On-chip integrated phase coding microwave signal generation system and generation method

Abstract

The invention relates to an on-chip integrated phase coding microwave signal generation system and method. The system comprises a laser, a polarization controller, a first chip end face coupler, a thin film lithium niobate optical chip, a second chip end face coupler, a signal generator, an optical fiber amplifier, an optical fiber isolator, a photoelectric detector and a microwave source. According to the invention, a first-order sideband of a phase modulation optical signal generated by the phase modulator is suppressed through filtering of the electrically tunable micro-ring resonator in the thin-film lithium niobate optical chip. The signal generator applies a periodically coded voltage signal to the electrically tunable micro-ring resonator, the position of a micro-ring harmonic peak is periodically controlled, and high and low levels of the voltage control signal correspond to the distance between two adjacent harmonic peaks of the electrically tunable micro-ring resonator and positive and negative first-order sidebands of the phase modulation optical signal. According to the invention, high-frequency and frequency-adjustable phase-coded microwave signals can be generated, and the system has the advantages of small voltage tuning range, flexible coding and simple system structure.

Description

Technical Field

[0001] The invention relates to a microwave photon signal generating system, in particular to an on-chip integrated phase coding signal generating system and a generating method. Background Art

[0002] Pulse compression technology is an important means to solve the contradiction between detection distance and distance resolution in radar applications. Among them, phase encoding of the transmitted signal is a pulse compression method with broad application prospects. Compared with the electrical generation method, the phase-coded microwave signal generated by photons has many advantages, including larger bandwidth and immunity to electromagnetic interference. At present, there are many ways to generate phase-coded microwave signals, and several typical methods are as follows:

[0003] 1) Based on optical pulse shaping and frequency-time mapping. This method is based on coupling between free space and optical fiber. Its system is complex and lossy, and its detection range is limited due to the limited time aperture of the generated microwave signal.

[0004] 2) Use coherent light of two different wavelengths to phase modulate one of the wavelengths. This method requires the use of a filter or a section of polarization-maintaining fiber to separate the two wavelengths of light, which limits the adjustability of the generated phase-encoded RF signal.

[0005] 3) Generate phase-coded signals based on mode-locked lasers and filters. The phase-coded signals in this method are actually generated in the electrical domain, so the time-bandwidth product is very small.

[0006] 4) Generate phase-coded microwave signals based on carrier suppression modulation and phase modulation. This method is that the two sidebands generated by carrier suppression modulation are split by wavelength-dependent devices, thereby performing phase modulation on one sideband. The two sidebands are then recombined and heterodyned at the photodetector (PD) to generate a phase-coded microwave signal. The key to this scheme is that a high-Q filter is required to effectively split the two sidebands, which is usually unstable and has a small operating bandwidth. There are other methods that map the two sidebands of the carrier suppression modulated signal to two orthogonal polarization directions, and then perform polarization modulation to generate phase-coded microwave signals.

[0007] The signal generation systems used in the above methods can usually only work at a single microwave frequency because the method of orthogonally polarizing the two sidebands is based on a certain length of polarization-maintaining fiber or a specific polarization-maintaining fiber Bragg grating (FBG). Summary of the invention

[0008] One of the purposes of the present invention is to provide an on-chip integrated phase-coded microwave signal generation system to solve the problems of complex structure and single output frequency existing in the existing microwave optical phase-coded generation system.

[0009] The second object of the present invention is to provide an on-chip integrated phase-coded microwave signal generation method to achieve the generation of a fast phase-coded microwave signal with a phase difference of 180°.

[0010] One of the purposes of the present invention is achieved in that:

[0011] An on-chip integrated phase-coded microwave signal generation system, comprising:

[0012] The laser is connected to the polarization controller through an optical fiber to provide an optical carrier signal for the system;

[0013] A polarization controller, connected to the laser and the first chip end face coupler through optical fibers, is used to control the polarization state of the optical carrier signal so that the optical carrier signal can enter the thin-film lithium niobate optical chip in a polarization state, thereby improving the optical coupling efficiency and transmission characteristics;

[0014] The first chip end face coupler is connected to the polarization controller and the phase modulator in the thin-film lithium niobate optical chip through optical fibers, and is used to couple the polarization state of the optical carrier signal into the phase modulator;

[0015] A thin-film lithium niobate optical chip has a built-in phase modulator and an electrically tunable micro-ring resonator; the input end of the phase modulator is connected to a first chip end face coupler, the output end is connected to the electrically tunable micro-ring resonator, and the RF input electrode is connected to a microwave source; the phase modulator is used to modulate the input optical carrier signal, and load the microwave modulated signal output by the microwave source onto the optical carrier signal to generate positive first-order sidebands and negative first-order sidebands, thereby forming a phase-modulated optical signal; the input end of the electrically tunable micro-ring resonator is connected to the phase modulator, the output end is connected to the second chip end face coupler, and the control end is connected to a signal generator; the electrically tunable micro-ring resonator is used to receive the phase-modulated optical signal output by the phase modulator and the periodically encoded voltage signal emitted by the signal generator, and the position of the micro-ring resonance peak is periodically controlled to filter out the positive first-order sideband or negative first-order sideband in the phase-modulated optical signal;

[0016] A microwave source, whose output end is connected to the RF input electrode of the phase modulator in the thin-film lithium niobate optical chip, and is used to output a microwave modulation signal to the phase modulator;

[0017] A signal generator, whose output end is connected to the control end of the electrically tunable microring resonator in the thin-film lithium niobate optical chip, is used to apply a periodically encoded voltage control signal to the electrically tunable microring resonator to control the position of the microring resonance peak;

[0018] The second chip end face coupler is connected to the electrically tunable microring resonator and the optical fiber amplifier through optical fibers, and is used to couple the single-sideband phase modulated optical signal output by the electrically tunable microring resonator to the optical fiber amplifier;

[0019] The optical fiber amplifier is connected to the second chip end face coupler and the optical fiber isolator through optical fibers, and is used to amplify the single-sideband phase modulated optical signal filtered by the electrically tunable micro-ring resonator to compensate for the end face coupling loss and increase the signal power entering the photodetector;

[0020] An optical fiber isolator, connected to the optical fiber amplifier and the photodetector through optical fibers, is used to ensure the directional transmission of the optical signal output by the optical fiber amplifier to avoid damage thereto; and

[0021] The photoelectric detector, whose input end is connected to the optical fiber isolator through an optical fiber, is used to convert the input optical signal into a microwave electrical signal for output.

[0022] The second object of the present invention is achieved in this way:

[0023] An on-chip integrated phase-coded microwave signal generation method comprises the following steps:

[0024] S1. Set up the on-chip integrated phase-coded microwave signal generating system described in the present invention.

[0025] S2. The laser transmits an optical carrier signal to the polarization controller, and the polarization controller applies polarization control to the input optical carrier signal to control the polarization state of the optical carrier signal passing through; the first chip end face coupler couples the polarization state of the optical carrier signal into the phase modulator in the thin-film lithium niobate integrated optical chip, and the phase modulator modulates the input optical carrier signal and loads the microwave modulated signal output by the microwave source onto the optical carrier signal to generate positive first-order sidebands and negative first-order sidebands, thereby forming a phase-modulated optical signal, and outputs it to the electrically tunable microring resonator in the thin-film lithium niobate integrated optical chip; the signal The signal generator applies a periodically encoded voltage control signal to the electrically tunable micro-ring resonator to periodically control the position of the micro-ring resonance peak, so that the electrically tunable micro-ring resonator filters out the positive first-order sideband or the negative first-order sideband in the phase modulated optical signal to form a single-sideband phase modulated optical signal; the single-sideband phase modulated optical signal is coupled and output to the optical fiber amplifier through the second chip end face coupler, and the optical fiber amplifier amplifies the input optical signal to compensate for the end face coupling loss; the amplified optical signal is transmitted directionally by the photoelectric isolator and then input into the photodetector, which converts it into a microwave electrical signal for output.

[0026] Furthermore, the high and low levels of the voltage control signal emitted by the signal generator correspond to the distance between two adjacent resonance peaks of the electrically tunable microring resonator in the thin film lithium niobate optical chip and the distance between adjacent positive first-order sidebands and negative first-order sidebands in the phase modulated optical signal.

[0027] The microwave signal generating system of the present invention is a link composed of a laser, a polarization controller, a thin-film lithium niobate optical chip, an optical fiber amplifier and a photodetector connected in sequence. The reasons why the microwave signal generating system of the present invention can generate a phase-coded signal are: 1. The phase difference between the positive first-order sideband and the negative first-order sideband of the optical signal output by the phase modulator is 180°; 2. The electrically tunable micro-ring resonator satisfies the high-speed tunability of the resonant wavelength. The two adjacent limited-wave resonant wavelengths of the electrically tunable micro-ring resonator are respectively used to suppress the positive first-order sideband and the negative first-order sideband of the modulation signal generated by the phase modulator; the voltage value applied to the electrically tunable micro-ring resonator is jointly determined by the radio frequency applied to the RF end of the phase modulator and the laser wavelength; the coding form of the phase-coded signal output by the link is determined by the coding form of the high and low levels of the driving signal generated by the signal generator; the frequency of the RF signal loaded onto the carrier by the system is the output phase-coded signal frequency, so the frequency of the phase-coded signal output by the system is determined by the frequency of the microwave signal loaded onto the carrier signal.

[0028] In order to achieve the two resonance peaks suppressing their positive first-order sidebands and negative first-order sidebands respectively, the distance between the resonance peaks and the phase modulation signal sidebands cannot be too large. Therefore, the output phase encoding signal frequency is also subject to the free spectrum range of the electrically tunable microring resonator.

[0029] In the present invention, the phase modulated optical signal output by the phase modulator includes a carrier signal and a positive first-order sideband and a negative first-order sideband. After passing through the electrically tuned microring resonator, the current converted by the photodetector PD can be expressed as:

[0030]

[0031] Where R is the sensitivity of the photodetector PD; P c is the power of the optical signal entering the PD after passing through the micro-ring. J1(β)=–J -1 (β) is the first-order positive and negative coefficients of the Bessel function of the first kind. H(ω) is the microring transfer function. When ω -1 =ω c –ω RF When ω1=ω c +ω RF When H(ω -1) corresponds to the transfer function of the micro-ring at the positive first-order sideband frequency position. The first half of formula (1) is the current obtained by the positive first-order sideband and the carrier beat frequency, and the second half is the current obtained by the negative first-order sideband and the carrier beat frequency. When no voltage signal is applied to the micro-ring:

[0032] H(ω1)=H(ω -1 ) (2)

[0033] Therefore, if the output of the phase modulator is directly detected by a photodetector, the beat frequency of the positive first-order sideband and the carrier will be completely offset by the beat frequency of the negative first-order sideband and the carrier, and there will be no output signal except the DC generated by the beat frequency. The first-order sideband needs to be filtered out to obtain the beat frequency signal. In the present invention, an electrically tunable microring resonator is used to achieve this function.

[0034] In the present invention, the signal generator controls the position of the resonance peak of the electrically tunable microring resonator. When the voltage control signal is at a low level V1, i.e., s(t)=0, the Nth resonance peak of the electrically tunable microring resonator is aligned and the negative first-order sideband of the phase modulated optical signal is filtered out. The phase modulated optical signal passes through the microring. At this time, under ideal conditions, H1(ω) in formula (1) -1 )=0. Therefore, the photocurrent converted by the photodetector PD can be expressed as:

[0035]

[0036] When the voltage applied to the electrically tunable microring resonator is V2, that is, s(t) = 1, the positive first-order sideband of the phase modulated optical signal is filtered out at the N+1th resonance peak of the electrically tunable microring resonator. At this time, under ideal conditions, H(ω1) = 0 in equation (1). Therefore, the photocurrent converted by PD can be expressed as:

[0037]

[0038] For the electrically tunable microring resonator, except for the notch point, the amplitudes at other wavelengths are basically the same, so:

[0039] H=H1(ω c )H1(ω1)=H2(ω c )H2(ω -1 ) (5)

[0040] Substituting formula (5) into formula (3) and formula (4) respectively, we can get:

[0041]

[0042] It can be seen from equation (6) that a 180° phase shift is obtained between state "1" and state "0", so a phase-coded microwave signal can be generated. At the same time, if the frequency of the microwave signal loaded on the carrier is changed, the frequency of the output phase-coded signal can also be changed.

[0043] The phase-coded signal generated by the microwave signal generation system of the present invention is generated by two adjacent resonance peak notches of the electrically tunable micro-ring resonator, so it has the advantages of small tuning amplitude and high signal frequency. In addition, the signal generator sends a low-frequency coding control voltage signal to the electrically tunable micro-ring resonator to control the periodicity of the phase jump of the output phase-coded signal, thereby realizing the flexible definition of the output phase-coded signal code type. The present invention can generate a high-frequency and frequency-adjustable phase-coded microwave signal, and has the characteristics of small voltage tuning range, flexible coding, simple system structure, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a system block diagram of the microwave signal generating system of the present invention.

[0045] Figure 2 This is a schematic diagram of the phase encoding principle.

[0046] Figure 3 It is the time domain diagram of the control signal of the operating point input at the control end of the electrically tunable microring resonator.

[0047] Figure 4 It is the time domain waveform of the phase encoding signal output by the electrically tunable microring resonator.

[0048] Figure 5 It is the phase-time diagram of the phase-encoded signal output by the electrically tunable microring resonator.

[0049] In the figure: 1. Laser, 2. Polarization controller, 3. First chip end coupler, 4. Thin film lithium niobate optical chip, 4-1. Phase modulator, 4-2. Electrically tunable microring resonator, 5. Optical fiber amplifier, 6. Signal generator, 7. Optical fiber isolator, 8. Photodetector, 9. Microwave source, 10. Second chip end coupler. DETAILED DESCRIPTION

[0050] The present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0051] like Figure 1 As shown, the microwave signal generating system of the present invention comprises a laser 1, a polarization controller 2, a first chip end coupler 3, a thin-film lithium niobate optical chip 4, a second chip end coupler 10, a signal generator 6, an optical fiber amplifier 5, an optical fiber isolator 7, a photodetector 8 and a microwave source 9, and the laser 1, the polarization controller 2, the thin-film lithium niobate optical chip 4, the optical fiber amplifier 5 and the photodetector 8 are connected in sequence to form a link. A phase modulator 4-1 and an electrically tunable microring resonator 4-2 are built into the thin-film lithium niobate optical chip 4.

[0052] The output end of the laser 1 is connected to the input end of the polarization controller 2 through an optical fiber to provide an optical carrier signal for the system. The output end of the polarization controller 2 is connected to the first chip end coupler 3 through an optical fiber to control the polarization state of the optical carrier signal passing through, so that the input optical carrier signal can enter the thin-film lithium niobate optical chip 4 in a polarization state, thereby improving the optical coupling efficiency and transmission characteristics. The output end of the first chip end coupler 3 is connected to the input end of the phase modulator 4-1 in the thin-film lithium niobate optical chip 4, and is used to couple the polarization state of the optical carrier signal output by the polarization controller 2 into the phase modulator 4-1. The output end of the phase modulator 4-1 is connected to the input end of the electrically adjustable microring resonator 4-2, and the RF input electrode of the phase modulator 4-1 is connected to the output end of the microwave source 9, and the microwave source 9 outputs a microwave modulated signal to the phase modulator 4-1. The function of the phase modulator 4-1 is to modulate the polarization state optical carrier signal coupled to the input, and load the microwave modulated signal output by the microwave source 9 onto the optical carrier signal to generate positive first-order sidebands and negative first-order sidebands, thereby forming a phase-modulated optical signal, and outputting it to the electrically tunable micro-ring resonator 4-2. The output end of the electrically tunable micro-ring resonator 4-2 is connected to the input end of the second chip end coupler 10, and the output end of the signal generator 6 is connected to the control end of the electrically tunable micro-ring resonator 4-2. The electrically tunable micro-ring resonator 4-2 receives the phase modulated optical signal output by the phase modulator 4-1 and the periodically encoded voltage control signal issued by the signal generator 6, respectively, and under the action of the voltage control signal, periodically controls the position of the micro-ring resonance peak, thereby filtering out the positive first-order sideband or negative first-order sideband in the phase modulated optical signal, and forming a single-sideband phase modulated optical signal. The output end of the second chip end coupler 10 is connected to the input end of the fiber amplifier 5 through an optical fiber, and is used to couple the single-sideband phase modulated optical signal output by the electrically tunable microring resonator 4-2 to the fiber amplifier 5. The output end of the fiber amplifier 5 is connected to the input end of the fiber isolator 7 through an optical fiber, and is used to amplify the single-sideband phase modulated optical signal filtered by the electrically tunable microring resonator 4-2 to compensate for the end coupling loss and increase the signal power entering the photodetector 8. The output end of the fiber isolator 7 is connected to the input end of the photodetector 8 through an optical fiber, and is used to ensure the directional transmission of the optical signal output by the fiber amplifier 5 to avoid damage to it. The photodetector 8 outputs the input optical signal after converting it into a microwave electrical signal.

[0053] The on-chip integrated phase-coded microwave signal generation method of the present invention comprises the following steps:

[0054] 1. Set up the on-chip integrated phase-coded microwave signal generation system described in the present invention.

[0055] 2. The laser 1 transmits an optical carrier signal to the polarization controller 2, and the polarization controller 2 applies polarization control to the input optical carrier signal to control the polarization state of the optical carrier signal passing through. The first chip end face coupler 3 couples the polarized optical carrier signal into the phase modulator 4-1 in the thin-film lithium niobate integrated optical chip 4. The phase modulator 4-1 modulates the input optical carrier signal and loads the microwave modulation signal output by the microwave source 9 onto the optical carrier signal to generate positive first-order sidebands and negative first-order sidebands, thereby forming a phase-modulated optical signal, and outputs it to the electrically tunable microring resonator 4-2 in the thin-film lithium niobate integrated optical chip 4. The signal generator 6 applies a periodically encoded voltage control signal to the electrically tunable microring resonator 4-2 in the thin-film lithium niobate optical chip 4 to periodically control the position of the microring resonance peak, so that the electrically tunable microring resonator 4-2 filters out the positive first-order sideband or negative first-order sideband in the phase-modulated optical signal to form a single-sideband phase-modulated optical signal. The single-sideband phase modulated optical signal is coupled and output to the optical fiber amplifier 5 through the second chip end coupler 10, and the optical fiber amplifier 5 amplifies the input optical signal to compensate for the end coupling loss. The amplified optical signal is transmitted through the photoelectric isolator 7 in a directional manner and then input to the photodetector 8, which converts it into a microwave electrical signal and outputs it.

[0056] Among them, the high and low levels of the voltage control signal emitted by the signal generator 6 correspond to the distance between two adjacent resonance peaks of the electrically tunable microring resonator 4-2 in the thin film lithium niobate optical chip 4 and the distance between adjacent positive first-order sidebands and negative first-order sidebands in the phase modulated optical signal.

[0057] In this embodiment, the laser 1 generates a continuous light wave of 1550nm and 13dBm as an optical carrier signal. The polarization controller 2 applies polarization control to the input optical carrier signal, and after the end face coupling of the first chip end face coupler 3, it enters the lithium niobate thin film chip 4. A phase modulator 4-1 and an electrically tunable microring resonator 4-2 are integrated in the lithium niobate thin film chip 4. The microwave source 9 sends an RF modulated signal to the phase modulator 4-1, and the RF modulated signal is loaded onto the optical carrier signal. The phase modulator 4-1 outputs a phase modulated optical signal with equal power positive first-order sidebands and negative first-order sidebands. The electrically tunable microring resonator 4-2 is used as an optical filter, and under the action of the voltage control signal sent by the signal generator 6, it can filter out a first-order sideband in the phase modulated optical signal. When the signal generator 6 sends a voltage control signal of 0-2.4V and a period of 10μs to the control end of the electrically adjustable microring resonator 4-2, the position of the microring resonance peak can be periodically controlled; when the voltage of the voltage control signal is 0V, the microring resonance peak is aligned with the positive first-order sideband and filtered out; when the voltage of the voltage control signal is 2.5V, the microring resonance peak is aligned with the negative first-order sideband and filtered out. After the sideband is suppressed, the phase modulated optical signal becomes a single-sideband phase modulated optical signal, and then passes through the output of the second chip end coupler 10 and enters the optical fiber amplifier 5. After the loss of the end coupling is compensated by the optical fiber amplifier 5, it is input to the photodetector 8 through the optical fiber isolator 7. The photodetector 8 converts the input optical signal into a microwave electrical signal and outputs it. Since the frequency of the output microwave electrical signal is relatively high, a mixer can be used for down-conversion to convert the high-frequency signal into a low-frequency signal so that a high-speed oscilloscope can be used for signal observation and acquisition.

[0058] The frequency of the phase-coded signal output by the microwave signal generating system of the present invention is the frequency of the microwave signal loaded onto the carrier. Therefore, the frequency of the output phase-coded signal is determined by the frequency of the microwave signal loaded onto the carrier signal.

[0059] like Figure 2 As shown, the basic principle of phase encoding of the system of the present invention is that the signal generator 6 applies a voltage control signal ( Figure 2 The signal voltage diagram on the left). At the time T1-T2, the voltage control signal is at a low level V1=0V, and at the time T2-T3, the voltage control signal is at a high level V2=2.4V. Figure 2 The upper and lower signal voltage diagrams in the middle part show the filtering of the positive and negative first-order sidebands of the carrier signal loaded with the microwave modulation signal by the electrically tunable microring resonator 4-2 at high and low levels respectively. Figure 2 In the upper and lower signal voltage diagrams in the middle part, the frequency f c The carrier wave, f c –fRF The negative first-order sideband is f c +f RF The positive first-order sideband is at the resonance peak of the electrically tunable microring resonator 4-2 on the left side of the carrier signal, which will suppress the negative first-order sideband of the phase modulated optical signal. The carrier and the positive first-order sideband signal enter the photodetector 8, and the two optical signals of different frequencies beat to generate an electrical signal with a phase of 180°. When the voltage control signal is 2.4V, the resonance peak of the electrically tunable microring resonator 4-2 on the right side of the carrier signal will suppress its positive first-order sideband, and the remaining carrier and the negative first-order sideband enter the photodetector 8, and the two optical signals of different frequencies beat to generate an electrical signal with a phase of 0°.

[0060] Figure 3 The waveform diagram of the periodic signal applied by the signal generator 6 in this embodiment to the control end of the electrically tunable micro-ring resonator 4-2 has a signal period of 10μs. When the voltage control signal is at a high level of 2.4V, the resonance peak of the electrically tunable micro-ring resonator suppresses the positive first-order sideband of the phase modulated optical signal; when the voltage control signal is at a low level of 0V, the resonance peak of the electrically tunable micro-ring resonator suppresses the negative first-order sideband of the phase modulated optical signal. In each cycle, the high and low levels are switched at different times to control the mutual switching of the phase between 0° and 180°.

[0061] like Figure 4 , Figure 5 As shown, at this time, the high level of the voltage control signal corresponds to the output of a microwave signal with a phase of 0°, and the low level of the voltage control signal corresponds to the output of a microwave signal with a phase of 180°. After the output phase coding signal is demodulated, it has a consistent corresponding relationship with the coding of the driving information generated by the signal generator 6.

Claims

1. An on-chip integrated phase-coded microwave signal generation system, characterized in that: include: The laser is connected to the polarization controller through an optical fiber to provide an optical carrier signal for the system; A polarization controller is connected to the laser and the first chip end face coupler through optical fibers, and is used to control the polarization state of the optical carrier signal so that the optical carrier signal can enter the thin-film lithium niobate optical chip in a polarization state; The first chip end face coupler is connected to the polarization controller and the phase modulator in the thin-film lithium niobate optical chip through optical fibers, and is used to couple the polarization state of the optical carrier signal into the phase modulator; A thin-film lithium niobate optical chip has a built-in phase modulator and an electrically tunable micro-ring resonator; the input end of the phase modulator is connected to a first chip end face coupler, the output end is connected to the electrically tunable micro-ring resonator, and the RF input electrode is connected to a microwave source; the phase modulator is used to modulate the input optical carrier signal, and load the microwave modulated signal output by the microwave source onto the optical carrier signal to generate positive first-order sidebands and negative first-order sidebands, thereby forming a phase-modulated optical signal; the input end of the electrically tunable micro-ring resonator is connected to the phase modulator, the output end is connected to the second chip end face coupler, and the control end is connected to a signal generator; the electrically tunable micro-ring resonator is used to receive the phase-modulated optical signal output by the phase modulator and the periodically encoded voltage signal emitted by the signal generator, and the position of the micro-ring resonance peak is periodically controlled to filter out the positive first-order sideband or negative first-order sideband in the phase-modulated optical signal; A microwave source, whose output end is connected to the RF input electrode of the phase modulator in the thin-film lithium niobate optical chip, and is used to output a microwave modulation signal to the phase modulator; A signal generator, whose output end is connected to the control end of the electrically tunable microring resonator in the thin-film lithium niobate optical chip, is used to apply a periodically encoded voltage control signal to the electrically tunable microring resonator to control the position of the microring resonance peak; The second chip end face coupler is connected to the electrically tunable microring resonator and the optical fiber amplifier through optical fibers, and is used to couple the single-sideband phase modulated optical signal output by the electrically tunable microring resonator to the optical fiber amplifier; The optical fiber amplifier is connected to the second chip end face coupler and the optical fiber isolator through optical fibers, and is used to amplify the single-sideband phase modulated optical signal filtered by the electrically tunable micro-ring resonator to compensate for the end face coupling loss and increase the signal power entering the photodetector; The optical fiber isolator is connected to the optical fiber amplifier and the photodetector through optical fibers to ensure the directional transmission of the optical signal output by the optical fiber amplifier; as well as The photoelectric detector, whose input end is connected to the optical fiber isolator through an optical fiber, is used to convert the input optical signal into a microwave electrical signal for output.

2. A method for generating an on-chip integrated phase-coded microwave signal, characterized in that: The following steps are involved: S1. Setting the on-chip integrated phase-coded microwave signal generating system as claimed in claim 1; S2, the laser transmits an optical carrier signal to the polarization controller, and the polarization controller applies polarization control to the input optical carrier signal to control the polarization state of the optical carrier signal passing through; the first chip end face coupler couples the polarization state of the optical carrier signal into the phase modulator in the thin-film lithium niobate integrated optical chip, the phase modulator modulates the input optical carrier signal, and loads the microwave modulated signal output by the microwave source onto the optical carrier signal to generate positive first-order sidebands and negative first-order sidebands, thereby forming a phase-modulated optical signal, and outputs it to the electrically tunable microring resonator in the thin-film lithium niobate integrated optical chip; The signal generator applies a periodically encoded voltage control signal to the electrically tunable micro-ring resonator to periodically control the position of the micro-ring resonance peak, so that the electrically tunable micro-ring resonator filters out the positive first-order sideband or the negative first-order sideband in the phase modulated optical signal to form a single-sideband phase modulated optical signal; the single-sideband phase modulated optical signal is coupled and output to the optical fiber amplifier through the second chip end face coupler, and the optical fiber amplifier amplifies the input optical signal to compensate for the end face coupling loss; the amplified optical signal is transmitted directionally by the photoelectric isolator and then input into the photoelectric detector, which converts it into a microwave electrical signal for output.

3. The on-chip integrated phase-coded microwave signal generation method according to claim 2, characterized in that: The high and low levels of the voltage control signal emitted by the signal generator correspond to the distance between two adjacent resonance peaks of the electrically tunable microring resonator in the thin-film lithium niobate optical chip and the distance between adjacent positive first-order sidebands and negative first-order sidebands in the phase modulated optical signal.

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