Device and method for generating millimeter waves based on parallel dual parallel modulators

Abstract

The present invention discloses a device and method for generating millimeter waves based on parallel dual parallel modulators, and relates to the technical field of millimeter wave generation. The device includes an adjustable laser, an optical power divider, a first dual parallel Mach-Zehnder modulator, a second dual parallel Mach-Zehnder modulator, an optical combiner, an optical phase shifter, an erbium-doped fiber amplifier, a photodetector, a radio frequency local oscillator source, a first electric power divider, a second electric power divider, a third electric power divider, a fourth electric power divider, a fifth electric power divider, a sixth electric power divider, a seventh electric power divider, a first electric phase shifter, a second electric phase shifter, a third electric phase shifter, a fourth electric phase shifter, a fifth electric phase shifter, a sixth electric phase shifter, and a seventh electric phase shifter. According to the device for generating millimeter waves based on parallel dual parallel modulators of the present invention, a millimeter wave signal with high purity, low phase noise, and high multiplication factor can be generated.

Description

Technical Field

[0001] The present invention relates to the technical field of millimeter wave generation, and in particular to a device and method for generating millimeter waves based on parallel dual parallel modulators. Background Art

[0002] At present, there are three main technologies for generating millimeter wave signals using optical methods, namely optical heterodyne, frequency up-conversion, and nonlinear modulation of external modulators. Among them:

[0003] 1. Optical heterodyning refers to the use of light waves of different frequencies from two lasers with narrow linewidths to beat in a photodetector, thereby generating a radio frequency signal with a frequency equal to the difference between the two light waves. However, the optical heterodyning method has strict restrictions on the linewidth of the light source, and often requires two or more such lasers, resulting in high system costs. At the same time, since phase-locked technology or lasers with special structures are required to improve the coherence of the two light waves involved in the beat, the system is more complex and costly.

[0004] 2. Frequency up-conversion is to first optically modulate the low-frequency intermediate frequency microwave signal to generate an optical intermediate frequency signal, and then use optical methods to convert the optical intermediate frequency signal into a higher-frequency optical radio frequency signal. After passing through a photodetector, an radio frequency signal with a higher frequency than the intermediate frequency microwave signal can be generated. For the frequency up-conversion method, frequency conversion is plagued by many problems such as incident power limitation, polarization control, and crosstalk, and is relatively complicated.

[0005] 3. The system structure corresponding to the nonlinear modulation method of the external modulator is simpler and less expensive than the first two, and can generate high-purity, low-phase-noise millimeter-wave signals. However, when it is necessary to generate millimeter-wave signals with a high frequency multiplication factor of more than 16 times, the signal quality generated is not good enough. Summary of the invention

[0006] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a device and method for generating millimeter waves based on parallel dual parallel modulators, which can generate millimeter wave signals with high purity, low phase noise and high frequency multiplication factor.

[0007] On the one hand, a device for generating millimeter waves based on parallel dual parallel modulators according to an embodiment of the present invention includes:

[0008] Tunable lasers;

[0009] An optical power splitter, whose input end is connected to the output end of the tunable laser;

[0010] A first dual parallel Mach-Zehnder modulator, an input end of which is connected to a first output end of the optical power divider;

[0011] A second dual parallel Mach-Zehnder modulator, whose input end is connected to the second output end of the optical power divider;

[0012] An optical combiner, wherein a first input end of the optical combiner is connected to an output end of the first dual parallel Mach-Zehnder modulator, and a second input end of the optical combiner is connected to an output end of the second dual parallel Mach-Zehnder modulator via an optical phase shifter;

[0013] An erbium-doped fiber amplifier, the input end of which is connected to the output end of the optical combiner;

[0014] A photoelectric detector, the input end of which is connected to the output end of the erbium-doped fiber amplifier;

[0015] RF local oscillator source;

[0016] A first electric power divider, an input end of which is connected to an output end of the radio frequency local oscillator;

[0017] a second electric power divider, an input end of which is connected to the first output end of the first electric power divider;

[0018] a third electric power divider, an input end of which is connected to the first output end of the second electric power divider;

[0019] a first electrical phase shifter, wherein a first end of the first electrical phase shifter is connected to a second output end of the second electrical power divider;

[0020] a fourth electric power divider, wherein an input end is connected to the second end of the first electric phase shifter, a first output end of the fourth electric power divider is connected to an electrode of a sub-modulator of the first dual parallel Mach-Zehnder modulator through the second electric phase shifter, and a second output end of the fourth electric power divider is connected to another electrode of the sub-modulator of the first dual parallel Mach-Zehnder modulator;

[0021] a third electric phase shifter, wherein a first end of the third electric phase shifter is connected to a first output end of the third electric power divider, a second end of the third electric phase shifter is connected to an electrode of another sub-modulator of the first dual parallel Mach-Zehnder modulator, and a second output end of the third electric power divider is connected to another electrode of the another sub-modulator of the first dual parallel Mach-Zehnder modulator;

[0022] a fourth electrical phase shifter, wherein a first end of the fourth electrical phase shifter is connected to a second output end of the first electrical power divider;

[0023] a fifth electric power divider, an input end of which is connected to the second end of the fourth electric phase shifter;

[0024] a fifth electrical phase shifter, wherein a first end of the fifth electrical phase shifter is connected to a first output end of the fifth electrical power divider;

[0025] a sixth electric power divider, wherein the input end is connected to the second end of the fifth electric phase shifter, the first output end of the sixth electric power divider is connected to an electrode of a sub-modulator of the second dual parallel Mach-Zehnder modulator through the sixth electric phase shifter, and the second output end of the sixth electric power divider is connected to another electrode of the sub-modulator of the second dual parallel Mach-Zehnder modulator;

[0026] A seventh electric power divider, wherein the input end is connected to the second output end of the fifth electric power divider, the first output end of the seventh electric power divider is connected to an electrode of another sub-modulator of the second dual parallel Mach-Zehnder modulator through a seventh electrical phase shifter, and the second output end of the seventh electric power divider is connected to another electrode of the another sub-modulator of the second dual parallel Mach-Zehnder modulator.

[0027] According to some embodiments of the present invention, the sub-modulators of the first dual parallel Mach-Zehnder modulator and the second dual parallel Mach-Zehnder modulator are biased at a maximum output point.

[0028] According to some embodiments of the present invention, the optical phase shifter introduces an optical phase difference of π into the first dual parallel Mach-Zehnder modulator and the second dual parallel Mach-Zehnder modulator.

[0029] According to some embodiments of the present invention, the first electrical phase shifter introduces an electrical phase difference of π / 2 for the two sub-modulators of the first dual parallel Mach-Zehnder modulator, and the fifth electrical phase shifter introduces an electrical phase difference of π / 2 for the two sub-modulators of the second dual parallel Mach-Zehnder modulator.

[0030] According to some embodiments of the present invention, the second electrical phase shifter introduces an electrical phase difference of π between two electrodes of a sub-modulator of the first dual parallel Mach-Zehnder modulator, the third electrical phase shifter introduces an electrical phase difference of π between two electrodes of another sub-modulator of the first dual parallel Mach-Zehnder modulator, the sixth electrical phase shifter introduces an electrical phase difference of π between two electrodes of a sub-modulator of the second dual parallel Mach-Zehnder modulator, and the seventh electrical phase shifter introduces an electrical phase difference of π between two electrodes of another sub-modulator of the second dual parallel Mach-Zehnder modulator.

[0031] According to some embodiments of the present invention, the fourth electrical phase shifter introduces an electrical phase difference of π / 4 to the first dual parallel Mach-Zehnder modulator and the second dual parallel Mach-Zehnder modulator.

[0032] According to some embodiments of the present invention, the modulation coefficients of the first dual parallel Mach-Zehnder modulator and the second dual parallel Mach-Zehnder modulator are 11.065 or 14.373.

[0033] On the other hand, according to the method for generating millimeter waves based on parallel dual parallel modulators according to an embodiment of the present invention, based on the device for generating millimeter waves based on parallel dual parallel modulators described in the above embodiment, the method comprises the following steps:

[0034] biasing the first dual parallel Mach-Zehnder modulator and the second dual parallel Mach-Zehnder modulator at a maximum output point;

[0035] introducing a first electrical phase difference into two sub-modulators of the first dual parallel Mach-Zehnder modulator through a first electrical phase shifter, and introducing the first electrical phase difference into two sub-modulators of the second dual parallel Mach-Zehnder modulator through a fifth electrical phase shifter;

[0036] introducing a second electrical phase difference into two electrodes of one submodulator of the first dual parallel Mach-Zehnder modulator through a second electrical phase shifter, introducing the second electrical phase difference into two electrodes of another submodulator of the first dual parallel Mach-Zehnder modulator through a third electrical phase shifter, introducing the second electrical phase difference into two electrodes of one submodulator of the second dual parallel Mach-Zehnder modulator through a sixth electrical phase shifter, and introducing the second electrical phase difference into two electrodes of another submodulator of the second dual parallel Mach-Zehnder modulator through a seventh electrical phase shifter;

[0037] introducing an optical phase difference into the first dual parallel Mach-Zehnder modulator and the second dual parallel Mach-Zehnder modulator through an optical phase shifter;

[0038] introducing a third electrical phase difference between the first dual parallel Mach-Zehnder modulator and the second dual parallel Mach-Zehnder modulator through a fourth electrical phase shifter;

[0039] adjusting the modulation coefficients of the first dual parallel Mach-Zehnder modulator and the second dual parallel Mach-Zehnder modulator;

[0040] The tunable laser emits light of a first preset frequency;

[0041] The optical power splitter equally divides the light into a first light path and a second light path, the first light path enters the first dual parallel Mach-Zehnder modulator, and the second light path enters the second dual parallel Mach-Zehnder modulator;

[0042] The radio frequency local oscillator source outputs a radio frequency signal of a second preset frequency;

[0043] The first electric power divider equally divides the radio frequency signal into a first radio frequency signal and a second radio frequency signal; the first radio frequency signal passes through a circuit composed of a second electric power divider, a first electric phase shifter, a third electric power divider, a fourth electric power divider, a second electric phase shifter, and a third electric phase shifter, and then is sent to each electrode of each sub-modulator of the first dual parallel Mach-Zehnder modulator; the second radio frequency signal passes through a circuit composed of a fourth electric phase shifter, a fifth electric power divider, a fifth electric phase shifter, a sixth electric power divider, a sixth electric phase shifter, a seventh electric power divider, and a seventh electric phase shifter, and then is sent to each electrode of each sub-modulator of the second dual parallel Mach-Zehnder modulator;

[0044] The first dual parallel Mach-Zehnder modulator outputs a modulated first light path to a first input end of an optical combiner, and the second dual parallel Mach-Zehnder modulator outputs a modulated second light path to a second input end of the optical combiner through the optical phase shifter;

[0045] The optical combiner outputs combined light, and after passing through the erbium-doped fiber amplifier, the combined light is beat-frequencyed at the photodetector to form a millimeter wave having a frequency 24 times that of the second preset frequency.

[0046] According to some embodiments of the present invention, the optical phase difference is π, the first electrical phase difference is π / 2, the second electrical phase difference is π, and the third electrical phase difference is π / 4.

[0047] According to some embodiments of the present invention, the modulation coefficient is 11.065 or 14.373.

[0048] The device and method for generating millimeter waves based on parallel dual parallel modulators according to the embodiment of the present invention have at least the following beneficial effects: by setting the bias voltage of the first dual parallel Mach-Zehnder modulator and the second dual parallel Mach-Zehnder modulator, and introducing an electrical phase difference into the radio frequency signal between the two electrodes of each sub-modulator, introducing an electrical phase difference between the radio frequency signals of the first dual parallel Mach-Zehnder modulator and the second dual parallel Mach-Zehnder modulator, and introducing an optical phase difference between the first dual parallel Mach-Zehnder modulator and the second dual parallel Mach-Zehnder modulator, it is possible to achieve the generation of high-quality millimeter wave signals with 24 times the frequency. Compared with the optical heterodyne scheme: there is no strict restriction on the line width of the light source; no phase locking is required, and the system is relatively simple. Compared with the frequency up-conversion scheme: there is no strict restriction on the incident power of the laser; no polarization control is required; no crosstalk is troubled. Compared with the existing external modulator nonlinear modulation scheme: it can generate millimeter waves with better signal quality than 16 times the frequency, and can reduce the requirements for the radio frequency frequency or modulator bandwidth of the radio frequency local oscillator RF LO.

[0049] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0051] Figure 1 It is a structural schematic diagram of a device for generating millimeter waves based on parallel dual parallel modulators according to an embodiment of the present invention;

[0052] Figure 2 This is the spectrum diagram with a modulation coefficient of 11.065 and an extinction ratio of 30dB;

[0053] Figure 3 This is the RF spectrum diagram with a modulation coefficient of 11.065 and an extinction ratio of 30dB;

[0054] Figure 4 This is the spectrum diagram with a modulation coefficient of 11.065 and an extinction ratio of 70dB;

[0055] Figure 5 This is the RF spectrum diagram with a modulation coefficient of 11.065 and an extinction ratio of 70dB;

[0056] Figure 6 This is the spectrum diagram with a modulation coefficient of 14.373 and an extinction ratio of 30dB;

[0057] Figure 7 This is the RF spectrum diagram with a modulation coefficient of 14.373 and an extinction ratio of 30dB;

[0058] Figure 8 This is the spectrum diagram with a modulation coefficient of 14.373 and an extinction ratio of 70dB;

[0059] Fig. 9 This is the RF spectrum diagram with a modulation coefficient of 14.373 and an extinction ratio of 70dB. DETAILED DESCRIPTION

[0060] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and are not to be construed as limitations on the present application. For the step numbers in the following embodiments, they are only provided for the convenience of explanation, and the order between the steps is not limited in any way, and the execution order of each step in the embodiment can be adaptively adjusted according to the understanding of those skilled in the art.

[0061] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0062] The terms "first", "second", "third" and "fourth" etc. in the specification and claims of the present invention and the drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units that are not listed, or may optionally include other steps or units that are inherent to these processes, methods, products or devices.

[0063] Reference to "embodiments" in the present invention means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0064] At present, there are three main technologies for generating millimeter wave signals using optical methods, namely optical heterodyne, frequency up-conversion, and nonlinear modulation of external modulators. Among them:

[0065] 1. Optical heterodyning refers to the use of light waves of different frequencies from two lasers with narrow linewidths to beat in a photodetector, thereby generating a radio frequency signal with a frequency equal to the difference between the two light waves. However, the optical heterodyning method has strict restrictions on the linewidth of the light source, and often requires two or more such lasers, resulting in high system costs. At the same time, since phase-locked technology or lasers with special structures are required to improve the coherence of the two light waves involved in the beat, the system is more complex and costly.

[0066] 2. Frequency up-conversion is to first optically modulate the low-frequency intermediate frequency microwave signal to generate an optical intermediate frequency signal, and then use optical methods to convert the optical intermediate frequency signal into a higher-frequency optical radio frequency signal. After passing through a photodetector, an radio frequency signal with a higher frequency than the intermediate frequency microwave signal can be generated. For the frequency up-conversion method, frequency conversion is plagued by many problems such as incident power limitation, polarization control, and crosstalk, and is relatively complicated.

[0067] 3. The system structure corresponding to the nonlinear modulation method of the external modulator is simpler and less expensive than the first two, and can generate high-purity, low-phase-noise millimeter-wave signals. However, when it is necessary to generate millimeter-wave signals with a high frequency multiplication factor of more than 16 times, the signal quality generated is not good enough.

[0068] To this end, the embodiment of the present invention provides a device and method for generating millimeter waves based on parallel dual parallel modulators. By setting the bias voltage of the first dual parallel Mach-Zehnder modulator and the second dual parallel Mach-Zehnder modulator, introducing an electrical phase difference in the radio frequency signal between the two electrodes of each sub-modulator, introducing an electrical phase difference between the radio frequency signals of the first dual parallel Mach-Zehnder modulator and the second dual parallel Mach-Zehnder modulator, and introducing an optical phase difference between the first dual parallel Mach-Zehnder modulator and the second dual parallel Mach-Zehnder modulator, the generation of high-quality millimeter wave signals with 24 times the frequency can be achieved. Compared with the optical heterodyne scheme: there is no strict restriction on the line width of the light source; no phase locking is required, and the system is relatively simple. Compared with the frequency up-conversion scheme: there is no strict restriction on the incident power of the laser; no polarization control is required; there is no crosstalk problem. Compared with the existing external modulator nonlinear modulation scheme: it can generate millimeter waves with better signal quality than 16 times the frequency, and can reduce the requirements for the radio frequency frequency or modulator bandwidth of the radio frequency local oscillator RF LO.

[0069] The following describes in detail an apparatus and method for generating millimeter waves based on parallel dual parallel modulators according to an embodiment of the present invention in conjunction with the accompanying drawings.

[0070] On the one hand, if Figure 1As shown, the device for generating millimeter waves based on parallel dual parallel modulators according to an embodiment of the present invention includes an adjustable laser CW Laser, an optical power divider OS, a first dual parallel Mach-Zehnder modulator DP-MZM-1, a second dual parallel Mach-Zehnder modulator DP-MZM-2, an optical combiner OC, an erbium-doped fiber amplifier EDFA, a photodetector PD, a radio frequency local oscillator RF LO, a first electric power divider ES-1, a second electric power divider ES-2, a third electric power divider ES-3, a fourth electric power divider ES-4, a fifth electric power divider ES-5, a sixth electric power divider ES-6, a seventh electric power divider ES-7, a first electric phase shifter EPS-1, a second electric phase shifter EPS-2, a third electric phase shifter EPS-3, a fourth electric phase shifter EPS-4, a fifth electric phase shifter EPS-5, a sixth electric phase shifter EPS-6, and a seventh electric phase shifter EPS-7. Among them, the input end of the optical power splitter OS is connected to the output end of the adjustable laser CW Laser, the first output end of the optical power splitter OS is connected to the input end of the first dual parallel Mach-Zehnder modulator DP-MZM-1, and the second output end of the optical power splitter OS is connected to the input end of the second dual parallel Mach-Zehnder modulator DP-MZM-2; the output end of the first dual parallel Mach-Zehnder modulator DP-MZM-1 is connected to the first input end of the optical combiner OC, the output end of the second dual parallel Mach-Zehnder modulator DP-MZM-2 is connected to the second input end of the optical combiner OC through the optical phase shifter OPS, the output end of the optical combiner OC is connected to the input end of the erbium-doped fiber amplifier EDFA, and the output end of the erbium-doped fiber amplifier EDFA is connected to the input end of the photodetector PD; the radio frequency local oscillator source RF The output end of LO is connected to the input end of the first electric power divider ES-1, the first output end of the first electric power divider ES-1 is connected to the input end of the second electric power divider ES-2, the first output end of the second electric power divider ES-2 is connected to the input end of the third electric power divider ES-3, the second output end of the second electric power divider ES-2 is connected to the first end of the first electric phase shifter EPS-1, the second end of the first electric phase shifter EPS-1 is connected to the input end of the fourth electric power divider ES-4, the first output end of the fourth electric power divider ES-4 is connected to an electrode of a sub-modulator (the upper sub-modulator) of the first dual parallel Mach-Zehnder modulator DP-MZM-1 through the second electric phase shifter EPS-2, and the second output end of the fourth electric power divider ES-4 is connected to another electrode of the upper sub-modulator of the first dual parallel Mach-Zehnder modulator DP-MZM-1;A first end of the third electric phase shifter EPS-3 is connected to a first output end of the third electric power divider ES-3, a second end of the third electric phase shifter EPS-3 is connected to an electrode of another sub-modulator (the lower sub-modulator) of the first dual parallel Mach-Zehnder modulator DP-MZM-1, and a second output end of the third electric power divider ES-3 is connected to another electrode of the lower sub-modulator of the first dual parallel Mach-Zehnder modulator DP-MZM-1; a first end of the fourth electric phase shifter EPS-4 is connected to a second output end of the first electric power divider ES-1, a second end of the fourth electric phase shifter EPS-4 is connected to an input end of the fifth electric power divider ES-5, a first output end of the fifth electric phase shifter ES-5 is connected to a first end of the fifth electric phase shifter EPS-5, a second end of the fifth electric phase shifter EPS-5 is connected to an input end of the sixth electric power divider ES-6, and the sixth electric power divider ES-6 is connected to a first output end of the fifth electric phase shifter EPS-5. The first output end of the splitter ES-6 is connected to an electrode of a sub-modulator (the upper sub-modulator) of the second dual parallel Mach-Zehnder modulator DP-MZM-2 through the sixth electrical phase shifter EPS-6, and the second output end of the sixth electrical power splitter ES-6 is connected to another electrode of the upper sub-modulator of the second dual parallel Mach-Zehnder modulator DP-MZM-2; the input end of the seventh electrical power splitter ES-7 is connected to the second output end of the fifth electrical power splitter ES-5, the first output end of the seventh electrical power splitter ES-7 is connected to an electrode of another sub-modulator (the lower sub-modulator) of the second dual parallel Mach-Zehnder modulator DP-MZM-2 through the seventh electrical phase shifter EPS-7, and the second output end of the seventh electrical power splitter ES-7 is connected to another electrode of the lower sub-modulator of the second dual parallel Mach-Zehnder modulator DP-MZM-2. ;

[0071] The working principle of the embodiment of the present invention is as follows: the light emitted by the tunable laser CW Laser is equally divided into two paths by the optical power divider OS, and respectively input into the first dual parallel Mach-Zehnder modulator DP-MZM-1 and the second dual parallel Mach-Zehnder modulator DP-MZM-2. The RF signal output by the RF local oscillator RF LO is equally divided into a first RF signal U1 and a second RF signal U2 by the first electrical power divider ES-1. The second electrical power divider ES-2 equally divides the first RF signal U1 into a third RF signal U3 and a fourth RF signal U4. After the third RF signal U3 passes through the first electrical phase shifter EPS-1, it is equally divided into a fifth RF signal U5 and a sixth RF signal U6 by the fourth electrical power divider ES-4. The fifth RF signal U5 passes through the second electrical phase shifter EPS-2 and is sent to an electrical phase shifter of a sub-modulator of the first dual parallel Mach-Zehnder modulator DP-MZM-1. The sixth RF signal U6 is sent to another electrode of a sub-modulator of the first dual parallel Mach-Zehnder modulator DP-MZM-1; the third electric power divider ES-3 divides the fourth RF signal U4 into a seventh RF signal U7 and an eighth RF signal U8, and the seventh RF signal U7 is sent to an electrode of another sub-modulator of the first dual parallel Mach-Zehnder modulator DP-MZM-1 after passing through the third electric power divider EPS-3, and the eighth RF signal U8 is sent to another electrode of another sub-modulator of the first dual parallel Mach-Zehnder modulator DP-MZM-1. electrodes; after the second RF signal U2 passes through the fourth electrical phase shifter EPS-4, it is equally divided into a ninth RF signal U9 and a tenth RF signal U10 by the fifth electrical power divider ES-5; after the ninth RF signal U9 passes through the fifth electrical phase shifter EPS-5, it is equally divided into an eleventh RF signal U11 and a twelfth RF signal U12 by the sixth electrical power divider ES-6; the eleventh RF signal U11 passes through the sixth electrical phase shifter EPS-6 and is sent to an electrode of a sub-modulator of the second dual parallel Mach-Zehnder modulator DP-MZM-2; the twelfth RF signal U12 is sent to Another electrode of a sub-modulator of the second dual parallel Mach-Zehnder modulator DP-MZM-2, the seventh electric power divider ES-7 divides the tenth RF signal U10 equally into a thirteenth RF signal U13 and a fourteenth RF signal U14, the thirteenth RF signal U13 is sent to an electrode of another sub-modulator of the second dual parallel Mach-Zehnder modulator DP-MZM-2 after passing through the seventh electrical phase shifter EPS-7, and the fourteenth RF signal U14 is sent to another electrode of another sub-modulator of the second dual parallel Mach-Zehnder modulator DP-MZM-2.The first light and the second light are modulated in the first dual parallel Mach-Zehnder modulator DP-MZM-1 and the second dual parallel Mach-Zehnder modulator DP-MZM-2 respectively, and the modulated light is output to the optical combiner OC. The optical combiner OC outputs the combined light. After the combined light passes through the erbium-doped fiber amplifier EDFA, it is beat-frequencyed in the photodetector PD, and thus microwaves (millimeter waves) with a frequency N times the frequency of the RF signal emitted by the RF local oscillator RFLO can be generated.

[0072] Furthermore, in an embodiment of the present invention, the second electrical phase shifter EPS-2 introduces an electrical phase difference of π between two electrodes of a sub-modulator of the first dual parallel Mach-Zehnder modulator DP-MZM-1, the third electrical phase shifter EPS-3 introduces an electrical phase difference of π between two electrodes of another sub-modulator of the first dual parallel Mach-Zehnder modulator DP-MZM-1, the sixth electrical phase shifter EPS-6 introduces an electrical phase difference of π between two electrodes of a sub-modulator of the second dual parallel Mach-Zehnder modulator DP-MZM-2, and the seventh electrical phase shifter EPS-7 introduces an electrical phase difference of π between two electrodes of another sub-modulator of the second dual parallel Mach-Zehnder modulator DP-MZM-2. At the same time, the sub-modulators of the first dual parallel Mach-Zehnder modulator DP-MZM-1 and the second dual parallel Mach-Zehnder modulator DP-MZM-2 are biased at the maximum output point. At this time, all odd sidebands ±1, ±3, ±5, ±7, etc. are suppressed. The first electrical phase shifter EPS-1 introduces an electrical phase difference of π / 2 to the two sub-modulators of the first dual parallel Mach-Zehnder modulator DP-MZM-1, and the fifth electrical phase shifter EPS-5 introduces an electrical phase difference of π / 2 to the two sub-modulators of the second dual parallel Mach-Zehnder modulator DP-MZM-2, so that the first dual parallel Mach-Zehnder modulator DP-MZM-1 and the second dual parallel Mach-Zehnder modulator DP-MZM-2 only output sidebands of 0, ±4, ±8, ±12, ±16, etc., which are integer multiples of the fourth order. By adjusting the modulation coefficients loaded on the first dual parallel Mach-Zehnder modulator DP-MZM-1 and the second dual parallel Mach-Zehnder modulator DP-MZM-2, the ±4th order sidebands can be suppressed. By introducing an appropriate phase difference between the RF signals of the first dual parallel Mach-Zehnder modulator DP-MZM-1 and the second dual parallel Mach-Zehnder modulator DP-MZM-2 through the fourth electrical phase shifter EPS-4, the ±8 and ±16 order sidebands can be suppressed. After the above processing, only the ±12 order sidebands are retained in the combined light output by the optical combiner OC, and the beat frequency is performed in the photodetector PD, so that a millimeter wave with a frequency 24 times the frequency of the RF signal emitted by the RF local oscillator RF LO can be generated. Since other redundant sidebands are well suppressed, high-purity, low-noise, high-quality millimeter wave signals can be generated.

[0073] Assume that the frequency of the light wave output by the tunable laser CW Laser is w 0 , strength is E 0 , the frequency of the RF signal output by the RF local oscillator is w RF The initial phase is The RF switch voltage of the first dual parallel Mach-Zehnder modulator DP-MZM-1 and the second dual parallel Mach-Zehnder modulator DP-MZM-2 is V π , the RF signal voltage loaded on the sub-modulators of the first dual parallel Mach-Zehnder modulator DP-MZM-1 and the second dual parallel Mach-Zehnder modulator DP-MZM-2 is V RF , the RF phase difference between the first dual parallel Mach-Zehnder modulator DP-MZM-1 and the second dual parallel Mach-Zehnder modulator DP-MZM-2 is The optical phase shifter OPS introduces an optical phase difference of Δθ between the first dual parallel Mach-Zehnder modulator DP-MZM-1 and the second dual parallel Mach-Zehnder modulator.

[0074] For Figure 1 The system shown in the figure can realize the generation of 24-fold frequency millimeter wave signal by setting the bias voltage of each sub-modulator of the first dual parallel Mach-Zehnder modulator DP-MZM-1 and the second dual parallel Mach-Zehnder modulator DP-MZM-2 and the RF signal phase difference between the two electrodes of each sub-modulator, the RF signal voltage between the two electrodes, the RF signal phase difference between the first dual parallel Mach-Zehnder modulator DP-MZM-1 and the second dual parallel Mach-Zehnder modulator DP-MZM-2, and the phase difference between the output light fields of the first dual parallel Mach-Zehnder modulator DP-MZM-1 and the second dual parallel Mach-Zehnder modulator. The specific process is as follows:

[0075] 1. Set the bias voltage and RF signal difference of DP-MZM-1 and DP-MZM-2:

[0076] The sub-modulators of DP-MZM-1 and DP-MZM-2 are biased at the maximum output point, and the electrical phase difference between the two electrodes of each sub-modulator is π, and the electrical phase difference between the two sub-modulators of the same dual parallel Mach-Zehnder modulator is π / 2. Then the light field output by DP-MZM-1 is in the form of:

[0077]

[0078] The light field output by DP-MZM-2 is in the form of:

[0079]

[0080] In this way, the output light field E after the optical combiner OC out It can be expressed as:

[0081] E out =E out1 +e jΔθ E out (3)

[0082] 2. Introduce optical phase difference in the output light field of DP-MZM-1 and DP-MZM-2:

[0083] Through the optical phase shifter OPS, an optical phase difference of π is introduced into the output light field of the first dual parallel Mach-Zehnder modulator DP-MZM-1 and the second dual parallel Mach-Zehnder modulator DP-MZM-2, that is:

[0084] Δθ=π (4)

[0085] Combining equations (1)-(4), we can get the output light field E out for:

[0086]

[0087] 3. Set the modulation coefficient of DP-MZM-1 and DP-MZM-2:

[0088] It can be seen from formula (5) that when the following conditions are met:

[0089] J 4 (m)=0 (6)

[0090] J -4 (m)=0 (7)

[0091] At this time, the 4th-order sideband is suppressed, and the modulation coefficient can be calculated as:

[0092] m=11.065 or 14.373 (8)

[0093] 4. Introduce a phase difference between the RF signals of DP-MZM-1 and DP-MZM-2:

[0094] From formula (5), we can see that when the following conditions are met:

[0095]

[0096] At this time, the 8th-order sideband and the 16th-order sideband will also be suppressed, and the calculation can be obtained:

[0097]

[0098] It can be seen that, based on the previous settings, by introducing a phase difference of π / 4 between the RF signals of DP-MZM-1 and DP-MZM-2 through the fourth electrical phase shifter EPS-4, the 8th-order sideband and the 16th-order sideband can be further suppressed.

[0099] Combining equations (5), (8) and (12), we can get the final output light field after being combined by the optical combiner OC:

[0100]

[0101] In this way, there is only a 12th-order sideband in the output light field, and the beat frequency is generated in the photodetector PD, so that a millimeter wave having a frequency equal to 24 times the frequency of the radio frequency signal of the radio frequency local oscillator source RF LO can be obtained.

[0102] According to the device for generating millimeter waves based on parallel dual parallel modulators of the embodiment of the present invention, by setting the bias voltage of the first dual parallel Mach-Zehnder modulator DP-MZM-1 and the second dual parallel Mach-Zehnder modulator DP-MZM-2, and introducing an electrical phase difference in the radio frequency signal between the two electrodes of each sub-modulator, introducing an electrical phase difference between the radio frequency signals of DP-MZM-1 and DP-MZM-2, and introducing an optical phase difference between DP-MZM-1 and DP-MZM-2, the generation of 24 times high-quality millimeter wave signals can be achieved. Compared with optical heterodyne, frequency up-conversion, and nonlinear modulation schemes of existing external modulators, the advantages of the present invention are as follows:

[0103] 1. Compared with the optical heterodyne solution:

[0104] 1) There is no strict restriction on the line width of the light source;

[0105] 2) No phase locking is required and the system is relatively simple.

[0106] 2. Relative to the frequency up-conversion scheme:

[0107] 1) There is no strict limit on the incident power of the laser;

[0108] 2) No polarization control is required;

[0109] 3) No crosstalk problems.

[0110] 3. Compared with the existing nonlinear modulation scheme of external modulator:

[0111] It is possible to generate a millimeter wave with a frequency higher than 16 times of the original frequency with good signal quality, and to reduce the requirements on the radio frequency of the radio frequency local oscillator RF LO or the modulator bandwidth.

[0112] The device for generating millimeter waves based on parallel dual parallel modulators of the present invention is verified by a specific embodiment as follows:

[0113] exist Figure 1 In the system structure, the frequency of the light wave emitted by the adjustable laser source CW Laser is 193.1THz, the line width is 10MHz, the optical power is 0dBm, the phase difference introduced by the optical phase shifter OPS is π, and the microwave frequency of the RF local oscillator RF LO is 8GHZ. The sub-modulators of DP-MZM-1 and DP-MZM-2 are biased at the maximum output point, that is, VDC1 = VDC2 = VDC3 = VDC4 = VDC5 = VDC6 = VDC7 = VDC8 = VDC9 = VDC10 = 0; the phase difference introduced by the second electrical phase shifter EPS-2, the third electrical phase shifter EPS-3, the sixth electrical phase shifter EPS-6 and the seventh electrical phase shifter EPS-7 is π, the phase difference introduced by the first electrical phase shifter EPS-1 and the fifth electrical phase shifter EPS-5 is π / 2, and the phase difference introduced by the fourth electrical phase shifter EPS-4 is π / 4. The modulation coefficients of DP-MZM-1 and DP-MZM-2 are set to 11.065 or 14.373. The gain of the erbium-doped fiber amplifier EDFA is 20dB, the noise figure is 4dB, the responsivity of the photodetector PD is 1A / W, and the dark current is 10nA.

[0114] Using Optisystem software, we can simulate and verify DP-MZM-1 and DP-MZM-2 with different extinction ratios based on the above parameters. Figure 2-9 are the spectrum and electric spectrum obtained by simulation. Among them, Figure 2 and Figure 3 They are the optical spectrum and radio frequency spectrum with a modulation coefficient of 11.065 and an extinction ratio of 30dB, the optical sideband suppression ratio is 25.6dB, and the radio frequency spurious suppression ratio is 43.5dB. The quality of optical millimeter wave and millimeter wave signals is relatively high. Figure 4 and Figure 5 They are the spectrum diagram and RF spectrum diagram with a modulation coefficient of 11.065 and an extinction ratio of 70dB. The redundant sidebands are almost completely suppressed, and the RF spurious suppression ratio is 43.3dB. The quality of optical millimeter wave and millimeter wave signals is very high. Figure 6 and Figure 7 They are the optical spectrum and radio frequency spectrum with a modulation coefficient of 14.373 and an extinction ratio of 30dB, the optical sideband suppression ratio is 35.9dB, and the radio frequency spurious suppression ratio is 30.9dB. The quality of optical millimeter wave and millimeter wave signals is high. Figure 8 and Fig. 9 They are the optical spectrum and radio frequency spectrum with a modulation coefficient of 14.373 and an extinction ratio of 70dB, the optical sideband suppression ratio is 37.1dB, and the radio frequency spurious suppression ratio is 30.3dB. The quality of optical millimeter wave and millimeter wave signals is high.

[0115] On the other hand, based on the above-mentioned device for generating millimeter waves based on parallel dual parallel modulators, the present invention also proposes a method for generating millimeter waves based on parallel dual parallel modulators, the method comprising the following steps:

[0116] Step (1): bias the first dual parallel Mach-Zehnder modulator DP-MZM-1 and the second dual parallel Mach-Zehnder modulator DP-MZM-2 at the maximum output point, that is,

[0117] VDC1=VDC2=VDC3=VDC4=VDC5=VDC6=VDC7=VDC8=VDC9=VDC10=0

[0118] Step (2): Introduce a first electrical phase difference into the two sub-modulators of the first dual parallel Mach-Zehnder modulator DP-MZM-1 through the first electrical phase shifter EPS-1, and introduce a first electrical phase difference into the two sub-modulators of the second dual parallel Mach-Zehnder modulator DP-MZM-2 through the fifth electrical phase shifter EPS-5; in this example, the first electrical phase difference is set to π / 2, and can also be set to other values ​​according to actual needs.

[0119] Step (3): Introduce a second electrical phase difference into two electrodes of a sub-modulator of the first dual parallel Mach-Zehnder modulator DP-MZM-1 through the second electrical phase shifter EPS-2, introduce a second electrical phase difference into two electrodes of another sub-modulator of the first dual parallel Mach-Zehnder modulator DP-MZM-1 through the third electrical phase shifter EPS-3, introduce a second electrical phase difference into two electrodes of a sub-modulator of the second dual parallel Mach-Zehnder modulator DP-MZM-2 through the sixth electrical phase shifter EPS-6, and introduce a second electrical phase difference into two electrodes of another sub-modulator of the second dual parallel Mach-Zehnder modulator DP-MZM-1 through the seventh electrical phase shifter EPS-7; in this example, the second electrical phase difference is set to π, and can also be set to other values ​​according to actual needs.

[0120] Step (4): Introduce an optical phase difference into the first dual parallel Mach-Zehnder modulator DP-MZM-1 and the second dual parallel Mach-Zehnder modulator DP-MZM-2 through an optical phase shifter OPS; in this example, the optical phase difference is set to π, and can also be set to other values ​​according to actual needs.

[0121] Step (5): Introduce a third electrical phase difference between the first dual parallel Mach-Zehnder modulator DP-MZM-1 and the second dual parallel Mach-Zehnder modulator DP-MZM-2 through the fourth electrical phase shifter EPS-4; in this example, the third electrical phase difference is set to π / 4, and can also be set to other values ​​according to actual needs.

[0122] Step (6): Adjust the modulation coefficients of the first dual parallel Mach-Zehnder modulator DP-MZM-1 and the second dual parallel Mach-Zehnder modulator DP-MZM-2; in this example, the modulation coefficients of DP-MZM-1 and DP-MZM-2 are adjusted to 11.065 or 14.373, and can also be set to other values ​​according to actual needs

[0123] Step (7): the tunable laser CW Laser emits light of a first preset frequency;

[0124] Step (8): the optical power splitter OS equally divides the light into a first light path and a second light path, the first light path enters the first dual parallel Mach-Zehnder modulator DP-MZM-1, and the second light path enters the second dual parallel Mach-Zehnder modulator DP-MZM-2;

[0125] Step (9): The radio frequency local oscillator RF LO outputs a radio frequency signal of a second preset frequency;

[0126] Step (10): the first electric power divider ES-1 divides the radio frequency signal equally into a first radio frequency signal and a second radio frequency signal. The first radio frequency signal passes through a circuit formed by the second electric power divider ES-2, the first electric phase shifter EPS-1, the third electric power divider ES-3, the fourth electric power divider ES-4, the second electric phase shifter EPS-2, and the third electric phase shifter EPS-3, and is then sent to each electrode of each sub-modulator of the first dual parallel Mach-Zehnder modulator DP-MZM-1. The second radio frequency signal passes through a circuit formed by the fourth electric phase shifter EPS-4, the fifth electric power divider ES-5, the fifth electric phase shifter EPS-5, the sixth electric power divider ES-6, the sixth electric phase shifter EPS-6, the seventh electric power divider ES-7, and the seventh electric phase shifter EPS-7, and is then sent to each electrode of each sub-modulator of the second dual parallel Mach-Zehnder modulator DP-MZM-2.

[0127] Specifically, the RF signal output by the RF local oscillator RF LO is equally divided into a first RF signal U1 and a second RF signal U2 by the first electric power divider ES-1, the first RF signal U1 is equally divided into a third RF signal U3 and a fourth RF signal U4 by the second electric power divider ES-2, the third RF signal U3 passes through the first electrical phase shifter EPS-1, and is equally divided into a fifth RF signal U5 and a sixth RF signal U6 by the fourth electric power divider ES-4, the fifth RF signal U5 passes through the second electrical phase shifter EPS-2 and is sent to one of the sub-modulators of the first dual parallel Mach-Zehnder modulator DP-MZM-1. The sixth RF signal U6 is sent to another electrode of a sub-modulator of the first dual parallel Mach-Zehnder modulator DP-MZM-1; the third electric power divider ES-3 divides the fourth RF signal U4 into a seventh RF signal U7 and an eighth RF signal U8, and the seventh RF signal U7 is sent to an electrode of another sub-modulator of the first dual parallel Mach-Zehnder modulator DP-MZM-1 after passing through the third electric power divider ES-3, and the eighth RF signal U8 is sent to another electrode of another sub-modulator of the first dual parallel Mach-Zehnder modulator DP-MZM-1. electrodes; after the second RF signal U2 passes through the fourth electrical phase shifter EPS-4, it is equally divided into a ninth RF signal U9 and a tenth RF signal U10 by the fifth electrical power divider ES-5; after the ninth RF signal U9 passes through the fifth electrical phase shifter EPS-5, it is equally divided into an eleventh RF signal U11 and a twelfth RF signal U12 by the sixth electrical power divider ES-6; the eleventh RF signal U11 passes through the sixth electrical phase shifter EPS-6 and is sent to an electrode of a sub-modulator of the second dual parallel Mach-Zehnder modulator DP-MZM-2; the twelfth RF signal U12 is sent to Another electrode of a sub-modulator of the second dual parallel Mach-Zehnder modulator DP-MZM-2, the seventh electric power divider ES-7 divides the tenth RF signal U10 equally into a thirteenth RF signal U13 and a fourteenth RF signal U14, the thirteenth RF signal U13 is sent to an electrode of another sub-modulator of the second dual parallel Mach-Zehnder modulator DP-MZM-2 after passing through the seventh electrical phase shifter EPS-7, and the fourteenth RF signal U14 is sent to another electrode of another sub-modulator of the second dual parallel Mach-Zehnder modulator DP-MZM-2.

[0128] Step (11): the first dual parallel Mach-Zehnder modulator DP-MZM-1 outputs the modulated first light to the first input end of the optical combiner OC, and the second dual parallel Mach-Zehnder modulator DP-MZM-2 outputs the modulated second light to the second input end of the optical combiner OC through the optical phase shifter OPS;

[0129] Specifically, the first light and the second light are modulated in the first dual parallel Mach-Zehnder modulator DP-MZM-1 and the second dual parallel Mach-Zehnder modulator DP-MZM-2 respectively, and the modulated light is output to the optical combiner OC, and the optical combiner OC outputs the combined light.

[0130] Step (12): the optical combiner OC outputs combined light, and the combined light passes through the erbium-doped fiber amplifier EDFA and then beats the light at the photodetector PD to form a millimeter wave with a frequency 24 times the second preset frequency.

[0131] Specifically, assuming that the first preset frequency of the light output by the tunable laser CW Laser is w 0 , strength is E 0 The second preset frequency of the RF signal output by the RF local oscillator is w RF The initial phase is The RF switch voltage of the first dual parallel Mach-Zehnder modulator DP-MZM-1 and the second dual parallel Mach-Zehnder modulator DP-MZM-2 is V π , the RF signal voltage loaded on the sub-modulators of the first dual parallel Mach-Zehnder modulator DP-MZM-1 and the second dual parallel Mach-Zehnder modulator DP-MZM-2 is V RF , the RF phase difference between the first dual parallel Mach-Zehnder modulator DP-MZM-1 and the second dual parallel Mach-Zehnder modulator DP-MZM-2 is The optical phase shifter OPS introduces an optical phase difference of Δθ between the first dual parallel Mach-Zehnder modulator DP-MZM-1 and the second dual parallel Mach-Zehnder modulator.

[0132] For Figure 1 The system shown in the figure can realize the generation of 24-fold frequency millimeter wave signal by setting the bias voltage of each sub-modulator of the first dual parallel Mach-Zehnder modulator DP-MZM-1 and the second dual parallel Mach-Zehnder modulator DP-MZM-2 and the RF signal phase difference between the two electrodes of each sub-modulator, the RF signal voltage between the two electrodes, the RF signal phase difference between the first dual parallel Mach-Zehnder modulator DP-MZM-1 and the second dual parallel Mach-Zehnder modulator DP-MZM-2, and the phase difference between the output light fields of the first dual parallel Mach-Zehnder modulator DP-MZM-1 and the second dual parallel Mach-Zehnder modulator. The specific process is as follows:

[0133] 1. Set the bias voltage and RF signal difference of DP-MZM-1 and DP-MZM-2:

[0134] The sub-modulators of DP-MZM-1 and DP-MZM-2 are biased at the maximum output point, and the electrical phase difference between the two electrodes of each sub-modulator is π, and the electrical phase difference between the two sub-modulators of the same dual parallel Mach-Zehnder modulator is π / 2. Then the light field output by DP-MZM-1 is in the form of:

[0135]

[0136] The light field output by DP-MZM-2 is in the form of:

[0137]

[0138] In this way, the output light field E after the optical combiner OC out It can be expressed as:

[0139] E out =E 0ut1 +e jΔθ E out (3)

[0140] 2. Introduce optical phase difference in the output light field of DP-MZM-1 and DP-MZM-2:

[0141] Through the optical phase shifter OPS, an optical phase difference of π is introduced into the output light field of the first dual parallel Mach-Zehnder modulator DP-MZM-1 and the second dual parallel Mach-Zehnder modulator DP-MZM-2, that is:

[0142] Δθ=π (4)

[0143] Combining equations (1)-(4), we can get the output light field E out for:

[0144]

[0145] 3. Set the modulation coefficient of DP-MZM-1 and DP-MZM-2:

[0146] It can be seen from formula (5) that when the following conditions are met:

[0147] J 4 (m)=0 (6)

[0148] J -4 (m)=0 (7)

[0149] At this time, the 4th-order sideband is suppressed, and the modulation coefficient can be calculated as:

[0150] m=11.065 or 14.373 (8)

[0151] 4. Introduce a phase difference between the RF signals of DP-MZM-1 and DP-MZM-2:

[0152] From formula (5), we can see that when the following conditions are met:

[0153]

[0154] At this time, the 8th-order sideband and the 16th-order sideband will also be suppressed, and the calculation can be obtained:

[0155]

[0156] It can be seen that, based on the previous settings, by introducing a phase difference of π / 4 between the RF signals of DP-MZM-1 and DP-MZM-2 through the fourth electrical phase shifter EPS-4, the 8th-order sideband and the 16th-order sideband can be further suppressed.

[0157] Combining equations (5), (8) and (12), we can get the final output light field after being combined by the optical combiner OC:

[0158]

[0159] In this way, there is only a 12th-order sideband in the output light field, and the beat frequency is generated in the photodetector PD, so that a millimeter wave having a frequency equal to 24 times the frequency of the radio frequency signal of the radio frequency local oscillator source RF LO can be obtained.

[0160] According to the method for generating millimeter waves based on parallel dual parallel modulators of the embodiment of the present invention, by setting the bias voltage of the first dual parallel Mach-Zehnder modulator DP-MZM-1 and the second dual parallel Mach-Zehnder modulator DP-MZM-2, and introducing an electrical phase difference in the radio frequency signal between the two electrodes of each sub-modulator, introducing an electrical phase difference between the radio frequency signals of DP-MZM-1 and DP-MZM-2, and introducing an optical phase difference between DP-MZM-1 and DP-MZM-2, the generation of 24 times high-quality millimeter wave signals can be achieved. Compared with optical heterodyne, frequency up-conversion, and nonlinear modulation schemes of existing external modulators, the advantages of the present invention are as follows:

[0161] 1. Compared with the optical heterodyne solution:

[0162] 1) There is no strict restriction on the line width of the light source;

[0163] 2) No phase locking is required and the system is relatively simple.

[0164] 2. Relative to the frequency up-conversion scheme:

[0165] 1) There is no strict limit on the incident power of the laser;

[0166] 2) No polarization control is required;

[0167] 3) No crosstalk problems.

[0168] 3. Compared with the existing nonlinear modulation scheme of external modulator:

[0169] 1) Compared with the existing 16-times and 20-times frequency schemes, the frequency multiplication factor is 24, which can reduce the requirements on the RF frequency of the RF local oscillator source RFLO or the modulator bandwidth;

[0170] 2) Compared with the existing 32-time frequency multiplication scheme, only one optical phase shifter is required, and the system cost is relatively low.

[0171] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. A device for generating millimeter waves based on parallel dual-parallel modulators, characterized in that: include: Tunable lasers; An optical power splitter, whose input end is connected to the output end of the tunable laser; A first dual parallel Mach-Zehnder modulator, an input end of which is connected to a first output end of the optical power divider; A second dual parallel Mach-Zehnder modulator, whose input end is connected to the second output end of the optical power divider; the sub-modulators of the first dual parallel Mach-Zehnder modulator and the second dual parallel Mach-Zehnder modulator are biased at a maximum output point, and the modulation coefficients of the first dual parallel Mach-Zehnder modulator and the second dual parallel Mach-Zehnder modulator are 11.065 or 14.373; An optical combiner, wherein a first input end of the optical combiner is connected to an output end of the first dual parallel Mach-Zehnder modulator, and a second input end of the optical combiner is connected to an output end of the second dual parallel Mach-Zehnder modulator via an optical phase shifter; An erbium-doped fiber amplifier, the input end of which is connected to the output end of the optical combiner; A photoelectric detector, the input end of which is connected to the output end of the erbium-doped fiber amplifier; RF local oscillator source; A first electric power divider, an input end of which is connected to an output end of the radio frequency local oscillator; a second electric power divider, an input end of which is connected to the first output end of the first electric power divider; a third electric power divider, an input end of which is connected to the first output end of the second electric power divider; a first electrical phase shifter, wherein a first end of the first electrical phase shifter is connected to a second output end of the second electrical power divider; a fourth electric power divider, wherein an input end is connected to the second end of the first electric phase shifter, a first output end of the fourth electric power divider is connected to an electrode of a sub-modulator of the first dual parallel Mach-Zehnder modulator through the second electric phase shifter, and a second output end of the fourth electric power divider is connected to another electrode of the sub-modulator of the first dual parallel Mach-Zehnder modulator; a third electric phase shifter, wherein a first end of the third electric phase shifter is connected to a first output end of the third electric power divider, a second end of the third electric phase shifter is connected to an electrode of another sub-modulator of the first dual parallel Mach-Zehnder modulator, and a second output end of the third electric power divider is connected to another electrode of the another sub-modulator of the first dual parallel Mach-Zehnder modulator; a fourth electrical phase shifter, wherein a first end of the fourth electrical phase shifter is connected to a second output end of the first electrical power divider; a fifth electric power divider, an input end of which is connected to the second end of the fourth electric phase shifter; a fifth electrical phase shifter, wherein a first end of the fifth electrical phase shifter is connected to a first output end of the fifth electrical power divider; a sixth electric power divider, wherein the input end is connected to the second end of the fifth electric phase shifter, the first output end of the sixth electric power divider is connected to an electrode of a sub-modulator of the second dual parallel Mach-Zehnder modulator through the sixth electric phase shifter, and the second output end of the sixth electric power divider is connected to another electrode of the sub-modulator of the second dual parallel Mach-Zehnder modulator; a seventh electric power divider, wherein the input end is connected to the second output end of the fifth electric power divider, the first output end of the seventh electric power divider is connected to an electrode of another sub-modulator of the second dual parallel Mach-Zehnder modulator through a seventh electrical phase shifter, and the second output end of the seventh electric power divider is connected to another electrode of the another sub-modulator of the second dual parallel Mach-Zehnder modulator; The optical phase shifter introduces an optical phase difference of π into the first dual parallel Mach-Zehnder modulator and the second dual parallel Mach-Zehnder modulator; The first electrical phase shifter introduces an electrical phase difference of π / 2 to the two sub-modulators of the first dual parallel Mach-Zehnder modulator, and the fifth electrical phase shifter introduces an electrical phase difference of π / 2 to the two sub-modulators of the second dual parallel Mach-Zehnder modulator; The second electrical phase shifter introduces an electrical phase difference of π between two electrodes of one sub-modulator of the first dual parallel Mach-Zehnder modulator, the third electrical phase shifter introduces an electrical phase difference of π between two electrodes of another sub-modulator of the first dual parallel Mach-Zehnder modulator, the sixth electrical phase shifter introduces an electrical phase difference of π between two electrodes of one sub-modulator of the second dual parallel Mach-Zehnder modulator, and the seventh electrical phase shifter introduces an electrical phase difference of π between two electrodes of another sub-modulator of the second dual parallel Mach-Zehnder modulator; The fourth electrical phase shifter introduces an electrical phase difference of π / 4 to the first dual parallel Mach-Zehnder modulator and the second dual parallel Mach-Zehnder modulator.

2. A method for generating millimeter waves based on parallel dual parallel modulators, characterized in that: Based on the device for generating millimeter waves based on parallel dual parallel modulators as claimed in claim 1, the method comprises the following steps: biasing the first dual parallel Mach-Zehnder modulator and the second dual parallel Mach-Zehnder modulator at a maximum output point; introducing a first electrical phase difference into two sub-modulators of the first dual parallel Mach-Zehnder modulator through a first electrical phase shifter, and introducing the first electrical phase difference into two sub-modulators of the second dual parallel Mach-Zehnder modulator through a fifth electrical phase shifter; introducing a second electrical phase difference into two electrodes of one submodulator of the first dual parallel Mach-Zehnder modulator through a second electrical phase shifter, introducing the second electrical phase difference into two electrodes of another submodulator of the first dual parallel Mach-Zehnder modulator through a third electrical phase shifter, introducing the second electrical phase difference into two electrodes of one submodulator of the second dual parallel Mach-Zehnder modulator through a sixth electrical phase shifter, and introducing the second electrical phase difference into two electrodes of another submodulator of the second dual parallel Mach-Zehnder modulator through a seventh electrical phase shifter; introducing an optical phase difference into the first dual parallel Mach-Zehnder modulator and the second dual parallel Mach-Zehnder modulator through an optical phase shifter; introducing a third electrical phase difference between the first dual parallel Mach-Zehnder modulator and the second dual parallel Mach-Zehnder modulator through a fourth electrical phase shifter; adjusting the modulation coefficients of the first dual parallel Mach-Zehnder modulator and the second dual parallel Mach-Zehnder modulator; The tunable laser emits light of a first preset frequency; The optical power splitter equally divides the light into a first light path and a second light path, the first light path enters the first dual parallel Mach-Zehnder modulator, and the second light path enters the second dual parallel Mach-Zehnder modulator; The radio frequency local oscillator source outputs a radio frequency signal of a second preset frequency; The first electric power divider equally divides the radio frequency signal into a first radio frequency signal and a second radio frequency signal; the first radio frequency signal passes through a circuit composed of a second electric power divider, a first electric phase shifter, a third electric power divider, a fourth electric power divider, a second electric phase shifter, and a third electric phase shifter, and then is sent to each electrode of each sub-modulator of the first dual parallel Mach-Zehnder modulator; the second radio frequency signal passes through a circuit composed of a fourth electric phase shifter, a fifth electric power divider, a fifth electric phase shifter, a sixth electric power divider, a sixth electric phase shifter, a seventh electric power divider, and a seventh electric phase shifter, and then is sent to each electrode of each sub-modulator of the second dual parallel Mach-Zehnder modulator; The first dual parallel Mach-Zehnder modulator outputs a modulated first light path to a first input end of an optical combiner, and the second dual parallel Mach-Zehnder modulator outputs a modulated second light path to a second input end of the optical combiner through the optical phase shifter; The optical combiner outputs combined light, and after passing through the erbium-doped fiber amplifier, the combined light is beat-frequencyed at the photodetector to form a millimeter wave having a frequency 24 times that of the second preset frequency.

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