Instantaneous spectral bandwidth expansion method

Abstract

The invention discloses an instantaneous spectral bandwidth expansion method, which relates to the technical field of carrier communication transmission, and comprises the following steps: a signal power division circuit divides a local oscillation signal into multiple paths, one path enters a frequency mixer, and the other path enters a coupling circuit after being subjected to amplitude-phase adjustment by an amplitude-phase adjustment circuit; the frequency mixer receives an intermediate frequency baseband signal and carries out frequency mixing output on the intermediate frequency baseband signal and an input local oscillator signal, the signal combining circuit carries out combining output on multiple paths of mixed signals, the coupling circuit couples multiple paths of amplitude-phase adjusted local oscillator branch signals into a signal channel, multiple paths of leaked local oscillator signals are respectively eliminated, and the output of the signal channel is output. And after the local oscillation signal is eliminated, a frequency band bandwidth expansion output signal is output through the radio frequency filter. According to the invention, the adaptive algorithm is used to learn the environmental interference fluctuation, the learning of the environmental interference can be completed in a short time, the requirement on the external environment is reduced, and the dependence on the surrounding environment is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of carrier communication transmission, and more particularly to an instantaneous spectrum bandwidth expansion method. Background Art

[0002] Modern communication technologies have advanced by leaps and bounds, but the process of spectrum shifting of analog signals is still indispensable. The essence of carrier communication transmission is to modulate voice or other information onto a higher carrier frequency band for long-distance transmission. Among them, the modulated voice or other information is called intermediate frequency (baseband signal) IF, the local carrier signal is called local oscillator signal LO, and the transmitted signal is called radio frequency signal RF. With the development of device technology capabilities, the volume of various components has been greatly reduced, and various multifunctional integrated circuits have emerged. However, due to non-linearity during the spectrum shifting process, there are unwanted local oscillator LO leakage and other spurious signals in the output radio frequency signal. Therefore, various analog filters are designed to complete frequency selection and clutter suppression, and digital filters are not seen in use in the radio frequency band with relatively high frequencies.

[0003] At the same time, according to the mixing principle, when the frequency of the intermediate frequency (baseband signal) IF signal is relatively low, the frequencies of the output radio frequency RF and the local oscillator LO are closest to each other, and the interval is only IF (when in a certain bandwidth, the lowest frequency of IF is taken), and they are very close. The output RF signal after spectrum shifting contains a relatively large amplitude of the local oscillator LO signal. Due to the limited order and finite rectangular coefficient of the analog filter, it is difficult to achieve good suppression of the LO signal, and even no suppression, thus making it impossible to achieve effective transmission.

[0004] In an instantaneous large bandwidth communication system, due to device performance limitations, the upper frequency limit of the intermediate frequency (baseband signal) IF is limited. Moreover, the filter corresponding to the large instantaneous bandwidth signal has a wider bandwidth, making it more difficult to suppress the local oscillator LO, that is, restricting the lower frequency limit of the intermediate frequency (baseband signal) IF. This also leads to limited bandwidth of the intermediate frequency (baseband signal) IF.

[0005] At the same time, the spectrum shifting circuit is also affected by temperature changes. To ensure operation across the entire temperature range, and due to other reasons, such as considerations of indicators such as phase linearity and group delay, the actual bandwidth of the analog filter is much wider than the signal bandwidth. To ensure a certain suppression ability, it is required that the lowest frequency of the intermediate frequency (baseband signal) IF be as high as possible.

[0006] Therefore, in the case where the intermediate frequency signal bandwidth is limited and the intermediate frequency is difficult to increase due to device performance, how to use a relatively narrow intermediate frequency bandwidth to achieve a large instantaneous bandwidth of the system is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0007] In view of this, the present invention provides a method for instantaneous spectral bandwidth expansion, introducing an adaptive algorithm when necessary to monitor the changes of leakage signals in real time, dynamically adjusting to eliminate the influence of parameters, and improving the stability of instantaneous spectral bandwidth expansion. To achieve the above object, the present invention adopts the following technical solutions:

[0008] A method for instantaneous spectral bandwidth expansion, comprising: a mixer, a signal power splitting circuit, a signal combining circuit, a coupling circuit, an amplitude-phase adjustment circuit, and a radio frequency filter. The signal power splitting circuit divides the local oscillator signal into multiple paths, one path enters the mixer, and the other path enters the coupling circuit after amplitude-phase adjustment through the amplitude-phase adjustment circuit. The mixer receives the intermediate frequency baseband signal and mixes the intermediate frequency baseband signal with the input local oscillator signal for output. The signal combining circuit combines the signals after mixing multiple paths for output. The coupling circuit couples the local oscillator branch signals after amplitude-phase adjustment of multiple paths into the signal channel to eliminate the multiple leaked local oscillator signals respectively, and outputs the frequency band bandwidth expansion output signal through the radio frequency filter after eliminating the local oscillator signal.

[0009] Optionally, local oscillators with different frequencies are simultaneously used to shift the signal to the corresponding frequency band.

[0010] Optionally, the amplitude of the local oscillator branch signal after amplitude-phase adjustment is the same as the amplitude of the leaked local oscillator signal in the output signal of the mixer, and the phases are opposite to each other, so that the leaked local oscillator signal in the combined radio frequency signal is canceled to form a direct current.

[0011] Optionally, the radio frequency filter does not suppress the local oscillator signal, and the radio frequency filter filters other spurious signals.

[0012] Optionally, the coupling circuit couples the local oscillator branch signals after amplitude-phase adjustment of multiple paths into the signal channel to eliminate the multiple leaked local oscillator signals respectively, including:

[0013] Collecting leakage signals respectively to obtain a first leaked local oscillator signal and a second leaked local oscillator signal;

[0014] Taking the first leaked local oscillator signal and the second leaked local oscillator signal as the input of the adaptive filter to obtain a target adaptive coefficient matrix;

[0015] According to the adaptive coefficient matrix, obtaining the external environment change of the first leaked local oscillator signal during the interference compensation process;

[0016] Constructing a first optimization function according to the external environment change of the first leaked local oscillator signal during the interference compensation process, and using the particle swarm algorithm to solve the optimization function to obtain a first interference compensation coefficient to complete the interference compensation of the first leaked local oscillator signal;

[0017] According to the adaptive coefficient matrix, obtain the external environment change of the second leaked local oscillator signal during the interference compensation process;

[0018] Construct a second optimization function according to the external environment change of the second leaked local oscillator signal during the interference compensation process, and use the particle swarm algorithm to solve the optimization function to obtain a second interference compensation coefficient, so as to complete the interference compensation of the second leaked local oscillator signal;

[0019] Complete the cancellation filtering of the leaked local oscillator signal by jointly compensating the interference of the first leaked local oscillator signal and the interference of the second leaked local oscillator signal.

[0020] Optionally, the obtaining of the target adaptive coefficient matrix includes:

[0021] Take the first leaked local oscillator signal and the second leaked local oscillator signal as the input of the first adaptive filter, and calculate the first adaptive filter error according to the second leaked local oscillator signal; according to the first leaked local oscillator signal and the first adaptive filter error, calculate the first adaptive coefficient; obtain the first initial adaptive coefficient matrix according to the first adaptive coefficient; for the next moment, based on the first initial adaptive coefficient matrix, perform iteration through the forward coefficient and the forward input to obtain the first target adaptive coefficient matrix.

[0022] Optionally, the obtaining of the external environment change of the first leaked local oscillator signal during the interference compensation process according to the adaptive coefficient matrix includes:

[0023] D2 = T(i)P(i); where T(i) is the second leaked local oscillator signal and P(i) is the first adaptive coefficient at the kth moment.

[0024] It can be seen from the above technical solutions that compared with the prior art, the present invention discloses an instantaneous spectrum bandwidth expansion method, which has the following beneficial effects:

[0025] The present invention provides a method for expanding instantaneous spectral bandwidth, which includes: a mixer, a signal power splitting circuit, a signal combining circuit, a coupling circuit, a amplitude-phase adjustment circuit, and a radio frequency filter. The signal power splitting circuit divides the local oscillator signal into multiple paths, one path enters the mixer, and the other path enters the coupling circuit after amplitude-phase adjustment through the amplitude-phase adjustment circuit. The mixer receives the intermediate frequency baseband signal and mixes it with the input local oscillator signal for output. The signal combining circuit combines the mixed signals of multiple paths for output. The coupling circuit couples the local oscillator branch signals of multiple paths after amplitude-phase adjustment into the signal channel to eliminate the leaked local oscillator signals of multiple paths respectively, and then outputs the frequency band bandwidth expanded output signal through the radio frequency filter after eliminating the local oscillator signal. The present invention can simultaneously use multiple local oscillator signals with different frequencies for spectral shifting, which can enhance the instantaneous bandwidth capacity of the system without requiring a baseband signal with a large instantaneous bandwidth (multiple signals with relatively narrow instantaneous bandwidths can be spectrally shifted to form a signal with a larger instantaneous bandwidth). Thus, the requirement for the large instantaneous bandwidth capacity of the baseband signal in a large instantaneous bandwidth system is reduced, and the manufacturing difficulty of integrated circuit chips is lowered. The present invention can achieve a high suppression ability for the leaked local oscillator signal without using a radio frequency filter. It is beneficial to design a general-purpose chip using modern integrated circuit technology, improve the integration level, and reduce the system cost. The present invention separately collects the leakage signals to obtain the first leaked local oscillator signal and the second leaked local oscillator signal, uses the first leaked local oscillator signal and the second leaked local oscillator signal as the input of the adaptive filter to obtain the target adaptive coefficient matrix; according to the adaptive coefficient matrix, obtains the external environment change of the first leaked local oscillator signal during the interference compensation process, constructs the first optimization function according to the external environment change of the first leaked local oscillator signal during the interference compensation process, uses the particle swarm algorithm to solve the optimization function to obtain the first interference compensation coefficient to complete the interference compensation for the first leaked local oscillator signal, and jointly completes the elimination and filtering of the leaked local oscillator signal through the interference compensation for the first leaked local oscillator signal and the interference compensation for the second leaked local oscillator signal, which can improve its compensation effect in a time-varying noise environment. On the other hand, the adaptive algorithm is used to learn the environmental interference fluctuations. The adaptive algorithm has a fast convergence speed and can complete the learning of environmental interference in a short time. The adaptive coefficient changes with the change of the environment, reducing the requirement for the external environment of the interference compensation site and the dependence on the surrounding environment. The present invention introduces the adaptive algorithm for the instability problem of the leakage signal, monitors the change of the leakage signal in real time, and dynamically adjusts the elimination parameters to ensure that the circuit can work stably under different conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required for the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can also be obtained based on the provided accompanying drawings.

[0027] Figure 1 It is a schematic diagram of the principle of an instantaneous spectrum bandwidth expansion method provided by the present invention. Detailed implementation manners

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0029] The embodiments of the present invention disclose an instantaneous spectrum bandwidth expansion method, as Figure 1 shown, including: a mixer, a signal power splitting circuit, a signal combining circuit, a coupling circuit, an amplitude-phase adjustment circuit, and a radio frequency filter. The signal power splitting circuit divides the local oscillator signal into multiple paths. One path enters the mixer, and the other path enters the coupling circuit after amplitude-phase adjustment through the amplitude-phase adjustment circuit. The mixer receives the intermediate frequency baseband signal and mixes it with the input local oscillator signal for output. The signal combining circuit combines the mixed signals of multiple paths for output. The coupling circuit couples the local oscillator branch signals after amplitude-phase adjustment of multiple paths into the signal channel to eliminate the leaked local oscillator signals of multiple paths respectively. After eliminating the local oscillator signals, the frequency band bandwidth expansion output signal is output through the radio frequency filter.

[0030] Furthermore, local oscillators with different frequencies are simultaneously used to shift the signal to the corresponding frequency band. The frequencies of different local oscillator signals are different, and the amplitudes and phases of the leaked local oscillator signals after mixing are not exactly the same.

[0031] Furthermore, the amplitude of the local oscillator branch signal after amplitude-phase adjustment is the same as the amplitude of the leaked local oscillator signal in the output signal of the mixer, and the phases are opposite to each other, so that the leaked local oscillator signals in the combined radio frequency signal are canceled to form direct current.

[0032] Furthermore, the radio frequency filter does not suppress the local oscillator signal, and the radio frequency filter filters other spurious signals.

[0033] In a specific embodiment, the signal power splitting circuit divides the local oscillator signal into n paths. One path enters the mixer, and the other path enters the coupling circuit after amplitude and phase adjustment by the amplitude and phase adjustment circuit. The mixer receives the intermediate frequency baseband signal and mixes the intermediate frequency baseband signal with the input local oscillator signal for output. The signal combining circuit combines and outputs the n paths of mixed signals. The coupling circuit couples the n paths of amplitude and phase adjusted local oscillator branch signals into the signal channel to eliminate the n paths of leaked local oscillator signals respectively. After eliminating the local oscillator signals, the frequency band bandwidth is extended and output through the RF filter. Specifically, the coupling circuit coupling the n paths of amplitude and phase adjusted local oscillator branch signals into the signal channel and eliminating the n paths of leaked local oscillator signals respectively includes: collecting the leakage signals respectively to obtain the first leaked local oscillator signal, the second leaked local oscillator signal,..., the nth leaked local oscillator signal.

[0034] In a specific embodiment, the local oscillator branch signal LO is injected through the local oscillator port of the mixer. The intermediate frequency baseband signal IF outputs the LO-IF signal and the LO+IF signal under the action of the local oscillator signal. The RF signal RF output by the mixer includes at least three signals: LO-IF, LO, and LO+IF. Taking LO-IF as the useful RF is the lower sideband mixing, and taking LO+IF as the useful RF is the upper sideband mixing. The leaked local oscillator signals are all spaced by IF from the useful signals.

[0035] In a specific embodiment, the coupling circuit couples the multiple paths of amplitude and phase adjusted local oscillator branch signals into the signal channel to eliminate the multiple paths of leaked local oscillator signals respectively, including:

[0036] Collecting the leakage signals respectively to obtain the first leaked local oscillator signal and the second leaked local oscillator signal;

[0037] Taking the first leaked local oscillator signal and the second leaked local oscillator signal as the input of the adaptive filter to obtain the target adaptive coefficient matrix;

[0038] According to the adaptive coefficient matrix, obtaining the external environment change of the first leaked local oscillator signal during the interference compensation process;

[0039] Constructing a first optimization function according to the external environment change of the first leaked local oscillator signal during the interference compensation process, and using the particle swarm algorithm to solve the optimization function to obtain the first interference compensation coefficient to complete the interference compensation of the first leaked local oscillator signal;

[0040] According to the adaptive coefficient matrix, obtaining the external environment change of the second leaked local oscillator signal during the interference compensation process;

[0041] Construct a second optimization function according to the external environment changes of the second leaked local oscillator signal during the interference compensation process, and use the particle swarm optimization algorithm to solve the optimization function to obtain the second interference compensation coefficient, so as to complete the interference compensation for the second leaked local oscillator signal;

[0042] Complete the elimination filtering of the leaked local oscillator signal by jointly compensating the interference of the first leaked local oscillator signal and the interference of the second leaked local oscillator signal.

[0043] Further, the separately collecting the leakage signals to obtain the first leaked local oscillator signal and the second leaked local oscillator signal includes: respectively obtaining the first leaked local oscillator signal and the second leaked local oscillator signal according to the external interference temperature field, the interference field of the local oscillator branch signal after leakage, the geomagnetic field, the external interference magnetic field, the external interference electric field, and the acquisition error of the leaked local oscillator signal.

[0044] In the specific implementation manner, the first leaked local oscillator signal and the second leaked local oscillator signal include:

[0045] T1(i) = β1μ1(δ1 + γ1 + τ1 + θ1) + υ1;

[0046] Wherein, δ1 is the geomagnetic field, γ1 is the external interference magnetic field, τ1 is the external interference electric field, θ1 is the external interference temperature field, μ1 is the acquisition error of the leaked local oscillator signal, υ1 is the interference field of the second local oscillator branch signal after leakage, and β1 is the initial value of the first leaked local oscillator signal;

[0047] T2(i) = β2μ2(δ2 + γ2 + τ2 + θ2) + υ2;

[0048] Wherein, δ2 is the geomagnetic field, γ2 is the external interference magnetic field, τ2 is the external interference electric field, θ2 is the external interference temperature field, μ2 is the acquisition error of the leaked local oscillator signal, υ2 is the interference field of the first local oscillator branch signal after leakage, and β2 is the initial value of the second leaked local oscillator signal.

[0049] Further, the using the first leaked local oscillator signal and the second leaked local oscillator signal as the input of the adaptive filter to obtain the target adaptive coefficient matrix includes:

[0050] Use the first leaked local oscillator signal and the second leaked local oscillator signal as the input of the first adaptive filter, and calculate the first adaptive filter error according to the second leaked local oscillator signal; calculate the first adaptive coefficient according to the first leaked local oscillator signal and the first adaptive filter error; obtain the first initial adaptive coefficient matrix according to the first adaptive coefficient; for the next moment, based on the first initial adaptive coefficient matrix, perform iteration through the forward coefficient and the forward input to obtain the first target adaptive coefficient matrix.

[0051] In the specific implementation manner, the steps for solving the first adaptive filter error are as follows:

[0052] o(k - 1) = q(k - 1) - T2(k - 1)P2(k - 1);

[0053] where q(k - 1) = T1(k - 1) is the first leakage local oscillator signal at time k - 1, T2(k - 1) is the first leakage local oscillator signal, and P2(k - 1) is the first adaptive coefficient at time k - 1;

[0054] By iterating through the forward coefficients and forward inputs, the expression for the first target adaptive coefficient matrix at time k is:

[0055] P2(k) = P2(k - 1) + 2ωe(k - 1)T2(k - 1);

[0056] where ω is the step size factor.

[0057] In the specific implementation manner, it further includes: using the first leakage local oscillator signal and the second leakage local oscillator signal as the inputs of the second adaptive filter, calculating the second adaptive filter error according to the first leakage local oscillator signal; calculating the second adaptive coefficient according to the second leakage local oscillator signal and the second adaptive filter error; obtaining the second initial adaptive coefficient matrix according to the second adaptive coefficient; for the next moment, based on the second initial adaptive coefficient matrix, iterating through the forward coefficients and forward inputs to obtain the second target adaptive coefficient matrix.

[0058] Further, the external environment changes of the first leakage local oscillator signal during the interference compensation according to the adaptive coefficient matrix include:

[0059] D1 = T1(i)P1(i); where T1(i) is the first leakage local oscillator signal and P1(i) is the first adaptive coefficient at time i.

[0060] Further, the external environment changes of the second leakage local oscillator signal during the interference compensation according to the adaptive coefficient matrix include:

[0061] D2 = T2(i)P2(i); where T2(i) is the second leakage local oscillator signal and P2(i) is the second adaptive coefficient at time i.

[0062] In the specific implementation manner, constructing a second optimization function according to the external environment changes of the second leakage local oscillator signal during the interference compensation, and using the particle swarm algorithm to solve the optimization function to obtain the second interference compensation coefficient to complete the interference compensation for the second leakage local oscillator signal includes:

[0063]

[0064] Among them, D2 is the external environment change value of the second leakage local oscillator signal during the interference compensation process. The modulus value output by the earth's magnetic field remains unchanged, and H = (μ2) -1 (T2(i) - υ2).

[0065] In the specific implementation manner, the particle swarm algorithm includes:

[0066] Randomly initialize each particle and set the position boundary range and velocity boundary range;

[0067] Based on the position boundary range and velocity boundary range, calculate the initial particle fitness value according to the fitness function, and record the historical optimal value P best and the global optimal value G best ;

[0068] Update the particle swarm velocity and constrain the out-of-bounds velocity, update the particle swarm position and constrain the out-of-bounds position;

[0069] Based on the updated particle swarm velocity and particle swarm position, calculate the target particle fitness value of the particle according to the fitness function;

[0070] For each particle, compare its target particle fitness value with its historical optimal fitness value. If it is better, use the target particle fitness value as the historical optimal value;

[0071] For each particle, compare its target particle fitness value with the fitness value of the optimal position experienced by the group. If it is better, use the target particle fitness value as the global optimal value;

[0072] Judge whether the maximum number of iterations is reached. If it is reached, output the global optimal value; if not, update the particle swarm velocity and constrain the out-of-bounds velocity, update the particle swarm position and constrain the out-of-bounds position.

[0073] In the specific implementation manner, an instantaneous spectrum bandwidth expansion method includes: a first mixer, a second mixer, a first signal power splitting circuit, a second signal power splitting circuit, a signal combining circuit, a coupling circuit, a first amplitude-phase adjustment circuit, a second amplitude-phase adjustment circuit, and a radio frequency filter;

[0074] The first signal power splitting circuit divides the local oscillator LO1 signal into two paths. One path enters the first mixer, and the other path enters the coupling circuit after amplitude-phase adjustment by the first amplitude-phase adjustment circuit. The first mixer receives the intermediate frequency baseband signal LF1 and mixes the intermediate frequency baseband signal LF1 with the input local oscillator LO1 signal for output. The mixed signal includes the local oscillator signal;

[0075] The second signal power distribution circuit divides the local oscillator LO2 signal into two paths. One path enters the second mixer, and the other path enters the coupling circuit after amplitude and phase adjustment by the second amplitude and phase adjustment circuit. The second mixer receives the intermediate frequency baseband signal LF2 and mixes the intermediate frequency baseband signal LF2 with the input local oscillator LO2 signal for output. The mixed signal includes the local oscillator signal;

[0076] The signal combining circuit combines and outputs the signals after mixing multiple paths. The coupling circuit couples the local oscillator branch signals after amplitude and phase adjustment of multiple paths into the signal channel, eliminates the local oscillator signals leaking from multiple paths respectively, functions as a filter circuit, and then outputs the RF output signal with extended frequency band width through the RF filter after eliminating the local oscillator signal. The RF filter does not need to suppress the local oscillator LO signal, but only filters other spurious signals.

[0077] In this specification, each embodiment is described in a progressive manner. The key point of each embodiment is to illustrate the differences from other embodiments. For the same or similar parts among the embodiments, reference can be made to each other. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple. For the relevant parts, reference can be made to the description in the method section.

[0078] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for extending instantaneous spectrum bandwidth, characterized in that: include: A mixer, a signal power division circuit, a signal combining circuit, a coupling circuit, an amplitude-phase adjustment circuit and a radio frequency filter. The signal power division circuit divides the local oscillator signal into multiple paths, one path enters the mixer, and the other path enters the coupling circuit after amplitude-phase adjustment by the amplitude-phase adjustment circuit. The mixer receives the intermediate frequency baseband signal and mixes the intermediate frequency baseband signal with the input local oscillator signal for output. The signal combining circuit combines the multiple mixed signals for output. The coupling circuit couples the multiple amplitude-phase adjusted local oscillator branch signals into the signal channel, eliminates the multiple leaked local oscillator signals respectively, and then outputs the frequency band bandwidth expansion output signal through the radio frequency filter after the local oscillator signal is eliminated.

2. The instantaneous spectrum bandwidth expansion method according to claim 1, characterized in that: At the same time, local oscillators of different frequencies are used to move the signal to the corresponding frequency band.

3. The instantaneous spectrum bandwidth expansion method according to claim 1, characterized in that: The amplitude of the local oscillator branch signal after amplitude and phase adjustment is the same as the amplitude of the leakage local oscillator signal in the mixer output signal, and the phases are opposite to each other, so that the leakage local oscillator signal in the RF signal output after combining is offset to form direct current.

4. The instantaneous spectrum bandwidth expansion method according to claim 1, characterized in that: The radio frequency filter does not suppress the local oscillator signal, and the radio frequency filter filters other stray signals.

5. The instantaneous spectrum bandwidth expansion method according to claim 1, characterized in that: The coupling circuit couples multiple amplitude-phase-adjusted local oscillator branch signals into the signal channel, and eliminates multiple leaked local oscillator signals respectively, including: Collecting leakage signals respectively to obtain a first leakage local oscillator signal and a second leakage local oscillator signal; Using the first leakage local oscillator signal and the second leakage local oscillator signal as inputs of an adaptive filter to obtain a target adaptive coefficient matrix; According to the adaptive coefficient matrix, the external environment change of the first leakage local oscillator signal during the interference compensation process is obtained; Constructing a first optimization function according to the external environment change of the first leakage local oscillator signal during the interference compensation process, solving the optimization function using a particle swarm algorithm, and obtaining a first interference compensation coefficient to complete the interference compensation of the first leakage local oscillator signal; According to the adaptive coefficient matrix, the external environment change of the second leakage local oscillator signal during the interference compensation process is obtained; Constructing a second optimization function according to the external environment change of the second leakage local oscillator signal during the interference compensation process, solving the optimization function using a particle swarm algorithm, and obtaining a second interference compensation coefficient to complete the interference compensation of the second leakage local oscillator signal; Elimination filtering of the leaked local oscillator signal is accomplished by compensating for the interference of the first leaked local oscillator signal and compensating for the interference of the second leaked local oscillator signal.

6. The instantaneous spectrum bandwidth expansion method according to claim 5, characterized in that: The obtaining of the target adaptive coefficient matrix comprises: The first leakage local oscillator signal and the second leakage local oscillator signal are used as inputs of the first adaptive filter, and the first adaptive filter error is calculated according to the second leakage local oscillator signal; the first adaptive coefficient is calculated according to the first leakage local oscillator signal and the first adaptive filter error; the first initial adaptive coefficient matrix is ​​obtained according to the first adaptive coefficient; for the next moment, based on the first initial adaptive coefficient matrix, it is iterated through the forward coefficients and the forward input to obtain the first target adaptive coefficient matrix.

7. The instantaneous spectrum bandwidth extension method according to claim 5, characterized in that: The step of obtaining the external environment change of the first leakage local oscillator signal during the interference compensation process according to the adaptive coefficient matrix includes: D2=T(i)P(i); where T(i) is the second leakage local oscillator signal, and P(i) is the first adaptive coefficient at time k.

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