CN115173949A - Duty ratio adjustable rectification cosine microwave signal generator, method and equipment - Google Patents
Duty ratio adjustable rectification cosine microwave signal generator, method and equipment Download PDFInfo
- Publication number
- CN115173949A CN115173949A CN202210648740.0A CN202210648740A CN115173949A CN 115173949 A CN115173949 A CN 115173949A CN 202210648740 A CN202210648740 A CN 202210648740A CN 115173949 A CN115173949 A CN 115173949A
- Authority
- CN
- China
- Prior art keywords
- axis
- polarization
- zehnder modulator
- drive mach
- signal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 28
- 230000010287 polarization Effects 0.000 claims abstract description 221
- 230000003287 optical effect Effects 0.000 claims description 81
- 230000035559 beat frequency Effects 0.000 claims description 21
- 230000010363 phase shift Effects 0.000 claims description 14
- 230000005540 biological transmission Effects 0.000 claims description 13
- 230000003321 amplification Effects 0.000 claims description 6
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 6
- 239000013307 optical fiber Substances 0.000 claims description 6
- NAWXUBYGYWOOIX-SFHVURJKSA-N (2s)-2-[[4-[2-(2,4-diaminoquinazolin-6-yl)ethyl]benzoyl]amino]-4-methylidenepentanedioic acid Chemical compound C1=CC2=NC(N)=NC(N)=C2C=C1CCC1=CC=C(C(=O)N[C@@H](CC(=C)C(O)=O)C(O)=O)C=C1 NAWXUBYGYWOOIX-SFHVURJKSA-N 0.000 claims description 3
- 238000004590 computer program Methods 0.000 description 10
- 230000008033 biological extinction Effects 0.000 description 6
- 238000010586 diagram Methods 0.000 description 6
- 238000012545 processing Methods 0.000 description 6
- 238000001228 spectrum Methods 0.000 description 6
- 230000006870 function Effects 0.000 description 4
- 230000008569 process Effects 0.000 description 4
- 238000004891 communication Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 230000007274 generation of a signal involved in cell-cell signaling Effects 0.000 description 3
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 2
- 239000005977 Ethylene Substances 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 238000003672 processing method Methods 0.000 description 2
- 101100498160 Mus musculus Dach1 gene Proteins 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000003750 conditioning effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 229940125730 polarisation modulator Drugs 0.000 description 1
- 230000008092 positive effect Effects 0.000 description 1
- 108090000623 proteins and genes Proteins 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000012827 research and development Methods 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/50—Transmitters
- H04B10/516—Details of coding or modulation
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/0136—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour for the control of polarisation, e.g. state of polarisation [SOP] control, polarisation scrambling, TE-TM mode conversion or separation
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/03—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on ceramics or electro-optical crystals, e.g. exhibiting Pockels effect or Kerr effect
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/21—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour by interference
- G02F1/212—Mach-Zehnder type
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/35—Non-linear optics
- G02F1/353—Frequency conversion, i.e. wherein a light beam is generated with frequency components different from those of the incident light beams
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/50—Transmitters
- H04B10/501—Structural aspects
- H04B10/503—Laser transmitters
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/60—Receivers
- H04B10/61—Coherent receivers
- H04B10/615—Arrangements affecting the optical part of the receiver
- H04B10/6151—Arrangements affecting the optical part of the receiver comprising a polarization controller at the receiver's input stage
Landscapes
- Physics & Mathematics (AREA)
- Nonlinear Science (AREA)
- Optics & Photonics (AREA)
- Engineering & Computer Science (AREA)
- General Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Chemical & Material Sciences (AREA)
- Ceramic Engineering (AREA)
- Crystallography & Structural Chemistry (AREA)
- Optical Communication System (AREA)
Abstract
The invention belongs to the technical field of photoelectronic devices and microwave photons, and discloses a duty ratio adjustable rectified cosine microwave signal generator, a method and equipment. The duty ratio-adjustable rectified cosine microwave signal generator comprises a continuous wave laser, a polarization controller, a radio frequency signal source, an electric splitter, an electric amplifier, a first electric phase shifter, a second electric phase shifter, a single-drive Mach-Zehnder modulator with a polarization main shaft as an X axis, a single-drive Mach-Zehnder modulator with a polarization main shaft as a Y axis, a photoelectric detector and a third electric phase shifter. The invention realizes the generation of the rectified cosine microwave signal with adjustable duty ratio for the first time, and the modulation coefficient of the single-drive Mach-Zehnder modulator with the polarization main shaft as the Y axis does not need to be fixed at a specific value and can be changed in a certain range, thereby increasing the flexibility of the system.
Description
Technical Field
The invention belongs to the technical field of photoelectronic devices and microwave photons, and particularly relates to a duty ratio adjustable rectified cosine microwave signal generator, a method and equipment.
Background
The generation of microwave signals is an important research direction in the field of microwave photonics, and has many applications, such as signal processing, radar, wireless communication systems, and the like. In recent years, researchers have proposed a number of microwave signal generation methods based on microwave photonic technology. In 2013 LiJing et al generated a triangular wave shaped microwave signal using a single driven Mach-zehnder modulator (MZM) (lij., ningt.g., peil., ethylene, photonic-assisted laser reconstruction rate [ J ]. Ieeephotonic technology l,2013,25 (10): 952-4), 2014, liweii et al generated a modulation of the microwave signal based on a double parallel MZM, generating a carrier and an odd-order sideband, a re-filter filtering out the odd-order sideband, and a photodetector to generate triangular and triangular shaped microwave signals (liw., wang.t., zhuhu.h. photonic radio-frequency-basic wave) using a single driven Mach-zehnder modulator (MZM): joh-zehnder modulator [ 1J., je et al (dach). In 2018, heYutong et al generated triangular, saw-tooth and square wave shaped microwave signals using cascaded MZMs with polarization characteristics (HeY.T., jiangY., ziY.J., ethylene, photonic microwave wave for generating microwave signals [ J ]. OptExpress,2018,26 (6): 7829-41). However, the duty ratio of the signal generated by the scheme is not adjustable, the modulation index of the MZM needs to be fixed at a specific value, the scheme is not flexible enough and the model of the rectified cosine microwave cannot be generated.
In 2022, chen xiaoyu et al realized a duty cycle adjustable triangular and square wave shaped microwave signal generation scheme (chenx.y., lig.y., shid.f., et al. Photonics conversion of a rectangular and rectangular microwave generator [ J ]. Ieeephotonics technol, 2022,34 (7): 4.). In the scheme, MZM is used for modulating radio frequency signals, the modulation signals are divided into two paths of optical signals, one path of optical signals is used for adjusting the amplitude of the optical signals by using an optical attenuator, and the other path of optical signals is used for adjusting the phase of the optical signals by using a dimmable delay line. When a proper direct current bias voltage and delay quantity of the MZM are set, triangular and square wave signals with adjustable duty ratio can be obtained, but the scheme can not obtain rectified cosine microwave signals with adjustable duty ratio.
In 2021, kumarR et al proposed a scheme for generating microwave signals of full-wave rectified sine and half-wave rectified sine
(Kumarr., raghowanshi S.K. Photonic Gene administration of multiple Shapesand SextupleMicrowave SignalBasedon polarization Modulator [ J ]. Ieee TMicrowThe 2021,69 (8): 3875-82.). The scheme is based on that a polarization MZM working at the maximum transmission point modulates a radio frequency signal to generate sidebands of each order, sets appropriate system parameters, and obtains full-wave rectification sine and half-wave rectification sine microwave signals after photoelectric detection.
Through the above analysis, the problems and defects of the prior art are as follows:
(1) The duty ratio of the rectified sinusoidal signal generated by the prior art is not adjustable, and the full-wave rectified sinusoidal signal or the half-wave rectified sinusoidal signal can only be fixedly obtained;
(2) In order to obtain half-wave rectified and full-wave rectified sinusoidal signals, the prior art needs to set the modulation index of the polarization MZM to be a fixed value, which causes insufficient system flexibility, and if the modulation index of the polarization MZM drifts and changes, the accuracy of the generated microwave signal will be reduced;
(3) The prior art does not generate a duty cycle adjustable rectified cosine signal.
Disclosure of Invention
To overcome the problems in the related art, the embodiments disclosed herein provide a rectified cosine microwave signal generator with adjustable duty ratio, a method and a device.
The technical scheme is as follows: a duty cycle adjustable rectified cosine microwave signal generator comprising:
the output end of the continuous wave laser is connected with the input end of the polarization controller;
the output end of the polarization controller is connected with the optical input end of the single-drive Mach-Zehnder modulator with the polarization main shaft as the X axis; the output end of the radio frequency signal source is connected with the input end of the power divider, and the output end of the power divider is respectively connected with the input ends of the power amplifier and the second electric phase shifter;
the output end of the electric amplifier is connected with the input end of a first electric phase shifter, and the output end of the first electric phase shifter is connected with the radio frequency signal input end of a single-drive Mach-Zehnder modulator with the polarization main shaft as the X axis; the output end of the second electric phase shifter is connected with the radio frequency signal input end of the single-drive Mach-Zehnder modulator with the polarization main shaft as the Y axis, and the optical signal output end of the single-drive Mach-Zehnder modulator with the polarization main shaft as the X axis is connected with the optical signal input end of the single-drive Mach-Zehnder modulator with the polarization main shaft as the Y axis; and the optical signal output end of the single-drive Mach-Zehnder modulator with the polarization main shaft as the Y axis is connected with the optical input end of the photoelectric detector, and the output end of the photoelectric detector is connected with the input end of the third electric phase shifter.
In one embodiment, the continuous wave laser and the polarization controller are connected with a single-drive Mach-Zehnder modulator with a polarization main axis of an X axis, the single-drive Mach-Zehnder modulator with the polarization main axis of the X axis and the single-drive Mach-Zehnder modulator with the polarization main axis of a Y axis are connected with the photoelectric detector through optical fibers; the radio frequency signal source and the electric power divider, the electric power divider and the electric amplifier, the electric power divider and the second electric phase shifter, the electric amplifier and the first electric phase shifter, the first electric phase shifter and the single-drive Mach-Zehnder modulator with the polarization main shaft as the X axis, the second electric phase shifter and the single-drive Mach-Zehnder modulator with the polarization main shaft as the Y axis, and the photoelectric detector and the third electric phase shifter are all connected by radio frequency lines.
Another objective of the present invention is to provide a method for generating a rectified cosine microwave signal with an adjustable duty cycle, comprising:
firstly, a polarization controller controls the polarization direction of an optical signal;
step two, the polarization controller outputs optical signals to enter a single-drive Mach-Zehnder modulator with a polarization main shaft as an X axis, and an output optical field of the single-drive Mach-Zehnder modulator with the polarization main shaft as the X axis is obtained;
thirdly, based on the output light field of the single-drive Mach-Zehnder modulator with the polarization main shaft as the X axis obtained in the second step, the output light field enters the single-drive Mach-Zehnder modulator with the polarization main shaft as the Y axis, and the output light field of the single-drive Mach-Zehnder modulator with the polarization main shaft as the Y axis is obtained;
enabling an optical signal output by the single-drive Mach-Zehnder modulator with the polarization main axis being the Y axis to enter the photoelectric detector for beat frequency, wherein when the optical signal is beat frequency, an output signal of the photoelectric detector is the superposition of a beat frequency result in the X polarization direction and a beat frequency result in the Y polarization direction;
step five, under the condition of small signal modulation, the electric signal output by the photoelectric detector passes through a third electric phase shifter to obtain a microwave signal; by adjusting theta for phase relation of each harmonic 1 ，θ 2 And theta 3 And generating a rectified cosine microwave signal with the duty ratio of 1/A.
Further, in the first step, the optical signal emitted by the continuous wave laser enters the single-drive mach-zehnder modulator whose polarization main axis is the X axis after passing through the polarization controller, and the output optical field of the continuous wave laser is set as E (t) = E 0 exp(jω 0 t)，E 0 And ω 0 Respectively representing the amplitude and angular frequency of the output light field; the included angle between the polarization controller and the X axis is alpha, then the output optical signal of the polarization controller is
Further, in the second step, when the optical signal of the polarization controller is input to the single-drive mach-zehnder modulator whose polarization principal axis is the X axis, since the polarization principal axis of the single-drive mach-zehnder modulator whose polarization principal axis is the X axis, only the light polarized in the X direction among the optical signals output by the polarization controller is modulated by the single-drive mach-zehnder modulator whose polarization principal axis is the X axis, and the optical signal in the Y direction directly passes through the single-drive mach-zehnder modulator whose polarization principal axis is the X axis; the single-drive Mach-Zehnder modulator with the polarization main axis as the X axis is arranged to work at an orthogonal transmission point, the expression of the radio-frequency signal output by the radio-frequency signal source is V (t) = Vsin (ω t), V and ω represent the amplitude and angular frequency of the radio-frequency signal, and then the output optical field of the single-drive Mach-Zehnder modulator with the polarization main axis as the X axis is represented as
Wherein m is 1 ＝gπV/2V π The modulation index of a single-drive Mach-Zehnder modulator with polarization principal axis as X axis, g the amplification factor of an electric amplifier, and V π Half-wave voltage, θ, for a single-drive Mach-Zehnder modulator having a principal axis of polarization as the X-axis 1 The phase shift introduced for the first electrical phase shifter.
Further, in step three, the output light field of the single-drive mach-zehnder modulator with the polarization main axis of the X-axis enters the single-drive mach-zehnder modulator with the polarization main axis of the Y-axis, only the light with the Y-polarization is modulated by the single-drive mach-zehnder modulator with the polarization main axis of the Y-axis, the single-drive mach-zehnder modulator with the polarization main axis of the Y-axis is set to work at the minimum transmission point, and the output light field is expressed as
Wherein m is 2 ＝πV/2V π Modulation index, theta, of a single-drive Mach-Zehnder modulator having a principal axis of polarization as the Y-axis 2 The phase shift introduced for the second electrical phase shifter.
Further, in step four, the optical signal output by the single-drive mach-zehnder modulator whose polarization main axis is the Y axis enters the photodetector to beat, when the optical signal beats, only the optical signal with the same polarization direction can beat, the output signal of the photodetector is the superposition of the beat result in the X polarization direction and the beat result in the Y polarization direction, and the output electrical signal is:
further, in step five, in the case of small signal modulation, only the third-order sidebands are analyzed, and the electrical signal output by the photodetector is represented as
Wherein DC is a direct current term; after passing through the third electric phase shifter, the obtained microwave signal has the expression of
For a rectified cosine signal, the expression y = | cos (ω) s T) |, period T s ＝T/2＝π/ω s For a rectified cosine signal with a duty cycle of η =1/A (A ≧ 1), the expression is
Expanding f (t) into a Fourier series of
Where dc is a direct current term, a n Is coefficient of Fourier series, and is expressed as
The first harmonic and the second harmonic are taken,
f(t)∝a 1 cos(2ω s t)+a 2 cos(4ω s t)+a 3 cos(6ω s t) (10)
as can be seen by comparing the formula (6) and the formula (10), the phase relationship of each harmonic is adjusted by θ 1 ，θ 2 And theta 3 Generating a rectified cosine microwave signal with a duty ratio of 1/A; the coefficients of the harmonics should satisfy the following equation
Further, for a given duty cycle of 1/A, a is calculated according to equation (9) 2 /a 1 And a 3 /a 1 (ii) a According to equation (12), solve for m 1 In equation (11), the right side a 2 /a 1 Is a known value, with two variables m on the left 2 And α, when solving the equation, m is specified 2 Then the angle alpha of the polarization controller is calculated when the modulation index m is 2 When the value of (b) is changed, equation (11) holds by adjusting the angle α of the polarization controller.
Another object of the present invention is to provide a signal processing method, a radar apparatus, and a wireless communication apparatus, wherein the signal processing method, the radar apparatus, and the wireless communication apparatus implement a rectified cosine microwave signal generation method with an adjustable duty cycle.
By combining all the technical schemes, the invention has the advantages and positive effects that:
first, aiming at the technical problems existing in the prior art and the difficulty in solving the problems, the technical problems to be solved by the technical scheme of the present invention are closely combined with results, data and the like in the research and development process, and some creative technical effects are brought after the problems are solved. The specific description is as follows:
in order to solve the problems in the background art, the invention provides a duty ratio-adjustable rectified cosine signal generator which can realize the generation of a rectified cosine microwave signal by changing 4 variable quantities based on two cascaded polarization MZMs by using a microwave photon technology and has an adjustable duty ratio.
Secondly, considering the technical solution as a whole or from the perspective of products, the technical effects and advantages of the technical solution to be protected by the present invention are specifically described as follows:
the single-drive Mach-Zehnder modulator is simple in structure, the generation of the rectified cosine microwave signals with the adjustable duty ratio is realized for the first time by utilizing the electro-optical modulation principle, the modulation coefficient of the single-drive Mach-Zehnder modulator with the Y-axis polarization main shaft is not required to be fixed at a specific value and can be changed within a certain range, and the flexibility of the system is improved.
Thirdly, as a creative auxiliary evidence of the claims of the invention, the technical scheme of the invention fills the technical blank in the industry at home and abroad: firstly, an optical method is adopted to generate a rectified cosine microwave signal with adjustable duty ratio.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and together with the description, serve to explain the principles of the disclosure.
Fig. 1 is a schematic structural diagram of a rectified cosine microwave signal generator with adjustable duty ratio according to an embodiment of the present invention;
FIG. 2 is a waveform diagram of a rectified cosine signal with a period of T/2 and a duty ratio of 1/A according to an embodiment of the present invention;
fig. 3 is a time domain diagram of a rectified cosine microwave signal with a duty cycle of 100% (a = 1) according to an embodiment of the present invention;
fig. 4 is a graph of a spectrum of a rectified cosine microwave signal with a duty cycle of 100% (a = 1) according to an embodiment of the present invention;
fig. 5 is a time domain diagram of a rectified cosine microwave signal with a duty cycle of 80% (a = 1.25) according to an embodiment of the present invention;
fig. 6 is a spectrum diagram of a rectified cosine microwave signal with a duty cycle of 80% (a = 1.25) according to an embodiment of the present invention;
fig. 7 is a time domain diagram of a rectified cosine microwave signal with a duty cycle of 50% (a = 2) according to an embodiment of the present invention;
fig. 8 is a graph of a spectrum of a rectified cosine microwave signal with a duty cycle of 50% (a = 2) according to an embodiment of the present invention;
in the figure: 1. a continuous wave laser; 2. a polarization controller; 3. a radio frequency signal source; 4. an electric power divider; 5. an electrical amplifier; 6. a first electrical phase shifter; 7. a second electrical phase shifter; 8. a single-drive Mach-Zehnder modulator with a polarization main axis as an X axis; 9. a single-drive Mach-Zehnder modulator with a polarization main axis as a Y axis; 10. a photodetector; 11. a third electric phase shifter.
Detailed Description
In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, but rather should be construed as broadly as the present invention is capable of modification in various respects, all without departing from the spirit and scope of the present invention.
1. Illustrative examples are illustrated:
the embodiment of the invention provides a method for generating a rectified cosine microwave signal with an adjustable duty ratio, which comprises the following steps:
firstly, a polarization controller controls the polarization direction of an optical signal;
step two, the polarization controller outputs optical signals to enter a single-drive Mach-Zehnder modulator with a polarization main shaft as an X axis, and an output optical field of the single-drive Mach-Zehnder modulator with the polarization main shaft as the X axis is obtained;
thirdly, based on the output light field of the single-drive Mach-Zehnder modulator with the polarization main shaft as the X axis obtained in the second step, the output light field enters the single-drive Mach-Zehnder modulator with the polarization main shaft as the Y axis, and the output light field of the single-drive Mach-Zehnder modulator with the polarization main shaft as the Y axis is obtained;
enabling the optical signal output by the single-drive Mach-Zehnder modulator with the polarization main axis being the Y axis to enter a photoelectric detector for beat frequency, wherein when the optical signal is beat frequency, the output signal of the photoelectric detector is the superposition of the beat frequency result in the X polarization direction and the beat frequency result in the Y polarization direction;
step five, under the condition of small signal modulation, the electric signal output by the photoelectric detector passes through a third electric phase shifter to obtain a microwave signal; by adjusting theta for the phase relation of each harmonic 1 ，θ 2 And theta 3 And generating a rectified cosine microwave signal with the duty ratio of 1/A.
Example 1
As shown in fig. 1, an embodiment of the present invention provides a rectified cosine microwave signal generator with an adjustable duty ratio, which includes a continuous wave laser 1, a polarization controller 2, a radio frequency signal source 3, an electrical power divider 4, an electrical amplifier 5, a first electrical phase shifter 6, a second electrical phase shifter 7, a single-drive mach-zehnder modulator 8 whose polarization main axis is an X axis, a single-drive mach-zehnder modulator 9 whose polarization main axis is a Y axis, a photodetector 10, and a third electrical phase shifter 11.
The output end of the continuous wave laser 1 is connected with the input end of the polarization controller 2. The output of the polarization controller 2 is connected to the optical input of a single-drive mach-zehnder modulator 8 having a principal axis of polarization as the X-axis. The output end of the radio frequency signal source 3 is connected with the input end of the power divider 4, and the output end of the power divider 4 is respectively connected with the input ends of the power amplifier 5 and the second electric phase shifter 7. The output end of the electric amplifier 5 is connected with the input end of the first electric phase shifter 6, the output end of the first electric phase shifter 6 is connected with the radio frequency signal input end of the single-drive Mach-Zehnder modulator 8 with the polarization main axis as the X axis, the output end of the second electric phase shifter 7 is connected with the radio frequency signal input end of the single-drive Mach-Zehnder modulator 9 with the polarization main axis as the Y axis, the optical signal output end of the single-drive Mach-Zehnder modulator 8 with the polarization main axis as the X axis is connected with the optical signal input end of the single-drive Mach-Zehnder modulator 9 with the polarization main axis as the Y axis, the optical signal output end of the single-drive Mach-Zehnder modulator 9 with the polarization main axis as the Y axis is connected with the optical input end of the photoelectric detector 10, and the output end of the photoelectric detector 10 is connected with the input end of the third electric phase shifter 11.
The continuous wave laser 1 is connected with a polarization controller 2, the polarization controller 2 is connected with a single-drive Mach-Zehnder modulator 8 with a polarization main shaft as an X axis, the single-drive Mach-Zehnder modulator 8 with the polarization main shaft as the X axis is connected with a single-drive Mach-Zehnder modulator 9 with the polarization main shaft as a Y axis, the single-drive Mach-Zehnder modulator 9 with the polarization main shaft as the Y axis is connected with a photoelectric detector 10 through optical fibers, a radio frequency signal source 3 is connected with an electric power divider 4, the electric power divider 4 is connected with an electric amplifier 5, the electric power divider 4 is connected with a second electric phase shifter 7, the electric amplifier 5 is connected with a first electric phase shifter 6, the first electric phase shifter 6 is connected with the single-drive Mach-Zehnder modulator 8 with the polarization main shaft as the X axis, the second electric phase shifter 7 is connected with the single-drive Mach-Zehnder modulator 9 with the polarization main shaft as the Y axis, and the photoelectric detector 10 is connected with a third electric phase shifter 11 through radio frequency wires.
In the embodiment of the present invention, an optical signal emitted by a continuous wave laser 1 passes through a polarization controller 2 and then enters a single-drive mach-zehnder modulator 8 whose polarization main axis is an X axis, and it is assumed that an output optical field of the continuous wave laser 1 is E (t) = E 0 exp(jω 0 t)，E 0 And ω 0 Representing the amplitude and angular frequency of the output light field, respectively. The included angle between the polarization controller 2 and the X axis is alpha, then the output optical signal of the polarization controller 2 is
When the optical signal of the polarization controller 2 is input to the single-drive mach-zehnder modulator 8 whose polarization main axis is the X axis, since the polarization main axis of the single-drive mach-zehnder modulator 8 whose polarization main axis is the X axis, only the light polarized in the X direction among the optical signals output from the polarization controller 2 is modulated by the single-drive mach-zehnder modulator 8 whose polarization main axis is the X axis, and the optical signal in the Y direction directly passes through the single-drive mach-zehnder modulator 8 whose polarization main axis is the X axis. The single-drive mach-zehnder modulator 8 with the polarization main axis as the X axis is set to operate at the orthogonal transmission point, the expression of the radio-frequency signal output by the radio-frequency signal source 3 is V (t) = Vsin (ω t), and V and ω represent the amplitude and angular frequency of the radio-frequency signal, so that the output optical field of the single-drive mach-zehnder modulator 8 with the polarization main axis as the X axis can be expressed as
Wherein m is 1 ＝gπV/2V π The modulation index of a single-drive Mach-Zehnder modulator 8 with its polarization principal axis as X-axis, g the amplification factor of the electrical amplifier 5, V π Half-wave voltage, theta, of a single-drive Mach-Zehnder modulator 8 having a principal axis of polarization as the X-axis 1 The phase shift introduced for the first electrical phase shifter 6. The output light field of the single-drive Mach-Zehnder modulator 8 with the polarization main axis of the X axis enters the single-drive Mach-Zehnder modulator 9 with the polarization main axis of the Y axis, at the moment, only the Y-polarized light is modulated by the single-drive Mach-Zehnder modulator 9 with the polarization main axis of the Y axis, the single-drive Mach-Zehnder modulator 9 with the polarization main axis of the Y axis is arranged to work at the minimum transmission point, and the output light field can be expressed as
Wherein m is 2 ＝πV/2V π Modulation index, theta, of a single-drive Mach-Zehnder modulator 9 having a principal axis of polarization as the Y-axis 2 The phase shift introduced for the second electrical phase shifter 7. The optical signal output by the single-drive mach-zehnder modulator 9 with the polarization main axis being the Y axis enters the photodetector 10 for beat frequency, and when the optical signal beats frequency, only the optical signal with the same polarization direction can beat frequency, so the output signal of the photodetector 10 is the superposition of the beat frequency result in the X polarization direction and the beat frequency result in the Y polarization direction, and the output electrical signal is:
in the case of small signal modulation, analyzing only the third-order sidebands, the electrical signal output by the photodetector 10 can be approximated as
Where DC is the direct current term. After passing through the third electric phase shifter 11, the obtained microwave signal has the expression
For a rectified cosine signal, the expression y = | cos (ω) s T) |, period T s ＝T/2＝π/ω s For a rectified cosine signal with a duty cycle of η =1/A (A ≧ 1), the expression is
The signal waveform is shown in fig. 2. Expanding f (t) into Fourier series of
Where dc is the direct current term, a n Coefficient of Fourier series, expressed as
The first harmonic and the second harmonic are taken,
f(t)∝a 1 cos(2ω s t)+a 2 cos(4ω s t)+a 3 cos(6ω s t) (10)
comparing the formula (6) and the formula (10), it can be seen that in order to generate the rectified cosine microwave signal with the duty ratio of 1/A, the phase relationship of each harmonic can be adjusted by adjusting theta 1 ，θ 2 And theta 3 To be implemented. The coefficients of the harmonics need to satisfy the following equations
Wherein m is 1 ＝gπV/2V π Modulation index, m, of a single-drive Mach-Zehnder modulator 8 having a principal axis of polarization as the X-axis 2 ＝πV/2V π Modulation index, J, of a single-drive Mach-Zehnder modulator 9 having a principal axis of polarization as the Y-axis n () The polarization angle α, a of the polarization controller 2 being a Bessel function of order n of the first kind 1 Is the amplitude of the 1 st harmonic wave, a 2 Is the 2 nd harmonic amplitude.
For a given duty cycle of 1/A, a can be calculated according to equation (9) 2 /a 1 And a 3 /a 1 . From equation (12), m can be solved 1 In equation (11), the right side a 2 /a 1 Is a known value, with two variables m on the left 2 And α, m can be specified when solving the equation 2 Then the angle alpha of the polarization controller 2 is calculated when the modulation index m is 2 When the value of the modulation index m is changed, the equation (11) can be satisfied by adjusting the angle α of the polarization controller 2, which also means that the modulation index m of the single-drive mach-zehnder modulator 9 with the polarization main axis being the Y axis in the rectified cosine microwave signal generator with the adjustable duty cycle provided by the present invention 2 And the setting is not required to be a specific value, so that the flexibility of the system is increased.
Example 2
The embodiment of the present invention provides a rectified cosine microwave signal generator with adjustable duty ratio, as shown in fig. 1, the system includes: the generator comprises a continuous wave laser 1, a polarization controller 2, a radio frequency signal source 3, an electric power divider 4, an electric amplifier 5, a first electric phase shifter 6, a second electric phase shifter 7, a single-drive Mach-Zehnder modulator 8 with a polarization main shaft of an X axis, a single-drive Mach-Zehnder modulator 9 with a polarization main shaft of a Y axis, a photoelectric detector 10 and a third electric phase shifter 11. The output end of the continuous wave laser 1 is connected with the input end of the polarization controller 2. The output of the polarization controller 2 is connected to the optical input of a single-drive mach-zehnder modulator 8 whose polarization principal axis is the X-axis. The output end of the radio frequency signal source 3 is connected with the input end of the electric power divider 4, and the output end of the electric power divider 4 is respectively connected with the input ends of the electric amplifier 5 and the electric second phase shifter 7. The output end of the electric amplifier 5 is connected with the input end of the first electric phase shifter 6, the output end of the first electric phase shifter 6 is connected with the radio-frequency signal input end of the single-drive Mach-Zehnder modulator 8 with the polarization main axis of the X axis, the output end of the second electric phase shifter 7 is connected with the radio-frequency signal input end of the single-drive Mach-Zehnder modulator 9 with the polarization main axis of the Y axis, the optical signal output end of the single-drive Mach-Zehnder modulator 8 with the polarization main axis of the X axis is connected with the optical signal input end of the single-drive Mach-Zehnder modulator 9 with the polarization main axis of the Y axis, the optical signal output end of the single-drive Mach-Zehnder modulator 9 with the polarization main axis of the Y axis is connected with the optical input end of the photoelectric detector 10, and the output end of the photoelectric detector 10 is connected with the input end of the third electric phase shifter 11.
The power of the continuous wave laser 1 is set to 0dBm, the wavelength is set to 1553.32nm, the half-wave voltage of the single-drive mach-zehnder modulator 8 with the polarization main axis as the X axis is 4V, the extinction ratio is 30dB, the continuous wave laser is set at the orthogonal transmission point, the half-wave voltage of the single-drive mach-zehnder modulator 9 with the polarization main axis as the Y axis is 4V, the extinction ratio is 30dB, and the continuous wave laser is set at the minimum transmission point.
The frequency of the radio frequency signal output by the radio frequency signal source 3 is 10GHz, the amplitude is 4V, and m can be calculated 2 =0.5, the amplification g of the electrical power amplifier 5 is set to 1.35, when m 1 ＝0.675。
The resulting rectified cosine microwave signal with a duty cycle of 100% (a = 1) is calculated from equation (9) 1 ，a 2 ，a 3 The values of (a) are 0.4244, -0.0849,0.0364, respectively, it can be calculated that the power difference between the 1 st harmonic and the 2 nd harmonic is 20 × log10 (0.4244/0.0849) =13.9774db, and the power difference between the 2 nd harmonic and the 3 rd harmonic is 20 × log10 (0.0849/0.0364) =7.3561dB.
The polarization angle α of the polarization controller 2 was set to 43.2 degrees, and the phase shift amount θ of the first electric phase shifter 6 was set 1 Is 0 degree, the phase shift amount theta of the second electric phase shifter 7 2 At-45 deg.C, a third electromigrationPhase shift amount θ of the phase detector 11 3 Is 90 degrees. The resulting time domain plot of the rectified cosine microwave signal with a duty cycle of 100% (a = 1) is shown in fig. 3, and the spectrum is shown in fig. 4.
Example 3
The embodiment of the present invention provides a rectified cosine microwave signal generator with adjustable duty ratio, as shown in fig. 1, the system includes: the generator comprises a continuous wave laser 1, a polarization controller 2, a radio frequency signal source 3, an electric power divider 4, an electric amplifier 5, a first electric phase shifter 6, a second electric phase shifter 7, a single-drive Mach-Zehnder modulator 8 with a polarization main shaft of an X axis, a single-drive Mach-Zehnder modulator 9 with a polarization main shaft of a Y axis, a photoelectric detector 10 and a third electric phase shifter 11. The output end of the continuous wave laser 1 is connected with the input end of the polarization controller 2. The output of the polarization controller 2 is connected to the optical input of a single-drive mach-zehnder modulator 8 whose polarization principal axis is the X-axis. The output end of the radio frequency signal source 3 is connected with the input end of the electric power divider 4, and the output end of the electric power divider 4 is respectively connected with the input ends of the electric amplifier 5 and the electric second phase shifter 7. The output end of the electric amplifier 5 is connected with the input end of the first electric phase shifter 6, the output end of the first electric phase shifter 6 is connected with the radio-frequency signal input end of the single-drive Mach-Zehnder modulator 8 with the polarization main axis of the X axis, the output end of the second electric phase shifter 7 is connected with the radio-frequency signal input end of the single-drive Mach-Zehnder modulator 9 with the polarization main axis of the Y axis, the optical signal output end of the single-drive Mach-Zehnder modulator 8 with the polarization main axis of the X axis is connected with the optical signal input end of the single-drive Mach-Zehnder modulator 9 with the polarization main axis of the Y axis, the optical signal output end of the single-drive Mach-Zehnder modulator 9 with the polarization main axis of the Y axis is connected with the optical input end of the photoelectric detector 10, and the output end of the photoelectric detector 10 is connected with the input end of the third electric phase shifter 11.
The power of the continuous wave laser 1 is set to 0dBm, the wavelength is set to 1553.32nm, the half-wave voltage of the single-drive mach-zehnder modulator 8 with the polarization main axis as the X axis is 4V, the extinction ratio is 30dB, the continuous wave laser is set at the orthogonal transmission point, the half-wave voltage of the single-drive mach-zehnder modulator 9 with the polarization main axis as the Y axis is 4V, the extinction ratio is 30dB, and the continuous wave laser is set at the minimum transmission point.
Radio frequency signal source 3 outputThe frequency of the radio frequency signal is 10GHz, the amplitude is 4V, and m can be calculated 2 =0.5, the amplification g of the electrical power amplifier 5 is set to 0.79, when m 1 ＝0.38。
A to generate a rectified cosine microwave signal with a duty cycle of 80% (a = 1.25) calculated according to equation (9) 1 ，a 2 ，a 3 Are 0.5282, -0.0341,0.0143, respectively, it can be calculated that the power difference between the 1 st harmonic and the 2 nd harmonic is 20 × log10 (0.5282/0.0341) =23.8009db, and the power difference between the 2 nd harmonic and the 3 rd harmonic is 20 × log10 (0.0341/0.0143) =7.5484dB.
The polarization angle α of the polarization controller 2 was set to 24.3 degrees, and the phase shift amount θ of the first electric phase shifter 6 was set 1 Is 90 degrees, the phase shift amount theta of the second electric phase shifter 7 2 The phase shift amount theta of the third electric phase shifter 11 is set to 0 degree 3 Is 0 degrees. The resulting time domain plot of the rectified cosine microwave signal with a duty cycle of 80% (a = 1.25) is shown in fig. 5 and the spectrum is shown in fig. 6.
Example 4
The embodiment of the present invention provides a rectified cosine microwave signal generator with adjustable duty ratio, as shown in fig. 1, the system includes: the generator comprises a continuous wave laser 1, a polarization controller 2, a radio frequency signal source 3, an electric power divider 4, an electric amplifier 5, a first electric phase shifter 6, a second electric phase shifter 7, a single-drive Mach-Zehnder modulator 8 with a polarization main shaft of an X axis, a single-drive Mach-Zehnder modulator 9 with a polarization main shaft of a Y axis, a photoelectric detector 10 and a third electric phase shifter 11. The output end of the continuous wave laser 1 is connected with the input end of the polarization controller 2. The output of the polarization controller 2 is connected to the optical input of a single-drive mach-zehnder modulator 8 whose polarization principal axis is the X-axis. The output end of the radio frequency signal source 3 is connected with the input end of the electric power divider 4, and the output end of the electric power divider 4 is respectively connected with the input ends of the electric amplifier 5 and the electric second phase shifter 7. The output end of the electric amplifier 5 is connected with the input end of the first electric phase shifter 6, the output end of the first electric phase shifter 6 is connected with the radio frequency signal input end of the single-drive Mach-Zehnder modulator 8 with the polarization main axis as the X axis, the output end of the second electric phase shifter 7 is connected with the radio frequency signal input end of the single-drive Mach-Zehnder modulator 9 with the polarization main axis as the Y axis, the optical signal output end of the single-drive Mach-Zehnder modulator 8 with the polarization main axis as the X axis is connected with the optical signal input end of the single-drive Mach-Zehnder modulator 9 with the polarization main axis as the Y axis, the optical signal output end of the single-drive Mach-Zehnder modulator 9 with the polarization main axis as the Y axis is connected with the optical input end of the photoelectric detector 10, and the output end of the photoelectric detector 10 is connected with the input end of the third electric phase shifter 11.
The power of the continuous wave laser 1 is set to 0dBm, the wavelength is set to 1553.32nm, the half-wave voltage of the single-drive mach-zehnder modulator 8 with the polarization main axis as the X axis is 4V, the extinction ratio is 30dB, the continuous wave laser is set at the orthogonal transmission point, the half-wave voltage of the single-drive mach-zehnder modulator 9 with the polarization main axis as the Y axis is 4V, the extinction ratio is 30dB, and the continuous wave laser is set at the minimum transmission point.
The frequency of the radio frequency signal output by the radio frequency signal source 3 is 10GHz, the amplitude is 4V, and m can be calculated 2 =0.5, the amplification g of the electrical power amplifier 5 is set to 0.5, when m 1 ＝0.25。
A to generate a rectified cosine microwave signal with a duty cycle of 50% (a = 2), calculated according to equation (9) 1 ，a 2 ，a 3 Is 0.5,0.2122,0, the power difference between the 1 st harmonic and the 2 nd harmonic can be calculated to be 20 × log10 (0.5/0.2122) =7.4445dB.
The polarization angle α of the polarization controller 2 was set to 43.4 degrees, and the phase shift amount θ of the first electric phase shifter 6 was set 1 The phase shift amount theta of the second electric phase shifter 7 is 270 degrees 2 The phase shift amount theta of the third electric phase shifter 11 is set to 0 degree 3 Is 180 degrees. The resulting time domain plot of the rectified cosine microwave signal with a duty cycle of 50% (a = 2) is shown in fig. 7, and the spectrum is shown in fig. 8.
In the above embodiments, the descriptions of the respective embodiments have respective emphasis, and reference may be made to the related descriptions of other embodiments for parts that are not described or illustrated in a certain embodiment.
For the information interaction, execution process and other contents between the above devices/units, the specific functions and technical effects brought by the method embodiments of the present invention based on the same concept can be referred to the method embodiments, and are not described herein again.
It will be apparent to those skilled in the art that, for convenience and brevity of description, only the above-mentioned division of the functional units and modules is illustrated, and in practical applications, the above-mentioned function distribution may be performed by different functional units and modules according to needs, that is, the internal structure of the apparatus is divided into different functional units or modules to perform all or part of the above-mentioned functions. Each functional unit and module in the embodiments may be integrated in one processing unit, or each unit may exist alone physically, or two or more units are integrated in one unit, and the integrated unit may be implemented in a form of hardware, or in a form of software functional unit. In addition, specific names of the functional units and modules are only used for distinguishing one functional unit from another, and are not used for limiting the protection scope of the present invention. The specific working processes of the units and modules in the system may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.
2. The application example is as follows:
application example 1
The rectified cosine microwave signal generator with adjustable duty ratio provided based on the above embodiment can be applied to computer equipment, and the computer equipment comprises: at least one processor, a memory, and a computer program stored in the memory and executable on the at least one processor, the processor implementing the signal conditioning principle in the duty cycle adjustable rectified cosine microwave signal generator provided in any of the above embodiments when executing the computer program.
Application example 2
The rectified cosine microwave signal generator with adjustable duty ratio provided based on the above embodiments may be applied to a computer-readable storage medium, where a computer program is stored, and when being executed by a processor, the computer program may implement the signal adjustment principle in the rectified cosine microwave signal generator with adjustable duty ratio provided in any of the above embodiments.
Application example 3
The duty ratio-adjustable rectified cosine microwave signal generator provided based on the above embodiments can be applied to an information data processing terminal, where the information data processing terminal is configured to provide a user input interface to implement the signal adjustment principle in the duty ratio-adjustable rectified cosine microwave signal generator provided in any of the above embodiments when the information data processing terminal is implemented on an electronic device, and the information data processing terminal is not limited to a mobile phone, a computer, or an exchange.
Application example 4
The rectified cosine microwave signal generator with adjustable duty ratio provided based on the above embodiments may be applied to a server, where the server is configured to provide a user input interface to implement the signal adjustment principle in the rectified cosine microwave signal generator with adjustable duty ratio provided in the above embodiments when the server is implemented on an electronic device.
Application example 5
Based on the rectified cosine microwave signal generator with adjustable duty ratio provided by the above embodiments, the generator can be applied to a computer program product, and when the computer program product runs on an electronic device, the signal adjustment principle in the rectified cosine microwave signal generator with adjustable duty ratio provided by the above embodiments can be implemented when the electronic device is executed.
The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, all or part of the flow of the method according to the embodiments of the present invention may be implemented by a computer program, which may be stored in a computer-readable storage medium and used for instructing related hardware to implement the steps of the embodiments of the method according to the embodiments of the present invention. Wherein the computer program comprises computer program code, which may be in the form of source code, object code, an executable file or some intermediate form, etc. The computer readable medium may include at least: any entity or device capable of carrying computer program code to a photographing apparatus/terminal apparatus, a recording medium, computer memory, read-only memory (ROM), random Access Memory (RAM), electrical carrier signal, telecommunications signal, and software distribution medium. Such as a usb-disk, a removable hard disk, a magnetic or optical disk, etc.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention, and the scope of the present invention is not limited thereto, and any modification, equivalent replacement, and improvement made by those skilled in the art within the technical scope of the present invention disclosed herein, which is within the spirit and principle of the present invention, should be covered by the present invention.
Claims (10)
1. The duty ratio-adjustable rectified cosine microwave signal generator is characterized by being provided with a continuous wave laser (1), wherein the output end of the continuous wave laser (1) is connected with the input end of a polarization controller (2), and the output end of the polarization controller (2) is connected with the light input end of a single-drive Mach-Zehnder modulator (8) with a polarization main shaft as an X axis; the output end of the radio frequency signal source (3) is connected with the input end of the power divider (4), and the output end of the power divider (4) is respectively connected with the input ends of the power amplifier (5) and the second electric phase shifter (7);
the output end of the electric amplifier (5) is connected with the input end of a first electric phase shifter (6), and the output end of the first electric phase shifter (6) is connected with the radio frequency signal input end of a single-drive Mach-Zehnder modulator (8) with the polarization main shaft as an X axis; the output end of the second electric phase shifter (7) is connected with the radio frequency signal input end of a single-drive Mach-Zehnder modulator (9) with a polarization main shaft as a Y axis, and the optical signal output end of a single-drive Mach-Zehnder modulator (8) with a polarization main shaft as an X axis is connected with the optical signal input end of the single-drive Mach-Zehnder modulator (9) with a polarization main shaft as a Y axis; the optical signal output end of the single-drive Mach-Zehnder modulator (9) with the polarization main shaft as the Y axis is connected with the optical input end of the photoelectric detector (10), and the output end of the photoelectric detector (10) is connected with the input end of the third electric phase shifter (11).
2. The duty ratio adjustable rectified cosine microwave signal generator according to claim 1, wherein the continuous wave laser (1) and the polarization controller (2) are connected by optical fibers, the polarization controller (2) and the single-drive mach-zehnder modulator (8) having the polarization main axis of X are connected by optical fibers, the single-drive mach-zehnder modulator (8) having the polarization main axis of X and the single-drive mach-zehnder modulator (9) having the polarization main axis of Y are connected by optical fibers, and the single-drive mach-zehnder modulator (9) having the polarization main axis of Y and the photodetector (10) are connected by optical fibers;
the radio frequency signal source (3) is connected with the electric power divider (4) through a radio frequency line, the electric power divider (4) is connected with the electric amplifier (5) through a radio frequency line, the electric power divider (4) is connected with the second electric phase shifter (7) through a radio frequency line, the electric amplifier (5) is connected with the first electric phase shifter (6) through a radio frequency line, the first electric phase shifter (6) is connected with the single-drive Mach-Zehnder modulator (8) with the polarization main shaft as the X axis through a radio frequency line, the second electric phase shifter (7) is connected with the single-drive Mach-Zehnder modulator (9) with the polarization main shaft as the Y axis through a radio frequency line, and the photoelectric detector (10) is connected with the third electric phase shifter (11) through a radio frequency line.
3. A method for generating a duty cycle adjustable rectified cosine microwave signal from a duty cycle adjustable rectified cosine microwave signal generator as claimed in any of claims 1-2, wherein the method for generating a duty cycle adjustable rectified cosine microwave signal comprises:
step one, a polarization controller (2) controls the polarization direction of an optical signal;
step two, the polarization controller (2) outputs optical signals to enter the single-drive Mach-Zehnder modulator (8) with the polarization main shaft as the X axis, and the single-drive Mach-Zehnder modulator (8) with the polarization main shaft as the X axis outputs an optical field;
thirdly, based on the output light field of the single-drive Mach-Zehnder modulator (8) with the polarization main shaft as the X axis obtained in the second step, the output light field enters the single-drive Mach-Zehnder modulator (9) with the polarization main shaft as the Y axis, and the output light field of the single-drive Mach-Zehnder modulator (9) with the polarization main shaft as the Y axis is obtained;
fourthly, enabling the optical signal output by the single-drive Mach-Zehnder modulator (9) with the polarization main shaft as the Y axis to enter a photoelectric detector for beat frequency, wherein when the optical signal is beat frequency, the output signal of the photoelectric detector is the superposition of the beat frequency result in the X polarization direction and the beat frequency result in the Y polarization direction;
step five, under the condition of small signal modulation, the electric signal output by the photoelectric detector passes through a third electric phase shifter (11) to obtain a microwave signal; by adjusting theta for phase relation of each harmonic 1 ，θ 2 And theta 3 And generating a rectified cosine microwave signal with the duty ratio of 1/A.
4. The method for generating the duty ratio-adjustable rectified cosine microwave signal according to claim 3, wherein in the first step, the optical signal emitted from the continuous wave laser (1) passes through the polarization controller (2) and then enters the single-drive Mach-Zehnder modulator (8) with the polarization main axis as the X axis, and the output optical field of the continuous wave laser (1) is set as E (t) = E 0 exp(jω 0 t)，E 0 And ω 0 Respectively representing the amplitude and angular frequency of the output light field; the included angle between the polarization controller (2) and the X axis is alpha, so that the output optical signal of the polarization controller (2) is
5. The duty cycle adjustable rectified cosine microwave signal generating method according to claim 3, wherein in the second step, when the optical signal of the polarization controller (2) is inputted into the single-drive Mach-Zehnder modulator (8) whose polarization principal axis is X-axis, only the light polarized in X direction is modulated by the single-drive Mach-Zehnder modulator (8) whose polarization principal axis is X-axis, and the optical signal in Y direction directly passes through the single-drive Mach-Zehnder modulator (8) whose polarization principal axis is X-axis, because the polarization principal axis of the single-drive Mach-Zehnder modulator (8) whose polarization principal axis is X-axis; the single-drive Mach-Zehnder modulator (8) with the polarization main axis as the X axis works at an orthogonal transmission point, the expression of the radio-frequency signal output by the radio-frequency signal source (3) is V (t) = Vsin (ω t), V and ω represent the amplitude and angular frequency of the radio-frequency signal, and then the output optical field of the single-drive Mach-Zehnder modulator (8) with the polarization main axis as the X axis is represented as
Wherein m is 1 ＝gπV/2V π The modulation index of a single-drive Mach-Zehnder modulator (8) with the polarization main axis as the X axis, g is the amplification factor of the electric amplifier (5), and V π Half-wave voltage, theta, of a single-drive Mach-Zehnder modulator (8) having a principal axis of polarization as the X-axis 1 A phase shift introduced for the first electrical phase shifter (6).
6. The method for generating duty cycle adjustable rectified cosine microwave signal according to claim 3, wherein in step three, the output light field of the single-drive Mach-Zehnder modulator (8) with polarization axis of X enters the single-drive Mach-Zehnder modulator (9) with polarization axis of Y, only the light with Y polarization is modulated by the single-drive Mach-Zehnder modulator (9) with polarization axis of Y, the single-drive Mach-Zehnder modulator (9) with polarization axis of Y is set to work at the minimum transmission point, and the output light field is expressed as
Wherein m is 2 ＝πV/2V π Modulation index, theta, of a single-drive Mach-Zehnder modulator (9) having a principal axis of polarization as the Y-axis 2 A phase shift introduced for the second electrical phase shifter (7).
7. The method for generating a duty cycle-adjustable rectified cosine microwave signal according to claim 3, wherein in step four, the optical signal output by the single-drive Mach-Zehnder modulator (9) having a Y-axis polarization principal axis enters the photodetector for beat frequency, when the optical signal is beat frequency, only the optical signal having the same polarization direction can be beat frequency, the output signal of the photodetector is a superposition of the beat frequency result in the X-polarization direction and the beat frequency result in the Y-polarization direction, and the output electrical signal is:
8. method for generating a duty cycle modulated rectified cosine microwave signal as claimed in claim 3, characterized in that in step five, in case of small signal modulation, only the third order sidebands are analyzed and the electrical signal output by the photodetector is represented as
Wherein DC is a direct current term; after passing through a third electric phase shifter (11), the expression of the obtained microwave signal is
For a rectified cosine signal, the expression y = | cos (ω) s T) |, period T s ＝T/2＝π/ω s For a rectified cosine signal with a duty cycle of η =1/A (A ≧ 1), the expression is
Expanding f (t) into a Fourier series of
Where dc is the direct current term, a n Is coefficient of Fourier series expressed as
The first harmonic and the second harmonic are taken,
f(t)∝a 1 cos(2ω s t)+a 2 cos(4ω s t)+a 3 cos(6ω s t) (10)
as can be seen by comparing the formula (6) and the formula (10), the phase relationship of each harmonic is adjusted by θ 1 ，θ 2 And theta 3 Generating a rectified cosine microwave signal with a duty ratio of 1/A; the coefficients of the harmonics need to satisfy the following equations
9. Method for generating a duty cycle adjustable rectified cosine microwave signal as claimed in claim 8, characterized in that for a given duty cycle 1/a, a is calculated according to equation (9) 2 /a 1 And a 3 /a 1 (ii) a According to equation (12), m is solved 1 In equation (11), the right side a 2 /a 1 Is a known value, with two variables m on the left 2 And α, when solving the equation, m is specified 2 Then the angle alpha of the polarization controller (2) is calculated when the modulation index m is 2 When the value of (b) is changed, equation (11) is satisfied by adjusting the angle α of the polarization controller (2).
10. A radar implementing the method of claim 3 for generating a duty cycle modulated rectified cosine microwave signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210648740.0A CN115173949A (en) | 2022-06-09 | 2022-06-09 | Duty ratio adjustable rectification cosine microwave signal generator, method and equipment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210648740.0A CN115173949A (en) | 2022-06-09 | 2022-06-09 | Duty ratio adjustable rectification cosine microwave signal generator, method and equipment |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115173949A true CN115173949A (en) | 2022-10-11 |
Family
ID=83484979
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210648740.0A Pending CN115173949A (en) | 2022-06-09 | 2022-06-09 | Duty ratio adjustable rectification cosine microwave signal generator, method and equipment |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115173949A (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0407919A2 (en) * | 1989-07-11 | 1991-01-16 | Harmonic Lightwaves, Inc. | Optical transmitters linearized by means of parametric feedback |
| CN104717166A (en) * | 2015-03-12 | 2015-06-17 | 华中科技大学 | FSK modulating system based on smoothing modulator |
| WO2021008189A1 (en) * | 2019-07-16 | 2021-01-21 | 南京航空航天大学 | Radar detection method and device based on bandwidth synthesis after microwave photon-assisted dechirping |
| CN112865874A (en) * | 2021-01-12 | 2021-05-28 | 上海交通大学 | Self-adaptive decryption optical encryption transmission system and method based on optical self-interference elimination |
| CN113972953A (en) * | 2020-07-24 | 2022-01-25 | 北京交通大学 | Triangular waveform generator based on two single-drive Mach-Zehnder modulators |
-
2022
- 2022-06-09 CN CN202210648740.0A patent/CN115173949A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0407919A2 (en) * | 1989-07-11 | 1991-01-16 | Harmonic Lightwaves, Inc. | Optical transmitters linearized by means of parametric feedback |
| CN104717166A (en) * | 2015-03-12 | 2015-06-17 | 华中科技大学 | FSK modulating system based on smoothing modulator |
| WO2021008189A1 (en) * | 2019-07-16 | 2021-01-21 | 南京航空航天大学 | Radar detection method and device based on bandwidth synthesis after microwave photon-assisted dechirping |
| CN113972953A (en) * | 2020-07-24 | 2022-01-25 | 北京交通大学 | Triangular waveform generator based on two single-drive Mach-Zehnder modulators |
| CN112865874A (en) * | 2021-01-12 | 2021-05-28 | 上海交通大学 | Self-adaptive decryption optical encryption transmission system and method based on optical self-interference elimination |
Non-Patent Citations (1)
| Title |
|---|
| 油海东等: "被动接入网ONU光接收机噪声对误码率影响的研究", 《青岛农业大学学报(自然科学版)》, 15 September 2007 (2007-09-15) * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Liu et al. | Photonic generation of microwave waveforms based on a polarization modulator in a Sagnac loop | |
| CN104459360B (en) | Microwave source phase noise test method and device based on microwave photon mixing technology | |
| He et al. | Photonic microwave waveforms generation based on two cascaded single-drive Mach-Zehnder modulators | |
| Wu et al. | Photonic microwave waveforms generation based on frequency and time-domain synthesis | |
| CN104020334A (en) | Electro-optical phase modulator half-wave voltage measurement system and measurement method | |
| CN111193548B (en) | Microwave photon waveform generation device and method based on cyclic frequency shift | |
| CN113972953B (en) | Triangular waveform generator based on two single-drive Mach-Zehnder modulators | |
| CN111010172B (en) | Frequency-tunable frequency-doubling triangular wave and square wave generating device and method | |
| CN105763260A (en) | Device and method of generating triangular waves by using phase modulator and Sagnac ring | |
| CN208079086U (en) | Quadruple optics triangle generator based on external modulation | |
| Ma et al. | Photonic generation of microwave triangular waveform based on polarization-dependent modulation efficiency of a single-drive Mach–Zehnder modulator | |
| Zhu et al. | Frequency-doubled microwave waveforms generation using a dual-polarization quadrature phase shift keying modulator driven by a single frequency radio frequency signal | |
| CN111541490B (en) | DPMZM-based QPSK-BPSK all-optical modulation format conversion system | |
| CN111193549B (en) | Optical frequency comb generation device and method based on bilateral cyclic frequency shift | |
| JP4991610B2 (en) | Method for measuring half-wave voltage of optical modulator | |
| CN115173949A (en) | Duty ratio adjustable rectification cosine microwave signal generator, method and equipment | |
| Li et al. | A simple and tunable photonic generation of frequency-doubled triangular waveform based on two cascaded modulators | |
| Li et al. | Photonic generation of frequency-doubled microwave waveform based on a PDM-MZM modulator | |
| Xia et al. | Photonic microwave waveforms generation based on pulse carving and superposition in time-domain | |
| Lv et al. | Flat optical frequency comb generation based on polarization modulator with RF frequency multiplication circuit and dual-parallel Mach-Zehnder modulator | |
| CN208079085U (en) | Increase the triangle generator of Dare modulator based on cascading Mach | |
| CN105827330A (en) | Method and system for millimeter wave generation | |
| CN113485035B (en) | High-flatness optical frequency comb generating device based on electro-optical modulator | |
| CN113098608B (en) | Radio signal up-conversion equipment | |
| CN115173948A (en) | Self-adaptive optical generator for rectified cosine microwave signals and microwave signal generation method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |