Six-channel broadband interference signal modulation system and method

Abstract

The invention discloses a six-channel broadband interference signal modulation system and method. The system comprises a digital processing module, a radio frequency signal frequency conversion conditioning module, a power dividing and combining module and a power management module. The digital processing module comprises six signal generation units, each unit comprises a radio frequency DAC, a clock chip and an OCXO crystal oscillator, and the digital processing module can directly generate a radio frequency signal of 10 MHz to 4 GHz and expand the radio frequency signal to 6 GHz through a frequency mixing technology; the radio frequency signal frequency conversion conditioning module carries out filtering, amplification, gain control and frequency conversion processing on the signals to generate six paths of independent radio frequency output signals; the power dividing and combining module divides six paths of signals into two power, one path of signals is directly output, the other path of signals is combined into one path of signals through the six-in-one combiner, seven paths of broadband interference signals are generated in total, and high-precision, wide-frequency-band and multi-channel broadband interference signal generation and control are achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of radio frequency signal processing, and particularly relates to a 6-channel broadband interference signal modulation system and method. Background Art

[0002] In the field of electronic countermeasures, higher requirements are put forward for the frequency coverage range and the number of channels of interference signals. Traditional interference signal generating devices usually can only provide a limited frequency coverage range and a small number of channels, making it difficult to meet the complex application requirements in the modern electronic warfare environment. In addition, the signal quality of most devices significantly deteriorates in the high-frequency band (such as above 4 GHz), especially there are significant deficiencies in frequency switching and power control accuracy, resulting in poor interference effects.

[0003] Most of the broadband interference signal modulation systems in the prior art adopt an analog mixing circuit structure, which not only has a high system complexity, but also has poor signal purity and stability. These systems perform poorly in terms of frequency step accuracy and mixing spurious suppression, and it is difficult to achieve high-precision frequency control. Especially in the scenario where multi-channel collaborative work is required, the consistency and synchronization of the system become the key bottlenecks.

[0004] In addition, the existing interference systems lack effective algorithm support in power adaptive control and cannot dynamically adjust the output power according to the signal characteristics of different frequency bands and different bandwidths, making the adaptability of the system in the complex electromagnetic environment poor. At the same time, the existing systems generally lack efficient image and harmonic suppression technologies, especially the suppression effect of spurious signals generated in the wide-band mixing process is limited, seriously affecting the signal quality and interference effect of the system. Summary of the Invention

[0005] The purpose of the present invention is to provide a 6-channel broadband interference signal modulation system and method, which can cover a wide frequency band range from 10 MHz to 6 GHz, achieve high-precision frequency control and power adaptive adjustment, provide functions of multi-channel independent output and combined output, and effectively solve the problems of low frequency step accuracy, poor mixing spurious suppression effect, and insufficient consistency and synchronization of multi-channel collaborative work in the prior art, and meet the complex application requirements in the modern electronic countermeasure environment.

[0006] The specific technical solutions are as follows:

[0007] A 6-channel broadband interference signal modulation system, the system includes: a digital processing module, a radio frequency signal frequency conversion conditioning module, a power splitting and combining module, and a power management module.

[0008] The digital processing module is used to generate broadband interference baseband signals, and the digital processing module includes 6 signal generation units, and each signal generation unit includes a radio frequency DAC, a clock chip, and an OCXO crystal oscillator.

[0009] The radio frequency signal frequency conversion and conditioning module is used to filter, amplify, perform gain control, and perform signal frequency conversion processing on the broadband interference baseband signal generated by the digital processing module, generating 6 radio frequency output signals.

[0010] The power splitting and combining module is used to split the 6 radio frequency output signals into two paths respectively. One path is used to directly output an independent broadband interference signal of 10 MHz to 6 GHz, and the other path is respectively input into a six-in-one combiner to synthesize one broadband interference signal, generating a total of seven broadband interference signals.

[0011] The power management module is used to provide the required DC voltage for the digital processing module and the radio frequency signal frequency conversion and conditioning module.

[0012] Further, in the digital processing module, the radio frequency DAC uses a 16-bit, 12.6 Gsps sampling rate chip AD9174. In the case of using the first Nyquist domain, it directly outputs a broadband interference baseband signal of 10 MHz to 4000 MHz; the control bit width of the numerically controlled oscillator inside the chip is 48 bit, the sampling rate of the DAC is 12 Gsps, and the minimum frequency step of the broadband interference baseband signal can be configured is 0.004 Hz: .

[0013] Further, in the digital processing module, the short-term frequency stability of the OCXO crystal oscillator is ppm, and the frequency jitter at 6 GHz output is 0.06 Hz; under the condition that the frequency fluctuation does not exceed 10% of the frequency step, its frequency step is 0.1 Hz.

[0014] Further, each signal generation unit includes: a low-frequency channel and a high-frequency channel, and the channel switching is controlled by a switch;

[0015] The low-frequency channel operates in the frequency band of 10 MHz to 4 GHz and directly generates a radio frequency signal through the AD9174 in the digital processing module.

[0016] The high-frequency channel operates in the frequency band of 4 GHz to 6 GHz, and generates the required broadband interference baseband signal by mixing the 3.5 GHz intermediate frequency signal generated by the AD9174 in the digital processing module with the local oscillator signal of 7.5 GHz to 9.5 GHz.

[0017] Further, the radio frequency signal frequency conversion and conditioning module is used to filter, amplify, perform gain control, and perform signal frequency conversion processing on the broadband interference baseband signal generated by the digital processing module. The specific link includes, in sequence and connected to the radio frequency DAC: a first attenuator, a first amplifier, a first bias Bias, a first attenuation, the first filter, the second attenuator.

[0018] When the signal passes through the second attenuator and the output power is between -60 dBm and -10 dBm, it directly passes through the second attenuation, the second filter and the third attenuation, and then enters the SMA for signal smoothing to obtain the RF output signal.

[0019] When the signal passes through the second attenuator and the output power is between -10 dBm and 16 dBm, a second amplifier, a second bias Bias, a fourth attenuation, a third amplifier and a third bias Bias are added before the second attenuation to ensure that the link gain is greater than 10 dBm.

[0020] Furthermore, both the first attenuator and the second attenuator are digitally controlled attenuators. The minimum step of the control of the digitally controlled attenuator is 0.5 dB. At the same time, a digital signal amplitude modulation module is designed inside the FPGA, with a modulation precision bit width of 16 bits. The minimum step of the output power is 0.1 dB, and the maximum output power is 93 dB.

[0021] Furthermore, the power management module provides a 5 - 12V DC voltage for the digital processing module and the RF signal frequency conversion conditioning module.

[0022] Based on the same inventive concept, the present invention also provides a 6 - channel broadband interference signal modulation method, which is implemented based on the system of the present invention. The method includes:

[0023] Generating a broadband interference baseband signal through the digital processing module. The broadband interference baseband signal satisfies: ; where is the number of sub - signals, is the amplitude of the th sub - signal, is the envelope modulation function, is the carrier frequency, is the phase modulation function.

[0024] Interpolating the baseband signal by interpolation filtering by times and times. The total gain of the interpolation filtering satisfies: , where is the digital compensation gain used to eliminate the amplitude loss introduced by the filter.

[0025] Perform digital mixing and frequency conversion on the interpolated digital signal, and change the output frequency of the RF signal by modifying the output frequency of the numerically controlled oscillator.

[0026] Convert the digitally processed signal into an analog RF signal through an RF DAC.

[0027] Filter, amplify, perform gain control, and signal frequency conversion processing on the analog RF signal through an RF signal frequency conversion conditioning module, thereby generating 6 independent broadband interference signals.

[0028] Further, the method further includes dynamic power control, adopting an adaptive power control algorithm:

[0029] , where is the output power, is the reference power, is the frequency-dependent attenuation function, is the signal bandwidth, is the environmental compensation factor, , and are weight coefficients; the weight coefficients , and are set by fitting the measured frequency-power curve, bandwidth-power curve, and environmental impact factor curve using the least squares method, where is used to compensate for the power loss caused by frequency, and its value range is 0.01 - 0.1; is used to compensate for the power attenuation caused by the increase in bandwidth, and its value range is 0.5 - 2.0; is used to compensate for the influence of environmental factors, and its value range is 0.1 - 1.0.

[0030] Further, the method adopts a double mixing suppression technique on the 4GHz - 6GHz high-frequency channel, and suppresses the images and harmonics generated by mixing using the following mathematical model: ; where is the center frequency, is the suppression bandwidth, is the filter order, is the phase compensation function, which is used to optimize the phase characteristics of the mixer.

[0031] Compared with the prior art, the beneficial effects of the present invention are:

[0032] The present invention uses high-performance programmable FPGA logic and high-performance dedicated DAC chips to achieve high-speed digital signal processing functions, and can directly generate high-quality RF signals in the range of 10 MHz to 4 GHz, and achieve a frequency coverage of up to 6 GHz through mixing technology. At the same time, the system adopts an adaptive power control algorithm and a secondary mixing suppression technology, effectively solving the problems of power fluctuation and mixing spurious when the frequency is switched. The six-channel design can realize the simultaneous output of multiple independent RF signals or the combination into a high-power signal output, greatly improving the flexibility and application scenario adaptability of the system. At the same time, the system has high integration, strong reliability and low power consumption, and is particularly suitable for the application requirements of portable and mobile electronic countermeasure equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 FIG. is a schematic diagram of the composition of a 6-channel wideband interference signal modulation system of the present invention;

[0034] Figure 2 FIG. is a schematic diagram of the link of the RF signal frequency conversion conditioning module of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art without making creative efforts based on the embodiments in the present invention belong to the scope of protection of the present invention.

[0036] Embodiment 1

[0037] As Figure 1 shown, FIG. is a schematic diagram of a 6-channel wideband interference signal modulation system of the present invention. The system includes: a digital processing module, an RF signal frequency conversion conditioning module, a power splitting / combining module, and a power management module.

[0038] The system of the present invention adopts a modular design architecture. Each functional module is interconnected through a high-speed data bus and a control interface to form a complete signal processing link. This modular design not only improves the reliability and maintainability of the system, but also facilitates function expansion and performance optimization according to actual application requirements. The digital processing module, as the core of the system, is responsible for signal generation and preliminary processing; the RF signal frequency conversion conditioning module is responsible for signal spectrum processing and power adjustment; the power splitting / combining module realizes signal distribution and synthesis; the power management module provides a stable and reliable power supply for the entire system to ensure the performance stability of the system under various working conditions.

[0039] The digital processing module is used to generate a broadband interference baseband signal. The digital processing module includes six signal generation units, and each signal generation unit includes a radio frequency DAC, a clock chip, and an OCXO crystal oscillator.

[0040] Each signal generation unit adopts an independent structural design to ensure the isolation between channels and the independent control ability of signals. The radio frequency DAC is responsible for converting digital signals into analog signals and is a key determinant of signal quality; the clock chip provides various clock signals required by the system to ensure data synchronization and processing accuracy; the OCXO crystal oscillator provides a high-precision reference frequency source for the entire system, and its frequency stability directly affects the frequency accuracy and phase noise performance of the system. These three parts work together to form a complete signal generation path to ensure the high quality and stability of the output signal.

[0041] The radio frequency signal frequency conversion and conditioning module is used to filter, amplify, control the gain, and perform signal frequency conversion on the broadband interference baseband signal generated by the digital processing module, generating six radio frequency output signals.

[0042] The radio frequency signal frequency conversion and conditioning module adopts a multi-stage amplification and precision filtering design to achieve precise conditioning of signals. In the filtering link, a high-performance filter is used to effectively suppress out-of-band spurs and mixing products; in the amplification link, a low-noise amplifier and a linear power amplifier are used to ensure the linearity and low-noise characteristics during signal amplification; the gain control combines a digital control attenuator and digital amplitude modulation to achieve wide-range and high-precision power control; the signal frequency conversion processing uses a high-performance mixer and a phase-locked loop to ensure the signal purity during frequency conversion.

[0043] The power splitting and combining module is used to split each of the six radio frequency output signals into two, one for directly outputting an independent broadband interference signal in the range of 10 MHz to 6 GHz, and the other for each to be input into a six-in-one combiner to synthesize a broadband interference signal, generating a total of seven broadband interference signals.

[0044] The power splitting and combining module adopts a Wilkinson power splitter and a microstrip combiner with low loss and high isolation to ensure the minimum loss and the best isolation between channels during signal splitting and combining. In the power splitting link, a broadband one-half power splitter is used, which has good power distribution balance and phase consistency.

[0045] The power management module is used to provide the required DC voltage for the digital processing module and the radio frequency signal frequency conversion and conditioning module.

[0046] This module includes multiple parts such as an input voltage protection circuit, a DC-DC conversion circuit, a linear voltage regulator circuit, and an output filter circuit. Through precise voltage control and noise suppression, it ensures the power quality of the system under various operating conditions. Especially for sensitive high-frequency circuits and digital processing circuits, independent power supply lines and isolation measures are adopted.

[0047] In the digital processing module, the RF DAC uses a 16-bit, 12.6 Gsps sampling rate chip AD9174. In the case of using the first Nyquist domain, it directly outputs a broadband interference baseband signal of 10 MHz to 4000 MHz; the control bit width of the numerically controlled oscillator inside the chip is 48 bits, the sampling rate of the DAC is 12 Gsps, and the minimum frequency step of the broadband interference baseband signal can be configured to 0.004 Hz: .

[0048] In the first Nyquist domain operating mode, the system can cover a wide frequency band range from 10 MHz to 4 GHz without an additional up-conversion link; the 48-bit numerically controlled oscillator control bit width provides extremely high frequency resolution, enabling the system to achieve sub-hertz level frequency step accuracy; at the same time, the built-in digital signal processing functions of AD9174, such as interpolation filtering and digital mixing, further enhance the signal processing ability and flexibility of the system.

[0049] In the digital processing module, the short-term frequency stability of the OCXO crystal oscillator is ppm, and the frequency jitter at 6 GHz output is 0.06 Hz; under the condition that the frequency fluctuation does not exceed 10% of the frequency step, its frequency step is 0.1 Hz.

[0050] Each signal generation unit includes: a low-frequency channel and a high-frequency channel, and the channel switching is controlled by a switch; the switch uses GaAs FET technology with low insertion loss and high isolation, has good linearity and broadband characteristics, and can support signal transmission throughout the operating frequency band. The channel switching is controlled by an FPGA and can achieve fast frequency hopping in milliseconds.

[0051] The low-frequency channel operates in the frequency band of 10 MHz to 4 GHz and directly generates radio frequency signals through the AD9174 in the digital processing module. The low-frequency channel adopts the direct digital synthesis (DDS) technology and directly generates radio frequency signals from 10 MHz to 4 GHz through the high-speed DAC of AD9174, avoiding the multi-stage mixing and filtering links in the superheterodyne architecture, greatly simplifying the signal link, and reducing the system complexity and cost. The direct digital synthesis technology has the characteristics of continuous phase and frequency agility, and can achieve fast frequency hopping and complex modulation methods. Especially in the low-frequency band, the system adopts special predistortion algorithms and digital compensation technologies to effectively overcome the performance attenuation problem of the DAC at the high-frequency end and ensure the signal quality near 4 GHz.

[0052] The high-frequency channel operates in the frequency band of 4 GHz to 6 GHz and generates the required wideband interference baseband signal by mixing the 3.5 GHz intermediate frequency signal generated by the AD9174 in the digital processing module with the local oscillator signal of 7.5 GHz to 9.5 GHz.

[0053] The high-frequency channel adopts a single-stage mixing up-conversion architecture. By mixing the 3.5 GHz intermediate frequency signal generated by AD9174 with the adjustable local oscillator signal, the signal coverage in the frequency band of 4 GHz to 6 GHz is achieved. The local oscillator signal is composed of a high-performance phase-locked loop (PLL) and a voltage-controlled oscillator (VCO), with a frequency range of 7.5 GHz to 9.5 GHz, and has the characteristics of low phase noise and high frequency stability. The mixing uses a high-linearity double-balanced mixer, which has good port isolation and spurious suppression performance.

[0054] As Figure 2 shown, it is a schematic diagram of the link of the radio frequency signal frequency conversion and conditioning module of the present invention. The radio frequency signal frequency conversion and conditioning module is used to filter, amplify, control the gain, and perform signal frequency conversion processing on the wideband interference baseband signal generated by the digital processing module. The specific link includes, in sequence and connected to the radio frequency DAC: a first attenuator, a first amplifier, a first bias Bias, a first attenuation, a first filter, and a second attenuator.

[0055] The link design of the radio frequency signal frequency conversion and conditioning module follows the principle of "small signal first", and through multi-stage amplification and precise control, high-quality signal processing is achieved. The first attenuator is responsible for adjusting the initial power level of the DAC output signal to avoid overloading distortion of the subsequent amplifier; the first amplifier is a low-noise amplifier (LNA), with high gain and low noise figure characteristics, used to increase the power level of the signal; the first bias provides the DC operating point required by the amplifier to ensure that the amplifier operates in the best linear region; the first π attenuator is used to finely adjust the amplifier output power and provide good impedance matching; the first filter is a high-performance bandpass filter to filter out out-of-band noise and spurs; the second attenuator is used to achieve wide-range power control.

[0056] When the signal passes through the second attenuator and the output power is between -60 dBm and -10 dBm, it directly passes through the second attenuator, the second filter and the third attenuator, and after inputting to the SMA for signal smoothing, the radio frequency output signal is obtained;

[0057] When the signal passes through the second attenuator and the output power is between -10 dBm and 16 dBm, before the second attenuator, a second amplifier, a second bias, a fourth attenuator, a third amplifier and a third bias are added; ensuring that the link gain is greater than 10 dBm.

[0058] The second π attenuator is mainly used for impedance matching and signal isolation to reduce the mutual influence between circuits; the second filter is a high-precision bandpass filter to further purify the signal spectrum and improve the signal purity; the third π attenuator provides the final power fine-tuning ability while maintaining impedance matching; the signal is finally output through the SMA connector, and the inside of the connector adopts special signal smoothing processing, including impedance gradient and electromagnetic interference suppression design, to ensure the integrity and purity of the signal at the transmission interface.

[0059] The first attenuator and the second attenuator are both digitally controlled attenuators. The minimum control step of the digitally controlled attenuator is 0.5 dB. At the same time, a digital signal amplitude modulation module is designed inside the FPGA, with a modulation precision bit width of 16 bits, the minimum output power step is 0.1 dB, and the maximum output power is 93 dB. The digitally controlled attenuator uses the PE43610A-X chip of PSEMI, which has a wide operating frequency band from DC to 6 GHz and good linear characteristics. Its 0.5 dB control step meets most power adjustment requirements.

[0060] The power management module provides 5 - 12V DC voltage for the digital processing module and the radio frequency signal frequency conversion and conditioning module.

[0061] Embodiment 2

[0062] A 6-channel broadband interference signal modulation method, implemented based on the system of Embodiment 1, the method includes the following steps:

[0063] Generate a broadband interference baseband signal through a digital processing module, the broadband interference baseband signal Satisfy: ; where, Is the number of sub-signals, Is the Amplitude of the th sub-signal, Is the envelope modulation function, Is the carrier frequency, Is the phase modulation function.

[0064] Perform Times and Times interpolation on the baseband signal through interpolation filtering, and the total gain of the interpolation filtering Satisfy: , where, Is the digital compensation gain, used to eliminate the amplitude loss introduced by the filter.

[0065] Perform digital mixing and frequency conversion on the digital signal after interpolation filtering, and change the output frequency of the RF signal by modifying the output frequency of the numerically controlled oscillator. The mixer selected is LTC5553, the LO frequency range of this device is 1 GHz to 20 GHz, the RF frequency range is 3 GHz to 20 GHz, and the IF frequency range is 0.5 GHz to 9 GHz. In this design, the DAC outputs a 3.5 GHz signal as the intermediate frequency signal, mixes it with the local oscillator signal of 7.5 GHz to 9.5 GHz, filters and outputs a 4 GHz to 6 GHz signal, and then performs fixed-point filtering and amplification on the intermediate frequency signal, which can effectively filter out out-of-band spurs.

[0066] Convert the digitally processed signal into an analog RF signal through an RF DAC. It can be known through the calculation of the transmission link that, on the premise of ensuring the output power, both channels are operating in the linear range, and no large harmonic signals will be generated due to power amplifier saturation.

[0067] Perform filtering, amplification, gain control, and signal frequency conversion processing on the analog RF signal through an RF signal frequency conversion conditioning module, so as to generate 6 independent-channel broadband interference signals.

[0068] The method also includes dynamic power control, adopting an adaptive power control algorithm:

[0069] , where, Is the output power, Is the reference power, is a frequency-dependent attenuation function, is the signal bandwidth, is the environmental compensation factor, , and are weight coefficients; the weight coefficients , and are set by fitting the measured frequency-power curve, bandwidth-power curve and environmental impact factor curve using the least squares method, where is used to compensate for the power loss caused by frequency, and its value range is 0.01 - 0.1; is used to compensate for the power attenuation caused by the increase in bandwidth, and its value range is 0.5 - 2.0; is used to compensate for the influence of environmental factors, and its value range is 0.1 - 1.0.

[0070] The method adopts a double mixing suppression technique on the 4GHz - 6GHz high-frequency channel, and suppresses the images and harmonics generated by mixing using the following mathematical model: ; where, is the center frequency, is the suppression bandwidth, is the filter order, is the phase compensation function, which is used to optimize the phase characteristics of the mixer.

[0071] The specific embodiments described above further elaborate on the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above description is only the specific embodiments of the present invention and is not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A 6-channel broadband interference signal modulation system, characterized in that: The system includes: a digital processing module, a radio frequency signal frequency conversion and conditioning module, a power division and combination module, and a power management module; The digital processing module is used to generate a broadband interference baseband signal, and the digital processing module includes 6 signal generation units, each of which includes a radio frequency DAC, a clock chip and an OCXO crystal oscillator; The RF signal frequency conversion and conditioning module is used to filter, amplify, gain control and perform signal frequency conversion processing on the broadband interference baseband signal generated by the digital processing module to generate 6-channel RF output signals; The power splitter and power combiner module is used to split the 6-way RF output signal into two, one of which is used to directly output an independent 10MHz-6GHz broadband interference signal, and the other two are respectively input into a 6-in-1 combiner to synthesize one broadband interference signal, thereby generating a total of seven broadband interference signals; The power management module is used to provide the required DC voltage for the digital processing module and the radio frequency signal frequency conversion and conditioning module.

2. The system according to claim 1, characterized in that In the digital processing module, the RF DAC uses a 16-bit, 12.6Gsps sampling rate chip AD9174, and directly outputs a 10MHz to 4000MHz broadband interference baseband signal when using the first Nyquist zone; the control bit width of the digital control oscillator inside the chip is 48bit, the sampling rate of the DAC is 12Gsps, and the configurable minimum frequency step of the broadband interference baseband signal is 0.004Hz: .

3. The system according to claim 2, characterized in that In the digital processing module, the short-term stability of the OCXO crystal oscillator frequency is ppm, the frequency jump at 6GHz output is 0.06Hz; under the condition that the frequency fluctuation does not exceed 10% of the frequency step, the frequency step is 0.1Hz.

4. The system according to claim 3, characterized in that Each signal generating unit includes: a low frequency channel and a high frequency channel, and the channel switching is controlled by a switch; The low-frequency channel operates in the frequency band of 10 MHz to 4 GHz, and directly generates a radio frequency signal through the AD9174 in the digital processing module; The high frequency channel operates in the 4 GHz to 6 GHz frequency band, and generates the required broadband interference baseband signal by mixing the 3.5 GHz intermediate frequency signal generated by the AD9174 in the digital processing module with the local oscillator signal 7.5 GHz to 9.5 GHz.

5. The system according to claim 4, characterized in that The RF signal frequency conversion conditioning module is used to filter, amplify, gain control and perform signal frequency conversion processing on the broadband interference baseband signal generated by the digital processing module. The specific link includes: a first attenuator, a first amplifier, a first bias Bias, a first Attenuation, first filter, second attenuator; When the signal passes through the second attenuator and the output power is between -60dBm and -10dBm, it directly passes through the second attenuation, second filter and third After attenuation, the signal is input into SMA for signal smoothing to obtain the RF output signal; When the signal passes through the second attenuator, the output power is between -10dBm and 16dBm. Add a second amplifier, a second bias, and a fourth Attenuation, third amplifier and third bias; ensure that the link gain is greater than 10dBm.

6. The system according to claim 5, characterized in that The first attenuator and the second attenuator are both digitally controlled attenuators, and the minimum control step of the digitally controlled attenuator is 0.5dB. At the same time, a digital signal amplitude modulation module is designed inside the FPGA, the modulation accuracy bit width is 16bit, the minimum output power step is 0.1dB, and the maximum output power is 93dB.

7. The system according to claim 6, characterized in that The power management module provides 5-12V DC voltage to the digital processing module and the radio frequency signal frequency conversion and conditioning module.

8. A 6-channel broadband interference signal modulation method, implemented based on the system according to any one of claims 1 to 7, characterized in that: The method comprises: A broadband interference baseband signal is generated by a digital processing module. satisfy: ;in, is the number of sub-signals, For the The amplitude of the sub-signal, is the envelope modulation function, is the carrier frequency, is the phase modulation function; The baseband signal is filtered through interpolation Double times interpolation, the total gain of the interpolation filter satisfy: ,in, It is a digital compensation gain, used to eliminate the amplitude loss introduced by the filter; Perform digital mixing and frequency conversion on the digital signal after interpolation filtering, and change the output frequency of the radio frequency signal by modifying the output frequency of the digital controlled oscillator; The digitally processed signal is converted into an analog RF signal through a RF DAC; The analog radio frequency signal is filtered, amplified, gain controlled, and signal frequency converted through a radio frequency signal conversion conditioning module, thereby generating 6 independent broadband interference signals.

9. The method according to claim 8, characterized in that The method also includes dynamic power control, using an adaptive power control algorithm: ,in, is the output power, is the reference power, is the frequency-dependent attenuation function, is the signal bandwidth, is the environmental compensation factor, , and is the weight coefficient; the weight coefficient , and The setting of is obtained by fitting the measured frequency-power curve, bandwidth-power curve and environmental impact factor curve using the least squares method, where Used to compensate for power loss caused by frequency, the value range is 0.01-0.1; Used to compensate for the power attenuation caused by the increase in bandwidth, the value range is 0.5-2.0; Used to compensate for the impact of environmental factors, the value range is 0.1-1.

0.

10. The method according to claim 9, characterized in that The method adopts the secondary mixing suppression technology on the 4GHz to 6GHz high frequency channel, and suppresses the image and harmonic waves generated by the mixing by using the following mathematical model: ;in, is the center frequency, To suppress bandwidth, is the filter order, is a phase compensation function used to optimize the phase characteristics of the mixer.

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