Dual-carrier frequency control array signal generation device and method based on microwave photons

Abstract

The invention discloses a microwave photon-based dual-carrier frequency control array signal generation device and method. The device comprises a laser LD and a 1: N optical coupler, an optical carrier output by the LD is divided into N channels by a 1: N optical coupler, and each channel sequentially comprises a PDM-DPMZM, a polarization controller PC, a polarizer Pol, an EDFA, a photoelectric detector PD and an antenna; wherein the PDM-DPMZM comprises an X-DPMZM and a Y-DPMZM which are parallel to each other, a polarization rotator (PR) and a polarization beam synthesizer (PBC); the X-DPMZM internally comprises a main modulator, an MZMX1 and an MZMX2, wherein the MZMX1 and the MZMX2 are parallel to each other; the Y-DPMZM internally comprises a main modulator, an MZMY1 and an MZMY2, wherein the MZMY1 and the MZMY2 are parallel to each other; and optical carriers output by the MZMX1 and the MZMX2 are modulated by a polarization rotator (PR) and are synthesized with optical carriers output by the Y-DPMZM by a polarization beam synthesizer (PBC). According to the invention, the system design can be simplified, the signal tunability is improved, a new solution is provided for realizing more effective distance and angle decoupling, and a basis is provided for the development of the future FDA radar technology.

Description

Technical Field

[0001] The present invention relates to the technical field of microwave photons and frequency-controlled arrays, and in particular to a dual-carrier frequency-controlled array signal generating device and method based on microwave photons. Background Art

[0002] Phased Array (PA) technology has been widely used in many fields due to its high gain, flexible scanning and excellent anti-interference ability. However, PA technology is limited by the frequency correlation of its signal, which causes its spatial pattern to depend only on the angle, limiting its distance-related applications. In order to overcome this limitation, the Frequency Diverse Array (FDA) technology was introduced in 2006. By introducing a frequency offset between adjacent array elements, the spatial pattern is made sensitive to both angle and distance, providing new possibilities for distance-dependent applications. Traditional FDA technology has an "S"-shaped spatial beam pattern, which leads to energy dispersion, is easily affected by interference and noise, and increases the risk of being detected by non-cooperative targets. Therefore, achieving a more concentrated beam pattern and decoupling the angle and distance dimensions become the key to improving FDA performance. So far, researchers have mainly used two methods to solve this challenge: frequency offset optimization and array optimization.

[0003] Although existing research has provided a variety of solutions for the decoupling of FDA beam patterns, the relevant literature is still relatively scarce, and traditional methods are limited by the performance of the electronics field when generating FDA signals. The emergence of microwave photonics (MWP) technology, with its unique advantages, provides a new method for the generation, transmission and processing of radar signals. MWP technology has a wider bandwidth and highly adjustable frequency response, which significantly improves the flexibility and reconfigurability of microwave signal generation systems, indicating its great potential in signal generation of FDA radar systems. However, the microwave photonic FDA signal generation methods reported so far face challenges such as high system complexity and insufficient tunability, and there are difficulties in achieving distance and angle decoupling. Summary of the invention

[0004] The purpose of the present invention is to provide a dual-carrier frequency-controlled array signal generating device and method based on microwave photons to overcome the problems existing in the prior art.

[0005] In order to achieve the above tasks, the present invention adopts the following technical solutions:

[0006] A dual-carrier frequency-controlled array signal generating device based on microwave photons, comprising: a laser LD and a 1:N optical coupler; the optical carrier output by the LD is divided into N channels by the 1:N optical coupler, and each channel sequentially comprises a polarization multiplexing dual parallel Mach-Zehnder modulator PDM-DPMZM, a polarization controller PC, a polarizer Pol, an erbium-doped fiber amplifier EDFA, a photodetector PD and an antenna; wherein: the radio frequency port of the PDM-DPMZM is respectively connected to an I / Q microwave signal and a radio frequency signal provided by an external signal source; PDM-DPMZM includes parallel X-DPMZM and Y-DPMZM, polarization rotator PR, and polarization beam combiner PBC; X-DPMZM contains the main modulator and parallel MZMX_1 and MZMX_2; Y-DPMZM contains the main modulator and parallel MZMY_1 and MZMY_2; the optical carrier output by MZMX_1 and MZMX_2 is modulated by polarization rotator PR, and is combined with the optical carrier output by Y-DPMZM by polarization beam combiner PBC.

[0007] A method for generating dual-carrier frequency-controlled array signals based on microwave photons, comprising:

[0008] Step 1, the continuous optical carrier output by the LD is injected into N channels respectively after passing through a 1:N optical coupler;

[0009] Step 2, in each channel, the optical carrier simultaneously enters the X-DPMZM and Y-DPMZM of PDM-DPMZM for signal modulation; in X_DPMZM, the DC bias of MZMX_2 is adjusted to make it work at the minimum point, and the optical carrier first implements suppressed carrier double-sideband modulation in MZMX_2, and the modulation signal is the radio frequency signal RF; at the same time, MZMX_1 is unloaded and modulated to work at the minimum point;

[0010] Step 3, in Y_DPMZM, the I / Q microwave signals with a phase difference of 90 degrees are input into MZMY_1 and MZMY_2 respectively, and MZMY_1 and MZMY_2 are controlled to work at the minimum point, and the main modulator works at the orthogonal point, and finally the suppressed carrier single sideband modulation SSB-CS of the optical carrier is realized;

[0011] Step 4, the optical carriers output from MZMX_1 and MZMX_2 of X_DPMZM are first modulated by the polarization rotator PR, and then synthesized with the optical carrier output from Y-DPMZM by the polarization beam combiner PBC, thereby generating a polarization multiplexing signal of PDM-DPMZM;

[0012] Step 5, the polarization multiplexing signal of PDM-DPMZM is sent to the erbium-doped fiber amplifier EDFA for power compensation after polarization control by the polarization controller PC and the polarizer Pol; then, the power-compensated optical carrier enters the photodetector PD for photoelectric signal conversion, and finally generates a single-channel dual-carrier FDA signal, which is sent to the antenna for transmission.

[0013] Furthermore, in X_DPMZM, the processing and output of the optical carrier are expressed as:

[0014] Assume that a continuous optical carrier enters each channel, denoted as E c (t) = E c exp(2πf c t); where E c and f c are the amplitude and frequency of the optical carrier respectively, and t is the time parameter; in X-DPMZM, the optical carrier input to MZMX_2 is driven by the RF signal V RF (t) = V RF sin(2πf RF t) modulation, where V RF and f RF Respectively represent the amplitude and frequency of the RF signal; when MZMX_1 is unloaded and the DC bias is adjusted to make it work at the minimum point, the optical carrier output by X-DPMZM can be expressed as:

[0015]

[0016] Among them, m RF =πV RF / 2V π,MZMX_1 is the modulation index of MZMX_1, is the DC bias of MZMX_1, V π,MZMX_1 is the half-wave voltage of MZMX_1, V DC_RF is the DC bias input amplitude of MZMX_1, J n (·) represents the first kind n-order Bessel function, e is a natural constant, and j is an imaginary unit;

[0017] By adjusting the DC bias MZMX_2 also works at the minimum value point, that is, the optical signal output by X_DPMZM can be expressed as:

[0018]

[0019] Furthermore, in Y_DPMZM, the processing and output of the optical carrier are expressed as:

[0020] In Y_DPMZM, the optical carrier enters MZMY_1 and MZMY_2 respectively, and one of the I / Q microwave signals with a phase difference of 90 degrees is represented as V n_I (t) = V n sin(2πΔf n t), where V n and Δf n are the amplitude and frequency of the signal respectively; another I / Q microwave signal with a phase difference of 90 degrees is represented by V n_Q (t) = V n cos(2πΔf n t), the two I / Q microwave signals are injected into MZMY_1 and MZMY_2 respectively; by adjusting the bias point, MZMY_1 and MZMY_2 work at the minimum point respectively, and the main modulator works at the orthogonal point. At this time, the optical signal output by Y_DPMZM is expressed as:

[0021]

[0022] Among them, m n is the modulation index of Y_DPMZM.

[0023] Furthermore, the optical carrier output by MZMX_1 and MZMX_2 of X_DPMZM is first modulated by the polarization rotator PR and then recorded as E X (t), and then combined with the optical carrier E output from Y-DPMZM Y (t) is synthesized by the polarization beam combiner PBC; at this time, the two signals with a 90° difference in polarization direction become polarization multiplexed signals, which can be expressed as:

[0024]

[0025] in, and Indicates different polarization modes.

[0026] Furthermore, PC and Pol are used to combine the optical carriers of two different polarization modes. The optical carrier after power compensation through EDFA can be expressed as:

[0027]

[0028] Among them, G EDFA is the compensation power of EDFA, α is the polarization azimuth, δ is the optical carrier E X (t), E Y (t) is the polarization phase difference.

[0029] Furthermore, the power-compensated EDFA optical signal is guided to the PD for photoelectric conversion, and the obtained photocurrent is expressed as:

[0030]

[0031] Among them, ∝ indicates positive correlation, is the amplitude of the dual-carrier FDA signal.

[0032] Compared with the prior art, the present invention has the following technical features:

[0033] The present invention can realize the generation of multi-channel, high-flatness FDA signals, and the generated directional pattern realizes an "X"-shaped directional pattern, which is very promising in distance and other related applications; the present invention can not only simplify the system design and improve the tunability of the signal, but also provide a new solution for achieving more effective distance and angle decoupling, providing strong support for the development of future FDA radar technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a structural diagram of a dual-carrier frequency-controlled array signal generating device based on microwave photons of the present invention;

[0035] Figure 2 This is the internal structure diagram of PDM-DPMZM;

[0036] Figure 3 Spectrum of the PDM-DPMZM output signal; wherein the frequency of the I / Q microwave signal in (a) is 1 MHz, and the frequency of the I / Q microwave signal in (b) is 1 GHz;

[0037] Figure 4 is the spectrum of EDFA output signal;

[0038] Figure 5 is the spectrum of the PD output signal; wherein the I / Q microwave signal frequency in (a) is 1 GHz, and the I / Q microwave signal frequency in (b) is 1 MHz;

[0039] Figure 6 It is the spectrum of 16-channel dual-carrier FDA signal;

[0040] Figure 7 (a)-(f) are the beam patterns formed by dual-carrier FDA signals of 4, 8, and 16 channels. DETAILED DESCRIPTION

[0041] See attached Figure 1The present invention provides a dual-carrier frequency-controlled array signal generating device based on microwave photons, comprising a laser (Laser Diode, LD) and a 1:N optical coupler; the optical carrier output by the laser is divided into N channels by the 1:N optical coupler, each channel comprises a polarization multiplexing dual-parallel Mach-Zehnder modulator (Polarization Multiplexing Dual-parallel Mach-Zehnder Modulator, PDM-DPMZM), a polarization controller (Polarization Controller, PC), a polarizer (Polarizer, Pol), an erbium-doped fiber amplifier (Erbium-doped Fiber Amplifier, EDFA), a photodetector (Photodetector, PD) and an antenna, wherein:

[0042] The output port of LD is connected to the input port of 1:N coupler, the N output ports of 1:N coupler are respectively connected to the input optical ports of N PDM-DPMZM, each output port of PDM-DPMZM is connected to the input port of PC; each output port of PC is connected to the input port of Pol; each output port of Pol is connected to the input port of EDFA; each output port of EDFA is connected to the input port of PD; finally, the output port of PD is connected to the antenna; the RF port of PDM-DPMZM is respectively connected to the I / Q microwave signal and RF signal provided by the external signal source;

[0043] In this scheme, PDM-DPMZM is an integrated and compact modulator with the internal structure as follows: Figure 2 The invention comprises two parallel DPMZMs (X-DPMZM and Y-DPMZM), a polarization rotator (Polarization Rotator, PR), and a polarization beam combiner (Polarization Beam Combiner, PBC). Each DPMZM contains a main modulator and two MZMs (MZMX_1, MZMX_2 or MZMY_1, MZMY_2); wherein the main modulator in the X-DPMZM is used to make the optical carriers in MZMX_1 and MZMX_2 produce a phase difference, and the main modulator in the Y-DPMZM is used to make the optical carriers in MZMY_1 and MZMY_2 produce a phase difference. The four modulators MZM constitute the basic unit of the integrated modulator, and the bias voltage is controlled by a DC signal to realize the modulation of different formats of different microwave signals.

[0044] On the basis of the above technical solution, the present invention further provides a method for generating dual-carrier frequency-controlled array signals based on microwave photons, comprising:

[0045] Step 1: The continuous optical carrier output by the LD is injected into N channels respectively after passing through a 1:N optical coupler to generate dual-carrier FDA signals of different frequencies.

[0046] Step 2, in each channel, the optical carrier simultaneously enters the X-DPMZM and Y-DPMZM of PDM-DPMZM for signal modulation; in X_DPMZM, adjust the DC bias of MZMX_2 to make it work at the minimum point, and the optical carrier first implements suppressed carrier double-sideband modulation in MZMX_2, and the modulated signal is the RF signal RF; at the same time, MZMX_1 is unloaded and modulated to work at the minimum point.

[0047] Step 3, in Y_DPMZM, the I / Q microwave signals with a phase difference of 90 degrees are input into MZMY_1 and MZMY_2 respectively, and MZMY_1 and MZMY_2 are controlled to work at the minimum point, and the main modulator works at the orthogonal point, finally realizing the single sideband modulation (SSB-CS) of the optical carrier;

[0048] Step 4, the optical carriers output from MZMX_1 and MZMX_2 of X_DPMZM are first modulated by the polarization rotator PR, and then synthesized with the optical carrier output from Y-DPMZM by the polarization beam combiner PBC, thereby generating a polarization multiplexing signal of PDM-DPMZM.

[0049] Step 5, the polarization multiplexing signal of PDM-DPMZM is sent to the erbium-doped fiber amplifier EDFA for power compensation after polarization control by the polarization controller PC and the polarizer Pol; then, the power-compensated optical carrier enters the photodetector PD for photoelectric signal conversion, and finally generates a single-channel dual-carrier FDA signal, which is sent to the antenna for transmission.

[0050] The mathematical principle of the present invention is as follows:

[0051] Assume that a continuous optical carrier enters each channel, denoted as E c (t) = E c exp(2πf c t); where E c and f c are the amplitude and frequency of the optical carrier respectively, and t is the time parameter; then, the optical carrier is input into the two DPMZMs (X-DPMZM and Y-DPMZM) in PDM-DPMZM for modulation; in X-DPMZM, the optical carrier input into MZMX_2 is modulated by the RF signal V RF (t) = V RF sin(2πfRF t) modulation, where V RF and f RF They represent the amplitude and frequency of the RF signal respectively; when MZMX_1 is unloaded and the DC bias is adjusted to make it work at the minimum point (the minimum point is the working state of suppressing the carrier), the optical carrier output by X-DPMZM can be expressed as:

[0052]

[0053] Among them, m RF =πV RF / 2V π,MZMX_1 is the modulation index of MZMX_1, is the DC bias of MZMX_1, V π,MZMX_1 is the half-wave voltage of MZMX_1, V DC_RF is the DC bias input amplitude of MZMX_1, J n (·) denotes the first kind n-th order Bessel function, e is a natural constant, and j is an imaginary unit.

[0054] By adjusting the DC bias MZMX_2 also works at the minimum value point, that is, the optical signal output by X_DPMZM can be expressed as:

[0055]

[0056] In Y_DPMZM, the optical carrier enters MZMY_1 and MZMY_2 respectively for carrier suppressed single sideband modulation SSB-CS; Assuming that one of the I / Q microwave signals with a phase difference of 90 degrees can be expressed as V n_I (t) = V n sin(2πΔf n t), where V n and Δf n are the amplitude and frequency of the signal respectively; another I / Q microwave signal with a phase difference of 90 degrees can be expressed as V n_Q (t) = V n cos(2πΔf n t), the two I / Q microwave signals are injected into MZMY_1 and MZMY_2 respectively; by adjusting the bias point, MZMY_1 and MZMY_2 work at the minimum point respectively, and the main modulator works at the orthogonal point. At this time, the optical signal output by Y_DPMZM can be expressed as:

[0057]

[0058] Among them, m n is the modulation index of Y_DPMZM.

[0059] Then, the optical carrier output from MZMX_1 and MZMX_2 of X_DPMZM is first modulated by polarization rotator PR and recorded as E X (t), and then combined with the optical carrier E output from Y-DPMZM Y (t) is synthesized by the polarization beam combiner PBC; at this time, the two signals with a 90° difference in polarization direction become polarization multiplexed signals, which can be expressed as:

[0060]

[0061] in, and Represent two different polarization modes respectively; PC and Pol are used to combine optical carriers of two different polarization modes together. The optical signal after power compensation through EDFA can be expressed as:

[0062]

[0063] Among them, G EDFA is the compensation power of EDFA, α is the polarization azimuth, δ is the optical carrier E X (t), E Y (t) is the polarization phase difference.

[0064] Subsequently, the power-compensated EDFA optical signal is guided to the PD for photoelectric conversion; ignoring the DC component and high-frequency component, the obtained photocurrent can be expressed as:

[0065]

[0066] Among them, ∝ indicates positive correlation, is the amplitude of the dual-carrier FDA signal.

[0067] From formula (8), we can see that the center frequencies of the generated dual-carrier FDA signals are f RF -Δf n and f RF +Δf n Therefore, the frequency of the generated FDA signal can be easily changed by adjusting the frequency of the RF signal and the I / Q microwave signal; in addition, the amplitude and phase can be adjusted by the PC in the link. Based on these characteristics, this method has flexible adjustability and can adapt to different scenarios and modes of FDA.

[0068] Example:

[0069] In this example, the device includes: a narrow linewidth tunable laser source, an integrated modulator PDM-DPMZM, a PC, a Pol, an EDFA, a spectrum analyzer, a spectrum analyzer, an oscilloscope, a signal generator, an arbitrary waveform generator AWG, and a DC power supply.

[0070] The continuous wave optical carrier signal of each path is generated by a narrow linewidth tunable laser source. The operating frequency range of the laser source is 191.50-196.25THz, the adjustable frequency accuracy is 0.01nm, and the maximum output power is 13.6dBm. The integrated modulator PDM-DPMZM is the core component of the experimental link, which is used to realize SSB-CS modulation of microwave signals and DSB modulation of RF signals. PC and Pol are used to control the different polarization state signals output by PDM-DPMZM. An EDFA with two working modes of automatic power control and automatic gain control is used to compensate for the power loss caused by the entire experimental link. Finally, the amplified optical signal is injected into PD for optical detection. In the entire experimental test system, the optical signal is monitored by an optical spectrum analyzer, and the electronic signal is observed by a spectrum analyzer or an oscilloscope. The microwave signal injected into PDM-DPMZM is generated by a signal generator, and the I / Q microwave signal with a phase difference of 90 degrees is generated by an arbitrary waveform generator. The DC power supply provides a DC signal.

[0071] In the example, the specific implementation steps of the method are:

[0072] In step 1, the operating frequency of the LD is 193.4THz and the output power is 13.6dBm. In X-DPMZM, the RF signal generated by the signal generator operates at a frequency of 10GHz and a power level of 15dBm. By adjusting the DC bias of the two sub-modulators so that they operate at the minimum point, DSB modulation is achieved. Similarly, in Y-DPMZM, the I / Q microwave signals generated by the AWG operate at a frequency of 1MHz, with a power level of 10dBm and a phase difference of 90 degrees. By adjusting the DC bias output of the DC source, the two sub-modulators of the DPMZM are set to operate at their minimum points, while the main modulator is aligned at the orthogonal point. With this configuration, an SSB-CS signal can be achieved. Finally, the spectrum of the optical signal containing two polarization states output by the PDM-DPMZM is as shown Figure 3 In order to better observe the SSB-CS component, the AWG is set to output a 1 GHz I / Q microwave signal. In this configuration, the spectrum of the PDM-DPMZM output is shown in (a). Figure 3 as shown in (b).

[0073] Step 2: After the optical signal from PDM-DPMZM is precisely polarized and coupled with Pol, it is injected into EDFA for power compensation. Considering the input power limit of PD, EDFA is set to automatic power control mode to ensure that the output power is stable at 5dBm. The spectrum of EDFA output signal is as follows: Figure 4 Shown

[0074] Step 3, the carefully adjusted optical signal, i.e., the power compensation after EDFA, is directly injected into the PD with a high responsivity of 0.6A / W for photoelectric detection. The generated dual-carrier FDA signal is observed using a spectrum analyzer, such as Figure 5 shown.

[0075] Step 4: Adjust the frequency of the I / Q microwave signal from 1 MHz to 16 MHz in 1 MHz increments. The PD generates a dual-carrier FDA signal through 16 channels, such as Figure 6 Inspection of the figure shows that the frequencies of these dual-carrier FDA signals for the 16 channels are centered around 10 GHz, with each channel having a frequency offset of n × 1 MHz, where n represents the respective channel number.

[0076] Step 5: Use an oscilloscope to take 4, 8, and 16 channels of dual-carrier FDA signals, and use MATLAB to perform beamforming. The resulting beamforming patterns are as follows: Figure 7 shown.

[0077] In summary, the dual-carrier frequency-controlled array signal generating device and method based on microwave photons of the present invention are simple and easy to implement, and can generate dual-carrier FDA signals with high flatness and high spurious suppression ratio within a wide bandwidth. The present invention has great prospects in applications such as frequency-controlled array radar.

[0078] The implementation of DSB and SSB-CS modulation in the present invention is not limited to PDM-DPMZM, and two DPMZMs can also be used to achieve the same effect.

[0079] In the present invention, the signal loaded into the PDM-DPMZM is not limited to a single frequency signal, but may also be other signals such as radar, communication, etc., such as a linear frequency modulation signal, a phase coded signal or a vector modulation signal.

[0080] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A dual-carrier frequency-controlled array signal generating device based on microwave photons, characterized in that: include: Laser LD and 1:N optical coupler; The optical carrier output by LD is divided into N channels by 1:N optical coupler, and each channel includes polarization multiplexing dual parallel Mach-Zehnder modulator PDM-DPMZM, polarization controller PC, polarizer Pol, erbium-doped fiber amplifier EDFA, photodetector PD and antenna in sequence; wherein: the radio frequency port of PDM-DPMZM is respectively connected to I / Q microwave signal and radio frequency signal provided by external signal source; PDM-DPMZM includes parallel X-DPMZM and Y-DPMZM, polarization rotator PR, polarization beam combiner PBC; X-DPMZM contains main modulator and parallel MZMX_1 and MZMX_2; Y-DPMZM contains main modulator and parallel MZMY_1 and MZMY_2; the optical carrier output by MZMX_1 and MZMX_2 is modulated by polarization rotator PR, and is combined with the optical carrier output by Y-DPMZM by polarization beam combiner PBC.

2. A method for generating dual-carrier frequency-controlled array signals based on microwave photons, characterized in that: include: Step 1, the continuous optical carrier output by the LD is injected into N channels respectively after passing through a 1:N optical coupler; Step 2, in each channel, the optical carrier simultaneously enters the X-DPMZM and Y-DPMZM of PDM-DPMZM for signal modulation; in X_DPMZM, the DC bias of MZMX_2 is adjusted to make it work at the minimum point, and the optical carrier first implements suppressed carrier double-sideband modulation in MZMX_2, and the modulation signal is the radio frequency signal RF; at the same time, MZMX_1 is unloaded and modulated to work at the minimum point; Step 3, in Y_DPMZM, the I / Q microwave signals with a phase difference of 90 degrees are input into MZMY_1 and MZMY_2 respectively, and MZMY_1 and MZMY_2 are controlled to work at the minimum point, and the main modulator works at the orthogonal point, and finally the suppressed carrier single sideband modulation SSB-CS of the optical carrier is realized; Step 4, the optical carriers output from MZMX_1 and MZMX_2 of X_DPMZM are first modulated by the polarization rotator PR, and then synthesized with the optical carrier output from Y-DPMZM by the polarization beam combiner PBC, thereby generating a polarization multiplexing signal of PDM-DPMZM; Step 5, the polarization multiplexing signal of PDM-DPMZM is sent to the erbium-doped fiber amplifier EDFA for power compensation after polarization control by the polarization controller PC and the polarizer Pol; then, the power-compensated optical carrier enters the photodetector PD for photoelectric signal conversion, and finally generates a single-channel dual-carrier FDA signal, which is sent to the antenna for transmission.

3. The dual-carrier frequency-controlled array signal generating device based on microwave photons according to claim 2 is characterized in that: In X_DPMZM, the processing and output of the optical carrier are expressed as: Assume that a continuous optical carrier enters each channel, denoted as E c (t) = E c exp(2πf c t); where E c and f c are the amplitude and frequency of the optical carrier respectively, and t is the time parameter; in X-DPMZM, the optical carrier input to MZMX_2 is driven by the RF signal V RF (t) = V RF sin(2πf RF t) modulation, where V RF and f RF Respectively represent the amplitude and frequency of the RF signal; when MZMX_1 is unloaded and the DC bias is adjusted to make it work at the minimum point, the optical carrier output by X-DPMZM can be expressed as: Among them, m RF =πV RF / 2V π,MZMX_1 is the modulation index of MZMX_1, is the DC bias of MZMX_1, V π,MZMX_1 is the half-wave voltage of MZMX_1, V DC_RF is the DC bias input amplitude of MZMX_1, J n (·) represents the first kind n-order Bessel function, e is a natural constant, and j is an imaginary unit; By adjusting the DC bias MZMX_2 also works at the minimum value point, that is, the optical signal output by X_DPMZM can be expressed as:

4. The dual-carrier frequency-controlled array signal generating device based on microwave photons according to claim 2 is characterized in that: In Y_DPMZM, the processing and output of the optical carrier are expressed as: In Y_DPMZM, the optical carrier enters MZMY_1 and MZMY_2 respectively, and one of the I / Q microwave signals with a phase difference of 90 degrees is represented as V n_I (t) = V n sin(2πΔf n t), where V n and Δf n are the amplitude and frequency of the signal respectively; another I / Q microwave signal with a phase difference of 90 degrees is represented by V n_Q (t) = V n cos(2πΔf n t), the two I / Q microwave signals are injected into MZMY_1 and MZMY_2 respectively; by adjusting the bias point, MZMY_1 and MZMY_2 work at the minimum point respectively, and the main modulator works at the orthogonal point. At this time, the optical signal output by Y_DPMZM is expressed as: Among them, m n is the modulation index of Y_DPMZM.

5. The dual-carrier frequency-controlled array signal generating device based on microwave photons according to claim 2 is characterized in that: The optical carrier output from MZMX_1 and MZMX_2 of X_DPMZM is first modulated by polarization rotator PR and then recorded as E X (t), and then combined with the optical carrier E output from Y-DPMZM Y (t) is synthesized by the polarization beam combiner PBC; at this time, the two signals with a 90° difference in polarization direction become polarization multiplexed signals, which can be expressed as: in, and Indicates different polarization modes.

6. The dual-carrier frequency-controlled array signal generating device based on microwave photons according to claim 2 is characterized in that: The optical carriers with two different polarization modes are combined by using PC and Pol. The optical carrier after power compensation by EDFA can be expressed as: Among them, G EDFA is the compensation power of EDFA, α is the polarization azimuth, δ is the optical carrier E X (t), E Y (t) is the polarization phase difference.

7. The dual-carrier frequency-controlled array signal generating device based on microwave photons according to claim 2 is characterized in that: The power-compensated EDFA optical signal is guided to the PD for photoelectric conversion, and the resulting photocurrent is expressed as: Among them, ∝ indicates positive correlation, is the amplitude of the dual-carrier FDA signal.

Images