An all-optical simultaneous multi-band multi-beam phased array transmitter and method thereof

Abstract

The present invention discloses an all-optical simultaneous multi-band multi-beam phased array transmitter and method thereof. The invention belongs to the field of radio frequency wireless communication and radar detection technology. The optical signals output by N wavelength continuously tunable lasers are combined by a first wavelength division multiplexer and then split into two beams by an optical power splitter. One optical signal is demultiplexed into N optical signals by a second wavelength division multiplexer and input into corresponding N carrier suppressed single-sideband modulators, where it is modulated by N electrical signals of different frequencies and amplified by an optical amplifier; then, it is combined by a third wavelength division multiplexer and split into M+1 beams by an optical power splitter, and then input into corresponding (M+1) photodetectors. The other optical signal is phase-shifted by a 1×(M+1) optical phase shift network, phase-modulated by corresponding (M+1) optical phase shifters, and then input into corresponding (M+1) photodetectors. The N different radio frequency signals obtained by the beat frequency of the photodetectors are coupled into the array antenna. By adjusting the wavelengths of the N lasers, the continuous scanning of the N beams can be independently controlled.

Description

Technical Field

[0001] The present invention belongs to the technical field of radio frequency wireless communications and relates to an all-optical simultaneous multi-band multi-beam phased array transmitter and a method thereof. Background Art

[0002] Phased array technology is widely used in radar, electronic reconnaissance, 5G / 6G wireless communication systems, satellite communication systems, and the Internet of Things. Compared to traditional aperture antenna technology and mechanical scanning techniques, phased array systems achieve flexible beam pointing and inertia-free rapid scanning by adjusting the phase and amplitude of the RF signal transmitted by each array element. Furthermore, a phased array system can simultaneously form multiple independent beams to perform functions such as identification, reconnaissance, tracking, and communication. In electronic reconnaissance applications, the multiple independent beams emitted by a phased array system can simultaneously track multiple targets, significantly improving the efficiency of the reconnaissance system. In wireless communication applications, the multiple independent beams generated by a phased array system can simultaneously communicate with multiple targets, significantly increasing spectrum efficiency and communication capacity. Furthermore, compared to traditional aperture antennas, the signals emitted by phased array systems are directional. While maintaining the same sensitivity, this significantly reduces the receiver antenna aperture, further reducing the size and volume of the receiver system, which is crucial for system miniaturization. In terms of reliability and stability, since the phased array system contains multiple array elements, when one or several array elements fail, the other array elements can continue to work, thus greatly enhancing the stability and reliability of the system.

[0003] The most important component of a phased array system is the beamforming network, which directly determines the bandwidth, power consumption, loss, reliability, electromagnetic interference resistance, and control complexity of the phased array beam transmission. Traditional phased array systems all use a purely electrical architecture, primarily composed of an electrical power distribution network, an analog electrical phase shifting network, and an electrical amplifier. This solution has low bandwidth, high power consumption, high loss, a complex structure, and weak electromagnetic interference resistance. Furthermore, multiple beams require multiple electrical phase shifting sub-networks, electrical power sub-networks, and multi-stage electrical amplifiers. The number of beams is severely limited by the number of sub-arrays and the number of antenna elements in the array antenna, resulting in poor scalability.

[0004] Another electrical phased array technology uses transceiver components, meaning each phased array antenna is connected to a set of RF transceiver components. Each transceiver component can independently control the phase and amplitude of the RF signal transmitted by the corresponding antenna, thus providing great flexibility. However, RF transceiver components have limited bandwidth, complex structure, and extremely high cost. For simultaneous multi-beamforming, these transceiver components still need to be divided into multiple sub-arrays, each of which independently controls a beam. Therefore, the number of beams in this solution is still limited by the number of phased array antenna elements. When the number of beams required exceeds hundreds, thousands of phased array antenna elements are required, which will significantly increase the system size, power consumption, and cost.

[0005] Compared to phased array antenna systems based on electrical components, RF phased array systems designed and constructed using optical solutions offer advantages such as wide bandwidth, low transmission loss, and strong resistance to electromagnetic interference. Currently, beamforming networks constructed using optical components are primarily true delay line networks, which utilize optical switches and delay waveguides to construct single-pass beamforming networks. This approach offers advantages such as wide bandwidth, no beam skew, and strong resistance to electromagnetic interference. However, for multi-beam phased array solutions, the system is extremely complex and requires multiple phased array subarrays to implement. Therefore, multi-beam phased array systems based on this approach are still limited by the number of subarrays and phased array antennas, hindering system expansion and multi-beam implementation.

[0006] Another optical RF phased array solution uses optical transceiver components, with each antenna unit corresponding to one optical transceiver component. In this solution, each transceiver component includes a modulator, an optical true delay line, and a photodetector. This solution offers advantages in terms of wide bandwidth and strong immunity to electromagnetic interference, but it still requires a subarray approach to provide multiple beams. In large-scale beamforming systems, this solution is structurally complex and requires a large number of subarrays to provide multiple beams, making it difficult to scale.

[0007] In summary, traditional electrical phased array solutions suffer from limited bandwidth, high transmission losses, and high system power consumption. While optical RF phased arrays can effectively increase system bandwidth and reduce transmission losses, they still require multiple antenna elements and subarrays to achieve simultaneous multi-beam systems. Therefore, when the number of beams in a phased array system reaches hundreds or more, system complexity, power consumption, and cost will increase significantly. Summary of the Invention

[0008] The purpose of the present invention is to overcome the bottleneck of the existing technology and provide an all-optical simultaneous multi-band multi-beam phased array transmitter and method thereof.

[0009] The technical solutions of the present invention are as follows:

[0010] In one aspect, the present invention provides an all-optical simultaneous multi-band multi-beam phased array transmitter, comprising:

[0011] N wavelength continuously tunable lasers in different bands;

[0012] The first wavelength division multiplexer combines the optical signals output by N wavelength continuously tunable lasers;

[0013] A first optical power splitter is used to split the optical signal combined by the first wavelength division multiplexer into two equal paths;

[0014] The modulation network module loads the radio frequency signals of different frequencies onto one of the optical signals after power splitting by the first optical power splitter;

[0015] The second optical power splitter divides the optical signal output by the modulation network module into M+1 equal paths;

[0016] The phase shift network module performs optical phase shift and optical phase calibration on the other optical signal after power splitting by the first optical power splitter, and outputs M+1 optical signals;

[0017] M+1 photodetectors, each of which has a first input port receiving the optical signal of the corresponding path equally divided by the second optical power splitter, and a second input port receiving the optical signal of the corresponding path of the phase-shift network module. Each photodetector beats the signal to obtain N radio frequency signals with different frequencies;

[0018] M+1 antenna units transmit N different radio frequency signals obtained by beating the photoelectric detector.

[0019] According to a preferred embodiment of the present invention, the modulation network module includes:

[0020] A second wavelength division multiplexer, which wavelength-divides one optical signal after power division by the first optical power splitter into N optical signals;

[0021] N carrier suppressed single sideband modulators respectively receive the N optical signals after wavelength division by the second wavelength division multiplexer, and modulate each optical signal using a radio frequency signal of a different frequency;

[0022] N optical amplifiers amplify the signals modulated by N carrier suppressed single-sideband modulators to compensate for the coupling loss in the link and the insertion loss of the device itself;

[0023] The third wavelength division multiplexer combines the optical signals amplified by the N optical amplifiers.

[0024] According to a preferred embodiment of the present invention, the phase-shift network module includes:

[0025] The optical phase shift network receives the other optical signal after the first optical power splitter and performs optical phase shift, outputting M+1 optical signals, and the phase difference between any two adjacent output optical signals is equal, and the phase difference is

[0026] M optical phase shifters perform optical phase calibration on the 2nd to M+1th optical signals output by the optical phase shift network.

[0027] On the other hand, the present invention provides an all-optical simultaneous multi-band multi-beamforming method based on the phased array transmitter, which comprises the following steps:

[0028] The optical signals output by N wavelength continuously tunable lasers of different wavelength bands are recorded as λ1, λ2, ..., λ N, the optical signal is combined by the first wavelength division multiplexer and input into the first optical power splitter, and is equally divided into two optical signal groups by the first optical power splitter;

[0029] One of the optical signal groups is input into the second wavelength division multiplexer and is wavelength-divided into N single-carrier signals with wavelengths of λ1, λ2, ..., λ N The N single-carrier optical signals are input into the corresponding N carrier suppressed single sideband modulators, and at the same time, N radio frequency signals with different frequencies f m1 , f m2 ,…,f mN The corresponding carrier suppressed single sideband modulators are modulated simultaneously, and the output carrier suppressed single sideband optical signals are amplified by erbium-doped fiber amplifiers;

[0030] N channels of suppressed single-sideband signals are combined into one optical signal by a third wavelength division multiplexer and then equally divided into M+1 optical signals by a second optical power splitter. The equally divided M+1 optical signals are respectively input into the first input ports of the corresponding M+1 photodetectors.

[0031] The other optical signal group equally divided by the first optical power splitter is input to the phase shift network module, and the optical phase shift and optical phase calibration are performed on the other optical signal after the first optical power splitter, and M+1 optical signals are output to the second input port of the corresponding photodetector, and the phase difference between the two adjacent output optical signals is

[0032] The M+1 radio frequency signals generated by the M+1 photodetectors are coupled to the M+1 antenna units through cables respectively; by adjusting the working wavelengths λ1, λ2, ..., λ N , you can get the frequency f m1 , f m2 ,…,f mN The directions of the N beams are independently controlled.

[0033] The third invention, the present invention also provides a method for integrating the phased array transmitter, which is to integrate some components of the phased array transmitter into an InP-based optical chip and an SOI-based optical chip;

[0034] The first optical power splitter, the second wavelength division multiplexer, the third wavelength division multiplexer, N carrier suppressed single sideband modulators, the second optical power splitter, the phase shift network module and M+1 photodetectors are integrated on the SOI-based optical chip; the SOI optical chip reserves optical input and output interfaces for coupling with the InP-based optical chip;

[0035] An array chip consisting of N semiconductor optical amplifiers (SOAs) is designed and fabricated on an InP-based optical chip.

[0036] Finally, the InP-based optical chip is integrated with the heterojunction on the base optical chip through flip-chip bonding or lens spatial coupling.

[0037] Compared with the existing technology, the present invention can simultaneously transmit multiple microwave phased array beams, and the frequency of each beam is different. In terms of electronic reconnaissance applications, the invention can track multiple targets at the same time; in terms of broadband wireless communications, the invention can communicate with multiple users at the same time without interfering with each other. Based on a new design architecture, the invention breaks the limitation of the number of beams of traditional electrical phased arrays on the number of array elements and the size of sub-arrays, and realizes a new type of simultaneous multi-beam phased array transmitter with strong scalability. At the same time, the invention is based on optical equipment and devices, and has advantages such as large bandwidth and strong resistance to electromagnetic interference. In addition, the present invention proposes an integration method for the invention system, which is based on SOI and InP photonic integration platform. Compared with the system built with optical discrete devices, this integration method has the advantages of small size, low power consumption, and strong stability, which will further promote the practical application of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a structural schematic diagram of the all-optical simultaneous multi-band multi-beam phased array transmitter of the present invention.

[0039] Figure 2 This is a structural diagram of an all-optical simultaneous multi-band multi-beam phased array transmitter after selecting a specific modulation network module and a phase shift network module in the embodiment.

[0040] Figure 3 It is a schematic diagram of the WDM spectrum channel of the present invention.

[0041] Figure 4 Schematic diagram of four 1×(M+1) OPSN structures of the present invention.

[0042] Figure 5 It is another schematic diagram of the N×(M+1) OPSN structure of the present invention.

[0043] Figure 6 It is a schematic diagram of the AF point spectrum of the link of the present invention.

[0044] Figure 7 Schematic diagram of the silicon-based CS-SSB Mod structure of the present invention.

[0045] Figure 8 It is a schematic diagram of the germanium PD structure of the present invention.

[0046] Figure 9 It is a cross-sectional schematic diagram of the SOI optical chip processing technology.

[0047] Figure 10 This is a schematic diagram of the structure of the InP SOA optical chip. DETAILED DESCRIPTION

[0048] The present invention will be further described and illustrated below in conjunction with specific embodiments. The embodiments are merely illustrative of the present disclosure and do not limit its scope. The technical features of the various embodiments of the present invention may be combined accordingly, provided that there is no conflict between them.

[0049] like Figure 1 The figure shows the structure of the all-optical simultaneous multi-band multi-beam phased array transmitter of the present invention. It includes: N continuously tunable wavelength lasers (CWLs) of different bands, a first wavelength division multiplexer (1×N WDM), a first optical splitter (OS), a modulation network module, a second optical splitter, a phase shift network module, M+1 photodetectors (PDs), and M+1 antenna elements (AEs). N and M are positive integers and are independent of each other. Among them, the first wavelength division multiplexer combines the optical signals output by N wavelength continuously tunable lasers; the first optical power splitter divides the optical signals combined by the first wavelength division multiplexer into two equal paths; the modulation network module loads radio frequency signals of different frequencies onto one of the optical signals after power splitting by the first optical power splitter; the second optical power splitter divides the optical signal output by the modulation network module into M+1 equal paths; the phase shift network module performs optical phase shift and optical phase calibration on the other optical signal after power splitting by the first optical power splitter, and outputs M+1 optical signals; the first input port of each photodetector receives the optical signal of the corresponding path after equal splitting by the second optical power splitter, and the second input port receives the optical signal of the corresponding path of the phase shift network module, and each photodetector beats the frequency to obtain N radio frequency signals with different frequencies; and the M+1 antenna units transmit the N different radio frequency signals obtained by the photodetector beat.

[0050] Figure 2 The figure is a schematic diagram of the structure of a specific all-optical simultaneous multi-band multi-beam phased array transmitter. The modulation network module in this embodiment includes: a second wavelength division multiplexer, N carrier-suppressed single sideband modulators (CS-SSB Mod), N optical amplifiers and a third wavelength division multiplexer.

[0051] The second wavelength division multiplexer wavelength-divides one optical signal after power division by the first optical power divider into N channels; N carrier suppressed single sideband modulators (CS-SSB Mods) respectively receive the N optical signals after wavelength division by the second wavelength division multiplexer and modulate each optical signal using radio frequency signals of different frequencies; N optical amplifiers respectively amplify the signals modulated by the N carrier suppressed single sideband modulators to compensate for coupling loss in the link and insertion loss of the device itself; the N optical amplifiers in this embodiment are N erbium-doped fiber amplifiers (EDFA); and the third wavelength division multiplexer combines the optical signals amplified by the N optical amplifiers.

[0052] The phase-shift network module includes: a 1×(M+1) optical phase-shift network (OPSN) and M optical phase shifters. The 1×(M+1) optical phase-shift network (OPSN) receives the other optical signal after the first optical power splitter and performs optical phase shifting, outputting M+1 optical signals, and the phase difference between any two adjacent output optical signals is equal, and the phase difference is It can be a positive value, zero or a negative value; the M optical phase shifters perform optical phase calibration on the 2nd to M+1th optical signals output by the optical phase shift network.

[0053] The first wavelength division multiplexer, the second wavelength division multiplexer, and the third wavelength division multiplexer of this embodiment have the same number of channels, bandwidth of each channel, and center wavelength, and are all 1×N wavelength division multiplexers (1×N Wavelength Demultiplexer, 1×N WDM).

[0054] from Figure 2 It can be seen that the main structure of this embodiment includes a 1×2 OS, a 1×(M+1) OS, N CWLs with continuously adjustable wavelengths in different bands, three identical 1×N WDMs, N CS-SSB Mods, N EDFAs, a 1×(M+1) OPSN, M OPSs, (M+1) PDs, and (M+1) AEs.

[0055] A 1×2 OS includes one optical input port and two optical output ports; a 1×(M+1) OS includes one optical input port and (M+1) optical output ports. The 1×(M+1)OS can be a 1×(M+1) multimode interferometer (MMI) structure or a tree structure based on a multi-level 1×2OS cascade. The three 1×N WDM structures are exactly the same. Due to the reversibility of the optical path (the optical input port and the optical output port can be interchanged), in WDM-1, the number of its optical input ports is N, and the number of its optical output ports is 1; in WDM-2, the number of its optical input ports is 1, and the number of its optical output ports is N; in WDM-3, the number of its optical input ports is N, and the number of its optical output ports is 1; the CS-SSB Mod contains one optical input port and an optical output port; the EDFA contains one optical input port and an optical output port; the 1×(M+1)OPSN contains one optical input port and (M+1) optical output ports; the OPS contains one optical input port and an optical output port; the PD contains two optical input ports and one RF signal output port; and the AE includes one RF input port.

[0056] like Figure 1 、 2 As shown, the output wavelengths are λ1, λ2, ..., λ N The laser wavelengths output by the N CWLs are input to the corresponding N optical input ports of WDM-1 and output after being combined by WDM-1. The optical output port of WDM-1 is connected to the optical input port of 1×2OS, which splits the combined optical signal of WDM-1 into two equal paths. One path is input to the optical input port of WDM-2, and the other path is input to the optical input port of 1×(M+1)OPSN. WDM-2 splits the input optical signal into N paths and outputs them from its N optical output ports. The wavelengths output from the corresponding N optical output ports are λ1, λ2, ..., λ N .

[0057] The optical carrier signals output by the N optical output ports of WDM-2 are respectively input into the corresponding N CS-SSB Mods, that is, the output wavelength of WDM-2 is λ N Connect the optical output port of the CS-SSB Mod-N to the optical input port of the CS-SSB Mod-N.

[0058] Frequency is f mN The RF electrical signal modulates the corresponding optical carrier λ through the RF input port of CS-SSB Mod-N N , the frequency of the output carrier suppressed single sideband signal is λ N +f mNThe modulated optical signal is amplified by EDFA-N to compensate for the coupling loss in the link and the insertion loss of the device itself, that is, the optical output port of CS-SSB Mod-N is connected to the optical input port of EDFA-N.

[0059] N carrier suppressed single sideband signals are combined into one optical signal through WDM-3, that is, the optical output port of CS-SSB Mod-N is connected to the Nth optical input port of WDM-3.

[0060] The optical carrier signal combined by the WDM-3 is power-equally split into (M+1) paths through 1×(M+1)OS, that is, the optical output port of the WDM-3 is connected to the optical input port of 1×(M+1)OS.

[0061] The optical signal output from the first optical output port of 1×(M+1)OS is input to an optical input port of PD-0, and the optical signals output from the second to (M+1)th optical output ports of 1×(M+1)OS are input to one of the optical input ports of PD-1 to PD-M respectively.

[0062] The optical signal input to the 1×(M+1) OPSN is output from its corresponding (M+1) optical output port, and the phase difference between the (M+1)th optical signal and the Mth optical signal is

[0063] To compensate for process-induced phase errors in the link and calibrate the link phase, an adjustable optical phase shifter is introduced at each optical output port of the 1×(M+1)OPSN. That is, the (M+1)th optical output port of the 1×(M+1)OPSN is connected to the optical input port of the OPS-M.

[0064] The first optical output port of the 1×(M+1)OPSN does not need to be connected to an OPS and is directly input to another optical input port of PD-0. The (M+1)th optical output port of the 1×(M+1)OPSN is connected to another optical input port of PD-M.

[0065] The radio frequency signals output by the M+1 PDs are transmitted to the corresponding M+1 AEs through cables, and the radio frequency signals are transmitted through the AEs.

[0066] like Figure 3 As shown in Figure 1, the bandwidth of the N WDM channels is greater than the wavelength tunable range Δλ of the CWL. Typically, the PD bandwidth is 50 GHz, so the spacing between adjacent WDM channels must be greater than the PD bandwidth, that is, greater than 50 GHz.

[0067] like Figure 4 As shown in Figure 2, we provide four structural diagrams of 1×(M+1)OPSN. Figure 4As shown in (a), the first 1×(M+1)OPSN consists of a 1×(M+1)MMI and (M+1) groups of delay waveguides. The waveguide length difference between two adjacent channels is ΔL, so the optical signals of adjacent channels will introduce a phase difference. like Figure 4 As shown in (b), the second 1×(M+1) OPSN consists of a tree structure consisting of multiple 1×2MMIs and (M+1) groups of delay waveguides. Similar to the first 1×(M+1) OPSN, the waveguide length difference between two adjacent channels is ΔL, so the optical signals of adjacent channels will introduce a phase difference. like Figure 4 As shown in (c) of Figure 1, the third 1×(M+1) OPSN consists of a tree structure composed of multiple directional couplers (DCs) and (M+1) groups of delay waveguides. Similar to the first 1×(M+1) OPSN, the waveguide length difference between two adjacent channels is ΔL, so the optical signals of adjacent channels will introduce a phase difference. like Figure 4 As shown in (d) in the figure, the fourth type of 1×(SM+1) OPSN is composed of multiple directional couplers (DC) cascaded in the same waveguide. Since the waveguide length difference between two adjacent channels is ΔL, a phase difference will be introduced for the optical signals of adjacent channels.

[0068] In addition, the 1×(M+1) OPSN used in the present invention can be implemented based on an arrayed waveguide grating structure, such as Figure 5 As shown, it includes N input ports (I1-I N ), M output ports (O1-O M ).

[0069] In order to simplify the operation steps of the present invention, the optical signal transmission and processing process of one laser CWL-N is used for description, and the optical signal transmission and processing processes generated by other lasers are the same as those of CWL-N.

[0070] The laser wavelength output by CWL-N is λ N , the corresponding angular frequency is ω N =2πc / λ N , c is the speed of light in vacuum. Therefore, the light field output by CWL-N can be expressed as: A1exp[j(ω N t-k1x1+θ1)], j represents the imaginary unit, t represents time, k1 represents the wave vector, x1 represents the optical path difference, θ1 represents the initial phase, and A1 represents the amplitude. Figure 2 The spectrum of point A in the link is as follows Figure 6As shown in (a), after 1×2 OS splitting, the spectrum corresponding to points B and C is as follows Figure 6 (b) and Figure 6 As shown in (c) in .

[0071] The wavelength is λ N The optical carrier signal is input into the CS-SSB Mod and is mN The RF signal modulation corresponds to Figure 1 The spectrum of point D is as follows Figure 6 As shown in (d), its frequency is c / λ N +f mN , the corresponding light field can be expressed as A2exp[j(ω N +2πf mN )t-k2x2+θ2)]. j represents the imaginary unit, t represents time, k2 represents the wave vector, x2 represents the optical path difference, θ2 represents the initial phase, and A2 represents the amplitude. To compensate for the coupling loss in the link and the insertion loss of the device itself, the optical signal output by CS-SSB Mod-N is input into EDFA-N for amplification. The amplified optical signal, i.e., the optical signal spectrum at point E, is shown as follows: Figure 6 As shown in (e), the light field can be expressed as: μA2exp[j(ω N +2πf mN )t-k2x2+θ2)], μ represents the optical power amplification factor of EDFA-N. After 1×(M+1)OS power division, the optical field signal from the first output port to the (M+1)th output port can be expressed as: ε0μA2exp[j(ω N +2πf mN )t-k2x2+θ2)], ε1μA2exp[j(ω N +2πf mN )t-k2x2+θ2)],…,ε M μA2exp[j(ω N +2πf mN )t-k2x2+θ2)], ε represents the attenuation coefficient introduced by the phase shift network.

[0072] The optical signal at point C is A1exp[j(ω N t-k1x1+θ1)], after 1×(M+1)OPSN phase shift, the light field from the first to the (M+1)th optical output port can be expressed as: γ0A1exp[j(ω N t-k1x1+θ1)], γ0, γ1, …, γ M The wavelength corresponding to the (M+1)th optical output port of 1×(M+1)OPSN is λN The spectrum of the light signal at point F is as follows Figure 6 As shown in (f) in .

[0073] Therefore, among PD-0 to PD-M, the optical signals input at both ends of the (M+1)th PD are: and ε M μA2exp[j(ω N +2πf mN )t-k2x2+θ2)], the RF electrical signal obtained after PD-M beat frequency can be expressed as: Therefore, the frequency obtained by beating two adjacent PDs is f mN The phase difference of the RF signal is The electrical signals output from PD-0 to PD-M are transmitted to AEs with equal spacing (AE-0, AE-1, ..., AE-(M-1), AE-M) via cables of equal length. N The frequency can be achieved as f mN The beam scans continuously.

[0074] The above process is the operating procedure of the all-optical simultaneous multi-band multi-beam phased array transmitter system of the present invention. In addition, the present invention proposes a system integration method to further reduce system complexity. The integration method of the present invention is mainly based on InP-based optical chips and SOI-based optical chips.

[0075] First, a 1×2 OS, WDM-2, WDM-3, N CS-SSB Mods (CS-SSB Mod-1 to CS-SSB Mod-N), 1×(M+1) OS, 1×(M+1) OPSN, OPS (OPS-1 to OPS-M), and (M+1) PDs (PD-0 to PD-M) are integrated on an SOI-based optical chip.

[0076] Then, SOAs (Semiconductor Optical Amplifiers) (SOA-1 to SOA-N) were designed and fabricated on the InP-based optical chip.

[0077] Finally, they are heterogeneously integrated together through flip-chip bonding or lens spatial coupling.

[0078] The silicon-based CS-SSB Mod structure integrated on the SOI optical chip is as follows: Figure 7As shown in the figure, it mainly includes two sub-MZMs. The operating points of the two sub-MZMs and the entire CS-SSB Mod are controlled by adjusting the on-chip titanium nitride thermoelectrode (TiN TOS). At the same time, the silicon-based modulator needs to use an external broadband electrical 90° mixer or an on-chip integrated 90° electrical mixer to achieve carrier suppressed single sideband modulation. The structure of the silicon germanium photodetector is as follows Figure 8 As shown, it contains two optical input ports PD-I1 and PD-I2 and an RF output port. The RF output port consists of three electrodes, G - ground electrode, S - signal electrode, and G - ground electrode. The corresponding SOI optical chip cross-section diagram is shown in Figure 9 shown.

[0079] Schematic diagram of the InP-based SOA optical amplifier structure Figure 10 As shown, it mainly includes an optical input port SOA-I and an optical output port SOA-O.

[0080] Based on the steps described in the above invention, all-optical simultaneous multi-band, multi-beam phased array beam scanning can be achieved, breaking the traditional architecture of multi-beam phased arrays built based on electrical and optical components. The number of beams is no longer limited by the size of the phased array sub-arrays, the number of transceiver components, and the number of antenna units. In radar applications, simultaneous multi-band, multi-target tracking and identification can be achieved, and in wireless communication applications, simultaneous multi-user directional communication can be achieved. In addition, this method realizes continuous multi-beam scanning, breaking the technical bottleneck of traditional optical phased arrays. At the same time, an integration method for this system is proposed, which greatly promotes the large-scale promotion and application of this solution.

[0081] The examples described above represent several implementations of the present invention. However, some details may vary in actual applications, and these differences remain within the scope of the present invention. It should be noted that any improvements or adjustments based on the concept and general framework of the present invention should fall within the scope of protection of the present invention. The scope of protection of the present invention shall be based on the appended claims.

Claims

1. An all-optical simultaneous multi-band multi-beam phased array transmitter, characterized in that: include: N wavelength continuously tunable lasers in different bands; The first wavelength division multiplexer combines the optical signals output by N wavelength continuously tunable lasers; A first optical power splitter is used to split the optical signal combined by the first wavelength division multiplexer into two equal paths; The modulation network module loads the radio frequency signals of different frequencies onto one of the optical signals after power splitting by the first optical power splitter; The second optical power splitter divides the optical signal output by the modulation network module into M+1 equal paths; The phase shift network module performs optical phase shift and optical phase calibration on the other optical signal after power splitting by the first optical power splitter, and outputs M+1 optical signals; M+1 photodetectors, each of which has a first input port receiving the optical signal of the corresponding path equally divided by the second optical power splitter, and a second input port receiving the optical signal of the corresponding path of the phase-shift network module. Each photodetector beats the signal to obtain N radio frequency signals with different frequencies; M+1 antenna units transmit N different radio frequency signals obtained by beating the photoelectric detector.

2. The all-optical simultaneous multi-band multi-beam phased array transmitter according to claim 1, characterized in that: The wavelength tunable range of the optical signals output by the N wavelength continuously tunable lasers is Δλ; and the interval between the central wavelengths of any two adjacent optical signals is the same.

3. The all-optical simultaneous multi-band multi-beam phased array transmitter according to claim 1, characterized in that: The modulation network module includes: A second wavelength division multiplexer, which wavelength-divides one optical signal after power division by the first optical power splitter into N optical signals; N carrier suppressed single sideband modulators respectively receive the N optical signals after wavelength division by the second wavelength division multiplexer, and modulate each optical signal using a radio frequency signal of a different frequency; N optical amplifiers amplify the signals modulated by N carrier suppressed single-sideband modulators to compensate for the coupling loss in the link and the insertion loss of the device itself; The third wavelength division multiplexer combines the optical signals amplified by the N optical amplifiers.

4. The all-optical simultaneous multi-band multi-beam phased array transmitter according to claim 3, characterized in that: The first wavelength division multiplexer, the second wavelength division multiplexer and the third wavelength division multiplexer have the same number of channels, bandwidth of each channel and central wavelength, and are all 1×N wavelength division multiplexers.

5. The all-optical simultaneous multi-band multi-beam phased array transmitter according to claim 4, characterized in that: The channel bandwidth of the first wavelength division multiplexer, the second wavelength division multiplexer and the third wavelength division multiplexer is greater than the wavelength tunable range Δλ of the wavelength continuously tunable laser; the interval between adjacent channels of the first wavelength division multiplexer, the second wavelength division multiplexer and the third wavelength division multiplexer is greater than the bandwidth of the photodetector.

6. The all-optical simultaneous multi-band multi-beam phased array transmitter according to claim 1, characterized in that: The N optical amplifiers are N erbium-doped fiber amplifiers; or are array chips composed of N semiconductor optical amplifiers SOA.

7. The all-optical simultaneous multi-band multi-beam phased array transmitter according to claim 1, characterized in that: The phase-shift network module includes: The optical phase shift network receives the other optical signal after the first optical power splitter splits the optical signal and performs optical phase shift, outputting M+1 optical signals, and the phase difference between the two adjacent output optical signals is M optical phase shifters perform optical phase calibration on the 2nd to M+1th optical signals output by the optical phase shift network.

8. The all-optical simultaneous multi-band multi-beam phased array transmitter according to claim 7, characterized in that: The optical phase shift network comprises an optical input port and (M+1) optical output ports; the phase difference of the optical signals output by any two adjacent optical output ports is equal, and the phase difference is 9. The all-optical simultaneous multi-band multi-beam phased array transmitter according to claim 7, characterized in that: The optical phase shift network is composed of a 1×(M+1) multimode coupling interferometer and M+1 groups of delay waveguides; Alternatively, the optical phase shifting network is composed of a tree structure consisting of multiple stages of 1×2 multimode coupled interferometers and M+1 groups of delay waveguides; Alternatively, the optical phase shift network is composed of a tree structure consisting of multi-stage directional couplers and (M+1) groups of delay waveguides; Alternatively, the optical phase shift network is formed by cascading multiple directional couplers in the same waveguide.

10. The all-optical simultaneous multi-band multi-beam phased array transmitter according to claim 7, characterized in that: The waveguide length difference between two adjacent channels of the optical phase shift network is ΔL, and the optical signals of the adjacent channels will introduce a phase difference.

11. The all-optical simultaneous multi-band multi-beam phased array transmitter according to claim 1, characterized in that: The electrical signals output by the M+1 photodetectors are transmitted to the M+1 antenna units at equal intervals via cables of equal length.

12. An all-optical simultaneous multi-band multi-beam forming method based on the all-optical simultaneous multi-band multi-beam phased array transmitter of claim 3, characterized in that: The steps include: The optical signals output by N wavelength continuously tunable lasers of different wavelength bands are recorded as λ1, λ2, ..., λ N , the optical signal is combined by the first wavelength division multiplexer and input into the first optical power splitter, and is equally divided into two optical signal groups by the first optical power splitter; One of the optical signal groups is input into the second wavelength division multiplexer and is wavelength-divided into N single-carrier signals with wavelengths of λ1, λ2, ..., λ N The N single-carrier optical signals are input into the corresponding N carrier suppressed single sideband modulators, and at the same time, N radio frequency signals with different frequencies f m1 , f m2 ,…,f mN The corresponding carrier suppressed single sideband modulators are modulated simultaneously, and the output carrier suppressed single sideband optical signals are amplified by erbium-doped fiber amplifiers; N channels of suppressed single-sideband signals are combined into one optical signal by a third wavelength division multiplexer and then equally divided into M+1 optical signals by a second optical power splitter. The equally divided M+1 optical signals are respectively input into the first input ports of the corresponding M+1 photodetectors. The other optical signal group equally divided by the first optical power splitter is input to the phase shift network module, and the optical phase shift and optical phase calibration are performed on the other optical signal after the first optical power splitter, and M+1 optical signals are output to the second input port of the corresponding photodetector, and the phase difference between the two adjacent output optical signals is The M+1 radio frequency signals generated by the M+1 photodetectors are coupled to the M+1 antenna units through cables respectively; by adjusting the working wavelengths λ1, λ2, ..., λ N , you can get the frequency f m1 , f m2 ,…,f mN The directions of the N beams are independently controlled.

13. A method for integrating an all-optical simultaneous multi-band multi-beam phased array transmitter according to claim 3, characterized in that: Integrating some components of the phased array transmitter onto an InP-based optical chip and an SOI-based optical chip; The first optical power splitter, the second wavelength division multiplexer, the third wavelength division multiplexer, N carrier suppressed single sideband modulators, the second optical power splitter, the phase shift network module and M+1 photodetectors are integrated on the SOI-based optical chip; the SOI optical chip reserves optical input and output interfaces for coupling with the InP-based optical chip; An array chip consisting of N semiconductor optical amplifiers (SOAs) is designed and prepared on an InP-based optical chip; finally, the InP-based optical chip is integrated with the heterojunction on the base optical chip through flip-chip bonding or lens spatial coupling.

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