A high-voltage frequency signal modulation device and method

Abstract

The application discloses a high-voltage frequency signal modulation device and method, relates to the field of airborne radar laser modulation, and is integrated on a circuit board and comprises a control module, a direct digital frequency synthesis driving module, a pulse modulation signal module, a frequency shift modulation signal module, a thermal bias driving module, an optoelectronic detection module and a laser module; the control module is connected with the modules to realize control and feedback; the direct digital frequency synthesis driving module is connected with the pulse modulation signal module and the frequency shift modulation signal module to generate a differential voltage signal; the pulse modulation signal module, the frequency shift modulation signal module, the thermal bias driving module and the optoelectronic detection module are connected with the laser module to realize driving and detection. Through modular integrated design, the application realizes stable output of a high-voltage frequency shift modulation signal, closed-loop control of laser light emission characteristics and cooperative cooperation of multiple modulation signals, and improves the integration degree, accuracy and stability of airborne radar laser modulation.

Description

Technical Field

[0001] This application relates to the field of airborne radar laser modulation, and in particular to a high-voltage frequency signal modulation device and method. Background Technology

[0002] Airborne radar's core functions, such as laser ranging and target detection, heavily rely on stable and precise laser output. However, the laser's output characteristics are highly susceptible to the voltage and frequency parameters of the driving signal. To ensure efficient laser detection in complex flight environments (wide temperature range, vibration, and high electromagnetic interference), high-precision pulse frequency modulation of the laser driving signal is necessary. Simultaneously, to create a difference between the signal light frequency and stray light frequency in airborne radar's laser detection scenarios, effectively separating the signal light from the stray light and thus improving radar detection sensitivity and accuracy, frequency shifting, pulse signal modulation, and frequency filtering techniques are required. Furthermore, the stringent frequency offset requirements of high-power laser systems in airborne radar necessitate the use of high-voltage frequency signal modulation technology.

[0003] However, high-voltage frequency signal modulation technologies often suffer from low module integration, poor controllability of modulation parameters, high signal transmission loss, and insufficient stability. Furthermore, most modulation schemes struggle to meet the requirements for generating high-voltage frequency-shift signals, failing to achieve precise matching between modulation parameters and laser output characteristics. Mainstream acousto-optic frequency-shift modulation schemes also suffer from drawbacks such as large space requirements, difficulty adapting to the miniaturized layout requirements of airborne equipment, poor coordination with the overall radar system, and insufficient resistance to vibration and electromagnetic interference. These limitations fail to meet the adaptability, reliability, and synergy requirements of airborne radar for modulation devices. Simultaneously, the relatively independent functional modules of traditional modulation devices lack effective collaborative control mechanisms, leading to signal distortion and module failures during modulation, affecting the accuracy of pulse modulation and frequency-shift modulation, and ultimately hindering the improvement of airborne radar detection performance.

[0004] Therefore, there is an urgent need for a high-voltage frequency signal modulation device to solve the problem of low integration of high-voltage frequency signal modulation technology modules and difficulty in meeting the requirements for high-voltage frequency shift signal generation, thereby improving the integration level of airborne radar laser modulation and the ability to generate high-voltage frequency shift signals. Summary of the Invention

[0005] The purpose of this application is to provide a high-voltage frequency signal modulation device and method, which can realize the coordinated control of pulse modulation, frequency shift modulation and thermal bias, meet the requirements of high-voltage frequency shift signal generation, improve module integration and controllability of modulation parameters, thereby improving the stability, accuracy and environmental adaptability of airborne radar laser modulation.

[0006] To achieve the above objectives, this application provides the following solution:

[0007] In a first aspect, this application provides a high-voltage frequency signal modulation device, which is integrated on a circuit board and includes:

[0008] The system includes a control module, a direct digital frequency synthesis drive module, a pulse modulation signal module, a frequency shift modulation signal module, a thermally modulated bias drive module, a photoelectric detection module, and a laser module.

[0009] The control module is connected to the direct digital frequency synthesis drive module, the pulse modulation signal module, the frequency shift modulation signal module, the thermally tuned bias drive module, and the photoelectric detection module, respectively; the direct digital frequency synthesis drive module is connected to the pulse modulation signal module and the frequency shift modulation signal module, respectively; the pulse modulation signal module, the frequency shift modulation signal module, the thermally tuned bias drive module, and the photoelectric detection module are connected to the laser module, respectively.

[0010] The laser module is used to emit laser light under the combined drive of pulse modulation signal, high voltage frequency shift modulation signal and thermally modulated bias drive signal, and sends the laser current feedback signal to the photoelectric detection module.

[0011] The photoelectric detection module is used to receive the current feedback signal from the laser module and convert the current feedback signal into a voltage feedback signal to be sent to the control module;

[0012] The control module is used to generate control signals according to modulation parameters; when the voltage feedback signal is received, the control signal is adjusted according to the voltage feedback signal, and the adjusted control signal is sent to the direct digital frequency synthesis drive module, the pulse modulation signal module and the frequency shift modulation signal module until the modulation end condition is met;

[0013] The direct digital frequency synthesis drive module is used to generate pulse-modulated differential voltage signals and frequency-shift-modulated differential voltage signals based on the adjusted control signals;

[0014] The pulse modulation signal module is used to convert pulse-modulated differential voltage signals into pulse-modulated signals;

[0015] The frequency shift modulation signal module is used to convert the frequency shift modulation differential voltage signal into a high-voltage frequency shift modulation signal.

[0016] Secondly, this application provides a high-voltage frequency signal modulation method including:

[0017] The control module receives modulation parameters and generates control signals based on the modulation parameters; the control signals include direct digital frequency synthesis control signals, pulse modulation control signals, frequency shift modulation control signals, and thermal bias control signals.

[0018] Based on the direct digital frequency synthesis control signal, pulse-modulated differential voltage signal and frequency-shift-modulated differential voltage signal are obtained;

[0019] Based on the pulse modulation control signal and the pulse modulation differential voltage signal, a pulse modulation signal is obtained;

[0020] Based on the frequency shift modulation control signal and the frequency shift modulation differential voltage signal, a high-voltage frequency shift modulation signal is obtained;

[0021] Based on the aforementioned thermal bias control signal, a thermal bias drive signal is obtained through constant current control operation;

[0022] The laser module is driven to emit laser light in coordination with the pulse modulation signal, the high voltage frequency shift modulation signal and the thermally adjusted bias drive signal.

[0023] Acquire the voltage feedback signal corresponding to the laser current feedback signal and the current sampling signal corresponding to the thermally adjusted bias drive signal;

[0024] The actual pulse repetition frequency is determined based on the voltage feedback signal, and the actual thermally adjustable bias current is determined based on the current sampling signal.

[0025] If the adjustment conditions are met, the control signal is adjusted using a preset adjustment method. The adjustment conditions include the deviation between the actual pulse repetition frequency and the target pulse repetition frequency exceeding a first preset threshold, or the deviation between the actual thermal bias current and the target current exceeding a second preset threshold. The preset adjustment method includes adjusting the direct digital frequency synthesis control signal, pulse modulation control signal, and frequency shift modulation control signal in the control signal by checking the software configuration of the direct digital frequency synthesis drive module or adding a temperature drift compensation algorithm if the deviation between the actual thermal bias current and the target current exceeds the second preset threshold; and adjusting the thermal bias control signal in the control signal by correcting the output current of the constant current drive unit if the deviation between the actual thermal bias current and the target current exceeds the second preset threshold.

[0026] Based on the adjusted control signal, the pulse modulation signal, the high-voltage frequency shift modulation signal, and the thermally tuned bias drive signal are regenerated to drive the laser module to emit laser light until the modulation end condition is met and modulation stops.

[0027] According to the specific embodiments provided in this application, this application has the following technical effects:

[0028] This application provides a high-voltage frequency signal modulation device and method. By integrating a control module, a direct digital frequency synthesis drive module, a pulse modulation signal module, a frequency shift modulation signal module, a thermally tuned bias drive module, a photoelectric detection module, and a laser module into one unit, it solves the problem of low integration of high-voltage frequency signal modulation technology modules, and realizes miniaturized layout and high integration of airborne radar laser modulation. The direct digital frequency synthesis drive module generates pulse modulation differential voltage signals and frequency shift modulation differential voltage signals, which are then converted into pulse modulation signals and high-voltage frequency shift modulation signals by the pulse modulation signal module and the frequency shift modulation signal module, solving the problem of difficulty in meeting the generation requirements of high-voltage frequency shift signals, and realizing stable output and precise control of high-voltage frequency shift modulation signals. The control module adjusts the control signal in real time according to the voltage feedback signal, solving the problems of poor controllability and insufficient stability of modulation parameters, and realizing closed-loop control and dynamic optimization of laser light output characteristics. Through the coordinated driving of pulse modulation signals, high-voltage frequency shift modulation signals, and thermally tuned bias drive signals, it solves the problem of relatively independent functional modules and lack of coordinated control mechanisms, realizing the coordinated cooperation of pulse modulation, frequency shift modulation, and thermally tuned bias, and improving the sensitivity and accuracy of airborne radar detection. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the functional modules of a high-voltage frequency signal modulation device provided in an embodiment of this application.

[0031] Figure 2 The pin diagram of the AD9106 chip provided in one embodiment of this application is shown.

[0032] Figure 3 The main circuit diagram of a pulse modulation signal module provided in an embodiment of this application is shown.

[0033] Figure 4 The pin diagram of the ADHV4710 chip provided in one embodiment of this application is shown.

[0034] Figure 5 This is a circuit diagram of a high-voltage operational amplifier for a frequency shift modulation signal module provided in an embodiment of this application.

[0035] Figure 6 The waveform diagram is shown in one embodiment of this application when the pulse modulation signal is a square wave signal.

[0036] Figure 7 The waveform diagram is shown for a high-voltage frequency shift modulation signal of 800ns sawtooth wave signal provided in an embodiment of this application.

[0037] Figure 8 The waveform diagram is shown for a high-voltage frequency shift modulation signal of 400ns sawtooth wave signal provided in an embodiment of this application.

[0038] Figure 9 The waveform diagram is shown for a 200ns sawtooth wave signal provided in an embodiment of this application. Detailed Implementation

[0039] The ADHV4710BSVZ high-voltage operational amplifier possesses unique technical advantages. It employs a dedicated high-voltage BCDMOS process, supports a wide high-voltage power supply range of ±12V to ±55V, and can stably achieve a maximum output voltage of ±52V under an output current of ±100mA. It also features an extremely high voltage slew rate of ±1300V / μs and a continuous output drive capability of ±1A, enabling it to accurately adapt to the amplitude requirements and frequency characteristics of the high-voltage frequency modulation signal in this application, ensuring the stability and signal integrity of the modulation process.

[0040] All relevant alternative technical approaches have been verified to have flaws:

[0041] Firstly, a solution using cascaded ordinary operational amplifiers and an external boost circuit is adopted. This solution requires cascading multiple ordinary operational amplifiers and using boost devices such as DC-DC converters to increase the output voltage. Although it can barely achieve high-voltage modulation of a certain amplitude, it has significant shortcomings: On the one hand, the cascaded circuit and boost module require a lot of extra space, which cannot meet the small-volume integrated circuit board design requirements of this application; on the other hand, the cascaded structure will lead to signal bandwidth attenuation and increased phase distortion, and the noise introduced by the boost circuit will destroy the integrity of the modulated signal. At the same time, the collaborative control of multiple devices reduces the circuit integration and reliability, and cannot achieve the high-amplitude stable modulation required by this application.

[0042] Secondly, the scheme of using a high-voltage transistor array to build the modulation circuit requires the design of complex driving logic circuits to control the switching state of the transistors. This not only increases the design complexity of the integrated circuit board, but also introduces additional harmonic interference due to the switching characteristics of the transistors, which cannot meet the purity requirements of the high-frequency modulation signal. More importantly, the high-voltage linear modulation range of the transistor array is limited, making it difficult to achieve the high-amplitude modulation required by this application.

[0043] Third, a modular solution using dedicated high-voltage signal generators is adopted. Although such modules can achieve partial high-voltage signal output, they are all independently packaged modular structures, which are bulky and have extremely poor compatibility with the integrated circuit board architecture of this application, making it impossible to achieve integrated design. At the same time, the amplitude upper limit of related dedicated modules is generally lower than the requirements of this application, and the frequency modulation flexibility is insufficient, making it unable to adapt to the dynamic modulation requirements of this application.

[0044] Therefore, although the relevant alternatives can achieve basic high-voltage signal processing or modulation functions, they all have core defects such as insufficient high-amplitude modulation capability, low integration level, and excessive size. However, the high-voltage frequency signal modulation device (high-voltage frequency modulation signal integrated circuit board) of this application can simultaneously meet the requirements of high-amplitude modulation, high integration, and small size.

[0045] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0046] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0047] In one exemplary embodiment, such as Figure 1 As shown, a high-voltage frequency signal modulation device is provided, which is integrated on a circuit board and includes:

[0048] The control module, direct digital frequency synthesis drive module, pulse modulation signal module, frequency shift modulation signal module, thermal bias drive module, photoelectric detection module, and laser module (not shown in the figure).

[0049] The control module is connected to the direct digital frequency synthesis drive module, the pulse modulation signal module, the frequency shift modulation signal module, the thermally tuned bias drive module, and the photoelectric detection module, respectively; the direct digital frequency synthesis drive module is connected to the pulse modulation signal module and the frequency shift modulation signal module, respectively; the pulse modulation signal module, the frequency shift modulation signal module, the thermally tuned bias drive module, and the photoelectric detection module are connected to the laser module, respectively.

[0050] The laser module is used to emit laser light under the combined drive of pulse modulation signal, high voltage frequency shift modulation signal and thermal bias drive signal, and sends the laser current feedback signal to the photoelectric detection module.

[0051] The photoelectric detection module is used to receive the current feedback signal from the laser module and convert the current feedback signal into a voltage feedback signal to be sent to the control module.

[0052] The control module generates control signals based on modulation parameters (such as those input by the user) and sends them to the direct digital frequency synthesis drive module, the pulse modulation signal module, and the frequency shift modulation signal module. Upon receiving the voltage feedback signal, the control signal is adjusted according to the voltage feedback signal, and the adjusted control signal is sent to the direct digital frequency synthesis drive module, the pulse modulation signal module, and the frequency shift modulation signal module until the modulation termination condition is met. The modulation termination condition includes receiving a stop command.

[0053] The direct digital frequency synthesis drive module is used to generate pulse-modulated differential voltage signals and frequency-shift-modulated differential voltage signals based on the adjusted control signals.

[0054] The pulse modulation signal module is used to convert pulse-modulated differential voltage signals into pulse-modulated signals.

[0055] The frequency shift modulation signal module is used to convert frequency shift modulation differential voltage signals into high-voltage frequency shift modulation signals.

[0056] With the above-mentioned device, this application can meet the core requirements of airborne radar laser output control, frequency shift separation of stray light, and high voltage frequency offset.

[0057] As an optional implementation, the control signals include direct digital frequency synthesis control signals, pulse modulation control signals, frequency shift modulation control signals, and thermal bias control signals.

[0058] The direct digital frequency synthesis driver module includes a direct digital frequency synthesis chip, a crystal oscillator unit, and a signal conversion unit.

[0059] The direct digital frequency synthesis chip is connected to the control module, the crystal oscillator unit, and the signal conversion unit, respectively.

[0060] The crystal oscillator unit is used to provide a differential clock signal and send it to the direct digital frequency synthesis chip.

[0061] The direct digital frequency synthesis chip is used to synthesize a control signal based on the direct digital frequency in the control signal, generate a pulse-modulated differential current signal and a frequency-shift-modulated differential current signal through a digital-to-analog conversion operation based on a differential clock signal, and send them to the signal conversion unit.

[0062] The signal conversion unit includes a first differential amplifier circuit and a second differential amplifier circuit; the first differential amplifier circuit is used to convert the pulse-modulated differential current signal into a pulse-modulated differential voltage signal (through differential amplification operation); the second differential amplifier circuit is used to convert the frequency-shift modulated differential current signal into a frequency-shift modulated differential voltage signal (through differential amplification operation).

[0063] As an optional implementation, the pulse modulation signal module includes a first digital-to-analog converter, a first gain control unit, and a first signal shaping unit connected in sequence.

[0064] The first digital-to-analog converter is also connected to the control module and is used to perform digital-to-analog conversion on the pulse modulation control signal in the control signal to obtain the first analog voltage signal.

[0065] The first gain control unit is also connected to the direct digital frequency synthesis drive module, which is used to perform gain adjustment operation on the pulse-modulated differential voltage signal based on the first analog voltage signal to obtain a gain pulse-modulated differential voltage signal.

[0066] The first signal shaping unit is also connected to the laser module and is used to perform signal shaping operations on the gain pulse modulated differential voltage signal to obtain a pulse modulated signal, and send the pulse modulated signal to the laser module; the signal shaping operation includes buffer driving operation, edge sharpening operation, and overshoot suppression operation.

[0067] As an optional implementation, the frequency shift modulation signal module includes a second digital-to-analog converter, a second gain control unit, a second signal shaping unit, and a high-voltage amplifier connected in sequence.

[0068] The second digital-to-analog converter is also connected to the control module and is used to perform digital-to-analog conversion on the frequency shift modulation control signal in the control signal to obtain the second analog voltage signal.

[0069] The second gain control unit is also connected to the direct digital frequency synthesis drive module, and is used to perform gain adjustment operation on the frequency shift modulation differential voltage signal based on the second analog voltage signal to obtain the gain frequency shift modulation differential voltage signal.

[0070] The second signal shaping unit is used to perform signal shaping operations on the gain-frequency-shift modulated differential voltage signal to obtain a shaped gain-frequency-shift modulated differential voltage signal; the signal shaping operation includes buffer driving operation, edge sharpening operation, and overshoot suppression operation.

[0071] The high-voltage amplification unit is also connected to the laser module and is used to perform high-voltage amplification on the shaped gain frequency-shift modulated differential voltage signal to obtain a high-voltage frequency-shift modulated signal.

[0072] As an optional implementation, the high-voltage frequency signal modulation device further includes a power supply module; the power supply module is used to convert the external input voltage into multiple working voltages through voltage conversion operations to power the control module, the direct digital frequency synthesis drive module, the pulse modulation signal module, the frequency shift modulation signal module, and the thermal bias drive module.

[0073] As an optional implementation, the high-voltage frequency signal modulation device further includes a power monitoring module.

[0074] The power monitoring module is connected to both the power module and the control module.

[0075] The power monitoring module includes a voltage follower and an analog-to-digital converter. The voltage follower is used to collect the operating voltages of each channel and perform signal conditioning on each channel to obtain multiple conditioned operating voltage signals. The analog-to-digital converter is used to perform analog-to-digital conversion on the conditioned operating voltage signals to obtain multiple power status signals and send the multiple power status signals to the control module. The signal conditioning includes impedance matching and noise suppression.

[0076] The control module is also used to determine the power supply operating status based on the power supply status signals. If all power supply status signals indicate that the corresponding operating voltage is within the preset voltage range, the power supply operating status is determined to be normal. If any power supply status signal indicates that the corresponding operating voltage exceeds the preset voltage range, the power supply operating status is determined to be abnormal, and power supply abnormality protection operation is performed only on the abnormal power supply path, while the other paths remain in normal operation. The power supply abnormality protection operation includes generating a power supply fault alarm signal, which is sent to the host computer as a trigger command through the communication interface to notify the host computer that the power supply is abnormal. Subsequently, in response to the alarm signal, the control module outputs detailed power supply abnormality fault information (at least including the abnormality type: overvoltage or undervoltage) through the communication interface and stores it in the host computer.

[0077] As an optional implementation, the thermally adjustable bias drive module includes a power supply switch unit, a constant current drive unit, and a current sampling feedback unit.

[0078] The power supply switch unit is also connected to the control module and the power supply module respectively, and is used to control the power supply from the power supply module to the constant current drive unit according to the switch enable signal of the control module.

[0079] The constant current drive unit is also connected to the control module and the laser module respectively, and is used to perform constant current control operation on the thermally adjustable bias control signal in the control signal to generate a thermally adjustable bias drive signal, and send the thermally adjustable bias drive signal to the laser module.

[0080] The current sampling feedback unit is also connected to the control module and is used to perform current sampling operation on the thermally adjustable bias drive signal to obtain a current sampling signal, and feed the current sampling signal back to the control module.

[0081] The control module is also used to adjust the thermal bias control signal according to the current sampling signal, and send the adjusted thermal bias control signal to the constant current drive unit.

[0082] As an optional implementation, the circuit board includes a high-voltage region and a low-voltage region.

[0083] Electrical isolation between the high-voltage and low-voltage areas is achieved through creepage distance and electrical clearance.

[0084] The high-voltage region includes the high-voltage amplification unit in the frequency shift modulation signal module.

[0085] The low-voltage region includes a control module, a direct digital frequency synthesis drive module, a pulse modulation signal module, all units in the frequency shift modulation signal module except for the high-voltage amplification unit, a power supply module, a power supply monitoring module, a photoelectric detection module, and a thermally adjustable bias drive module.

[0086] As an optional implementation, the laser module is a thin-film lithium niobate pulse frequency shifter.

[0087] The following uses a specific high-voltage frequency signal modulation process as an example to illustrate this application.

[0088] like Figure 1 As shown, this embodiment provides a high-voltage frequency signal modulation device integrated on a circuit board for realizing frequency shifting and pulse modulation of airborne radar. It includes a power supply module, an MCU module (control module), a DDS (Direct Digital Synthesis) driver module, a pulse modulation signal module, a frequency shift modulation signal module, a thermally adjustable bias driver module, an MPD (Monitor Photodiode) module (photoelectric detection module), and a power monitoring module. All modules are electrically connected through copper foil traces inside the circuit board, working together to meet the precise and stable operation requirements of airborne radar. The specific connection relationships are as follows:

[0089] The output of the power module is connected to the power inputs of the MCU module, DDS driver module, pulse modulation signal module, frequency shift modulation signal module, thermally adjustable bias driver module, MPD module, and power monitoring module, respectively. The control signal output of the MCU module is connected to the control signal inputs of the DDS driver module, pulse modulation signal module, frequency shift modulation signal module, and thermally adjustable bias driver module, respectively. The feedback signal input of the MCU module is connected to the signal outputs of the MPD module and power monitoring module, respectively. The signal output of the DDS driver module is connected to the signal inputs of the pulse modulation signal module and frequency shift modulation signal module, respectively. The signal outputs of the pulse modulation signal module, frequency shift modulation signal module, and thermally adjustable bias driver module are connected to the thin-film lithium niobate pulse frequency shifter, respectively. The input of the MPD module is connected to the MPD pin of the thin-film lithium niobate pulse frequency shifter, and the input of the power monitoring module is connected to the output of the power module.

[0090] In this embodiment, the specific selection of each module is as follows:

[0091] 1. Power Supply Module: ① Composed of DC-DC (Direct Current-to-Direct Current) converter chips TPS62140RGTR and MP3425DL, along with filter capacitors and inductors. Input voltage is 12V, output voltages are 5.5V and 55V respectively; ② Composed of DC-DC converter chips TPS63700DRCR and TLV62084DSGR, along with filter capacitors and inductors. Input voltage is 5.5V, output voltages are -5.5V and 3.3V for digital circuit power supply; ③ Uses LDO (Low Voltage Detector). The dropout regulator (TPS7A9101DSKR) consists of a dropout regulator chip and a filter capacitor, with an input voltage of 5.5V, an output voltage of 4.1V, and analog circuit power supply voltages of 5V and 3.3V; ④ It consists of an LDO chip TPS72301DBVT and a filter capacitor, with an input voltage of -5.5V and an output voltage of -5V (analog circuit power supply voltage); ⑤ It consists of voltage reference chips REF3212AIDBVT and REF3225AIDBVT and a filter capacitor, with an input voltage of 3.3V (analog circuit power supply voltage) and output voltages of 1.25V and 2.5V respectively. The above output voltages power different modules respectively. 5.5V powers the power supply module, 55V powers the pulse modulation signal module, and -5.5V powers the power supply module. The digital circuit power supply voltage is 3.3V for the MCU module, DDS driver module, pulse modulation signal module, frequency shift modulation signal module, and thermally adjustable bias driver module; 4.1V powers the thermally adjustable bias driver module. The analog circuit power supply voltage is 5V for the DDS driver module, pulse modulation signal module, frequency shift modulation signal module, thermally adjustable bias driver module, and MPD module. The analog circuit power supply voltage is 3.3V for the MCU module, DDS driver module, pulse modulation signal module, frequency shift modulation signal module, thermally adjustable bias driver module, and MPD module. The analog circuit power supply voltage is -5V for the DDS driver module, pulse modulation signal module, frequency shift modulation signal module, and MPD module; 1.25V powers the MCU module and pulse modulation signal module; and 2.5V powers the thermally adjustable bias driver module.

[0092] 2. MCU Module: The core MCU (Microcontroller Unit) chip is an STM32F103RBT7TR, featuring multiple GPIO (General Purpose Input / Output) interfaces and an ADC (Analog-to-Digital Converter) interface, enabling the generation of multi-channel control signals and the acquisition and processing of feedback signals. A clocking scheme of "external 8MHz crystal oscillator + internal PLL (Phase-Locked Loop)" is adopted. An external 8MHz passive crystal oscillator with a 10pF load capacitor is used, and the internal PLL multiplies the frequency to 72MHz as the system's main clock, providing a stable and high-speed clock for computation and peripheral drive. An external CAT24C256WI-GT3 EEPROM (Electrically Erasable Programmable Read-Only Memory) module is used. 2 The C (Inter-Integrated Circuit) interface has a storage capacity of 256KB, enabling long-term storage of control parameters and acquired data even after power failure. Data reading and writing can be achieved through software adaptation.

[0093] 3. DDS Driver Module: The AD9106BCPZEL7 is used as the DDS chip. The pin diagram of the AD9106 chip is shown below. Figure 2As shown, this chip is a four-channel, low-power, 12-bit resolution, 180MSPS sampling rate digital-to-analog converter (DAC). It integrates a DDS module and a 4096×12-bit mode memory, and supports configuration via SPI (Serial Peripheral Interface), enabling the generation and output of complex waveforms. The AD9106BCPZEL7 chip's DDS module uses a 24-bit tuning word, achieving a frequency resolution of 10.8Hz / LSB (Least Significant Bit). It supports single-channel frequency output for each of the four DAC channels and independent programmable phase-shift output for each channel. Under a 3.3V power supply, its maximum differential current output can reach 8mA, providing a stable differential signal source for subsequent signal processing. An external 156.25MHz active crystal oscillator is used as the clock input source for the AD9106BCPZEL7 chip. The crystal oscillator output is connected to the CLKP and CLKN pins of the AD9106BCPZEL7 chip via AC (Alternating Current) coupling to achieve differential clock signal input, providing a precise clock reference for the DDS module and ensuring the frequency accuracy and phase noise performance of the output signal. The ADA4817-1ACPZ operational amplifier is selected as the core conversion device. This single-channel voltage feedback operational amplifier has a gain-bandwidth product of 410MHz and a slew rate of 870V / µs, enabling efficient processing of high-frequency differential signals. Two independent ADA4817-1ACPZ operational amplifier circuits are configured for the two pairs of differential signals output from the AD9106BCPZEL7 chip, configured in differential amplification mode through an external resistor network to achieve the conversion of differential current signals to single-ended voltage signals. The configured matching resistor reduces signal reflection, and the feedback resistor is used to adjust the op-amp gain to ensure that the amplitude of the output single-ended signal meets the requirements of the back-end circuitry.

[0094] 4. Pulse Modulation Signal Module: This module consists of a digital-to-analog converter (DAC) and a shaping circuit. The DAC uses the DAC8532IDGK chip, a 16-bit dual-channel low-power DAC with rail-to-rail voltage output and a serial interface. Its reference voltage input is connected to a 1.25V power supply from the power module, converting the input digital pulse signal into a corresponding analog voltage signal. The output of the DAC8532IDGK chip is connected to the control input of the gain control unit, enabling the transmission of the analog voltage signal to the gain control unit. The gain control unit uses the VCA824IDGST chip, a wideband voltage-controlled gain operational amplifier with a 710MHz small-signal bandwidth and a gain adjustment range of over 40dB. Its VG pin, the gain control input, is directly connected to the output of the DAC8532IDGK chip, receiving the analog voltage signal output from the DAC. The gain of the VCA824IDGST chip is adjusted by changing the amplitude of this analog voltage signal. The VCA824IDGST chip's signal input terminal receives the single-ended pulse signal to be processed. After gain adjustment, the pulse signal is transmitted from its output terminal to the signal shaping unit. The signal shaping unit uses the OPA817DTKR chip, a high-speed voltage feedback operational amplifier with an 800MHz bandwidth and a 1000V / us slew rate. Its input terminal is connected to the output terminal of the VCA824IDGST chip. Through an external feedback circuit, the input pulse signal is subjected to high-speed buffering, edge sharpening, and overshoot suppression processing, ultimately outputting the required standard pulse signal. The pulse width of the signal is designed to be selectable at 200ns, 400ns, and 800ns.

[0095] The main circuit diagram of the pulse modulation signal module in this embodiment is as follows: Figure 3 As shown, it mainly consists of a gain control unit U26, a signal shaping unit U45, and supporting passive components such as resistors, capacitors, and inductors. It is used to adjust the gain, filter, and drive amplify the DDS_VOUT2 signal output by the DDS drive module, and finally output the PULSE_DRV / PULSE_RF_DRV pulse modulation signal.

[0096] U26 is a gain control unit of model VCA824IDGST. Its core pins include: pin 3 (VG, gain control terminal), pin 4 (+Vin, non-inverting input terminal), pin 5 (RG+, positive terminal of gain resistor), pin 6 (RG-, negative terminal of gain resistor), pin 7 (-Vin, inverting input terminal), pin 1 (FB, feedback terminal), and pin 9 (output terminal). The AVCC_5V power supply is connected to the U26 power pin via inductor L30, with capacitors C134 and C135 connected in parallel to AGND. The AVCC_-5V power supply is connected to another power pin of the U26 via inductor L31, with capacitors C139 and C140 connected in parallel to AGND. DDS_VOUT2 The signal is connected to pin 4 of U26; pin 7 of U26 is connected to AGND via resistor R136, forming a single-ended to differential input impedance matching circuit; resistor R130 is connected between pins 5 and 6 of U26 to set the basic gain value; pin 1 of U26 is connected to pin 9 via resistor R127 to form a feedback loop; pin 3 of U26 is connected to the PULSE_VG control signal, and the gain is dynamically controlled by adjusting the voltage at the VG terminal; pin 9 of U26 is connected to the test point V_PULSE (TP30) via resistor R132; the test point V_PULSE signal is divided by resistor R221 and then connected to the non-inverting input of the signal shaping unit U45 via R231.

[0097] U45 is the signal shaping unit of model OPA817DTKR. Its core pins include: pin 4 (Vin+, non-inverting input), pin 3 (Vin-, inverting input), and pin 7 (Vout, output). The AVCC_5V power supply is connected to the U45 power pin via ferrite bead L43, with capacitors C237 and C238 connected in parallel to AGND. The AVCC_-5V power supply is connected to another power pin of U45 via ferrite bead L44, with capacitors C239 and C240 ​​connected in parallel to AGND. Pin 4 of U45 is connected to the test point V_PULSE to receive the signal conditioned by U26. Pin 3 of U45 is connected to pin 2 via resistor R223, with capacitor C241 connected in parallel to AGND, forming a negative feedback and phase compensation loop to suppress op-amp self-oscillation. Pin 7 of U45 outputs the PULSE_RF_DRV signal (pulse modulation signal) via resistor R224. The test point PULSE_DRV (TP39) is used for signal monitoring.

[0098] 5. Frequency Shift Modulation Signal Module: This module consists of a digital-to-analog converter (DAC) and a shaping circuit. The DAC uses a DAC8532IDGK chip, with its reference voltage input connected to a 1.25V power supply module. Its output is connected to the control input of the gain control unit. The gain control unit uses a VCA824IDGST chip, with its VG pin (gain control input) directly connected to the output of the DAC8532IDGK chip. It receives the analog voltage signal output from the DAC and adjusts the gain of the VCA824IDGST chip by changing the amplitude of this analog voltage signal. The single-ended pulse signal to be processed is input to the VCA824IDGST chip. After gain adjustment, the pulse signal is transmitted from its output to the signal shaping unit. The signal shaping unit uses an OPA817DTKR chip, with its input connected to the output of the VCA824IDGST chip. An external feedback circuit performs high-speed buffering, edge sharpening, and overshoot suppression on the input pulse signal. The ADHV4710BSVZ high-voltage operational amplifier is used as the core device for high-voltage amplification. The pin diagram of the ADHV4710 chip is shown below. Figure 4 As shown, the input of the ADHV4710BSVZ is connected to the output of the OPA817DTKR high-speed operational amplifier to receive the shaped pulse signal and amplify its amplitude by 40 times before outputting it. The ADHV4710BSVZ high-voltage operational amplifier is equipped with external transconductance resistors and external compensation capacitors to ensure circuit stability at 40x gain and to achieve adjustment of the output signal slew rate and stable drive of infinite capacitive loads. It can ultimately generate high-voltage frequency-shift modulated signals with pulse widths selectable at 200ns, 400ns, and 800ns, and waveforms selectable as square waves, triangle waves, sawtooth waves, and arbitrary waves. The signal amplitude range corresponds to the selected pulse widths of 15V, 30V, and 48V, respectively.

[0099] The high-voltage operational amplifier circuit diagram of the frequency shift modulation signal module in this embodiment is as follows: Figure 5 As shown, the core uses the ADHV4710BSVZ high-voltage operational amplifier chip U47A, which, together with passive components, forms a signal input, SPI communication control, power supply decoupling, feedback compensation, and output drive network. This network enables high-voltage amplification and conditioning of the SHIFT_RF input signal, ultimately outputting the SHIFT_RF_DRV frequency-shift modulated signal. It also supports reset control, temperature monitoring, and logic level output functions.

[0100] U47A is a high-voltage operational amplifier, model ADHV4710BSVZ. Its key pins and function definitions are as follows: Pin 1 (SDN_RESET, shutdown / reset control), Pin 36 (RESET, reset), Pin 40 (CS, chip select), Pin 38 (SDI, serial data input), Pin 37 (SDO, serial data output), Pin 39 (SCLK, serial clock), Pin 42 (VCC_5V, 5V logic power supply), Pin 44 (VREF_5V, 5V reference power supply), Pins 13 / 14 / 15 (HVCC, high-voltage power supply), Pins 27 / 28 / 29 / 30 / 31 (VHEE). Pins 1-80 are: high voltage negative power supply terminal, pin 3 (INP, non-inverting input terminal), pin 4 (INPB, non-inverting input bias terminal), pin 6 (INNB, inverting input bias terminal), pin 7 (INN, inverting input terminal), pin 17 (COMP_H, high voltage compensation terminal), pin 23 (COMP_L, low voltage compensation terminal), pins 19 / 20 / 21 (OUT1 / OUT2 / OUT3, high voltage output terminal), pin 34 (COMP_T, temperature compensation terminal), pin 76 (VLOGIC_OUT, logic level output terminal), pin 77 (TMP, temperature monitoring terminal), and pin 80 (SDN_IO, shutdown / reset IO terminal).

[0101] The AVCC_5V power supply is connected to pin 42 of U47A via a ferrite bead L45, with capacitors C271 and C272 connected in parallel to AGND to filter and decouple the 5V logic power supply and suppress power supply noise. Pin 44 of U47A is connected to the 5V reference power supply, pins 13 / 14 / 15 are connected to the high-voltage positive power supply, and pins 27 / 28 / 29 / 30 / 31 are connected to the high-voltage negative power supply to power the chip's high-voltage amplifier module. The RF_SDN_RESET signal is connected to pin 1 of U47A, and the RF_RESET_N signal is connected to pin 36 to control the chip's shutdown and reset. Pins 39, 37, 38, and 40 of U47A are connected to the SPI_DDS_RF_SCK, SPI_DDS_RF_SDO, SPI_DDS_RF_SDI, and SPI_RF_CS_N signals, respectively, forming the SPI serial communication interface. A series resistor R242 is connected to pin 37 to achieve impedance matching of the SPI bus and improve communication stability. Pin 77 is connected to the SHIFT_RF_ The TMP signal enables real-time monitoring of the chip's operating temperature; the SHIFT_RF input signal is connected to pin 3 of U47A via resistor R266; pin 4 of U47A is connected to AGND via resistor R262 to achieve bias grounding of the in-phase input, ensuring stable DC level of the input signal; pins 17 / 23 of U47A are connected to the common output node of pins 19 / 20 / 21 of the chip via capacitors C273 and C274, and this node is also connected to AGND via resistor R264 and capacitor C276, forming a high-voltage loop compensation network to suppress self-oscillation of the high-voltage amplifier module; pin 23 of U47A is connected to AGND via capacitor C275 to achieve phase compensation of the low-voltage loop, improving circuit stability; R264 and R260 are connected to the feedback network to achieve signal gain amplification; the output node of U47A outputs the SHIFT_RF_DRV signal via resistor R265, and the test point SHIFT_DRV (TP29) is used to monitor the amplitude and waveform of the high-voltage frequency-shift modulation signal.

[0102] 6. Thermally Adjustable Bias Drive Module: The core function of this module is to provide a stable thermally adjustable bias power supply for the laser and to achieve precise adjustment and real-time monitoring of the bias current. This module mainly consists of a power supply switch unit, a constant current drive unit, and a current sampling feedback unit, realizing closed-loop control of the laser's thermally adjustable bias state and effectively improving the stability and reliability of the laser's operation. The power supply switch unit uses the TPS22975DSGR switch chip as its core, mainly used to control the switching of the 4.1V power supply voltage to the laser's thermally adjustable bias anode. The switch enable signal for this unit is provided by the MCU. The TPS22975DSGR chip has a low control input threshold and is directly compatible with common MCU logic levels, requiring no additional level conversion circuitry. The constant current drive unit is connected between the laser's thermally adjustable bias cathode and ground. Its core function is to provide a stable constant current output for the laser's thermally adjustable bias. It mainly consists of a digital-to-analog converter unit, CMOS transistors, and operational amplifiers MAX4475AUT+T and OPA2340EA / 2K5. The digital-to-analog converter (DAC) uses a DAC8532IDGK chip with a reference voltage of 2.5V. It converts the received digital signal into a corresponding analog voltage signal, which serves as the gate drive voltage. This analog voltage is then output through an operational amplifier MAX4475AUT+T and a voltage divider resistor network to the gate of a CMOS transistor (Complementary Metal-Oxide-Semiconductor). The CMOS transistor operates in the constant current region, with its drain connected to the thermally adjustable cathode of the laser and its source grounded. The conduction state of the CMOS transistor is adjusted by changing the gate drive voltage, thereby controlling the current in the thermally adjustable bias circuit of the laser to achieve constant current output. The current sampling feedback unit includes an operational amplifier OPA2340EA / 2K5, which collects the output current of the constant current drive unit in real time and feeds the sampled signal back to the MCU, enabling real-time current monitoring and closed-loop regulation. The maximum output current of the designed constant current source circuit is 42mA.

[0103] 7. MPD Module: Amplifies and filters the photocurrent signal output by the MPD of the thin-film lithium niobate pulse frequency shifter and converts it into a voltage signal. The signal is then converted from analog to digital by the MCU to accurately detect the optical power of the thin-film lithium niobate pulse frequency shifter.

[0104] 8. Power monitoring module: The OPA2340EA / 2K5 operational amplifier is used as a voltage follower to monitor the output voltage of the power module in real time, rail-to-rail.

[0105] Based on the same inventive concept, this application also provides a high-voltage frequency signal modulation method applied to the high-voltage frequency signal modulation device mentioned above. The solution provided by this method is similar to the solution described in the above method. Therefore, the specific limitations in one or more embodiments of the high-voltage frequency signal modulation method provided below can be found in the limitations of the high-voltage frequency signal modulation device described above, and will not be repeated here.

[0106] In one exemplary embodiment, a high-voltage frequency signal modulation method is provided, comprising:

[0107] The control module receives modulation parameters (input by the user) and generates control signals based on the modulation parameters; the control signals include direct digital frequency synthesis control signals, pulse modulation control signals, frequency shift modulation control signals, and hot-adjustment bias control signals; the modulation parameters include pulse width, pulse frequency, and delay.

[0108] Based on the direct digital frequency synthesis control signal, pulse-modulated differential voltage signals and frequency-shift-modulated differential voltage signals are obtained (through digital-to-analog conversion and differential amplification operations).

[0109] Based on the pulse modulation control signal and the pulse modulation differential voltage signal, a pulse modulation signal is obtained; specifically, based on the pulse modulation control signal, gain adjustment and signal shaping operations are performed on the pulse modulation differential voltage signal to obtain the pulse modulation signal.

[0110] Based on the frequency shift modulation control signal and the frequency shift modulation differential voltage signal, a high-voltage frequency shift modulation signal is obtained; specifically, based on the frequency shift modulation control signal, gain adjustment operation, signal shaping operation, and high-voltage amplification operation are performed on the frequency shift modulation differential voltage signal.

[0111] Based on the thermally adjustable bias control signal, a thermally adjustable bias drive signal is obtained through constant current control operation.

[0112] The laser module emits laser light in coordination with the pulse modulation signal, the high-voltage frequency shift modulation signal, and the thermally modulated bias drive signal.

[0113] Obtain the voltage feedback signal corresponding to the laser current feedback signal and the current sampling signal corresponding to the thermally adjusted bias drive signal.

[0114] The actual pulse repetition frequency is determined based on the voltage feedback signal, and the actual thermally adjustable bias current is determined based on the current sampling signal.

[0115] If the adjustment conditions are met, the control signal is adjusted using a preset adjustment method. The adjustment conditions include the deviation between the actual pulse repetition frequency and the target pulse repetition frequency exceeding a first preset threshold, or the deviation between the actual thermal bias current and the target current exceeding a second preset threshold. The preset adjustment method includes adjusting the direct digital frequency synthesis control signal, pulse modulation control signal, and frequency shift modulation control signal in the control signal by checking the software configuration of the direct digital frequency synthesis drive module or adding a temperature drift compensation algorithm if the deviation between the actual thermal bias current and the target current exceeds the second preset threshold; and adjusting the thermal bias control signal in the control signal by correcting the output current of the constant current drive unit if the deviation between the actual thermal bias current and the target current exceeds the second preset threshold.

[0116] As an optional implementation, if the deviation between the actual pulse repetition frequency and the target pulse repetition frequency exceeds a first preset threshold, the following steps are performed: First, read the current software configuration parameters of the direct digital frequency synthesis driver module; second, check whether the software configuration parameters are consistent with the preset standard configuration. If there is a configuration error or parameter loss, reload and solidify the standard software configuration; third, collect the current ambient temperature and the module's operating temperature, calculate and add a temperature drift compensation value based on the pre-stored temperature-frequency offset curve; finally, based on the corrected configuration parameters and the temperature drift compensation value, synchronously adjust the direct digital frequency synthesis control signal, pulse modulation control signal, and frequency shift modulation control signal in the control signals to bring the actual pulse repetition frequency back to the target pulse repetition frequency range.

[0117] If the deviation between the actual thermal bias current and the target current exceeds the second preset threshold, the following steps are performed: First, the actual current value output from the constant current drive unit to the thermal bias port is acquired in real time and the difference is calculated with the preset target current value; second, a current correction amount is generated using a proportional-integral adjustment algorithm based on the current deviation value; third, the current correction amount is written into the digital-to-analog converter of the constant current drive unit to correct the output current of the constant current drive unit; finally, the adjusted thermal bias control signal is updated and output based on the corrected output current to stabilize the actual thermal bias current within the target current range.

[0118] Based on the adjusted control signal, the pulse modulation signal, the high-voltage frequency shift modulation signal, and the thermally tuned bias drive signal are regenerated to drive the laser module to emit laser light until the modulation termination condition is met and modulation stops; the modulation termination condition includes receiving a stop command.

[0119] In another exemplary embodiment of this application, the high-voltage frequency signal modulation experiment process is as follows:

[0120] Step 1: Experimental preparation: Connect the high-voltage frequency signal modulation circuit board designed in this embodiment for realizing airborne radar frequency shifting and pulse modulation to an external 12V power supply. The circuit board has a built-in thin-film lithium niobate pulse frequency shifting device connected to the constant current source circuit in the pulse modulation signal module, frequency shift modulation signal module, MPD module and thermally adjustable bias drive module.

[0121] Step 2: System Startup: Turn on the external power supply. The power module will work, converting the 12V voltage to 1.25V, 2.5V, 3.3V, 4.1V, 5V, 55V, and -5V output voltages to power each module and ensure stable operation of each module to meet the requirements of airborne radar. The power monitoring module will collect the output voltage signal of the power module in real time.

[0122] Step 3: Modulation Signal Generation: The host computer sends control commands to the MCU module to set the trigger mode and target parameters of the modulation signal (adapting to the requirements of airborne radar): pulse width 200ns, 400ns, 800ns, default pulse frequency 10kHz, delay 0us-1us. The MCU module receives the host computer commands and generates corresponding control signals: It sends a control signal to the AD9106BCPZEL7 chip in the DDS driver module to control it to generate pulse modulation differential signals and frequency shift modulation differential signals, and converts the differential signals into single-ended signals; it sends a control signal to the pulse modulation signal module to control the gain to amplify the amplitude of the pulse modulation signal, generating a pulse frequency modulation signal with the corresponding pulse width and amplitude; it sends a control signal to the frequency shift modulation signal module to control the gain to amplify the amplitude of the frequency shift modulation signal and input it to the high-voltage operational amplifier ADHV4710BSVZ chip, generating a high-voltage frequency modulation signal with the corresponding pulse width and amplitude; it sends a drive control signal to the thermally adjustable bias drive module to enable the constant current source circuit connected to the thermally adjustable bias electrode built into the thin-film lithium niobate pulse frequency shift device.

[0123] Step 4: Device Light Emission Control: The pulse modulation signal module outputs 3V, 10kHz, 200ns-800ns pulse modulation signals to the thin-film lithium niobate pulse frequency shifter. The frequency shift modulation signal module outputs 15V-48V, 10kHz, 200ns-800ns high-voltage frequency modulation signals to the thin-film lithium niobate pulse frequency shifter. The thermally adjustable bias drive module outputs thermally adjustable bias signals to the thin-film lithium niobate pulse frequency shifter. The maximum thermally adjustable bias current can reach 42mA. Driven by the modulation signals, the device emits laser light, providing support for the realization of airborne radar measurement functions.

[0124] Step 5: Light emission detection and feedback: The MPD module receives the current signal from the device in real time, amplifies and filters it, converts it into a voltage signal, and then transmits it to the MCU module after matching processing; the MCU module acquires the electrical signal through the ADC interface, analyzes it and finds that the actual pulse repetition frequency of the device is 80.13MHz, ensuring that the output signal meets the parameter requirements of airborne radar frequency shift and pulse modulation.

[0125] Step 6: Parameter Adjustment and Stable Operation: The target pulse repetition frequency of the thin-film lithium niobate pulse frequency shifter is 80MHz. If the pulse repetition frequency is not within ±0.5% of the error range, the problem can be addressed by troubleshooting the DDS drive module in the software configuration, or by adding a temperature drift compensation algorithm to resolve the error caused by large crystal oscillator temperature drift. Since the actual pulse repetition frequency is within ±0.5% of the error range, it meets the requirements. Therefore, the MCU module maintains the current modulation parameters unchanged, and the system enters a stable operating state, continuously providing a stable high-voltage frequency modulation signal to the airborne radar. The power monitoring module acquires the voltage signal and then conditions it using a voltage follower. The conditioned analog voltage signal is then sent to the ADC for analog-to-digital conversion. The converted digital signal is finally transmitted to the host computer to continuously monitor the power supply status. When all voltages are detected to be within ±5% of the nominal voltage, the power supply is operating normally.

[0126] Step 7: Experimental Verification: Continuously run the system and use an oscilloscope to monitor the pulse modulation signal output from the pulse modulation signal module and the frequency shift modulation signal module, as well as the high-voltage frequency shift modulation signal, in real time. The waveform diagram when the pulse modulation signal is a square wave is shown below. Figure 6 As shown, the waveforms of sawtooth wave signals with pulse widths of 800ns, 400ns, and 200ns are respectively as follows: Figure 7-9 As shown. By Figure 6-9 It can be seen that the frequency fluctuation is ≤ ±0.2MHz, the pulse width fluctuation is ≤ ±1ns, and the output voltage fluctuation is ≤ ±0.5V, proving that the high-voltage frequency signal modulation implementation method of this embodiment has good stability and accuracy, and can stably adapt to the application requirements of airborne radar.

[0127] In summary, this application has the following beneficial effects:

[0128] 1. High degree of integration: This application integrates eight functional modules, including the DDS drive module, pulse modulation signal module, and frequency shift modulation signal module, into a single unit using a dedicated circuit board. This simplifies the system structure, reduces the number of interconnecting lines between modules, lowers signal transmission loss, and improves system stability and reliability. Compared to airborne radar-related acousto-optic frequency shifting schemes, the integrated design of this application significantly reduces the space required, solving the problems of large size and difficulty in adapting to airborne installation space in acousto-optic frequency shifting schemes. This provides strong support for the miniaturization of airborne radar systems.

[0129] 2. High Modulation Accuracy: The DDS drive module accurately generates the initial frequency signal. Combined with the pulse modulation module, the frequency shift modulation signal module for signal amplification, shaping, and modulation, and the real-time feedback control from the MCU module, precise control of parameters such as frequency, phase, and pulse width of the high-voltage frequency signal is achieved, ensuring the stability of the laser's output characteristics. This precise modulation performance can accurately match the stringent parameter requirements of airborne radar for frequency shift and pulse modulation signals, ensuring the accuracy of core radar functions such as detection and positioning. Compared to the insufficient modulation accuracy of acousto-optic frequency shifting schemes, this offers significant advantages.

[0130] 3. High Security: A power monitoring module monitors the power status in real time, effectively preventing system damage caused by power failure. Simultaneously, the power module incorporates corresponding protection circuits, further enhancing system safety. This safety design effectively addresses issues such as electromagnetic interference and voltage fluctuations encountered during airborne radar operation, and can withstand other potential power risks in the airborne environment, preventing system failures from affecting normal radar operation. It offers higher safety redundancy compared to related acoustic-optical frequency shifting solutions.

[0131] 4. Wide Adaptability: The MCU module allows for flexible control, enabling adjustment of modulation parameters to meet the driving requirements of different laser models. Furthermore, the thermally adjustable bias drive module features temperature and bias current compensation, adapting to various ambient temperatures and expanding its application range. It is particularly well-suited for the complex operating environment of airborne radar, characterized by wide temperature ranges, vibration, and high electromagnetic interference. Compared to the acousto-optic frequency shifting scheme's poor environmental adaptability and susceptibility to temperature fluctuations, this application can operate stably under various airborne conditions. Simultaneously, its flexible parameter adjustment capabilities can adapt to the modulation requirements of different airborne radar specifications, resulting in stronger compatibility.

[0132] 5. High level of intelligence: The MPD module enables real-time detection and feedback of the laser's output signal power. The MCU module dynamically adjusts the modulation strategy based on the feedback information, achieving closed-loop control of the modulation process, reducing manual intervention costs and improving modulation efficiency. More importantly, the modules in this application work collaboratively via dedicated circuit boards, achieving a level of coordination with the overall airborne radar system far exceeding traditional acousto-optic frequency shifting schemes—avoiding the problems of complex connections between the acousto-optic frequency shifting module and other radar components, severe signal interference, and poor compatibility, thus improving the overall system's operational stability and collaborative efficiency.

[0133] 6. A high-voltage and low-voltage partitioned layout is adopted, dividing the circuit board into a high-voltage area and a low-voltage area. Reliable electrical isolation between the two areas is achieved through creepage distance and electrical clearance. The high-voltage area integrates only the high-voltage amplification unit in the frequency shift modulation signal module, while the low-voltage area integrates all other functional modules. This layout blocks the conduction of high-voltage interference, ensures electrical safety, and further optimizes the rationality of the integrated layout.

[0134] In one exemplary embodiment, a computer-readable storage medium is provided storing a computer program that, when executed by a processor, implements the steps in the above-described method embodiments.

[0135] In one exemplary embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above-described method embodiments.

[0136] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.

[0137] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments described above. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM).

[0138] The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0139] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0140] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A high-voltage frequency signal modulation device, characterized in that, The high-voltage frequency signal modulation device is integrated on a circuit board, and the high-voltage frequency signal modulation device includes: The system includes a control module, a direct digital frequency synthesis drive module, a pulse modulation signal module, a frequency shift modulation signal module, a thermally modulated bias drive module, a photoelectric detection module, and a laser module. The control module is connected to the direct digital frequency synthesis drive module, the thermally tuned bias drive module, and the photoelectric detection module, respectively; the direct digital frequency synthesis drive module is connected to the pulse modulation signal module and the frequency shift modulation signal module, respectively; the pulse modulation signal module, the frequency shift modulation signal module, the thermally tuned bias drive module, and the photoelectric detection module are connected to the laser module, respectively. The laser module is used to emit laser light under the combined drive of pulse modulation signal, high voltage frequency shift modulation signal and thermally modulated bias drive signal, and sends the laser current feedback signal to the photoelectric detection module. The photoelectric detection module is used to receive the current feedback signal from the laser module and convert the current feedback signal into a voltage feedback signal to be sent to the control module; The control module is used to generate a control signal based on the modulation parameters; upon receiving the voltage feedback signal, it adjusts the control signal according to the voltage feedback signal and sends the adjusted control signal to the direct digital frequency synthesis drive module until the modulation end condition is met. The direct digital frequency synthesis drive module is used to generate pulse-modulated differential voltage signals and frequency-shift-modulated differential voltage signals based on the adjusted control signals; The pulse modulation signal module is used to convert pulse-modulated differential voltage signals into pulse-modulated signals; The frequency shift modulation signal module is used to convert the frequency shift modulation differential voltage signal into a high-voltage frequency shift modulation signal.

2. The high-voltage frequency signal modulation device according to claim 1, characterized in that, The control signals include direct digital frequency synthesis control signals, pulse modulation control signals, frequency shift modulation control signals, and thermal bias control signals; The direct digital frequency synthesis driver module includes a direct digital frequency synthesis chip, a crystal oscillator unit, and a signal conversion unit; The direct digital frequency synthesis chip is connected to the control module, the crystal oscillator unit, and the signal conversion unit, respectively. The crystal oscillator unit is used to provide a differential clock signal and send it to the direct digital frequency synthesis chip; The direct digital frequency synthesis chip is used to synthesize control signals based on the direct digital frequency in the control signal, generate pulse-modulated differential current signals and frequency-shift-modulated differential current signals through digital-to-analog conversion based on differential clock signals, and send them to the signal conversion unit. The signal conversion unit includes a first differential amplifier circuit and a second differential amplifier circuit; the first differential amplifier circuit is used to convert the pulse-modulated differential current signal into a pulse-modulated differential voltage signal; the second differential amplifier circuit is used to convert the frequency-shift modulated differential current signal into a frequency-shift modulated differential voltage signal.

3. The high-voltage frequency signal modulation device according to claim 2, characterized in that, The pulse modulation signal module includes a first digital-to-analog converter, a first gain control unit, and a first signal shaping unit connected in sequence; The first digital-to-analog conversion unit is also connected to the direct digital frequency synthesis drive module, and is used to perform digital-to-analog conversion on the pulse modulation control signal in the control signal to obtain the first analog voltage signal; The first gain control unit is also connected to the direct digital frequency synthesis drive module, which is used to perform gain adjustment operation on the pulse modulation differential voltage signal based on the first analog voltage signal to obtain a gain pulse modulation differential voltage signal; The first signal shaping unit is also connected to the laser module and is used to perform signal shaping operations on the gain pulse modulated differential voltage signal to obtain a pulse modulated signal, and send the pulse modulated signal to the laser module; the signal shaping operation includes buffer driving operation, edge sharpening operation, and overshoot suppression operation.

4. The high-voltage frequency signal modulation device according to claim 2, characterized in that, The frequency shift modulation signal module includes a second digital-to-analog converter, a second gain control unit, a second signal shaping unit, and a high-voltage amplifier unit connected in sequence. The second digital-to-analog conversion unit is also connected to the direct digital frequency synthesis drive module, and is used to perform digital-to-analog conversion on the frequency shift modulation control signal in the control signal to obtain the second analog voltage signal; The second gain control unit is also connected to the direct digital frequency synthesis drive module, and is used to perform gain adjustment operation on the frequency shift modulation differential voltage signal based on the second analog voltage signal to obtain the gain frequency shift modulation differential voltage signal; The second signal shaping unit is used to perform signal shaping operations on the gain-frequency-shift modulated differential voltage signal to obtain a shaped gain-frequency-shift modulated differential voltage signal; the signal shaping operation includes buffer driving operation, edge sharpening operation, and overshoot suppression operation; The high-voltage amplification unit is also connected to the laser module and is used to perform high-voltage amplification on the shaped gain frequency-shift modulated differential voltage signal to obtain a high-voltage frequency-shift modulated signal.

5. The high-voltage frequency signal modulation device according to claim 2, characterized in that, The high-voltage frequency signal modulation device also includes a power supply module; the power supply module is used to convert the external input voltage into multiple working voltages through voltage conversion operations, and to supply power to the control module, the direct digital frequency synthesis drive module, the pulse modulation signal module, the frequency shift modulation signal module and the thermal bias drive module.

6. The high-voltage frequency signal modulation device according to claim 5, characterized in that, The high-voltage frequency signal modulation device also includes a power monitoring module; The power monitoring module is connected to both the power module and the control module. The power monitoring module includes a voltage follower and an analog-to-digital converter (ADC). The voltage follower is used to acquire each operating voltage and perform signal conditioning on each voltage to obtain multiple conditioned operating voltage signals. The ADC is used to perform analog-to-digital conversion on each conditioned operating voltage signal to obtain multiple power status signals, and then sends these multiple power status signals to the control module. The signal conditioning includes impedance matching and noise suppression. The control module is also used to determine the power supply operating status based on the power supply status signals; if all power supply status signals indicate that the corresponding operating voltage is within the preset voltage range, the power supply operating status is determined to be normal; if any power supply status signal indicates that the corresponding operating voltage exceeds the preset voltage range, the power supply operating status is determined to be abnormal, and power supply abnormality protection operation is executed.

7. The high-voltage frequency signal modulation device according to claim 5, characterized in that, The thermal bias drive module includes a power supply switch unit, a constant current drive unit, and a current sampling feedback unit; The power supply switch unit is also connected to the control module and the power supply module respectively, and is used to control the power supply from the power supply module to the constant current drive unit according to the switch enable signal of the control module. The constant current drive unit is also connected to the control module and the laser module respectively, and is used to perform constant current control operation on the thermally tuned bias control signal in the control signal to generate a thermally tuned bias drive signal, and send the thermally tuned bias drive signal to the laser module. The current sampling feedback unit is also connected to the control module and is used to perform current sampling operation on the thermally adjustable bias drive signal to obtain a current sampling signal, and feed the current sampling signal back to the control module. The control module is also used to adjust the thermal bias control signal according to the current sampling signal, and send the adjusted thermal bias control signal to the constant current drive unit.

8. The high-voltage frequency signal modulation device according to claim 4, characterized in that, The circuit board includes a high-voltage region and a low-voltage region; Electrical isolation between the high-voltage and low-voltage areas is achieved through creepage distance and clearance. The high-voltage region includes the high-voltage amplification unit in the frequency shift modulation signal module; The low-voltage region includes a control module, a direct digital frequency synthesis drive module, a pulse modulation signal module, all units in the frequency shift modulation signal module except for the high-voltage amplification unit, a power supply module, a power supply monitoring module, a photoelectric detection module, and a thermally adjustable bias drive module.

9. The high-voltage frequency signal modulation device according to claim 1, characterized in that, The laser module is a thin-film lithium niobate pulse frequency shifter.

10. A high-voltage frequency signal modulation method, characterized in that, The high-voltage frequency signal modulation method is applied to the control module of the high-voltage frequency signal modulation device according to any one of claims 1-9, and the high-voltage frequency signal modulation method includes: The control module receives modulation parameters and generates control signals based on the modulation parameters; the control signals include direct digital frequency synthesis control signals, pulse modulation control signals, frequency shift modulation control signals, and thermal bias control signals. Based on the direct digital frequency synthesis control signal, pulse-modulated differential voltage signal and frequency-shift-modulated differential voltage signal are obtained; Based on the pulse modulation control signal and the pulse modulation differential voltage signal, a pulse modulation signal is obtained; Based on the frequency shift modulation control signal and the frequency shift modulation differential voltage signal, a high-voltage frequency shift modulation signal is obtained; Based on the aforementioned thermal bias control signal, a thermal bias drive signal is obtained through constant current control operation; The laser module is driven to emit laser light in coordination with the pulse modulation signal, the high voltage frequency shift modulation signal and the thermally adjusted bias drive signal. Acquire the voltage feedback signal corresponding to the laser current feedback signal and the current sampling signal corresponding to the thermally adjusted bias drive signal; The actual pulse repetition frequency is determined based on the voltage feedback signal, and the actual thermally adjustable bias current is determined based on the current sampling signal. If the adjustment conditions are met, the control signal is adjusted using a preset adjustment method. The adjustment conditions include the deviation between the actual pulse repetition frequency and the target pulse repetition frequency exceeding a first preset threshold, or the deviation between the actual thermal bias current and the target current exceeding a second preset threshold. The preset adjustment method includes adjusting the direct digital frequency synthesis control signal, pulse modulation control signal, and frequency shift modulation control signal in the control signal by checking the software configuration of the direct digital frequency synthesis drive module or adding a temperature drift compensation algorithm if the deviation between the actual thermal bias current and the target current exceeds the second preset threshold; and adjusting the thermal bias control signal in the control signal by correcting the output current of the constant current drive unit if the deviation between the actual thermal bias current and the target current exceeds the second preset threshold. Based on the adjusted control signal, the pulse modulation signal, the high-voltage frequency shift modulation signal, and the thermally tuned bias drive signal are regenerated to drive the laser module to emit laser light until the modulation end condition is met and modulation stops.

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