Frequency spectrum shifting system and method for ultra-wideband pulse signal

Abstract

The invention provides a frequency spectrum shifting system and method for an ultra-wideband pulse signal, belongs to the technical field of communication, and can perform frequency spectrum shifting on the ultra-wideband pulse signal, thereby improving the frequency band of the ultra-wideband pulse signal and further improving the detection performance of the ultra-wideband pulse signal in a target detection process. The system comprises a clock circuit, a digital waveform generator, a modulation signal source, a band-pass filter, a single-pole single-throw switch and a signal amplifier.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and in particular to a spectrum shifting system and method for an ultra-wideband pulse signal. Background Art

[0002] Ultra-wideband time-domain detection technology achieves target detection by emitting nanosecond-scale time-domain pulse signals. Due to the extremely short duration and rich spectral components of time-domain signals, this technology offers the advantages of high range resolution, minimal ambiguity, high ranging and positioning accuracy, and the ability to penetrate media (walls, jungle, ground, etc.) for detection.

[0003] It's well known that higher operating frequencies in detection equipment make it easier to achieve high-resolution imaging and high-precision tracking of targets. However, the ultra-wideband pulse signals used in existing ultra-wideband time-domain detection technology are limited to lower frequency bands, limiting their performance in target detection. Summary of the Invention

[0004] The present invention proposes a spectrum shifting system and method for ultra-wideband pulse signals, which can perform spectrum shifting on ultra-wideband pulse signals, thereby increasing the frequency band of the ultra-wideband pulse signals and further improving the detection performance of the ultra-wideband pulse signals in the target detection process.

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

[0006] The present invention provides a spectrum shifting system for an ultra-wideband pulse signal, comprising:

[0007] A clock circuit, used to provide a clock signal for the spectrum shifting system;

[0008] A digital waveform generator, used to receive the clock signal sent by the clock circuit and generate an ultra-wideband pulse baseband signal and a switch control signal;

[0009] A modulation signal source is used to receive the clock signal sent by the clock circuit and generate a modulation signal; the modulation signal source is electrically connected to the digital waveform generator;

[0010] a switching modulator for receiving an ultra-wideband pulse baseband signal and a modulation signal, and performing spectrum shifting on the ultra-wideband pulse baseband signal using the modulation signal to obtain a spectrum-shifted ultra-wideband pulse signal; wherein the frequency of the spectrum-shifted ultra-wideband pulse signal is higher than that of the ultra-wideband pulse baseband signal; and the time domain waveform of the spectrum-shifted ultra-wideband pulse signal is completely coherent;

[0011] a bandpass filter for receiving the spectrum-shifted ultra-wideband pulse signal and filtering out noise signals in the spectrum-shifted ultra-wideband pulse signal to obtain a filtered ultra-wideband modulated pulse signal;

[0012] A single-pole single-throw switch is used to receive a switch control signal and a filtered ultra-wideband modulated pulse signal, and suppress out-of-band radiation leakage and mismatch reflection signals of the filtered ultra-wideband modulated pulse signal during a pulse interval through the switch control signal to obtain an ultra-wideband time-domain pulse signal;

[0013] The signal amplifier is used to receive the ultra-wideband time-domain pulse signal and amplify the ultra-wideband time-domain pulse signal to obtain a detection signal; the detection signal is used for target detection.

[0014] In summary, the spectrum shifting system for an ultra-wideband pulse signal provided by the present invention uses a digital waveform generator to generate an ultra-wideband pulse baseband signal, uses a modulation signal source to generate a modulation signal, and performs on-off modulation on the ultra-wideband pulse baseband signal based on the modulation signal to achieve upward shifting of the spectrum of the ultra-wideband pulse baseband signal. The above-mentioned spectrum shifting method can expand the frequency range of the ultra-wideband pulse baseband signal to the microwave and millimeter wave bands, thereby resolving the limitation that the spectrum of existing impulse pulses is mainly concentrated below 6 GHz (i.e., the band below 6 GHz in the HF band, VHF band, UHF band, and SHF band).

[0015] In an implementation of the first aspect, the ultra-wideband pulse signal after spectrum shifting satisfies the following formula:

[0016] f L =M×f r

[0017] Among them, f L is the repetition frequency of the ultra-wideband pulse baseband signal, M is a natural number, f r is the frequency of the modulation signal source.

[0018] Based on the formula provided by the above implementation, the time-domain waveform of the ultra-wideband pulse signal after spectrum shifting is fully coherent, thereby ensuring a good spectrum shifting effect for the ultra-wideband pulse baseband signal. Temporal coherence refers to the strict phase synchronization and waveform consistency of two or more signals in the time domain, which can achieve stable interference or synthesis effects.

[0019] In one implementation of the first aspect, the spectral energy center of the ultra-wideband pulse baseband signal is located in the HF band, VHF band, UHF band, or SHF band; and the ultra-wideband pulse signal after spectrum shifting is located in the X band, K band, Ku band, or Ka band. Based on this implementation, the spectral energy center of the ultra-wideband pulse baseband signal can be shifted to the X band, K band, Ku band, or Ka band, providing broader development prospects for ultra-wideband impulse detection technology.

[0020] In an implementation of the first aspect, a first input terminal of the switching modulator is electrically connected to an output terminal of a modulation signal source, and a second input terminal of the switching modulator is electrically connected to an output terminal of a digital waveform generator that outputs an ultra-wideband pulse baseband signal;

[0021] The input end of the bandpass filter is electrically connected to the output end of the switching modulator;

[0022] The input end of the single-pole single-throw switch is electrically connected to the output end of the bandpass filter, and the control end of the single-pole single-throw switch is electrically connected to the output end of the digital waveform generator outputting the switch control signal;

[0023] The input end of the signal amplifier is electrically connected to the output end of the single-pole single-throw switch.

[0024] In one implementation of the first aspect, the digital waveform generator includes an FPGA and a DAC electrically connected in sequence, the input end of the FPGA is coupled to the input end of the digital waveform generator, the output end of the DAC is coupled to the output end of the digital waveform generator, and the FPGA parallel port controls the DAC to generate an ultra-wideband pulse baseband signal.

[0025] The aforementioned FPGA refers to a Field-Programmable Gate Array (FPGA), a highly flexible semiconductor device. A DAC, a Digital-to-Analog Converter (DAC), is an electronic device that quickly converts digital signals into analog signals. Its core features are high conversion rate and wide bandwidth, and it is specifically designed for scenarios requiring real-time, high-frequency signal generation. In the above implementation, the FPGA parallel port controls the DAC to generate an ultra-wideband pulse baseband signal, which has the advantages of high flexibility and the ability to program key parameters such as the width and amplitude of the output pulse, spectrum distribution, repetition period, or frequency. Furthermore, the signal's time-domain waveform can be arbitrarily reconstructed and agilely changed, making it very easy to achieve Gaussian pulse signals of different derivative orders, or sine waves modulated by a Gaussian envelope.

[0026] In an implementation of the first aspect, the modulation signal source includes a broadband signal source chip, the input end of the broadband signal source chip is coupled with the input end of the modulation signal source, and the output end of the broadband signal source chip is coupled with the output end of the modulation signal source; the broadband signal source chip communicates with the FPGA network port, and the FPGA controls the broadband signal source chip to generate a modulation signal.

[0027] It should be noted that the frequency of the broadband signal source chip is configurable, and thus the frequency of the broadband signal source chip can be configured through FPGA to adjust the frequency of the modulation signal.

[0028] In one implementation of the first aspect, a switching modulator includes a PIN diode and a coupler electrically connected in sequence; a first input terminal of the PIN diode is coupled to a first input terminal of the switching modulator, a second input terminal of the PIN diode is coupled to a second input terminal of the switching modulator, a control terminal of the PIN diode is coupled to a third input terminal of the switching modulator, and an output terminal of the coupler is coupled to an output terminal of the switching modulator. In this implementation, the switching modulator has the characteristics of low cost, small size, and easy implementation.

[0029] In a second aspect, the present invention further provides a spectrum shifting method for an ultra-wideband pulse signal, based on a spectrum shifting system for an ultra-wideband pulse signal provided in the first aspect, comprising:

[0030] The digital waveform generator receives the clock signal sent by the clock circuit and generates an ultra-wideband pulse baseband signal and a switch control signal;

[0031] The modulation signal source receives the clock signal sent by the clock circuit and generates a modulation signal;

[0032] The switching modulator receives an ultra-wideband pulse baseband signal and a modulation signal, and performs spectrum shifting on the ultra-wideband pulse baseband signal using the modulation signal to obtain a spectrum-shifted ultra-wideband pulse signal. The frequency of the spectrum-shifted ultra-wideband pulse signal is higher than that of the ultra-wideband pulse baseband signal, and the time domain waveform of the spectrum-shifted ultra-wideband pulse signal is completely coherent.

[0033] The bandpass filter receives the spectrum-shifted ultra-wideband pulse signal and filters out the noise signal in the spectrum-shifted ultra-wideband pulse signal to obtain a filtered ultra-wideband modulated pulse signal.

[0034] The single-pole single-throw switch receives a switch control signal and a filtered ultra-wideband modulated pulse signal, and suppresses out-of-band radiation leakage and mismatch reflection signals of the filtered ultra-wideband modulated pulse signal during a pulse interval through the switch control signal, thereby obtaining an ultra-wideband time-domain pulse signal.

[0035] The signal amplifier receives the ultra-wideband time-domain pulse signal and amplifies the ultra-wideband time-domain pulse signal to obtain a detection signal for target detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is one of the structural diagrams of a spectrum shifting system for an ultra-wideband pulse signal provided in an embodiment of the present application;

[0037] Figure 2 This is a second structural diagram of a spectrum shifting system for ultra-wideband pulse signals provided in an embodiment of the present application;

[0038] Figure 3is a circuit diagram of a switching modulator provided in an embodiment of the present application;

[0039] Figure 4 Schematic diagram of the waveforms of the ultra-wideband pulse baseband signal, modulation signal, spectrum-shifted ultra-wideband pulse signal, switch control signal, and detection signal provided in an embodiment of the present application;

[0040] Figure 5 Schematic diagram of a spectrum shifting method for an ultra-wideband pulse signal provided in an embodiment of the present application;

[0041] Figure 6 3 is a waveform diagram of the kth order derivative (k is 1, 2 or 3) of a unipolar Gaussian pulse provided in an embodiment of the present application;

[0042] Figure 7 Schematic diagram of the time domain waveform and normalized power spectrum of a unipolar Gaussian pulse with order k=12 provided in an embodiment of the present application;

[0043] Figure 8 This is a schematic diagram of the time domain waveform and normalized power spectrum of the Gaussian envelope sine wave pulse signal provided in an embodiment of the present application. DETAILED DESCRIPTION

[0044] In the description and claims of the present invention, the terms "first" and "second" are used to distinguish different objects rather than to describe a specific order of objects.

[0045] In the embodiments of this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of this application should not be interpreted as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0046] In order to solve the problem in the background technology that the ultra-wideband pulse signal used in the existing ultra-wideband time domain detection technology is limited to a lower frequency band, which limits the detection performance of the ultra-wideband pulse signal in the target detection process, the embodiment of the present application provides a spectrum shifting system and method for an ultra-wideband pulse signal, which can perform spectrum shifting on the ultra-wideband pulse signal, thereby increasing the frequency band of the ultra-wideband pulse signal, and further improving the detection performance of the ultra-wideband pulse signal in the target detection process.

[0047] For example, Figure 1 As shown, an embodiment of the present application provides a spectrum shifting system for an ultra-wideband pulse signal, including a clock circuit, a digital waveform generator, a modulation signal source, a bandpass filter, a single-pole single-throw switch, and a signal amplifier.

[0048] The above clock circuit is used to provide a clock signal for the spectrum shifting system.

[0049] The digital waveform generator is used to receive the clock signal sent by the clock circuit and generate an ultra-wideband pulse baseband signal and a switch control signal.

[0050] In the embodiment of this application, Figure 1 ,like Figure 2 As shown, the digital waveform generator includes an FPGA and a DAC electrically connected in sequence, the input end of the FPGA is coupled to the input end of the digital waveform generator, the output end of the DAC is coupled to the output end of the digital waveform generator, and the FPGA parallel port controls the DAC to generate an ultra-wideband pulse baseband signal.

[0051] Optionally, the DAC can be a high-speed DAC (High-Speed ​​Digital-to-Analog Converter). The embodiments of the present application do not limit the specific model of the DAC. The sampling rate of the DAC can be 20Gsps, and the maximum output is an ultra-wideband pulse baseband signal of 10GHz. The FPGA controls the DAC to output an ultra-wideband pulse baseband signal with a specific spectrum distribution, time width and repetition frequency based on the clock signal (i.e., external clock) generated by the clock circuit. The pulse width of the ultra-wideband pulse baseband signal is in the nanosecond order, and the repetition frequency is in the megahertz order. The DAC can output a baseband UWB time domain waveform of about 1GHz, and the waveform width is about 2ns.

[0052] The modulation signal source is used to receive the clock signal sent by the clock circuit and generate a modulation signal. The modulation signal source is electrically connected to the digital waveform generator.

[0053] In the embodiment of this application, Figure 1 ,like Figure 2 As shown, the modulation signal source includes a broadband signal source chip. The input of the broadband signal source chip is coupled to the input of the modulation signal source, and the output of the broadband signal source chip is coupled to the output of the modulation signal source. The broadband signal source chip communicates with the FPGA network port, and the FPGA controls the broadband signal source chip to generate the modulation signal.

[0054] The switching modulator is configured to receive an ultra-wideband pulse baseband signal and a modulation signal, and perform spectrum shifting on the ultra-wideband pulse baseband signal using the modulation signal to generate a spectrum-shifted ultra-wideband pulse signal. Specifically, a first input terminal of the switching modulator is electrically connected to an output terminal of a modulation signal source, and a second input terminal of the switching modulator is electrically connected to an output terminal of a digital waveform generator that outputs the ultra-wideband pulse baseband signal.

[0055] The frequency of the spectrum-shifted ultra-wideband pulse signal is higher than that of the ultra-wideband pulse baseband signal. Specifically, the spectrum energy center of the ultra-wideband pulse baseband signal is located in the HF band, VHF band, UHF band, or SHF band; and the spectrum-shifted ultra-wideband pulse signal is located in the X band, K band, Ku band, or Ka band.

[0056] The time domain waveform of the spectrum-shifted ultra-wideband pulse signal is completely coherent. The spectrum-shifted ultra-wideband pulse signal satisfies the following formula:

[0057] f L =M×f r

[0058] Among them, f L is the repetition frequency of the ultra-wideband pulse baseband signal, M is a natural number, f r is the frequency of the modulation signal source.

[0059] In the embodiment of this application, Figure 1 ,like Figure 2 As shown, the above-mentioned switching modulator includes a PIN diode and a coupler electrically connected in sequence; the first input end of the PIN diode is coupled to the first input end of the switching modulator, the second input end of the PIN diode is coupled to the second input end of the switching modulator, and the control end of the PIN diode is coupled to the third input end of the switching modulator; the output end of the coupler is coupled to the output end of the switching modulator.

[0060] In one application scenario, the circuit diagram of the switching modulator is as follows: Figure 3 As shown, the above-mentioned ultra-wideband pulse baseband signal is S(t), and the above-mentioned modulation signal is u L (t), the modulated signal u L In the first half cycle of (t), the PIN diode is turned on, the ultra-wideband pulse baseband signal S(t) passes through the PIN diode, and then the spectrum-shifted ultra-wideband pulse signal Sout(t) is obtained through the coupler and output to the load (post-stage circuit); in the modulation signal u L In the second half of the cycle (t), the diode cannot conduct, and the ultra-wideband pulse baseband signal S(t) cannot pass through the PIN diode. The conduction voltage of the PIN diode is 0.3V, so the switching modulation signal u L The amplitude should reach 0.5V, and the peak-to-peak value should reach 1Vpp, which is more appropriate. At this time, the spectrum shifting efficiency of the switching modulator is higher.

[0061] The bandpass filter is used to receive the spectrum-shifted ultra-wideband pulse signal and filter out the noise signal in the spectrum-shifted ultra-wideband pulse signal to obtain a filtered ultra-wideband modulated pulse signal. Specifically, the input end of the bandpass filter is electrically connected to the output end of the switching modulator.

[0062] Optionally, the bandpass filter can be a miniaturized, low-cost LTCC surface-mount filter. Using one LTCC bandpass filter in conjunction with another LTCC bandpass filter can effectively suppress high-order frequency conversion components, modulation signals, and baseband signals. Other types of filters may also be used for the bandpass filter, and the present embodiment does not limit the type of the bandpass filter.

[0063] The above-mentioned single-pole single-throw switch is used to receive a switch control signal and a filtered ultra-wideband modulated pulse signal, and suppress the out-of-band radiation leakage and mismatched reflection signal of the filtered ultra-wideband modulated pulse signal during the pulse interval through the switch control signal to obtain an ultra-wideband time-domain pulse signal. Specifically, the input end of the single-pole single-throw switch is electrically connected to the output end of the bandpass filter, and the control end of the single-pole single-throw switch is electrically connected to the output end of the digital waveform generator that outputs the switch control signal. In the embodiment of the present application, the above-mentioned single-pole single-throw switch is a high-speed nanosecond-level broadband RF switch with a response speed of approximately 10ns.

[0064] The signal amplifier is used to receive and amplify ultra-wideband time-domain pulse signals to generate a detection signal, which is used for target detection. Specifically, the input of the signal amplifier is electrically connected to the output of a single-pole, single-throw switch. The signal amplifier selects a microwave or millimeter-wave amplifier for the frequency band corresponding to the frequency conversion, with a gain of 20dB and an output 1dB compression point of at least 25dBm, which can meet the detection requirements of most application scenarios.

[0065] The waveforms of the above-mentioned ultra-wideband pulse baseband signal, modulation signal, ultra-wideband pulse signal after spectrum shifting, switch control signal and detection signal are as follows: Figure 4 shown.

[0066] In summary, in the spectrum shifting system for an ultra-wideband pulse signal provided by an embodiment of the present application, a digital waveform generator is used to generate an ultra-wideband pulse baseband signal, a modulation signal source is used to generate a modulation signal, and the ultra-wideband pulse baseband signal is modulated on and off based on the modulation signal to achieve upward shifting of the spectrum of the ultra-wideband pulse baseband signal. The above-mentioned spectrum shifting method can expand the frequency range of the ultra-wideband pulse baseband signal to the microwave and millimeter wave bands, thereby resolving the limitation that the spectrum of existing impulse pulses is mainly concentrated below 6 GHz (i.e., the band below 6 GHz in the HF band, VHF band, UHF band, and SHF band).

[0067] Correspondingly, such as Figure 5 As shown, an embodiment of the present application provides a spectrum shifting method for an ultra-wideband pulse signal, including S101-S106.

[0068] S101 , a digital waveform generator receives a clock signal from a clock circuit and generates an ultra-wideband pulse baseband signal and a switch control signal.

[0069] In this embodiment, the FPGA parallel port in the digital waveform generator controls the DAC to generate an ultra-wideband pulse baseband signal.

[0070] In one application scenario, the ultra-wideband pulse baseband signal is a unipolar Gaussian pulse signal, and the waveform s(t) of the unipolar Gaussian pulse signal is expressed as follows.

[0071]

[0072] Where: α is the shaping factor. Different values ​​of α will result in different amplitude and duration of the unipolar Gaussian pulse signal. p ,

[0073] The time domain waveform and spectral density of the differential pulse signal of the unipolar Gaussian pulse signal are different from those of the unipolar Gaussian pulse signal. By taking the 1st to 3rd order derivatives of the unipolar Gaussian pulse signal s(t), we can obtain:

[0074] The first-order derivative is:

[0075]

[0076] The second-order derivative is:

[0077]

[0078] The third-order derivative is:

[0079]

[0080] When the shaping factor α = 0.1ns, the waveform of the kth order derivative (k is 1, 2 or 3) of the unipolar Gaussian pulse is as follows: Figure 6 When k=12th order, the time domain waveform and normalized power spectrum of the unipolar Gaussian pulse are as follows: Figure 7 shown.

[0081] Therefore, when α is constant, the peak frequency of the k-th order derivative Gaussian pulse increases with the increase of k. By controlling α and the order k, Gaussian pulse signals with different spectral characteristics can be designed.

[0082] Taking several cycles of sine waves (or cosine waves) and adding appropriate envelope modulation can also form an ultra-wideband time-domain narrow pulse signal. Its time-domain expression is:

[0083] s(t)=m(t)sin(2πft),0<t≤NT (5)

[0084] Wherein, T=1 / f; N is an integer.

[0085] Usually m(t) is taken as Gaussian Function, that is:

[0086]

[0087] The time domain waveform and normalized power spectrum of the Gaussian envelope sine wave pulse signal are as follows: Figure 8 Its parameters are α = 0.5ns and the sine wave frequency is 1GHz.

[0088] S102: The modulation signal source receives the clock signal sent by the clock circuit and generates a modulation signal.

[0089] In the embodiment of the present application, the FPGA in the digital waveform generator controls the broadband signal source chip to generate a modulated signal.

[0090] S103 , the switch modulator receives the ultra-wideband pulse baseband signal and the modulation signal, and performs spectrum shifting on the ultra-wideband pulse baseband signal through the modulation signal to obtain a spectrum-shifted ultra-wideband pulse signal.

[0091] The frequency of the ultra-wideband pulse signal after spectrum shifting is higher than that of the ultra-wideband pulse baseband signal; and the time domain waveform of the ultra-wideband pulse signal after spectrum shifting is completely coherent.

[0092] In one implementation of S103 above, it is assumed that the waveform s(t) of the ultra-wideband pulse baseband signal is expressed as follows.

[0093]

[0094] The above-mentioned ultra-wideband pulse baseband signal waveform s(t) is sent to the switching modulator composed of PIN diodes, and the modulation signal is a frequency f L , a sine wave with an amplitude of A, then the modulated signal waveform u L The expression of (t) is as follows.

[0095]

[0096] in, is the initial phase of the sine wave signal. Then s(t) is u L The expression of the ultra-wideband pulse signal waveform Sout(t) obtained after (t) signal modulation is as follows.

[0097]

[0098] After filtering out the low-frequency components in Sout(t), the expression of the ultra-wideband pulse signal waveform after spectrum shifting is as follows.

[0099]

[0100] It can be seen that the waveform width of the ultra-wideband pulse signal after spectrum shifting remains unchanged, and the carrier frequency in the ultra-wideband pulse signal after spectrum shifting is increased to the sum of the ultra-wideband pulse baseband signal frequency and the modulation signal frequency f+f L .

[0101] Furthermore, in order to ensure that the initial phase of each pulse waveform is consistent after the spectrum is shifted, it is necessary to satisfy the certain time relationship between the modulation signal source frequency and the repetition frequency of the baseband pulse, that is, the leading edge of each baseband pulse corresponds to the same position (or the same initial phase) of the modulation signal. ).

[0102] S104 , a bandpass filter receives the spectrum-shifted ultra-wideband pulse signal, and filters out noise signals in the spectrum-shifted ultra-wideband pulse signal to obtain a filtered ultra-wideband modulated pulse signal.

[0103] S105. The single-pole single-throw switch receives the switch control signal and the filtered ultra-wideband modulated pulse signal, and suppresses the out-of-band radiation leakage and mismatch reflection signal of the filtered ultra-wideband modulated pulse signal during the pulse interval through the switch control signal to obtain an ultra-wideband time-domain pulse signal.

[0104] S106 , the signal amplifier receives the ultra-wideband time-domain pulse signal and amplifies the ultra-wideband time-domain pulse signal to obtain a detection signal for target detection.

[0105] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments.

[0106] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A spectrum shifting system for ultra-wideband pulse signals, characterized in that: include: A clock circuit, configured to provide a clock signal for the spectrum shifting system; A digital waveform generator, configured to receive the clock signal from the clock circuit and generate an ultra-wideband pulse baseband signal and a switch control signal; A modulation signal source, configured to receive the clock signal sent by the clock circuit and generate a modulation signal; The modulation signal source is electrically connected to the digital waveform generator; a switching modulator, configured to receive the ultra-wideband pulse baseband signal and the modulation signal, and perform spectrum shifting on the ultra-wideband pulse baseband signal using the modulation signal to obtain a spectrum-shifted ultra-wideband pulse signal; wherein the frequency of the spectrum-shifted ultra-wideband pulse signal is higher than that of the ultra-wideband pulse baseband signal; and the time domain waveform of the spectrum-shifted ultra-wideband pulse signal is completely coherent; a bandpass filter, configured to receive the spectrum-shifted ultra-wideband pulse signal and filter out noise signals from the spectrum-shifted ultra-wideband pulse signal to obtain a filtered ultra-wideband modulated pulse signal; a single-pole single-throw switch, configured to receive the switch control signal and the filtered ultra-wideband modulated pulse signal, and suppress out-of-band radiation leakage and mismatched reflection signals of the filtered ultra-wideband modulated pulse signal during a pulse pause period through the switch control signal to obtain an ultra-wideband time-domain pulse signal; The signal amplifier is used to receive the ultra-wideband time-domain pulse signal and amplify the ultra-wideband time-domain pulse signal to obtain a detection signal; the detection signal is used for target detection.

2. The system according to claim 1, wherein The ultra-wideband pulse signal after spectrum shifting satisfies the following formula: f L ＝ M×f r Among them, f L is the repetition frequency of the ultra-wideband pulse baseband signal, M is a natural number, and f r is the frequency of the modulation signal source.

3. The system according to claim 1 or 2, characterized in that The spectrum energy center of the ultra-wideband pulse baseband signal is located in the HF band, VHF band, UHF band or SHF band; the ultra-wideband pulse signal after spectrum shifting is located in the X band, K band, Ku band or Ka band.

4. The system according to claim 1, wherein The first input terminal of the switching modulator is electrically connected to the output terminal of the modulation signal source, and the second input terminal of the switching modulator is electrically connected to the output terminal of the digital waveform generator outputting the ultra-wideband pulse baseband signal; The input end of the bandpass filter is electrically connected to the output end of the switching modulator; The input end of the single-pole single-throw switch is electrically connected to the output end of the bandpass filter, and the control end of the single-pole single-throw switch is electrically connected to the output end of the digital waveform generator outputting the switch control signal; The input end of the signal amplifier is electrically connected to the output end of the single-pole single-throw switch.

5. The system according to claim 4, wherein: The digital waveform generator includes an FPGA and a DAC electrically connected in sequence, the input end of the FPGA is coupled to the input end of the digital waveform generator, the output end of the DAC is coupled to the output end of the digital waveform generator, and the FPGA parallel port controls the DAC to generate the ultra-wideband pulse baseband signal.

6. The system according to claim 5, wherein: The modulation signal source includes a broadband signal source chip, the input end of the broadband signal source chip is coupled to the input end of the modulation signal source, and the output end of the broadband signal source chip is coupled to the output end of the modulation signal source; The broadband signal source chip communicates with the FPGA network port, and the FPGA controls the broadband signal source chip to generate the modulated signal.

7. The system according to claim 4, wherein: The switching modulator includes a PIN diode and a coupler electrically connected in sequence; a first input end of the PIN diode is coupled to a first input end of the switching modulator, a second input end of the PIN diode is coupled to a second input end of the switching modulator, and a control end of the PIN diode is coupled to a third input end of the switching modulator; and an output end of the coupler is coupled to an output end of the switching modulator.

8. A spectrum shifting method for an ultra-wideband pulse signal, based on the spectrum shifting system for an ultra-wideband pulse signal according to any one of claims 1 to 7, characterized in that: include: The digital waveform generator receives the clock signal sent by the clock circuit and generates an ultra-wideband pulse baseband signal and a switch control signal; The modulation signal source receives the clock signal sent by the clock circuit and generates a modulation signal; The switching modulator receives the ultra-wideband pulse baseband signal and the modulation signal, and performs spectrum shifting on the ultra-wideband pulse baseband signal using the modulation signal to obtain an ultra-wideband pulse signal after spectrum shifting; wherein the frequency of the ultra-wideband pulse signal after spectrum shifting is higher than that of the ultra-wideband pulse baseband signal; and the time domain waveform of the ultra-wideband pulse signal after spectrum shifting is completely coherent; The bandpass filter receives the spectrum-shifted ultra-wideband pulse signal and filters out the noise signal in the spectrum-shifted ultra-wideband pulse signal to obtain a filtered ultra-wideband modulated pulse signal; The single-pole single-throw switch receives the switch control signal and the filtered ultra-wideband modulated pulse signal, and suppresses the out-of-band radiation leakage and mismatch reflection signal of the filtered ultra-wideband modulated pulse signal during the pulse interval through the switch control signal to obtain an ultra-wideband time-domain pulse signal; The signal amplifier receives the ultra-wideband time-domain pulse signal and amplifies the ultra-wideband time-domain pulse signal to obtain a detection signal for target detection.

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