CN106771689B - A kind of ultra wide band phase noise measuring system - Google Patents
A kind of ultra wide band phase noise measuring system Download PDFInfo
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- CN106771689B CN106771689B CN201710130665.8A CN201710130665A CN106771689B CN 106771689 B CN106771689 B CN 106771689B CN 201710130665 A CN201710130665 A CN 201710130665A CN 106771689 B CN106771689 B CN 106771689B
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R29/00—Arrangements for measuring or indicating electric quantities not covered by groups G01R19/00 - G01R27/00
- G01R29/26—Measuring noise figure; Measuring signal-to-noise ratio
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Abstract
The present invention relates to a kind of ultra wide band phase noise measuring system, mainly solve that current phase noise measuring system precision is low, error is big, system structure is complicated, at high cost, is not easy the problem of realizing ultra-wide tape test and adaptive testing.The system comprises modulation control module, the optical modulator module being connected with modulation control module, the photoelectric detection module being connected with optical modulator module, the low-pass filter being connected with photoelectric detection module, the computer being connected with low-pass filter.The present invention uses the design scheme based on balance photodetector to preferably resolve the problem, can be used in the test of ultra-wide band radio-frequency microwave signal phase noise.
Description
Technical field
The present invention relates to test macro field, be related specifically to it is a kind of for communicating, remote-control romote-sensing, instrument and meter, aviation
Space Equipment, radar imagery, the ultra wide band phase noise measuring system in the fields such as Medical Instruments.
Background technique
Currently, the direct frequency spectrograph method that the main useful microwave device of the measurement of microwave signal source phase noise is realized,
Beat method, frequency-discrimination method and Phase Demodulation.Direct frequency spectrograph method method is simple, but by frequency spectrograph dynamic range and minimum resolution bandwidth
Limitation, this method are only suitable for the signal source that measurement drift is smaller, phase noise is relatively high.Beat method and Phase Demodulation utilize locking phase
Method is converted to the mutual phase fluctuation of signal the variation of corresponding latch voltage, then improves measurement with certain multiplication factor
Resolution ratio, but the method must use the frequency synthesis of low noise as standard frequency, so that being using the method
The device is complicated, cost is high for system.Frequency-discrimination method solves the problems, such as big delay, but since frequency-discrimination method is using common electric frequency mixer, mixes
The flatness of frequency device and frequency response are very big on measurement result influence, and are difficult to for the mixing bandwidth of common electric frequency mixer being extended to
40GHz or more, it is therefore desirable to the method for multiple frequency conversion be carried out to high-frequency microwave signal source to realize the measurement to its phase noise.
It makes an uproar therefore it provides one kind can be realized the reasonable high-frequency microwave signal source phase of ultra wide band, high-precision, simple structure
Sounding test system is with regard to necessary.
Summary of the invention
For existing microwave signal source phase noise measuring system measurement accuracy, low, system constitutes complicated, cost to the present invention
It is excessively high, be difficult to realize the problems such as ultra-wideband detection, propose it is a kind of based on balance photodetector ultra wide band phase noise measurement
System.
To solve the above problems, technical solution of the present invention includes: to provide a kind of ultra wide band phase noise measuring system, it is described
System includes modulation control module, the optical modulator module being connected with modulation control module, the light being connected with optical modulator module
Electric detecting module, the low-pass filter 204 being connected with photoelectric detection module, the computer 205 being connected with low-pass filter；
Modulation control module control optical modulator module operating point is within the scope of linear modulation always；
Microwave signal to be measured is modulated on light wave the optical modulator module and then output light carries radiofrequency signal；
The light that optical modulator module exports is carried radiofrequency signal and is converted into microwave signal to be measured by the photoelectric detection module
The direct current signal of phase noise information.
Further, the modulation control module includes modulating driver 105, the 1st light being connected with modulating driver
Electric explorer 103 and the 2nd photodetector 107.
Further, the optical modulator module includes narrow linewidth distributed feedback laser 101, distributed anti-with narrow linewidth
The polarization-maintaining fiber coupler 102 that feedback laser is connected, the intensity type optical modulator being connected with polarization-maintaining fiber coupler 102
104, the 1st single-mode optical-fibre coupler 108 being connected with intensity type optical modulator 104；
The modulating frequency of the intensity type optical modulator 104 is greater than tested microwave signal frequency.
Further, the coupling ratio of the polarization-maintaining fiber coupler 102 is 1:99.
Further, the coupling ratio of the 1st single-mode optical-fibre coupler 108 is 1:99.
Further, the photoelectric detection module includes the 2nd single-mode optical-fibre coupler 109, with the 2nd single-mode optical-fibre coupler
109 the 1st fibre delay lines 201 and the 2nd fibre delay line 202 being connected, with the 1st fibre delay line and the 2nd fibre delay line
The adjustment of balance photodetector 203 being connected；
The coupling ratio of 2nd single-mode optical-fibre coupler 109 is 50:50；
The three dB bandwidth frequency of the adjustment of balance photodetector 203 is greater than tested microwave signal frequency.
Further, the 1st fibre delay line 201 includes photoswitch 1, the fiber optic loop 1 and optical fiber connecting with photoswitch 1
Ring 2, the photoswitch 2 being connected with fiber optic loop 1 and fiber optic loop 2.
Further, the length of the fiber optic loop 1 is 5 kms, and the length of fiber optic loop 2 is 300~500 meters.
Further, the 2nd fibre delay line 202 is automatically controlled fibre delay line, and length is not more than 10 millimeters.
The present invention also provides a kind of application methods for ultra wide band phase noise measuring system, it is characterised in that: described
Method includes:
(1) microwave signal frequency parameter to be measured, range parameter, phase noise parameter is arranged in open system.
(2) the generation polarised light of narrow linewidth distributed feedback laser 101 enters intensity type light through polarization-maintaining fiber coupler 102
Modulator 104；
(3) modulator driver 105 is worked by procedure auto-control intensity type optical modulator in linear work point, access
Microwave signal to be measured；
(4) the 2nd fibre delay line is adjusted, makes the output of adjustment of balance photodetector 203 for microwave signal phase to be measured
The direct current signal of position noise information；
(5) data acquisition is carried out, algorithm process is carried out to acquired data and obtains the phase noise of microwave signal to be measured
As a result；
(6) power-off operation is executed.
The present invention is based on balance photodetectors, and ultra wide band phase can be realized and make an uproar without multiple frequency conversion or segmentation frequency conversion
Sound test, the 1st fibre delay line of big retardation are used to provide to provide different prolong to the phase noise measurement at different frequency deviations
Chi Liang, the 2nd fibre delay line are used to adjust into balanced detector two paths of signals to be in orthogonal operating point.It has the beneficial effect that:
Effect one: realizing the test of ultra wide band phase noise without multiple frequency conversion or segmentation frequency conversion, system constitute it is simple, at
This is lower, measurement frequency band is wider；
Effect two: the error that multiple components introduce is reduced, test flatness and accuracy are improved；
Effect three: calibrating and demarcates the best test mode of test macro, improves the adaptive measuring ability of test macro.
Detailed description of the invention
Present invention will be further explained below with reference to the attached drawings and examples.
Attached drawing 1 is the general frame of the invention.
Attached drawing 2 is detailed diagram of the invention.
Attached drawing 3 is software flow pattern of the invention.
In attached drawing 2, narrow linewidth belt distributed feedback laser -101, polarization-maintaining fiber coupler -102, photodetector 1-
103, intensity type optical modulator -104, modulating driver -105, microwave signal -106 to be measured, photodetector 2-107, single-mode optics
Fine coupler 1-108, single-mode optical-fibre coupler 2-109, fibre delay line 1-201, fibre delay line 2-202, adjustment of balance light
Electric explorer -203, low-pass filtering -204, computer -205.
Specific embodiment
In order to make the objectives, technical solutions, and advantages of the present invention clearer, with reference to embodiments, to the present invention
It is further elaborated.It should be appreciated that the specific embodiments described herein are merely illustrative of the present invention, it is not used to
Limit the present invention.
Embodiment 1
As shown in Figure 1, the present embodiment provides a kind of ultra wide band phase noise measuring system and application method, the test system
System includes modulation control module, the optical modulator module being connected with modulation control module, the photoelectricity being connected with optical modulator module
Detecting module, the low-pass filter being connected with photoelectric detection module, the computer being connected with low-pass filter.
As shown in Fig. 2, the modulation control module includes modulating driver 105, to be connected with modulating driver 105
1 photodetector 103 and the 2nd photodetector 107；
The modulation control module is by the 1st photodetector 103 and the 2nd photodetector 107 from polarization-maintaining fiber coupler
102 and the 1st single-mode optical-fibre coupler 108, which couples resulting optical signal and is transformed into electric signal, to be controlled by modulator driver 105
Optical modulator module operating point is within the scope of linear modulation always.
The optical modulator module includes narrow linewidth distributed feedback laser 101, with narrow linewidth distributed feedback laser
101 polarization-maintaining fiber couplers 102 being connected, the intensity type optical modulator 104 being connected with polarization-maintaining fiber coupler 102, with
The 1st single-mode optical-fibre coupler 108 that intensity type optical modulator 104 is connected；
The optical modulator module passes through intensity type light tune using the polarised light that narrow linewidth distributed feedback laser 101 generates
Side microwave signal to be measured is modulated on light wave device 104 processed and then output light carries radiofrequency signal；
The modulating frequency of the intensity type optical modulator 104 is greater than tested microwave signal frequency.
The coupling ratio of the polarization-maintaining fiber coupler 102 is 1:99, generates narrow linewidth distributed feedback laser 101
The centesimal signal of polarised light is coupled into the 1st photodetector 103, and percent ninety-nine signal enters intensity type light tune
Device 104 processed.
The coupling ratio of 1st single-mode optical-fibre coupler 108 is 1:99, makes 104 output signal of intensity type optical modulator
1 percent are coupled into the 2nd photodetector 107, and percent ninety-nine signal enters photoelectric detection module.
The photoelectric detection module includes the 2nd single-mode optical-fibre coupler 109, is connected with the 2nd single-mode optical-fibre coupler 109
The 1st fibre delay line 201 and the 2nd fibre delay line 202, the height being connected with the 1st fibre delay line and the 2nd fibre delay line
Speed balance photodetector 203；
The light that the photoelectric detection module exports optical modulator module carries radiofrequency signal through the 2nd single-mode optical-fibre coupler 109
It is divided into two-way, adjustment of balance photodetector 203 is entered by the 1st fibre delay line 201 all the way, another way passes through the 2nd optical fiber
Delay line 202 enters adjustment of balance photodetector 203, and adjustment of balance photodetector 203 is converted to light load radiofrequency signal
Direct current signal with microwave signal phase noise information to be measured；
The coupling ratio of 2nd single-mode optical-fibre coupler 109 is 50:50, is made into the 2nd single-mode optical-fibre coupler 109
Light carries radiofrequency signal etc. point and enters the 1st fibre delay line 201 and the 2nd fibre delay line 202；
The three dB bandwidth frequency of the adjustment of balance photodetector 203 is greater than tested microwave signal frequency, is guaranteed with this
Systematic survey bandwidth.
1st fibre delay line 201 includes photoswitch 1, the fiber optic loop 1 and fiber optic loop 2 connecting with photoswitch 1, with light
The photoswitch 2 that fine ring 1 is connected with fiber optic loop 2.
The length of the fiber optic loop 1 is 5 kms, and the length of fiber optic loop 2 is 300~500 meters.
2nd fibre delay line 202 is automatically controlled fibre delay line, and length is not more than 10 millimeters.
1st fibre delay line 201 and the 2nd fibre delay line 202 are used to adjust into balance photodetector two-way
Phase difference between signal.
The direct current signal with microwave signal phase noise information to be measured that adjustment of balance photodetector 203 exports passes through
It is handled to obtain final phase noise test result by computer acquisition after low-pass filter, signal processing flow is as follows:
(1) the input microwave signal to be measured indicates are as follows: V=Vocos(2πfot+2πΔfτ)；
Wherein, VoFor microwave signal amplitude, Δ f is microwave signal frequency shake, and 2 π Δ f τ are microwave signal frequency shake
Phase noise after one section of delay, τ.
(2) light of the optical modulator module output carries radiofrequency signal and divides through the 2nd single-mode optical-fibre coupler 109 for two-way, warp
After 1st fibre delay line 201 reaches adjustment of balance photodetector 203 are as follows: V=Vo cos(2πfot+2πΔfτd)；
Wherein, τdFor the retardation of the 1st fibre delay line 201.
(3) light of the optical modulator module output carries radiofrequency signal and divides through the 2nd single-mode optical-fibre coupler 109 for two-way, warp
After 2nd fibre delay line 202 reaches adjustment of balance photodetector 203 are as follows: V=Vo cos(2πfot+2πΔfτo)；
Wherein, τoFor the retardation of the 2nd fibre delay line 202.
(4) two paths of signals is after adjustment of balance photodetector 203 are as follows:
(5) adjusting the 2nd fibre delay line 202 makes 2 π fot+πΔfτo-πΔfτd=(2m+1) pi/2, at this time adjustment of balance light
Electric explorer 203 exports are as follows:
(6) the retardation τ of the 2nd fibre delay line 202oMinimum, the adjustment of balance light with microwave signal frequency shake Δ f
The output of electric explorer 203 further indicates that are as follows:
(7) pass through the formulaProgress Fourier transformation can be obtained microwave signal phase to be measured and make an uproar
Sound.
The present embodiment also provides a kind of application method for ultra wide band phase noise measuring system, which comprises
(1) microwave signal frequency parameter to be measured, range parameter, phase noise parameter is arranged in open system；
(2) the generation polarised light of narrow linewidth distributed feedback laser 101 enters intensity type light through polarization-maintaining fiber coupler 102
Modulator 104；
(3) modulating driver 105 is worked by procedure auto-control intensity type optical modulator in linear work point, access to
Survey microwave signal；
(4) the 2nd fibre delay line is adjusted, making the output of adjustment of balance photodetector 203 is direct current signal；
(5) data acquisition is carried out, algorithm process is carried out to acquired data and obtains the phase noise of microwave signal to be measured
As a result；
(6) power-off operation is executed.
Although the illustrative specific embodiment of the present invention is described above, in order to the technology of the art
Personnel are it will be appreciated that the present invention, but the present invention is not limited only to the range of specific embodiment, to the common skill of the art
For art personnel, as long as long as various change the attached claims limit and determine spirit and scope of the invention in, one
The innovation and creation using present inventive concept are cut in the column of protection.
Claims (9)
1. a kind of ultra wide band phase noise measuring system, it is characterised in that: the system comprises modulation control modules, control with modulation
The optical modulator module that molding block is connected, the photoelectric detection module being connected with optical modulator module, is connected with photoelectric detection module
The low-pass filter (204) connect, the computer being connected with low-pass filter (205)；
Modulation control module control optical modulator module operating point is within the scope of linear modulation always；
Microwave signal to be measured is modulated on light wave the optical modulator module and then output light carries radiofrequency signal；
The light that optical modulator module exports is carried radiofrequency signal and is converted into microwave signal phase to be measured by the photoelectric detection module
The direct current signal of noise information；
The photoelectric detection module includes the 2nd single-mode optical-fibre coupler (109), is connected with the 2nd single-mode optical-fibre coupler (109)
The 1st fibre delay line (201) and the 2nd fibre delay line (202), with the 1st fibre delay line (201) and the 2nd fibre delay line
(202) the adjustment of balance photodetector (203) being connected；
The direct current signal with microwave signal phase noise information to be measured of adjustment of balance photodetector (203) output is logical
It crosses after the low-pass filter (204) and final phase noise test result is obtained by the computer (205) acquisition process, believe
Number process flow is as follows:
(1) inputting microwave signal to be measured indicates are as follows: V=Vocos(2πfot+2πΔfτ)；
Wherein, VoFor microwave signal amplitude, Δ f is microwave signal frequency shake, and 2 π Δ f τ are that microwave signal frequency shake passes through one
Phase noise after section delay, τ；
(2) the light load radiofrequency signal of the optical modulator module output is divided into two-way through the 2nd single-mode optical-fibre coupler (109), through the 1st
After fibre delay line (201) reaches adjustment of balance photodetector (203) are as follows: V=Vocos(2πfot+2πΔfτd)；
Wherein, τdFor the retardation of the 1st fibre delay line 201；
(3) the light load radiofrequency signal of the optical modulator module output is divided into two-way through the 2nd single-mode optical-fibre coupler (109), through the 2nd
After fibre delay line (202) reaches adjustment of balance photodetector (203) are as follows:
V=Vocos(2πfot+2πΔfτo)；
Wherein, τoFor the retardation of the 2nd fibre delay line 202；
(4) two paths of signals is after adjustment of balance photodetector (203) are as follows:
(5) adjusting the 2nd fibre delay line (202) makes 2 π fot+πΔfτo-πΔfτd=(2m+1) pi/2, at this time adjustment of balance photoelectricity
Detector (203) output are as follows:
(6) the retardation τ of the 2nd fibre delay line (202)oMinimum, the adjustment of balance photoelectricity with microwave signal frequency shake Δ f
Detector (203) output further indicates that are as follows:
(7) pass through the formulaCarrying out Fourier transformation can be obtained microwave signal phase noise to be measured.
2. a kind of ultra wide band phase noise measuring system according to claim 1, it is characterised in that: the modulation control mould
Block includes modulating driver (105), the 1st photodetector (103) being connected with modulating driver and the 2nd photodetector
(107)。
3. a kind of ultra wide band phase noise measuring system according to claim 1, it is characterised in that: the optical modulator module
Including narrow linewidth distributed feedback laser (101), the polarization maintaining optical fibre being connected with narrow linewidth distributed feedback laser (101)
Coupler (102), the intensity type optical modulator (104) being connected with polarization-maintaining fiber coupler (102), with intensity type optical modulator
(104) the 1st single-mode optical-fibre coupler (108) being connected；
The modulating frequency of the intensity type optical modulator (104) is greater than tested microwave signal frequency.
4. a kind of ultra wide band phase noise measuring system according to claim 3, it is characterised in that: the polarization maintaining optical fibre coupling
The coupling ratio of clutch (102) is 1:99.
5. a kind of ultra wide band phase noise measuring system according to claim 3, it is characterised in that: the 1st single-mode optics
The coupling ratio of fine coupler (108) is 1:99.
6. a kind of ultra wide band phase noise measuring system according to claim 1, it is characterised in that: the 2nd single-mode optics
The coupling ratio of fine coupler (109) is 50:50；
The three dB bandwidth frequency of the adjustment of balance photodetector (203) is greater than tested microwave signal frequency.
7. a kind of ultra wide band phase noise measuring system according to claim 6, it is characterised in that: the 1st optical fiber prolongs
Slow line (201) includes photoswitch 1, and the fiber optic loop 1 and fiber optic loop 2 connecting with photoswitch 1 are connected with fiber optic loop 1 and fiber optic loop 2
Photoswitch 2.
8. a kind of ultra wide band phase noise measuring system according to claim 7, it is characterised in that: the fiber optic loop 1
Length is 5 kms, and the length of fiber optic loop 2 is 300~500 meters.
9. a kind of ultra wide band phase noise measuring system according to claim 6, it is characterised in that: the 2nd optical fiber prolongs
Slow line (202) is automatically controlled fibre delay line, and length is not more than 10 millimeters.
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| CN104062514A (en) * | 2014-07-02 | 2014-09-24 | 中国电子科技集团公司第四十一研究所 | Device and method for measuring pulse carrier phase noise |
| CN104764941A (en) * | 2009-09-23 | 2015-07-08 | 光电波公司 | Measuring phase noise in radio frequency, microwave or millimeter signals based on photonic delay |
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2017
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| CN104764941A (en) * | 2009-09-23 | 2015-07-08 | 光电波公司 | Measuring phase noise in radio frequency, microwave or millimeter signals based on photonic delay |
| CN104062514A (en) * | 2014-07-02 | 2014-09-24 | 中国电子科技集团公司第四十一研究所 | Device and method for measuring pulse carrier phase noise |
| CN105207043A (en) * | 2015-09-23 | 2015-12-30 | 北京邮电大学 | Photoelectric oscillator |
| CN105306053A (en) * | 2015-11-05 | 2016-02-03 | 中国电子科技集团公司第四十一研究所 | Digital PLL (Phase-Locked Loop) based phase noise measuring device and method |
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