Microwave photonics device and method for large dynamic range microwave photonics frequency conversion

Abstract

The present disclosure provides a microwave photon frequency conversion device and method with a large dynamic range, which is applied to the technical field of microwave photon technology. The device comprises: an optical source module for providing an optical carrier; an unequal ratio electrical signal beam splitting module for splitting received radio frequency signals and local oscillator signals into two unequal ratio electrical signals; an unequal ratio optical splitting parallel modulation module for splitting the optical carrier into two unequal ratio optical signals, loading the two electrical signals onto the corresponding optical signals respectively, and then combining the beams to obtain an optical modulation signal; a detection module for converting the optical modulation signal into a target intermediate frequency signal; wherein the power ratio of the optical signal and the electrical signal satisfies a preset relationship.

Description

Technical Field

[0001] This disclosure relates to the field of microwave photonics technology, and in particular to a microwave photonics frequency conversion device and method with a large dynamic range. Background Technology

[0002] Microwave photonics technology combines the advantages of microwave and fiber optic communication, featuring high bandwidth, low loss, multi-band operation, and resistance to electromagnetic interference, gradually becoming a research hotspot in current communication systems. Among these, spurious-free dynamic range (SFDR) is a crucial indicator in frequency conversion systems, used to measure the tolerance range of a radar system to microwave signal power. Most microwave photonics frequency converters use Mach-Zehnder modulators for photoelectric conversion, and their nonlinear transfer functions inherently introduce third-order intermodulation distortion (IMD3). This distortion component limits the spurious-free dynamic range of microwave photonics frequency converters. Furthermore, although there is considerable research on the large dynamic range of microwave photonic RF transmission links, the introduction of a local oscillator signal during frequency conversion makes most of these systems unsuitable for microwave photonics frequency conversion systems. Therefore, achieving a microwave photonics frequency conversion system with high linearity and a large dynamic range has become a current research focus. Summary of the Invention

[0003] In view of this, the present disclosure provides a microwave photonic frequency conversion device and method with a large dynamic range.

[0004] According to the first aspect of this disclosure, a microwave photonic frequency conversion device with a large dynamic range is provided, comprising: a light source module for providing an optical carrier; an unequal-ratio electrical signal beam splitting module for splitting a received radio frequency signal and a local oscillator signal into two unequal-ratio electrical signals; an unequal-ratio parallel modulation module for splitting the optical carrier into two unequal-ratio optical signals, and then combining the two electrical signals onto their respective optical signals to obtain an optical modulation signal; and a detection module for converting the optical modulation signal into a target intermediate frequency signal; wherein the power ratio of the optical signal and the electrical signal satisfies a preset relationship.

[0005] According to embodiments of this disclosure, the non-uniform electrical signal beam splitting module includes: a beam combiner for combining a radio frequency signal and a local oscillator signal to obtain a mixed signal; and an electrical power divider for splitting the mixed signal into two paths, wherein an electrical attenuator attenuates one path of the signal to obtain a first radio frequency input signal and a second radio frequency input signal, respectively.

[0006] According to embodiments of this disclosure, the parallel modulation module for unequal-splitting optical carriers includes: an optical beam splitter for dividing an optical carrier into two paths, one path outputting a first optical carrier and the other path outputting a second optical carrier after attenuation by an optical attenuator; a first Mach-Zehnder modulator for loading a first radio frequency signal onto the first optical carrier to obtain a first radio frequency modulated signal; a second Mach-Zehnder modulator for loading a second radio frequency signal onto the second optical carrier after attenuation by an optical attenuator to obtain a second radio frequency modulated signal; and an optical beam combiner for combining the first radio frequency modulated signal and the second radio frequency modulated signal to obtain an optical modulated signal.

[0007] According to embodiments of this disclosure, the parallel modulation module for unequal-ratio optical beam splitting includes: an unequal-ratio optical beam splitter for unequally splitting an optical carrier into two paths to obtain a first optical carrier and a second optical carrier; a first Mach-Zehnder modulator for loading a first radio frequency signal onto the first optical carrier to obtain a first radio frequency modulated signal; a second Mach-Zehnder modulator for loading a second radio frequency signal onto the second optical carrier to obtain a second radio frequency modulated signal; and an optical beam combiner for combining the first radio frequency modulated signal and the second radio frequency modulated signal to obtain an optical modulated signal.

[0008] According to embodiments of this disclosure, the half-wave voltages of the first Mach-Zehnder modulator and the second Mach-Zehnder modulator are respectively and ,and The first Mach-Zehnder modulator operates at the minimum bias point, and the second Mach-Zehnder modulator operates at the maximum bias point.

[0009] According to embodiments of this disclosure, in the same modulator, the power ratios of the first radio frequency signal and the first optical carrier satisfy the following relationship:

[0010]

[0011] Where, x 2 The power percentage of the first optical carrier, 1-x 2 y represents the power percentage of the second optical carrier. 2 The power percentage of the first radio frequency signal, 1-y 2 This represents the power percentage of the second radio frequency signal.

[0012] According to an embodiment of this disclosure, the detection module includes: a detector for beating the optical modulation signal to obtain an intermediate frequency signal, and performing photoelectric conversion on the intermediate frequency signal to obtain a target intermediate frequency signal.

[0013] According to an embodiment of this disclosure, the detection module further includes: an optical amplifier, used to receive and amplify the optical modulation signal and then input it to the detector.

[0014] According to an embodiment of this disclosure, the detection module further includes an electrical filter for filtering the intermediate frequency signal after photoelectric conversion to obtain the target intermediate frequency signal.

[0015] According to a second aspect of this disclosure, a microwave photonic frequency conversion method with a large dynamic range is provided, comprising: acquiring an optical carrier output by a light source module; receiving a radio frequency signal and a local oscillator signal, and dividing the received radio frequency signal and local oscillator signal into two unequal electrical signals through an unequal ratio electrical signal beam splitting module; dividing the optical carrier into two unequal optical signals through an unequal ratio parallel modulation module, and then combining the two electrical signals onto their respective optical signals to obtain an optical modulation signal; and converting the optical modulation signal into a target intermediate frequency signal through a detection module; wherein the power ratio of the optical signal and the electrical signal satisfies a preset relationship.

[0016] The at least one technical solution used in the embodiments of this disclosure has at least the following beneficial effects:

[0017] By employing a parallel modulator structure with unequal optical and unequal RF loading, two intensity modulators with different half-wave voltages are connected in parallel, positioned at their minimum and maximum bias points, respectively. Simultaneously, an optical attenuator is added to the optical input of one modulator, and an electrical attenuator is added to the RF input port of the other modulator. By adjusting the attenuation of the optical and electrical attenuators, the third-order intermodulation signal generated during frequency conversion can be suppressed, improving the linearity and spurious-free dynamic range of the frequency converter.

[0018] By ensuring that the power ratio of the radio frequency signal and the power ratio of the optical carrier signal meet a preset relationship, the third-order intermodulation signal generated during frequency conversion can be suppressed, leaving only the residual fifth-order harmonic, thereby improving linearity and increasing the spurious-free dynamic range of the frequency converter.

[0019] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this disclosure, nor is it intended to limit the scope of this disclosure. Other features of this disclosure will become readily apparent from the following description. Attached Figure Description

[0020] The above and other objects, features and advantages of this disclosure will become clearer from the following description of embodiments with reference to the accompanying drawings, in which:

[0021] Figure 1 This schematic diagram illustrates an application of a microwave photonic frequency conversion device with a large dynamic range according to an embodiment of the present disclosure.

[0022] Figure 2 This illustration schematically demonstrates the principle of third-order intermodulation signal (IMD3) suppression in an application example of a microwave photonic frequency conversion device with a large dynamic range according to an embodiment of the present disclosure;

[0023] Figure 3 The illustration schematically shows an application example (left) of a microwave photonic frequency conversion device with a large dynamic range according to an embodiment of the present disclosure and the output spectrum (right) of a frequency conversion system with a single MZM structure.

[0024] Figure 4 The illustrations depict an application example (solid line) of a microwave photonic frequency converter with a large dynamic range according to embodiments of the present disclosure, and a frequency converter system (dashed line) with a single MZM structure and spurious-free dynamic range.

[0025] [Explanation of Labels in the Attached Image]

[0026] 1-Light source module; 2-Unequal ratio electrical signal beam splitting module; 201-Beam combiner; 202-Electrical power divider; 203-Electrical attenuator; 3-Unequal ratio parallel modulation module; 301-Optical beam splitter; 302-First Mach-Zehnder modulator; 303-Optical attenuator; 304-Second Mach-Zehnder modulator; 305-Optical beam combiner; 4-Detection module; 401-Optical amplifier; 402-Detector; 403-Electrical filter. Detailed Implementation

[0027] The embodiments of the present disclosure will now be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the disclosure. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of the present disclosure for ease of explanation. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concepts of the present disclosure.

[0028] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The terms “comprising,” “including,” etc., as used herein indicate the presence of features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0029] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0030] When using expressions such as "at least one of A, B and C", they should generally be interpreted in accordance with the meaning that is commonly understood by those skilled in the art (e.g., "a system having at least one of A, B and C" should include, but is not limited to, a system having A alone, a system having B alone, a system having C alone, a system having A and B, a system having A and C, a system having B and C, and / or a system having A, B and C, etc.).

[0031] This disclosure provides a microwave photonic frequency conversion device with a large dynamic range. Before introducing the technical solution provided by this disclosure, the relevant technologies involved in this disclosure will be explained.

[0032] Because filtering and amplification devices and digital-to-analog converters cannot effectively process high-frequency signals, detection modules are an indispensable part of modern electronic communication systems such as radar, remote sensing, and radio frequency communication transceivers. Frequency conversion technology is divided into up-conversion and down-conversion. In the receiver, the captured high-frequency signal needs to be down-converted to an intermediate frequency (IF) before processing; while in the transmitter, the processed IF signal needs to be up-converted to a high frequency before transmission. In recent years, communication systems such as radar, wireless communication, and satellite communication have been developing towards higher frequencies, larger bandwidths, and higher speeds. Microwave receivers, as an indispensable component of communication systems, are therefore facing the challenge of achieving higher performance.

[0033] Traditional microwave frequency conversion technology can no longer meet the high-frequency, high-bandwidth requirements of next-generation electronic systems. Microwave photonics technology, which integrates the advantages of microwave and fiber optic communication, boasts features such as high bandwidth, low loss, multi-band operation, and resistance to electromagnetic interference, and has gradually become a research hotspot in current communication systems. Spurious-free dynamic range (SFDR) is a crucial indicator in frequency conversion systems, used to measure the tolerance range of a radar system to microwave signal power. Most microwave photonics frequency converters use Mach-Zehnder modulators for photoelectric conversion, and their nonlinear transfer functions inherently introduce third-order intermodulation distortion (IMD3). This distortion component limits the spurious-free dynamic range of microwave photonics frequency converters. Furthermore, although there is considerable research on the large dynamic range of microwave photonics RF transmission links, these systems are largely unsuitable for microwave photonics frequency conversion systems because frequency conversion requires the introduction of a local oscillator signal. Therefore, achieving a microwave photonics frequency conversion system with high linearity and a large dynamic range has become a current research focus.

[0034] The following will be through Figures 1-4 A microwave photonic frequency conversion device with a large dynamic range according to embodiments of the present disclosure will be described in detail.

[0035] Figure 1 The illustration shows a schematic diagram of the application of a microwave photonic frequency conversion device with a large dynamic range according to an embodiment of the present disclosure.

[0036] like Figure 1 As shown, the microwave photonic frequency conversion device with a large dynamic range in this embodiment includes: a light source module 1, an unequal ratio electrical signal beam splitting module 2, an unequal ratio parallel modulation module 3, and a detection module 4.

[0037] Light source module 1 is used to provide optical carrier.

[0038] The unequal-ratio electrical signal splitting module 2 is used to split the received radio frequency signal and local oscillator signal into two electrical signals with unequal ratios.

[0039] The parallel modulation module 3 for unequal-ratio optical carrier is used to split the optical carrier into two optical signals with unequal ratios, and then load the two electrical signals onto the corresponding optical signals and combine them to obtain an optical modulation signal.

[0040] Detection module 4 is used to convert the optical modulation signal into the target intermediate frequency signal.

[0041] The power ratio of optical signals and electrical signals meets a preset relationship.

[0042] For example, the light source module can be a laser, which is used to provide an optical carrier.

[0043] The unequal ratio electrical signal beam splitter 2 is used to split the input radio frequency signal (RF) and local oscillator signal (LO) into two unequal ratio paths (e.g., 20:80).

[0044] The parallel modulation module 3 for unequal-ratio optical signals first divides the optical carrier into two unequal-ratio paths (e.g., 70:30), then loads one RF signal (20% power) onto one optical carrier (70% power), and loads the other LO signal (80% power) onto the other optical carrier (30% power). The two modulated optical signals are then combined to obtain the optical modulation signal.

[0045] The detection module 4 is used to beat the optical modulation signal to obtain the intermediate frequency signal.

[0046] In some embodiments, the parallel modulation module 3 for unequal beam splitting includes: an optical beam splitter 301, an optical attenuator 303, a first Mach-Zehnder modulator 302, a second Mach-Zehnder modulator 304, and an optical beam combiner 305.

[0047] Optical beam splitter 301 is used to split an optical carrier into two equal paths to obtain a first optical carrier and a second optical carrier; first Mach-Zehnder modulator 302 is used to load a first radio frequency signal onto the first optical carrier to obtain a first radio frequency modulated signal; second Mach-Zehnder modulator 304 is used to load a second radio frequency signal onto the second optical carrier after it has been attenuated by optical attenuator 302 to obtain a second radio frequency modulated signal; optical beam combiner 305 is used to combine the first radio frequency modulated signal and the second radio frequency modulated signal to obtain an optical modulated signal.

[0048] In one example, the optical beam splitter 301 splits the optical carrier into two paths. One path is connected to the first Mach-Zehnder modulator MZM1 to provide the first optical carrier for MZM1. The other path is connected to the optical attenuator 303, and after being attenuated by the optical attenuator 303, it becomes the second optical carrier and enters the second Mach-Zehnder modulator 304MZM2.

[0049] The half-wave voltages of the first Mach-Zehnder modulator and the second Mach-Zehnder modulator 304 are respectively and ,and The first Mach-Zehnder modulator operates at the minimum bias point, and the second Mach-Zehnder modulator 304 operates at the maximum bias point.

[0050] The half-wave voltages of MZM1 and MZM2 are respectively and ,and One of MZM1 and MZM2 operates at the minimum bias point and the other at the maximum bias point. The unequal beam-ratio effect of the parallel modulator structure is achieved by adjusting the optical attenuator 303. The optical power ratio of the first optical carrier entering MZM1 to the second optical carrier entering MZM2 is... : .

[0051] In some embodiments, the non-uniform electrical signal beam splitting module 2 includes a beam combiner 201 and an electrical power divider 202.

[0052] The combiner 201 is used to combine the radio frequency signal and the local oscillator signal to obtain a mixed signal;

[0053] The power divider 202 is used to split the mixed signal into two paths. The electrical attenuator 203 attenuates one of the signals to obtain the first radio frequency input signal and the second radio frequency input signal. The first radio frequency input signal is input to the first Mach-Zehnder modulator, and the second radio frequency input signal is input to the second Mach-Zehnder modulator 304.

[0054] In some embodiments, the radio frequency signal is a two-tone signal.

[0055] For example, the mixed signal is divided into two signals by the power divider 302, and the two signals contain radio frequency signals and local oscillator signals.

[0056] In one example, the power divider PS302 receives the mixed signal (RF+LO) and splits it into two paths. One path connects to the electrical attenuator 303, where it is attenuated to become the first RF input signal, which is then input to the RF input port of MZM1. The other path connects to the RF input port of MZM2, providing the second RF input signal to MZM2. Adjusting the electrical attenuator 303 achieves the unequal-ratio electrical signal splitting effect of the unequal-ratio electrical signal splitting structure. The optical power ratio of the first optical carrier entering MZM1 to the second optical carrier entering MZM2 is... : .

[0057] In some embodiments, by adjusting the attenuation of the optical attenuator 303 and the electrical attenuator 303, the power ratio of the first radio frequency signal entering MZM1 / MZM2 and the first optical carrier satisfies the following formula:

[0058]

[0059] Among them, x 2 The power percentage of the first optical carrier, 1-x 2 y represents the power percentage of the second optical carrier. 2 The power percentage of the first radio frequency signal, 1-y 2 This represents the power percentage of the second radio frequency signal.

[0060] The first optical carrier entering MZM1 is modulated by the first radio frequency input signal to obtain the first radio frequency modulated optical signal, and the second optical carrier entering MZM2 is modulated by the second radio frequency input signal to obtain the second radio frequency modulated optical signal; the optical combiner (305) is used to combine the first radio frequency modulated optical signal output after modulation by MZM1 and the second radio frequency modulated optical signal output after modulation by MZM2 to obtain the optical modulated signal.

[0061] In other embodiments, an unequal ratio optical beam splitter 301 (70:30 splitting ratio) can be used instead of the combination of optical beam splitter 301 and optical attenuator 303.

[0062] Specifically, the parallel modulation module 3 for unequal beam splitting includes: an unequal beam splitter 301, a first Mach-Zehnder modulator, a second Mach-Zehnder modulator 304, and a beam combiner 305.

[0063] An unequal-ratio optical beam splitter 301 is used to unequally split an optical carrier into two paths to obtain a first optical carrier and a second optical carrier; a first Mach-Zehnder modulator 302 is used to load a first radio frequency signal onto the first optical carrier to obtain a first radio frequency modulated signal; a second Mach-Zehnder modulator 304 is used to load a second radio frequency signal onto the second optical carrier to obtain a second radio frequency modulated signal; and an optical beam combiner 305 is used to combine the first radio frequency modulated signal and the second radio frequency modulated signal to obtain an optical modulated signal.

[0064] The unequal-ratio optical beam splitter 301 can divide an optical carrier into a first optical carrier and a second optical carrier with different optical powers according to a preset optical power ratio. For example, if the preset optical power ratio is 20:80, the unequal-ratio optical beam splitter 301 can directly obtain a first optical carrier and a second optical carrier with an optical power ratio of 20:80 by dividing the optical carrier into unequal segments.

[0065] Similarly, an unequal ratio electrical beam splitter (20:80 splitting ratio) can be used to replace the combination of electrical power divider 302 and electrical attenuator 303.

[0066] In some embodiments, the detection module 4 includes an optical amplifier 401 and a detector 402.

[0067] Optical amplifier 401 is used to receive and amplify optical modulation signals. Detector 402 is used to beat the amplified optical modulation signal to obtain an intermediate frequency (IF) signal, and then perform photoelectric conversion on the IF signal to obtain the target IF signal.

[0068] Specifically, the optical amplifier 401 is used to receive and amplify the optical modulation signal and is connected to the detector 402; the detector 402 is used to beat the amplified optical modulation signal to obtain an intermediate frequency signal and complete photoelectric conversion to obtain the target intermediate frequency signal.

[0069] In some embodiments, the detection module 4 further includes an electrical filter 403.

[0070] The electrical filter 403 filters the intermediate frequency signal after photoelectric conversion, removes stray signals, and obtains the frequency-converted intermediate frequency signal (IF).

[0071] Figure 2 This illustration schematically demonstrates the principle of third-order intermodulation signal (IMD3) suppression in an application example of a microwave photonic frequency conversion device with a large dynamic range according to an embodiment of the present disclosure; Figure 3 The illustration schematically shows an application example (left) of a microwave photonic frequency conversion device with a large dynamic range according to an embodiment of the present disclosure and the output spectrum (right) of a frequency conversion system with a single MZM structure. Figure 4The illustrations illustrate application examples (solid lines) of a microwave photonic frequency converter with a large dynamic range according to embodiments of the present disclosure and a frequency converter system (dashed lines) with a single MZM structure and spurious-free dynamic range.

[0072] Based on the aforementioned microwave photonic frequency conversion device with a large dynamic range, this disclosure also provides a microwave photonic frequency conversion method with a large dynamic range. A detailed description follows.

[0073] The microwave photonic frequency conversion method with a large dynamic range in this embodiment includes operations S110 to S140.

[0074] In operation S110, the optical carrier output by the light source module is acquired.

[0075] In operation S120, radio frequency signals and local oscillator signals are received, and the received radio frequency signals and local oscillator signals are divided into two unequal electrical signals by the unequal ratio electrical signal beam splitting module 2.

[0076] In operation S130, the optical carrier is divided into two optical signals with unequal ratios by a parallel modulation module, and the two electrical signals are loaded onto the corresponding optical signals and then combined to obtain an optical modulation signal.

[0077] In operation S140, the optical modulation signal is converted into the target intermediate frequency signal through the detection module 4.

[0078] The power ratio of optical signals and electrical signals meets a preset relationship.

[0079] In one example, the amplitude of the laser output is Angular frequency is Optical carrier:

[0080]

[0081] The optical carrier enters the parallel modulator structure with unequal beam ratios, and is split into two equal parts by the optical beam splitter 301. The optical attenuator 303 is adjusted so that the power ratio of the first optical carrier entering MZM1 (302) to the power ratio of the second optical carrier entering MZM2 is 1. At this time, the first optical carrier Second optical carrier They are respectively:

[0082]

[0083]

[0084] Adjust the DC bias voltages of MZM1 and MZM2 to make them operate at the minimum and maximum bias points, respectively; the radio frequency (RF) signal is a two-tone signal with amplitude and angular frequency of [missing information]. , , , For convenience, it is generally used The amplitude and angular frequency of the local oscillator signal LO are respectively , Therefore, the RF signal and the LO signal are represented as follows:

[0085]

[0086]

[0087] The radio frequency (RF) signal and the local oscillator (LO) signal enter the unequal-ratio electrical signal splitting module 2, and are divided into two equal parts by the power divider PS302. The electrical attenuator 303 is adjusted to ensure that the power ratio of the first RF input signal entering MZM1 to the second RF input signal entering MZM2 is [value missing]. For example, MZM1 operates at the minimum offset point, and MZM2 (304) operates at the maximum offset point. At this time, the first optical carrier of MZM1... The first radio frequency modulated optical signal obtained by modulating the first radio frequency input signal and the second optical carrier entering MZM2 The second radio frequency modulated optical signal obtained by modulating the second radio frequency input signal After Bessel expansion (Bessel Function) and ignoring components of order 2 and above, the results are as follows:

[0088] in , , These are the modulation coefficients for the RF and LO signals.

[0089] Optical combiner 305 is used to combine the first radio frequency modulated optical signal output after MZM1 modulation. The second radio frequency modulated optical signal is output after MZM2 modulation. By combining the beams, an optical modulation signal is obtained. :

[0090]

[0091] Optical modulation signal After amplification by optical amplifier 4, photoelectric detection is performed by detector 5. Detector 5 operates on the square law principle, and the photocurrent can be obtained by beat frequency measurement using detector 5:

[0092]

[0093] Where η is the responsivity of the detector. , These are the first radio frequency modulated optical signals. Second radio frequency modulated optical signal For a frequency converter, the current in the electric domain, its fundamental frequency signal FH is... , The third-order intermodulation signal IMD3 is , ,for , In this regard, the phases of its FH and IMD3 can be referenced. Figure 2 The principle shown.

[0094] Based on the above, the currents of the fundamental frequency signal and the third-order intermodulation signal can be calculated as follows:

[0095] For small signals ,have:

[0096]

[0097] Substituting these values ​​into the current formulas for the fundamental frequency signal and the third-order intermodulation signal, we get:

[0098]

[0099]

[0100] By adjusting the optical attenuator 303 in the parallel modulator structure with unequal beam ratio and the electrical attenuator 303 in the electrical signal splitting structure with unequal beam ratio, the proportion of RF power entering the MZM1 is adjusted. and optical power The percentage is satisfied:

[0101]

[0102] at this time The third-order intermodulation signal is canceled out, and the principle is as follows: Figure 2 As shown. This achieves the effect of suppressing the third-order intermodulation signal, leaving only the residual fifth-order harmonic, thereby improving linearity and increasing the spurious-free dynamic range of the frequency converter system.

[0103] To verify the beneficial effects of this application, Figure 1Simulation tests were conducted on a frequency converter with a single MZM structure. For the scheme corresponding to the embodiment of this disclosure, the simulation settings for the half-wave voltages of MZM1 and MZM2 were 6V and 4V respectively, with MZM1 operating at the minimum bias point and MZM2 operating at the maximum bias point. In contrast, the simulation settings for the single MZM structure frequency converter system were: MZM half-wave voltage 6V, operating at the minimum bias point, with other conditions consistent with this scheme. The frequencies of the radio frequency (RF) signals were 19.9GHz and 20.1GHz, the frequency of the local oscillator (LO) signal was 21.8GHz, the baseband signals were 1.7GHz and 1.9GHz, and the third-order intermodulation signals were 1.5GHz and 2.1GHz.

[0104] analyze Figure 3 It can be seen that when the fundamental frequency signal power of both the frequency conversion system in this embodiment and the single MZM structure is -39dBm, the third-order intermodulation signal power of the frequency conversion system with the single MZM structure is -82dBm, and the third-order intermodulation signal power of this embodiment is less than -100dBm, which is submerged in the noise floor. According to the comparison of the simulation results, it can be seen that the microwave photonic frequency conversion method and device with a large dynamic range provided by this application embodiment has low nonlinear distortion, and the third-order intermodulation suppression can reach more than 18dB under simulation conditions.

[0105] analyze Figure 4 It can be obtained that: the slope of the fitting curve for the third-order intermodulation signal in this embodiment is approximately 5, which is the residual fifth-order harmonic; the slope of the fitting curve for the third-order intermodulation signal of the single MZM structure frequency converter system is approximately 3, which is the normal third-order intermodulation signal; the spurious-free dynamic range (SFDR) of this embodiment can reach 105.01 dB·Hz when the noise floor is -155 dBm / Hz. 4 / 5 Compared to the 94.47 dB·Hz of a single MZM structure frequency converter system 2 / 3 It improved by 10.54 dB.

[0106] In this disclosure, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure according to the specific circumstances.

[0107] In the description of this disclosure, it should be understood that the terms "longitudinal", "length", "circumferential", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this disclosure and simplifying the description, and do not indicate or imply that the subsystem or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this disclosure.

[0108] Throughout the accompanying drawings, identical elements are represented by the same or similar reference numerals. Conventional structures or constructions have been omitted where they may cause confusion in understanding this disclosure. Furthermore, the shapes, dimensions, and positional relationships of the components in the drawings do not reflect actual size, scale, or actual positional relationships. Additionally, any reference numerals placed between parentheses in the claims should not be construed as limiting the claims.

[0109] Similarly, to simplify this disclosure and aid in understanding one or more of the various aspects of the disclosure, in the above description of exemplary embodiments of the present disclosure, various features of the present disclosure are sometimes grouped together in a single embodiment, figure, or description thereof. The use of terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refers to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present disclosure. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0110] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this disclosure, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0111] Those skilled in the art will understand that the features described in the various embodiments and / or claims of this disclosure can be combined or combined in various ways, even if such combinations or combinations are not explicitly described in this disclosure. In particular, the features described in the various embodiments and / or claims of this disclosure can be combined or combined in various ways without departing from the spirit and teachings of this disclosure. All such combinations and / or combinations fall within the scope of this disclosure.

[0112] The embodiments of this disclosure have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of this disclosure. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. The scope of this disclosure is defined by the appended claims and their equivalents. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of this disclosure, and all such substitutions and modifications should fall within the scope of this disclosure.

Claims

1. A microwave photonic frequency conversion device with a large dynamic range, comprising: Light source module (1), used to provide optical carrier; The unequal ratio electrical signal beam splitting module (2) is used to split the received radio frequency signal and local oscillator signal into two unequal ratio electrical signals; The parallel modulation module (3) for unequal-ratio optical carrier is used to divide the optical carrier into two optical signals with unequal ratios, and then combine the two electrical signals onto the corresponding optical signals to obtain an optical modulation signal. The detection module (4) is used to convert the optical modulation signal into a target intermediate frequency signal; The power ratio of the optical signal and the electrical signal satisfies a preset relationship.

2. The apparatus according to claim 1, wherein the non-uniform electrical signal beam splitting module (2) comprises: A beam combiner (201) is used to combine the radio frequency signal and the local oscillator signal to obtain a mixed signal; The power divider (202) is used to split the mixed signal into two paths, wherein the electrical attenuator (203) attenuates one path of the signal to obtain the first radio frequency input signal and the second radio frequency input signal respectively.

3. The apparatus according to claim 2, wherein the parallel modulation module (3) for unequal beam division comprises: An optical beam splitter (301) is used to divide the optical carrier into two equal paths, one of which is output as the first optical carrier and the other is output as the second optical carrier after being attenuated by an optical attenuator; a first Mach-Zehnder modulator (302) is used to load a first radio frequency signal onto the first optical carrier to obtain a first radio frequency modulated signal; The second Mach-Zehnder modulator (304) is used to load the second radio frequency signal onto the second optical carrier after it has been attenuated by the optical attenuator (303) to obtain the second radio frequency modulated signal; An optical combiner (305) is used to combine the first radio frequency modulation signal and the second radio frequency modulation signal to obtain an optical modulation signal.

4. The apparatus according to claim 1, wherein the parallel modulation module (3) for unequal beam division comprises: An unequal-ratio optical beam splitter is used to unequally split the optical carrier into two paths to obtain a first optical carrier and a second optical carrier. A first Mach-Zehnder modulator (302) is used to load a first radio frequency signal onto the first optical carrier to obtain a first radio frequency modulated signal; The second Mach-Zehnder modulator (304) is used to load the second radio frequency signal onto the second optical carrier to obtain the second radio frequency modulated signal; An optical combiner (305) is used to combine the first radio frequency modulation signal and the second radio frequency modulation signal to obtain an optical modulation signal.

5. The apparatus according to claim 2 or 3, wherein the half-wave voltages of the first Mach-Zehnder modulator (302) and the second Mach-Zehnder modulator (304) are respectively and ,and The first Mach-Zehnder modulator (302) operates at the minimum bias point, and the second Mach-Zehnder modulator (304) operates at the maximum bias point.

6. In the apparatus according to claim 5, the power ratios of the first radio frequency signal and the first optical carrier in the same modulator satisfy the following relationship: in, x 2 The power percentage of the first optical carrier, 1-x 2 y represents the power percentage of the second optical carrier. 2 The power percentage of the first radio frequency signal, 1-y 2 This represents the power percentage of the second radio frequency signal.

7. The apparatus according to claim 1, wherein the detection module (4) comprises: The detector (402) is used to beat the optical modulation signal to obtain an intermediate frequency signal, and to perform photoelectric conversion on the intermediate frequency signal to obtain a target intermediate frequency signal.

8. The apparatus according to claim 7, wherein the detection module (4) further comprises: An optical amplifier (401) is used to receive and amplify the optical modulation signal and input it to the detector (5).

9. The apparatus according to claim 8, wherein the detection module (4) further comprises: The electrical filter (403) is used to filter the intermediate frequency signal after photoelectric conversion to obtain the target intermediate frequency signal.

10. A microwave photonic frequency conversion method with a large dynamic range, comprising: Obtain the optical carrier wave output by light source module 1; The radio frequency signal and the local oscillator signal are received, and the received radio frequency signal and the local oscillator signal are divided into two unequal electrical signals by the unequal electrical signal beam splitting module (2); The optical carrier is divided into two optical signals with unequal ratios by a parallel modulation module (3), and the two electrical signals are loaded onto the corresponding optical signals and then combined to obtain an optical modulation signal. The optical modulation signal is converted into a target intermediate frequency signal by the detection module (4); The power ratio of the optical signal and the electrical signal satisfies a preset relationship.

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