Reconfigurable microwave photon interference signal generation method and device

Abstract

The invention discloses a reconfigurable microwave photon interference signal generation method. Respectively carrying out acousto-optic modulation frequency shift with different frequency shift amounts on the two paths of homologous optical carrier signals, wherein the frequency shift amount of the first path is a fixed value; carrying out carrier suppression single sideband modulation on the first path of signal after frequency shift by using the original signal; a dual-drive Mach-Zehnder modulator is utilized to modulate the second path of signal after frequency shift, and one path of bias voltage of the dual-drive Mach-Zehnder modulator is set to be zero potential; the two paths of modulation signals are subjected to beat frequency to obtain interference signals, and multi-mode interference signal reconstruction is realized by controlling the frequency shift amount of the second path of signals and the waveforms and parameters of the two paths of radio frequency input signals and the other path of bias voltage of the dual-drive Mach-Zehnder modulator. The invention also discloses a reconfigurable microwave photon interference signal generation device. According to the invention, the reconfigurable interference signals of multiple interference modes can be generated, and the system structure and the control mode are simple.

Description

Technical Field

[0001] The invention relates to a reconfigurable microwave photon interference signal generating method and device, belonging to the technical field of microwave photons. Background Art

[0002] Jamming signal generation plays a critical role in modern electronic warfare systems. Key jammer characteristics include operating bandwidth, response speed, and the ability to generate multiple decoy targets. In traditional electronics, digital radio frequency memory (DRF) is a typical method for generating deceptive jamming signals. This method first downconverts the received RF signal and samples it using an analog-to-digital converter (ADC) for digital storage. The stored signal is then processed by a digital signal processor (DSP) to generate the desired jamming pattern. This is then converted back to the analog domain using a digital-to-analog converter (DAC), upconverted, and transmitted. However, its operating bandwidth is limited by the instantaneous bandwidth of components such as the ADC and DAC. Furthermore, the real-time processing requirements of complex decoy algorithms place high demands on DSP computing power, a problem that is particularly prominent in large-scale decoy target generation scenarios.

[0003] Microwave photonics, with its advantages of large working bandwidth, anti-electromagnetic interference, and parallel processing capabilities, provides a highly promising solution for the generation of interference signals. Typical microwave photonic interference signal generation methods mainly include photonic-assisted radio frequency memory technology and optical domain multi-dimensional parameter control technology. Among them, the photonic-assisted radio frequency memory system (see [D. Zhu, W. Chen, S. Liu, et al. "Photonics-assisted radio frequency memory," Journal of Lightwave Technology, 40 (3), 624-631 (2022).]) can be realized through microwave photonic mixing and digital radio frequency memory technology. The application of microwave photonic mixing technology enables its operating frequency range to reach 40 GHz; at the same time, the introduction of digital radio frequency memory ensures the system's flexible modulation and reconstruction capabilities. However, this method is still limited by the performance of digital radio frequency memory; in addition, the radio frequency signal can also be converted to the optical domain through modulation and stored in the optical domain using an optical loop. The system structure of this solution is relatively complex and the stability is not high.

[0004] Jamming can also be achieved by manipulating the multidimensional parameters of microwave signals (frequency, phase, amplitude, etc.) in the optical domain. Frequency control is particularly crucial, as it directly affects the measurement of target range and velocity. Furthermore, precise frequency control is crucial for jamming the azimuth dimension of inverse synthetic aperture radar imaging. In the microwave photonics field, frequency control can be achieved through methods such as frequency mixing, sawtooth signal modulation, and acousto-optic modulators. The frequency shift introduced by microwave photon mixing is typically in the GHz range, making it difficult to precisely control the generation of false targets and reducing the reliability of false target information. While applying a sawtooth signal using a phase modulator can achieve relatively precise frequency shifts, achieving ideal rise / fall times and precise amplitude control using the sawtooth waveform remains challenging, which can introduce numerous spurious signals.

[0005] In addition, a series of false targets can be generated by performing multiple frequency shifts in the optical domain. Currently, typical methods for achieving multiple frequency shifts include using optical frequency combs and cyclic frequency shift loops. According to Fourier transform, the comb signal in the frequency domain corresponds to a periodic pulse sequence in the time domain (see [N. Picqué, TW "Frequency comb spectroscopy," Nature Photonics, 13(3), 146-157(2019).]). Therefore, temporal pulse sampling of the signal can also effectively generate multiple false targets. Temporal sampling in the optical domain can be achieved through electro-optical modulation and a gating mechanism based on optical switches. However, due to the inherent delay of the system, the center of the false target group always lags behind the true target, which limits the flexibility of control to a certain extent.

[0006] In summary, although there are various schemes for generating jamming signals based on microwave photonic technology, there is still a lack of schemes that can achieve dynamic reconfiguration of multiple jamming modes, especially the scheme that can achieve jamming effects of distance, speed, angle and multiple false target groups by simply controlling the type of driving signal. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to overcome the deficiencies of the existing technology and provide a reconfigurable microwave photon interference signal generation method, which can realize the reconfigurable interference signal generation under multiple interference modes and has a simple system structure and control method.

[0008] The present invention specifically adopts the following technical solutions to solve the above technical problems:

[0009] A reconfigurable microwave photon interference signal generation method is disclosed. The method comprises the following steps: performing acousto-optic modulation frequency shifting with different frequency shift amounts on two continuous optical carrier signals of the same source, wherein the frequency shift amount of the first continuous optical carrier signal is a constant value; performing carrier suppressed single-sideband modulation on the frequency-shifted first continuous optical carrier signal using the original signal to obtain a first modulated signal; modulating the frequency-shifted second continuous optical carrier signal using a dual-driven Mach-Zehnder modulator to obtain a second modulated signal, wherein one bias voltage of the dual-driven Mach-Zehnder modulator is set to zero potential; beating the first modulated signal with the second modulated signal to obtain an interference signal, and realizing reconstruction of interference signals in multiple modes by controlling the frequency shift amount of the second continuous optical carrier signal and the waveforms and parameters of the two RF input signals and the other bias voltage of the dual-driven Mach-Zehnder modulator.

[0010] In the first embodiment, the two RF input signals controlling the dual-drive Mach-Zehnder modulator are both a constant DC voltage of 2V. π , V π The half-wave voltage of the dual-drive Mach-Zehnder modulator is set, and the other bias voltage is adjusted so that the dual-drive Mach-Zehnder modulator operates at the maximum transmission point, thereby realizing the frequency shift interference mode, and reconstructing the false target position information or speed information by changing the frequency shift amount of the second continuous optical carrier signal.

[0011] In a second embodiment, the two RF input signals of the dual-drive Mach-Zehnder modulator are controlled to be the same cosine signal, and the bias voltage of the other channel is adjusted so that the dual-drive Mach-Zehnder modulator operates at the maximum transmission point, thereby generating a frequency domain replication interference pattern of a false target group in the form of a Bessel function distribution. The number, spacing, and spatial distribution of the false target group are reconstructed by changing the amplitude and frequency of the cosine signal, and the center position of the false target group is reconstructed by changing the frequency shift amount of the second continuous optical carrier signal.

[0012] In the third embodiment, the two RF input signals for controlling the dual-drive Mach-Zehnder modulator are periodic rectangular pulse signals with a phase difference of 180°, and the high and low level values ​​of the periodic rectangular pulse signals are V π / 2, 0, V π The half-wave voltage of the dual-drive Mach-Zehnder modulator is set, and the other bias voltage is adjusted so that the dual-drive Mach-Zehnder modulator operates at the minimum transmission point, thereby realizing a time-domain sampling interference pattern for generating a false target group distributed in a sinc function. The number, interval, and spatial distribution of the false target group are reconstructed by changing the duty cycle and frequency of the periodic rectangular pulse signal, and the center position of the false target group is reconstructed by changing the frequency shift amount of the second continuous optical carrier signal.

[0013] In a fourth embodiment, the two RF input signals of the dual-driven Mach-Zehnder modulator are controlled to be cosine signals of different frequencies, and the bias voltage of the other channel is adjusted so that the dual-driven Mach-Zehnder modulator operates at the maximum transmission point, thereby generating a composite frequency domain replication interference pattern of a false target group in the form of a linear superposition distribution of two Bessel functions, and reconstructing the number, interval, and two-dimensional spatial distribution of the false target group by changing the amplitude and frequency of the two cosine signals, and reconstructing the center position of the false target group by changing the frequency shift amount of the second continuous optical carrier signal.

[0014] In the fifth embodiment, the two RF input signals of the dual-drive Mach-Zehnder modulator are controlled to be the same cosine signal, and the bias voltage of the other channel is controlled by a periodic rectangular pulse signal, the high and low level values ​​of the periodic rectangular pulse signal are V π , 0, V π The half-wave voltage of the dual-drive Mach-Zehnder modulator is used to realize the time-frequency joint control interference pattern of the false target group with the joint distribution of the sinc function and the Bessel function, and the number, interval and two-dimensional spatial distribution of the false target group are reconstructed by changing the duty cycle and frequency of the periodic rectangular pulse signal and the amplitude and frequency of the cosine signal, and the center position of the false target group is reconstructed by changing the frequency shift amount of the second continuous optical carrier signal.

[0015] Based on the same inventive concept, the following technical solutions can also be obtained

[0016] A reconfigurable microwave photon interference signal generating device, comprising:

[0017] Two acousto-optic modulators, used to perform acousto-optic modulation frequency shifting of two continuous optical carrier signals of the same source with different frequency shift amounts, wherein the frequency shift amount of the first continuous optical carrier signal is a constant value;

[0018] A first electro-optical modulation module is configured to perform carrier suppressed single sideband modulation on the frequency-shifted first continuous optical carrier signal using the original signal to obtain a first modulated signal;

[0019] a second electro-optical modulation module, configured to modulate the frequency-shifted second continuous optical carrier signal using a dual-drive Mach-Zehnder modulator to obtain a second modulated signal, wherein one bias voltage of the dual-drive Mach-Zehnder modulator is set to zero potential;

[0020] A photoelectric detection module, configured to beat the first modulated signal with the second modulated signal to obtain an interference signal;

[0021] The control module is used to achieve reconstruction of interference signals in multiple modes by controlling the frequency shift amount of the second continuous optical carrier signal and the waveforms and parameters of the two RF input signals and the other bias voltage of the dual-drive Mach-Zehnder modulator.

[0022] In the first embodiment, the control module controls the two RF input signals of the dual-drive Mach-Zehnder modulator to be a constant DC voltage of 2V. π , V π The half-wave voltage of the dual-drive Mach-Zehnder modulator is set, and the other bias voltage is adjusted so that the dual-drive Mach-Zehnder modulator operates at the maximum transmission point, thereby realizing the frequency shift interference mode, and reconstructing the false target position information or speed information by changing the frequency shift amount of the second continuous optical carrier signal.

[0023] In a second embodiment, a control module controls the two RF input signals of the dual-drive Mach-Zehnder modulator to be the same cosine signal, and adjusts the bias voltage of the other channel so that the dual-drive Mach-Zehnder modulator operates at the maximum transmission point, thereby generating a frequency domain replication interference pattern of a false target group in the form of a Bessel function distribution, and reconstructing the number, interval, and spatial distribution of the false target group by changing the amplitude and frequency of the cosine signal, and reconstructing the center position of the false target group by changing the frequency shift amount of the second continuous optical carrier signal.

[0024] In the third embodiment, the control module controls the two RF input signals of the dual-drive Mach-Zehnder modulator to be periodic rectangular pulse signals with a phase difference of 180°, and the high and low level values ​​of the periodic rectangular pulse signals are V π / 2, 0, V π The half-wave voltage of the dual-drive Mach-Zehnder modulator is set, and the other bias voltage is adjusted so that the dual-drive Mach-Zehnder modulator operates at the minimum transmission point, thereby realizing a time-domain sampling interference pattern for generating a false target group distributed in a sinc function. The number, interval, and spatial distribution of the false target group are reconstructed by changing the duty cycle and frequency of the periodic rectangular pulse signal, and the center position of the false target group is reconstructed by changing the frequency shift amount of the second continuous optical carrier signal.

[0025] In a fourth embodiment, a control module controls the two RF input signals of the dual-drive Mach-Zehnder modulator to be cosine signals of different frequencies, and adjusts the bias voltage of the other channel so that the dual-drive Mach-Zehnder modulator operates at a maximum transmission point, thereby generating a composite frequency domain replication interference pattern of a false target group in the form of a linear superposition distribution of two Bessel functions, and reconstructing the number, interval, and two-dimensional spatial distribution of the false target group by changing the amplitude and frequency of the two cosine signals, and reconstructing the center position of the false target group by changing the frequency shift amount of the second continuous optical carrier signal.

[0026] In the fifth embodiment, the control module controls the two RF input signals of the dual-drive Mach-Zehnder modulator to be the same cosine signal, and uses a periodic rectangular pulse signal to control the bias voltage of the other channel, wherein the high and low level values ​​of the periodic rectangular pulse signal are V π , 0, V π The half-wave voltage of the dual-drive Mach-Zehnder modulator is used to realize the time-frequency joint control interference pattern of the false target group with the joint distribution of the sinc function and the Bessel function, and the number, interval and two-dimensional spatial distribution of the false target group are reconstructed by changing the duty cycle and frequency of the periodic rectangular pulse signal and the amplitude and frequency of the cosine signal, and the center position of the false target group is reconstructed by changing the frequency shift amount of the second continuous optical carrier signal.

[0027] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0028] The present invention uses microwave photonic technology to perform signal processing, such as frequency shifting, frequency domain replication, and time domain sampling. It can achieve multiple interference modes, such as distance, speed, angle, and multi-dimensional false target interference, without the need for complex signal processing in the digital domain. It has significant advantages in instantaneous bandwidth and working bandwidth.

[0029] Based on parallel acousto-optic modulator technology, the present invention achieves precise control of microwave signal frequency, improves the accuracy and range of frequency shift, and solves the problem of false targets lagging behind real targets due to system processing delays through negative frequency shift by leveraging its bidirectional frequency shift characteristics.

[0030] The system structure of the present invention is simple, the control method is easy to implement, and the input of control signal type and parameters can be further realized by designing a graphical user interface of the control module. The user only needs to input numerical values ​​to complete the programming switching of the interference mode without recompiling the code or adjusting the hardware link, which greatly facilitates the user's operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a block diagram of a specific implementation structure of the microwave photon interference signal generating device of the present invention;

[0032] Figure 2 A graphical user interface for the microwave photon interference signal generating device of the present invention;

[0033] Figure 3 As the experimental demonstration results of the present invention, the spectrum diagram of the de-skewed signal is shown, and the origin of the spectrum diagram is the frequency of the real target; among them, (a) is the real target spectrum under interference-free conditions; (b) is the spectrum after applying -1MHz frequency shift interference; (c) is the spectrum after introducing 4MHz frequency domain replication interference; (d) is the spectrum after introducing 4MHz time domain sampling interference with a duty cycle of 60%; (e) is the spectrum after introducing 5MHz and 1MHz composite frequency domain replication interference; (f) is the spectrum after introducing 5MHz, 1MHz frequency and 60% duty cycle time-frequency joint control interference. DETAILED DESCRIPTION

[0034] In response to the shortcomings of the existing technology, the solution of the present invention is to perform signal processing on the original signal in the optical domain based on microwave photonic technology, such as frequency shifting, frequency domain replication and time domain sampling. By simply controlling the type and parameters of the RF signal, dynamic reconfiguration of various interference modes can be achieved, such as distance, speed, angle and multi-dimensional false target interference.

[0035] The reconfigurable microwave photon interference signal generation method proposed in the present invention is as follows:

[0036] Two continuous optical carrier signals of the same source are subjected to acousto-optic modulation frequency shift with different frequency shift amounts, wherein the frequency shift amount of the first continuous optical carrier signal is a constant value; the first continuous optical carrier signal after frequency shift is subjected to carrier suppressed single-sideband modulation using the original signal to obtain a first modulated signal; the second continuous optical carrier signal after frequency shift is modulated using a dual-driven Mach-Zehnder modulator to obtain a second modulated signal, wherein one bias voltage of the dual-driven Mach-Zehnder modulator is set to zero potential; the first modulated signal and the second modulated signal are beat by each other to obtain an interference signal, and by controlling the frequency shift amount of the second continuous optical carrier signal and the waveforms and parameters of the two RF input signals and the other bias voltage of the dual-driven Mach-Zehnder modulator, multiple modes of interference signal reconstruction are achieved.

[0037] The reconfigurable microwave photon interference signal generating device proposed in the present invention comprises:

[0038] Two acousto-optic modulators, used to perform acousto-optic modulation frequency shifting of two continuous optical carrier signals of the same source with different frequency shift amounts, wherein the frequency shift amount of the first continuous optical carrier signal is a constant value;

[0039] A first electro-optical modulation module is configured to perform carrier suppressed single sideband modulation on the frequency-shifted first continuous optical carrier signal using the original signal to obtain a first modulated signal;

[0040] a second electro-optical modulation module, configured to modulate the frequency-shifted second continuous optical carrier signal using a dual-drive Mach-Zehnder modulator to obtain a second modulated signal, wherein one bias voltage of the dual-drive Mach-Zehnder modulator is set to zero potential;

[0041] A photoelectric detection module, configured to beat the first modulated signal with the second modulated signal to obtain an interference signal;

[0042] The control module is used to achieve reconstruction of interference signals in multiple modes by controlling the frequency shift amount of the second continuous optical carrier signal and the waveforms and parameters of the two RF input signals and the other bias voltage of the dual-drive Mach-Zehnder modulator.

[0043] To facilitate public understanding, the technical solution of the present invention is described in detail below through a specific embodiment with reference to the accompanying drawings:

[0044] like Figure 1 As shown, the interference signal generating device of this embodiment includes: a laser, two acousto-optic modulators, a 90° bridge, a dual-parallel Mach-Zehnder modulator, a dual-drive Mach-Zehnder modulator, a photodetector, and a control module including two signal generators.

[0045] like Figure 1 As shown, the laser generates an amplitude of E in , frequency f c The optical carrier signal is divided into two paths by the optical beam splitter, and the upper branch passes through a fixed frequency f A The driven acousto-optic modulator 1 shifts the frequency of the optical carrier to f c +f A The original signal s(t) obtained by the receiving antenna is then loaded onto the dual-parallel Mach-Zehnder modulator through a 90° bridge. By setting the DC bias voltage, the dual-parallel Mach-Zehnder modulator operates in the carrier-suppressed single-sideband modulation state, thereby obtaining a first-order optical sideband signal. Assume that the output modulated optical signal is x1(t), s(t) = V R cos(2πf R t+πkt 2 ) is a commonly used linear frequency modulation signal. Under small signal modulation conditions, the signal can be expressed as:

[0046]

[0047] Where J1(m1) represents the first-order Bessel function of the first kind, m1 represents the modulation coefficient, and fR and k represent the center frequency and chirp rate of the linear FM signal, respectively.

[0048] In the lower branch, the frequency f A -f B The RF signal drives the acousto-optic modulator 2, causing the optical carrier to generate f A -f B The frequency-shifted optical signal is input into a dual-drive Mach-Zehnder modulator (DD-MZM). The DD-MZM consists of two phase modulators, each with an RF input port and a bias voltage port on its upper and lower arms. The bias voltage port of one arm is grounded, and the control module dynamically adjusts the waveforms and parameters of the two RF input signals and the other bias voltage to reconstruct a variety of interference signals.

[0049] The typical interference modes that can be achieved by this device are as follows:

[0050] The first is the frequency shift interference mode, which can achieve interference in distance, speed and angle dimensions by performing frequency shift operations on the original signal. At this time, the DD-MZM dual RF port inputs a constant DC voltage, namely V RF1 (t) = V RF2 (t) = V, and adjust the bias voltage to make it work at the maximum transfer point (MATP). When V = 2V π When , the modulator only introduces a fixed phase shift of 2π, which is equivalent to not changing the amplitude and phase of the original signal. After the upper and lower paths are combined and passed through the photodetector for beat frequency, an output electrical signal with only the original signal frequency changed is obtained, which is expressed as follows:

[0051] I1(t)∝cos[2π(f R +f B )t+πkt 2 ](2)

[0052] In order to better evaluate the interference effect, the generated interference signal is mixed with the original signal to perform a de-skewing operation, and the resulting baseband intermediate frequency signal is converted to the frequency domain through Fourier transform. Its frequency domain expression is as follows:

[0053]

[0054] Where LPF represents the low-pass filter operation, Δτ is the time delay between the original signal and the echo signal after interference, and f true =kΔτ is the frequency information of the real target. Frequency shift f B The frequency of the driving signal of the AOM 2 can be changed to achieve the regulation from Hz to MHz. BThe position information of the real target can be tampered with. Leveraging the characteristics of fine frequency shift, velocity deception can be achieved, providing a solution for angular interference in inverse synthetic aperture radar imaging. More importantly, leveraging the bidirectional frequency shift characteristics of the acousto-optic modulator, negative frequency shift can offset the problem of false targets lagging behind the real target due to system processing delays, allowing false targets to flexibly appear in front of or behind the real target. Frequency shift jamming, as a basic jamming mode, can be used in conjunction with other subsequent jamming modes.

[0055] The second is the frequency domain replication interference mode, which performs multiple frequency shifts on the original signal in the optical domain and obtains a series of false targets after de-skewing. In this case, the DD-MZM dual RF ports input the same cosine signal, namely V RF1 (t) = V RF2 (t) = V m cos(2πf m t). In this case, the phase difference between the input signals of the upper and lower arms of the DD-MZM is 0, which is equivalent to a phase modulator. Modulating a high-power cosine signal can generate multiple optical comb teeth. Adjusting the bias voltage of the DD-MZM to make it work at MATP, the output signal expression is as follows:

[0056]

[0057] Where m2 = πV m / V π represents the modulation coefficient, V π Represents the half-wave voltage of DD-MZM. The expression of the interference signal obtained by combining the upper and lower signals and beating the frequency is as follows:

[0058] I2(t)∝cos[2π(f R +f B )t+πkt 2 -m2 cos(2πf m t)](5)

[0059] The frequency domain expression of the intermediate frequency signal obtained after mixing with the original signal is as follows:

[0060]

[0061] Among them, J q (m2) represents the qth order Bessel function of the first kind. From the above formula, we can see that after removing the skew, the frequency interval is f m , the amplitude of the false target group is affected by the modulation coefficient m2 and is in the form of a Bessel function distribution. The number, interval and spatial distribution of the false target group can be reconstructed by changing the amplitude and frequency of the cosine signal. The center position of the false target group can be determined by the frequency shift f B Flexible control.

[0062] The third type is the time-domain sampling interference mode. According to Fourier transform, the spectrum corresponding to time-domain periodic pulse sampling exhibits a comb-like structure. Therefore, time-domain pulse sampling of the signal can also effectively generate multiple false targets. In this case, the DD-MZM dual RF port input is a periodic rectangular pulse signal with a phase difference of 180°, expressed as follows:

[0063]

[0064] Among them, V H , V L , τ and T s Represent the high level value, low level value, pulse width, and sampling repetition period of the periodic rectangular pulse signal. In this case, the phase difference between the upper and lower arms of the DD-MZM input signal is 180°, which is equivalent to an intensity modulator. Adjusting the bias voltage of the DD-MZM so that it operates at the minimum transmission point (MITP) results in the following output signal expression:

[0065]

[0066] From the above formula, we can see that when V H =V π / 2, V L = 0, the optical signal power is maximum during the high level period and 0 during the low level period. Therefore, the above formula is simplified to:

[0067]

[0068] The expression of the interference signal obtained by combining the upper and lower signals is as follows:

[0069]

[0070] The frequency domain expression of the intermediate frequency signal obtained after mixing with the original signal is as follows:

[0071]

[0072] From the above formula, we can see that after the de-skewing operation, a group of false targets with a sinc function distribution is obtained, and by changing the duty cycle τf of the periodic rectangular pulse signal s and frequency f s , the number, interval and spatial distribution of false target groups can be dynamically adjusted by changing the frequency shift f B Realize the reconstruction of the center position of the false target group.

[0073] The fourth is the composite frequency domain replication jamming mode. Its core mechanism is to generate false targets simultaneously in multiple dimensions by using cosine jamming signals of different frequencies, thereby effectively improving the jamming efficiency and complexity. At this time, the DD-MZM dual RF ports input cosine signals of different frequencies, namely V RF1 (t) = V x cos(2πf x t), V RF2 (t) = V y cos(2πf y t), adjust the bias voltage of DD-MZM to make it work at MATP, and the output signal expression is as follows:

[0074]

[0075] The expression of the interference signal obtained by combining the upper and lower signals is as follows:

[0076]

[0077] The frequency domain expression of the intermediate frequency signal obtained after mixing with the original signal is as follows:

[0078]

[0079] From the above formula, we can know that by adjusting the frequency f x and f y Selecting different dimensions to interfere with false targets, the false target group is distributed in the form of two Bessel functions linearly superimposed, which can generate a two-dimensional false target network and break through the distance limitation; by changing the amplitude and frequency of the two-way cosine signal, the number, interval and two-dimensional spatial distribution of the false target group can be reconstructed, and by changing the frequency shift f B Realize the reconstruction of the center position of the false target group.

[0080] The fifth is the time-frequency joint control interference mode, which combines the characteristics of time-domain sampling interference and frequency-domain replication interference to obtain a more complex interference effect. In this case, the DD-MZM dual RF ports input the same cosine signal, namely V RF1 (t) = V RF2 (t) = V m cos(2πf m t), its bias voltage is controlled by a periodic rectangular pulse signal, and the output expression is as follows:

[0081]

[0082] From the above formula, we can see that when V H =V π , V L= 0, the optical signal power is 0 during the high level period and the optical signal power is maximum during the low level period. Therefore, the above formula is simplified to:

[0083]

[0084] The expression of the interference signal obtained by combining the upper and lower signals is as follows:

[0085]

[0086] The frequency domain expression of the intermediate frequency signal obtained after mixing with the original signal is as follows:

[0087]

[0088] The above formula shows that this method can obtain a series of false targets in the two-dimensional false target jamming mode, and the false target group is distributed in a complex sinc function and Bessel function. By changing the duty cycle and frequency of the periodic rectangular square wave signal, as well as the amplitude and frequency of the cosine signal, the number, interval and two-dimensional spatial distribution of the false target group can be adjusted; similarly, by changing the frequency shift f B The center position of the false target group can be reconstructed.

[0089] The control module of this embodiment has the following features: Figure 2 In the graphical user interface shown, users only need to change the control signal type and parameters through numerical input, thereby implementing precise program control of the two dual-channel programmable signal generators, dynamically configuring key parameters such as signal type, frequency, and power for each channel to achieve different interference effects.

[0090] In order to verify the technical effect of the technical solution of the present invention, the above specific embodiments were experimentally verified, and the results are as follows: Figure 3 As shown. Under interference-free conditions, the spectrum of the true echo signal and the original signal after de-skewing is shown in (a), and the frequency of the true target is set as the origin; after applying -1MHz frequency shift interference, the spectrum of the interference signal and the original signal after de-skewing is shown in (b), and it can be seen that the target is moved back by -1MHz, which can introduce erroneous distance information; after introducing 4MHz frequency domain copy interference and 4MHz, 60% duty cycle time domain sampling interference, the spectrum of the de-skewing signal is shown in (c) and (d), respectively, and it can be seen that a group of false targets is generated with an interval of 4MHz, and the distribution shows the characteristics of Bessel function and sinc function respectively; after introducing 5MHz and 1MHz composite frequency domain copy interference and 5MHz, 1MHz frequency and 60% duty cycle time-frequency joint control interference, the spectrum of the de-skewing signal is shown in (e) and (f), respectively, and it can be seen that the distribution of the false target group is more complex, and the number of false targets reaches more than 20, thereby verifying the feasibility and effectiveness of the technical solution of the present invention.

Claims

1. A reconfigurable microwave photon interference signal generation method, characterized in that: Two continuous optical carrier signals of the same source are subjected to acousto-optic modulation frequency shifting with different frequency shift amounts, wherein the frequency shift amount of the first continuous optical carrier signal is a constant value; the frequency-shifted first continuous optical carrier signal is subjected to carrier suppressed single-sideband modulation using the original signal to obtain a first modulated signal; and the frequency-shifted second continuous optical carrier signal is modulated using a dual-drive Mach-Zehnder modulator to obtain a second modulated signal, wherein one bias voltage of the dual-drive Mach-Zehnder modulator is set to zero potential. The first modulated signal and the second modulated signal are beat together to obtain an interference signal, and the reconstruction of interference signals in multiple modes is achieved by controlling the frequency shift amount of the second continuous optical carrier signal and the waveforms and parameters of the two RF input signals and the other bias voltage of the dual-drive Mach-Zehnder modulator.

2. The reconfigurable microwave photon interference signal generation method according to claim 1, characterized in that: The two RF input signals controlling the dual-drive Mach-Zehnder modulator are both constant DC voltage 2V. π , V π The half-wave voltage of the dual-drive Mach-Zehnder modulator is set, and the other bias voltage is adjusted so that the dual-drive Mach-Zehnder modulator operates at the maximum transmission point, thereby realizing the frequency shift interference mode, and reconstructing the false target position information or speed information by changing the frequency shift amount of the second continuous optical carrier signal.

3. The reconfigurable microwave photon interference signal generation method according to claim 1, characterized in that: The two RF input signals of the dual-drive Mach-Zehnder modulator are controlled to be the same cosine signal, and the bias voltage of the other channel is adjusted so that the dual-drive Mach-Zehnder modulator operates at the maximum transmission point, thereby generating a frequency domain replication interference pattern of a false target group in the form of a Bessel function distribution. The number, interval, and spatial distribution of the false target group are reconstructed by changing the amplitude and frequency of the cosine signal, and the center position of the false target group is reconstructed by changing the frequency shift amount of the second continuous optical carrier signal.

4. The reconfigurable microwave photon interference signal generation method according to claim 1, wherein: The two RF input signals for controlling the dual-drive Mach-Zehnder modulator are periodic rectangular pulse signals with a phase difference of 180°, and the high and low level values ​​of the periodic rectangular pulse signals are V π / 2, 0, V π The half-wave voltage of the dual-drive Mach-Zehnder modulator is set, and the other bias voltage is adjusted so that the dual-drive Mach-Zehnder modulator operates at the minimum transmission point, thereby realizing a time-domain sampling interference pattern for generating a false target group distributed in a sinc function. The number, interval, and spatial distribution of the false target group are reconstructed by changing the duty cycle and frequency of the periodic rectangular pulse signal, and the center position of the false target group is reconstructed by changing the frequency shift amount of the second continuous optical carrier signal.

5. The reconfigurable microwave photon interference signal generation method according to claim 1, characterized in that: The two RF input signals of the dual-drive Mach-Zehnder modulator are controlled to be cosine signals of different frequencies, and the bias voltage of the other channel is adjusted so that the dual-drive Mach-Zehnder modulator operates at the maximum transmission point, thereby generating a composite frequency domain replication interference pattern of a false target group in the form of a linear superposition distribution of two Bessel functions. The number, interval, and two-dimensional spatial distribution of the false target group are reconstructed by changing the amplitude and frequency of the two cosine signals, and the center position of the false target group is reconstructed by changing the frequency shift amount of the second continuous optical carrier signal.

6. The reconfigurable microwave photon interference signal generation method according to claim 1, characterized in that: The two RF input signals of the dual-drive Mach-Zehnder modulator are controlled to be the same cosine signal, and the bias voltage of the other channel is controlled by a periodic rectangular pulse signal, the high and low level values ​​of the periodic rectangular pulse signal are V π , 0, V π The half-wave voltage of the dual-drive Mach-Zehnder modulator is used to realize the time-frequency joint control interference pattern of the false target group with the joint distribution of the sinc function and the Bessel function, and the number, interval and two-dimensional spatial distribution of the false target group are reconstructed by changing the duty cycle and frequency of the periodic rectangular pulse signal and the amplitude and frequency of the cosine signal, and the center position of the false target group is reconstructed by changing the frequency shift amount of the second continuous optical carrier signal.

7. A reconfigurable microwave photon interference signal generating device, characterized in that: include: Two acousto-optic modulators, used to perform acousto-optic modulation frequency shifting of two continuous optical carrier signals of the same source with different frequency shift amounts, wherein the frequency shift amount of the first continuous optical carrier signal is a constant value; A first electro-optical modulation module is configured to perform carrier suppressed single sideband modulation on the frequency-shifted first continuous optical carrier signal using the original signal to obtain a first modulated signal; a second electro-optical modulation module, configured to modulate the frequency-shifted second continuous optical carrier signal using a dual-drive Mach-Zehnder modulator to obtain a second modulated signal, wherein one bias voltage of the dual-drive Mach-Zehnder modulator is set to zero potential; A photoelectric detection module, configured to beat the first modulated signal with the second modulated signal to obtain an interference signal; The control module is used to achieve reconstruction of interference signals in multiple modes by controlling the frequency shift amount of the second continuous optical carrier signal and the waveforms and parameters of the two RF input signals and the other bias voltage of the dual-drive Mach-Zehnder modulator.

8. The reconfigurable microwave photon interference signal generating device according to claim 7, characterized in that: The control module controls the two RF input signals of the dual-drive Mach-Zehnder modulator to be a constant DC voltage of 2V. π , V π The half-wave voltage of the dual-drive Mach-Zehnder modulator is set, and the other bias voltage is adjusted so that the dual-drive Mach-Zehnder modulator operates at the maximum transmission point, thereby realizing the frequency shift interference mode, and reconstructing the false target position information or speed information by changing the frequency shift amount of the second continuous optical carrier signal.

9. The reconfigurable microwave photon interference signal generating device according to claim 7, characterized in that: The control module controls the two RF input signals of the dual-drive Mach-Zehnder modulator to be the same cosine signal, and adjusts the bias voltage of the other channel so that the dual-drive Mach-Zehnder modulator operates at the maximum transmission point, thereby generating a frequency domain replication interference pattern of a false target group in the form of a Bessel function distribution. The number, spacing, and spatial distribution of the false target group are reconstructed by changing the amplitude and frequency of the cosine signal, and the center position of the false target group is reconstructed by changing the frequency shift amount of the second continuous optical carrier signal.

10. The reconfigurable microwave photon interference signal generating device according to claim 7, characterized in that: The control module controls the two RF input signals of the dual-drive Mach-Zehnder modulator to be periodic rectangular pulse signals with a phase difference of 180°. The high and low level values ​​of the periodic rectangular pulse signals are V π / 2, 0, V π The half-wave voltage of the dual-drive Mach-Zehnder modulator is set, and the other bias voltage is adjusted so that the dual-drive Mach-Zehnder modulator operates at the minimum transmission point, thereby realizing a time-domain sampling interference pattern for generating a false target group distributed in a sinc function. The number, interval, and spatial distribution of the false target group are reconstructed by changing the duty cycle and frequency of the periodic rectangular pulse signal, and the center position of the false target group is reconstructed by changing the frequency shift amount of the second continuous optical carrier signal.

11. The reconfigurable microwave photon interference signal generating device according to claim 7, characterized in that: The control module controls the two RF input signals of the dual-drive Mach-Zehnder modulator to be cosine signals of different frequencies, and adjusts the bias voltage of the other channel so that the dual-drive Mach-Zehnder modulator operates at the maximum transmission point, thereby generating a composite frequency domain replication interference pattern of a false target group in the form of a linear superposition distribution of two Bessel functions. The number, spacing, and two-dimensional spatial distribution of the false target group are reconstructed by changing the amplitude and frequency of the two cosine signals, and the center position of the false target group is reconstructed by changing the frequency shift amount of the second continuous optical carrier signal.

12. The reconfigurable microwave photon interference signal generating device according to claim 7, characterized in that: The control module controls the two RF input signals of the dual-drive Mach-Zehnder modulator to be the same cosine signal, and uses a periodic rectangular pulse signal to control the bias voltage of the other channel. The high and low level values ​​of the periodic rectangular pulse signal are V π , 0, V π The half-wave voltage of the dual-drive Mach-Zehnder modulator is used to realize the time-frequency joint control interference pattern of the false target group with the joint distribution of the sinc function and the Bessel function, and the number, interval and two-dimensional spatial distribution of the false target group are reconstructed by changing the duty cycle and frequency of the periodic rectangular pulse signal and the amplitude and frequency of the cosine signal, and the center position of the false target group is reconstructed by changing the frequency shift amount of the second continuous optical carrier signal.

Images