching unit, N input ports and K×N output ports for the Butler matrix unit, K×N input ports and K×N output ports for the beam spreader unit, K×N photoelectric conversion units, and K×N power amplifiers.

[0121] In this application, the radio frequency signal is converted into an optical signal by an electro-optical conversion unit. The optical signal is then divided into multiple groups of optical signals by a wavelength grouping multiplexing unit. The wavelengths of adjacent optical signals are evenly spaced. After grouping delay processing by a beamforming network unit, multiple first-beam optical signals are obtained. These multiple first-beam optical signals are then processed by a beam spreading unit, and different groups of first-beam optical signals are delayed to obtain multiple second-beam optical signals. These second-beam optical signals are then processed and transmitted via a phased array antenna. Each of the multiple first-beam optical signals can correspond to multiple beams pointing in the same direction. After delay processing by a beam spreading unit, the resulting multiple second-beam optical signals can each correspond to beams pointing in different directions. Compared to radio frequency devices that do not incorporate wavelength grouping multiplexing units and beam spreading units, the phased array antenna in this application transmits a denser beam with a wider beam coverage, meeting the access needs of multiple users.

[0122] In this application, multiple units in the radio frequency device can be integrated into one chip, or they can be integrated into different chips. This application does not specifically limit this. For example, the electro-optic conversion unit, wavelength grouping and multiplexing unit, beamforming network unit, and beam spreading unit can be integrated into one chip, or the electro-optic conversion unit and wavelength grouping and multiplexing unit can be integrated into one chip, and the beamforming network unit and beam spreading unit can be integrated into one chip respectively. This is only an example.

[0123] This application provides a communication device, including the aforementioned radio frequency device and a phased array antenna; the phased array antenna is used to feed multiple electrical signals into the antenna elements of the phased array antenna to form multiple directional beam signals, the number of which is the same as the number of radio frequency signals. As shown in Figure 19, Figure 19 is based on Figure 18 with the addition of a phased array antenna, and N×M power amplifiers are respectively connected to the antenna elements of the phased array antenna.

[0124] Specifically, the communication device also includes a baseband processing unit and an intermediate frequency (IF) radio frequency (RF) unit; the baseband processing unit is used to generate an IF signal; the RF unit is used to convert the IF signal into an RF signal. As shown in Figure 20, the baseband processing unit generates an IF signal through coding modulation, the IF signal is converted into an RF signal by the RF unit, and the RF signal is output by the communication device shown in Figure 19 as having multiple beams with different directions.

[0125] Typically, the number of beams generated by a communication device is the same as the number of antenna elements in a phased array antenna. However, depending on the specific application, fewer or more beams may be generated, depending on actual needs. This application does not specifically limit this number.

[0126] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0127] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A radio frequency device, characterized by, It includes an electro-optical conversion unit, a wavelength grouping and multiplexing unit, a beamforming network unit, and a beam spreading unit; The electro-optic conversion unit is used to modulate multiple radio frequency signals onto optical signals of different wavelengths; The wavelength grouping multiplexing unit is used to divide the optical signals of different wavelengths into multiple groups according to wavelength to obtain multiple groups of optical signals. The wavelengths of adjacent optical signals are equally periodically spaced, and the multiple groups of optical signals correspond to different output ports of the wavelength grouping multiplexing unit. The beamforming network unit is used to delay the multiple groups of optical signals to obtain multiple first beam optical signals. The delay amount of the optical signals within the same group is the same, while the delay amount of the optical signals in different groups is different. The beam extension module is used to delay the multiple first beam optical signals to obtain multiple second beam optical signals. The delay amounts of the multiple first beam optical signals corresponding to the same group of optical signals are not the same. The number of the multiple second beam optical signals is the same as the number of the multiple first beam optical signals. The multiple second beam optical signals are processed and then transmitted through the phased array antenna.

2. The radio-frequency device according to claim 1, characterized in that The beamforming unit comprises K×N groups of beamforming subunits. Each group of beamforming subunits includes a wavelength demultiplexer, M delay units, and a wavelength division multiplexer. The wavelength demultiplexer and the wavelength division multiplexer have wavelength periodicity. N is the same as the number of input ports of the beamforming network unit. The value of M is related to the number of optical signals in the multiple groups of optical signals. The multiple first beam optical signals are K×N, and K×N is the same as the number of antenna elements of the phased array antenna. N, K, and M are all positive integers. The wave demultiplexer is used to demultiplex the K×N first beam optical signals into M sub-channel first beam optical signals, and each sub-channel first beam optical signal in the M sub-channel first beam optical signals includes N first beam optical signals. The M delay units are used to delay the optical signal of the first beam of the M sub-path respectively, so as to obtain the delayed optical signal of the M sub-path. The wavelength division multiplexer is used to converge the M-path delayed optical signal into a second-beam optical signal.

3. The radio-frequency device according to claim 2, characterized in that The delay values ​​of the first beam optical signals of each sub-path in the M-path first beam optical signal are not the same. The delay value is related to the period of the carrier of the radio frequency signal, the output port number and input port number of the wavelength division multiplexer in the beam spreading sub-unit, the number of the beam spreading sub-unit, and K×N; or, the delay value is related to the period of the carrier of the radio frequency signal, the number of the beam spreading sub-unit, and the additional phase shift value. The additional phase shift value is related to the angle difference between the corresponding beam of the second beam optical signal and the corresponding beam of the first beam optical signal.

4. The radio-frequency device according to claim 3, characterized in that The delay values ​​of the M delayers corresponding to the same number in adjacent beam spreader subunits in different groups are the same.

5. The radio frequency device of any of claims 2-4, wherein, The wavelength grouping multiplexing unit is used to divide signals of different wavelengths into N groups of optical signals. Each group of optical signals includes M optical signals. The wavelength interval of adjacent optical signals in the M optical signals is a first value, which ensures that the optical signal spectra corresponding to adjacent wavelengths in the M optical signals do not overlap.

6. The radio-frequency device according to claim 1, characterized in that The beam spreading unit comprises X×Y groups of beam spreading sub-units, each group of which includes a beam demultiplexer and an M... x ×M y A delay unit and a wavelength division multiplexer, wherein the wavelength division multiplexer and the wavelength division multiplexer are wavelength periodic; X is K. x ×N x Y is K y ×N y The N x ×N y The M has the same number of input ports as the beamforming network unit. x ×M y The value of K is related to the number of optical signals in the multiple sets of optical signals. The multiple first beam optical signals are X×Y channels, where X is the same as the number of antenna elements in the horizontal direction of the phased array antenna, and Y is the same as the number of antenna elements in the vertical direction of the phased array antenna. x、 N x K y、 N y M x、 M y All are positive integers; The wavelength division multiplexer is configured to demultiplex the X×Y first beam optical signals into M x ×M y sub-path first beam optical signals, and the M x ×M y sub-path first beam optical signals each include N x ×N y first beam optical signals. The M x ×M y delay units are used for delaying the M x ×M y sub-path first beam optical signals respectively to obtain M x ×M y sub-path delayed optical signals. The wavelength division multiplexer is configured to combine the M x ×M y sub-path delayed optical signals into one second beam optical signal.

7. The radio-frequency device according to claim 6, characterized in that The M x ×M y The delay values ​​of the first beam optical signals of each sub-path in the first beam optical signal are not the same. The delay value is related to the period of the carrier of the radio frequency signal, the output port number and input port number of the wavelength division multiplexer in the beam spreading sub-unit, the number of the beam spreading sub-unit, and X×Y; or, the delay value is related to the period of the carrier of the radio frequency signal, the number of the beam spreading sub-unit, and the additional phase shift value. The additional phase shift value is related to the angle difference between the corresponding beam of the second beam optical signal and the corresponding beam of the first beam optical signal.

8. The radio-frequency device according to claim 7, characterized in that The difference of the delay values of the M delay units in the adjacent beam spreading sub-units in different groups of beam spreading sub-units is same. x ×M y The difference of the delay values of the M delay units in the adjacent beam spreading sub-units in different groups of beam spreading sub-units is same.

9. The radio frequency device of any of claims 6-8, wherein, The wavelength group multiplexing unit is used to divide signals of different wavelengths into N. x ×N y Groups of optical signals, each group of optical signals including M x ×M y A light signal, the M x ×M y The wavelength interval between adjacent optical signals in a given optical signal is a second value, which makes the M x ×M y The optical signal spectra corresponding to adjacent wavelengths in an optical signal do not overlap.

10. The radio frequency device of any one of claims 1-9, wherein, Also includes: Photoelectric conversion unit; The photoelectric conversion unit is used to perform photoelectric conversion on the multiple second beam optical signals to obtain multiple electrical signals, the number of which is the same as the number of the multiple second beam optical signals.

11. The radio frequency device of any of claims 1-10, wherein, The electro-optic conversion unit includes multiple light emitting units.

12. The radio-frequency device according to claim 11, characterized in that Each of the optical emitting units outputs optical signals of different wavelengths in a time-division manner.

13. The radio frequency device of any one of claims 1-12, wherein, Also includes: Optical switching unit; The optical switching unit is used to input the multiple sets of optical signals to the beamforming network unit. The number of input ports of the optical switching unit is less than or equal to the number of output ports of the optical switching unit, and the number of output ports of the optical switching unit is the same as the number of input ports of the beamforming network unit.

14. The radio-frequency device according to any of claims 1 to 13, characterized in that Also includes: Power amplifiers, the number of which is the same as the number of photoelectric conversion units; The power amplifier is used to amplify the plurality of electrical signals to obtain an amplified electrical signal, and transmit the amplified electrical signal to the phased array antenna.

15. The radio-frequency device according to any of claims 1 to 14, characterized in that The beamforming network unit is an optical Butler matrix unit.

16. A communications device, characterized by Includes the radio frequency device and phased array antenna as described in any one of claims 1 to 15; The phased array antenna is used to feed multiple electrical signals into the antenna elements of the phased array antenna to form multiple directional beam signals, the number of which is the same as the number of multiple radio frequency signals.

17. The apparatus of claim 16, wherein, It also includes a baseband processing unit and a mid-frequency radio unit; The baseband processing unit is used to generate intermediate frequency signals; The intermediate frequency (IF) unit is used to convert the IF signal into an RF signal.

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