CN203881848U - Device for measuring linewidth and frequency-discrimination gradient of atom frequency mark based on photocell - Google Patents

Device for measuring linewidth and frequency-discrimination gradient of atom frequency mark based on photocell Download PDF

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CN203881848U
CN203881848U CN201420195153.1U CN201420195153U CN203881848U CN 203881848 U CN203881848 U CN 203881848U CN 201420195153 U CN201420195153 U CN 201420195153U CN 203881848 U CN203881848 U CN 203881848U
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frequency
photocell
physical system
output terminal
phase
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雷海东
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Jianghan University
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Abstract

本实用新型涉及一种基于光电池测量原子频标的线宽及鉴频斜率的装置，包括功率放大器、物理系统、光电池、前置放大器、相敏检波器、微处理器、数模转换器、压控晶体振荡器、调制频率放大器和射频倍频电路，所述功率放大器作用于物理系统上，所述物理系统、光电池、前置放大器和相敏检波器依次相连，所述微处理器与所述相敏检波器和数模转换器相连，所述数模转换器、压控晶体振荡器和射频倍频电路依次相连，所述微处理器通过调制频率放大器与所述射频倍频电路相连，所述射频倍频电路与所述物理系统相连。本实用新型是利用原子频标体系内现有数字化伺服回路及压控晶体振荡器，完成物理系统的线宽及鉴频斜率测量，测量方便，且测量结果可靠。

The utility model relates to a device for measuring the line width and frequency discrimination slope of an atomic frequency standard based on a photocell, comprising a power amplifier, a physical system, a photocell, a preamplifier, a phase-sensitive detector, a microprocessor, a digital-to-analog converter, a voltage control Crystal oscillator, modulation frequency amplifier and radio frequency multiplier circuit, the power amplifier acts on the physical system, the physical system, photocell, preamplifier and phase sensitive detector are connected in sequence, the microprocessor is connected to the phase The sensitive detector is connected with the digital-to-analog converter, and the digital-to-analog converter, the voltage-controlled crystal oscillator and the radio frequency frequency multiplication circuit are connected in sequence, and the microprocessor is connected with the radio frequency frequency multiplication circuit through a modulation frequency amplifier, and the The radio frequency multiplication circuit is connected with the physical system. The utility model uses the existing digital servo loop and voltage-controlled crystal oscillator in the atomic frequency standard system to complete the line width and frequency discrimination slope measurement of the physical system, and the measurement is convenient and the measurement result is reliable.

Description

A kind of based on the photoelectric cell measurement live width of atomic frequency standard and the device of frequency discrimination slope
Technical field
The utility model relates to a kind of live width of atomic frequency standard and device of frequency discrimination slope measured, and is specifically related to a kind of based on the photoelectric cell measurement live width of atomic frequency standard and the device of frequency discrimination slope.
Background technology
A Rb atom frequency marking comprises after the physical system moulding such as spectrum lamp, integrated filtering resonance bubble, resonator cavity, next step can verify by experiments such as parameter optimizations the performance of atomic frequency standard complete machine, and wherein more important focus can be placed in the live width of complete machine, we wish that live width is more narrow better.In addition be equivalent to the effect of a frequency discriminator due to physical system, we wish that it has good frequency discrimination performance, i.e. frequency discrimination slope.And traditional way is the absorption curve that scans physical system by sweep generator, carry out writing scan data by corresponding registering instrument, thus the live width of the system of acquisition.And this way passes through to change the frequency of sweep generator by traditional measurement live width method such as sweep generator and registering instrument, act on physical system, then record the signal through the output of Photoelectric Detection link by registering instrument, such way will be by means of peripheral instrument, and should not store and calculate, be not easy to measure, and unreliable.
Utility model content
Technical problem to be solved in the utility model is to provide a kind of based on the photoelectric cell measurement live width of atomic frequency standard and the device of frequency discrimination slope, can facilitate, measure reliably live width and the frequency discrimination slope of atomic frequency standard.
The technical scheme that the utility model solves the problems of the technologies described above is as follows: a kind of based on the photoelectric cell measurement live width of atomic frequency standard and the device of frequency discrimination slope, comprise power amplifier, physical system, photoelectric cell, prime amplifier, phase-sensitive detector (PSD), microprocessor, digital to analog converter, VCXO, modulating frequency amplifier and radio frequency frequency multiplier circuit, described power amplifier acts in described physical system, described physical system, photoelectric cell, prime amplifier is connected successively with phase-sensitive detector (PSD), and described microprocessor is provided with record data input end, and described record data input end is connected with described phase-sensitive detector (PSD), and described microprocessor is provided with synchronous signal output end, modulation signal output terminal and record data output terminal, described synchronous signal output end is connected with described phase-sensitive detector (PSD), and described record data output terminal is connected with described digital to analog converter, described digital to analog converter, VCXO is connected successively with radio frequency frequency multiplier circuit, and described microprocessor is connected with described radio frequency frequency multiplier circuit by modulating frequency amplifier, and described radio frequency frequency multiplier circuit is connected with described physical system.
On the basis of technique scheme, the utility model can also do following improvement.
Further, described power amplifier acts on the position that described physical system is connected with described photoelectric cell.
Further, described synchronous signal output end output synchronizing signal, described modulation signal output terminal output modulation signal, the phase place of the synchronizing signal of described synchronous signal output end output is identical with the phase place of the modulation signal of described modulation signal output terminal output.
Further, described record data output terminal is connected with the mode that described digital to analog converter increases progressively by voltage single step.
Further, described physical system comprises connected successively spectrum lamp, integrated filtering resonance bubble resonant cavity.
Further, described photoelectric cell is attached to the afterbody of the resonator cavity of described physical system.
Further, described photoelectric cell is silicon photocell.
The beneficial effects of the utility model are: the utility model is to utilize existing digitizing servo loop and VCXO in atomic frequency standard system, completes live width and the frequency discrimination slope measurement of physical system, and it is convenient to measure, and measurement result is reliable.
Brief description of the drawings
Fig. 1 is a kind of structured flowchart of measuring the live width of atomic frequency standard and the device of frequency discrimination slope based on photoelectric cell of the utility model;
Fig. 2 is a kind of frequency discrimination S curve map based on phase detector obtains in the photoelectric cell measurement live width of atomic frequency standard and the device of frequency discrimination slope of the utility model.
Embodiment
Below in conjunction with accompanying drawing, principle of the present utility model and feature are described, example, only for explaining the utility model, is not intended to limit scope of the present utility model.
As shown in Figure 1, a kind of based on the photoelectric cell measurement live width of atomic frequency standard and the device of frequency discrimination slope, comprise power amplifier, physical system, photoelectric cell, prime amplifier, phase-sensitive detector (PSD), microprocessor, digital to analog converter, VCXO, modulating frequency amplifier and radio frequency frequency multiplier circuit, described power amplifier acts in described physical system, described physical system, photoelectric cell, prime amplifier is connected successively with phase-sensitive detector (PSD), and described microprocessor is provided with record data input end, and described record data input end is connected with described phase-sensitive detector (PSD), and described microprocessor is provided with synchronous signal output end, modulation signal output terminal and record data output terminal, described synchronous signal output end is connected with described phase-sensitive detector (PSD), and described record data output terminal is connected with described digital to analog converter, described digital to analog converter, VCXO is connected successively with radio frequency frequency multiplier circuit, and described microprocessor is connected with described radio frequency frequency multiplier circuit by modulating frequency amplifier, and described radio frequency frequency multiplier circuit is connected with described physical system.Wherein, described power amplifier acts on the position that described physical system is connected with described photoelectric cell; Described synchronous signal output end output synchronizing signal, described modulation signal output terminal output modulation signal, the phase place of the synchronizing signal of described synchronous signal output end output is identical with the phase place of the modulation signal of described modulation signal output terminal output; The mode that described record data output terminal increases progressively by voltage single step with the described digital to analog converter described physical system that is connected comprises connected successively spectrum lamp, integrated filtering resonance bubble resonant cavity; Described photoelectric cell is attached to the afterbody of the resonator cavity of described physical system; Described photoelectric cell is silicon photocell.
Principle of work of the present utility model is as follows: the light that described physical system is sent by the spectrum lamp of its radiation source appearing after integrated resonance absorption bubble, light signal is passed to photoelectric cell, in this process, power amplifier passes to photronic signal to physics system and carries out power amplification, makes the easier minimum signal power detecting in physical system of photoelectric cell, described photoelectric cell detects the size that appear light of the light being sent by radiation source spectrum lamp after resonance absorption bubble, and light signal is converted to electric signal, the electric signal that described prime amplifier passes over photoelectric cell amplifies and then passes to phase-sensitive detector (PSD), simultaneously described microprocessor produces synchronizing signal, and described synchronizing signal is passed to phase-sensitive detector (PSD), the synchronizing signal that described phase-sensitive detector (PSD) passes over microprocessor is differentiated modulating signal phase and frequency-selecting processing to the electric signal of the described amplification passing over as a reference, described in described microprocessor records, phase-sensitive detector (PSD) is differentiated modulating signal phase and the rear data of frequency-selecting processing to electric signal, and the mode that described data are increased progressively according to voltage single step is by the frequency signal output of VCXO described in described digital to analog converter control, the frequency signal of described VCXO output passes to radio frequency frequency multiplier circuit, described microprocessor also produces a modulation signal and act on radio frequency frequency multiplier circuit after modulating frequency amplifier amplifies simultaneously, modulating frequency amplifier is the modulating frequency that improves signal, make light detecting signal frequency avoid the region that modulating frequency noise is stronger, reduce the impact of flicker noise, the frequency signal of the modulation signal that described microprocessor produces and voltage controlled oscillator output is synthetic small interrogation signals in radio frequency frequency multiplier circuit, and acts on physical system, successively circulation.
In the utility model, photronic effect is that the optical radiation energy that is loaded with atomic resonance transition information is transformed to electric energy, and in the process that realizes this conversion, completes the transmission of information.Photoelectric cell is the interface link of linking up physical system and electronic system, and it is light path element and circuit component, has the double attribute of optics and electronics.As light path element, it is light detecting signal receiver, is the output port of prime optical system; As circuit component, it is signal generator, is the input port of follow-up electronic system.Just because of having utilized photronic double attribute, the contact of just having set up physical system and electronic circuit, makes to be communicated with to each other.Therefore, determining of the selection of photoelectric cell type and duty is most important to the craftmanship of electro-optical system, is a major issue of system.
In passive-type atomic frequency standard light detection, adopt the photoelectric cell of silicon photocell as light detecting device, its performance directly affects the quality of light detection output effect.In actual testing circuit, photoelectric cell is directly attached to the afterbody of resonator cavity, in order to detect the size that appear light of the light being sent by radiation source spectrum lamp after resonance absorption bubble.As can be seen here, the noise of whole optical detection circuit depends on photoelectric cell itself to a great extent, on concrete selective light battery size, except the thermonoise of whole optical detection circuit and shot noise impact should being taken into account, also should meet following some:
(1) sensitive photoelectric conversion capacity: make given input optical signal have best signal transmission coefficient under the nonlinear distortion condition allowing, obtain maximum power, voltage or electric current output.
(2) dynamic response capability fast: meet the desired frequency selectivity of signalling channel or the quick response to transient signal.
(3) best input ability: have for the necessary signal to noise ratio (S/N ratio) of reliable detection or minimum detectable signal power.For this reason, what be connected with described physical system at photoelectric cell locates to be provided with power amplifier, makes the power amplification of physical system, and then the signal of the minimum power of physical system is easily detected by photoelectric cell, improves photronic input ability.
(4) stability of long-term work and reliability.
For Rb atom frequency marking, the degree of stability of its output frequency has following formula:
σ y ( τ ) = 0.11 Q ( S / N ) · 1 τ - - - ( 1 )
In formula, Q is the quality factor relevant to absorption peak live width, and Q value is higher, and live width is narrower, and corresponding frequency discrimination slope is also larger.S/N is the signal to noise ratio (S/N ratio) of quantized system, and under the certain condition of signal, noise is less, is more conducive to the short steady of system.
The noise of quantized system is mainly photronic flicker noise, thermonoise, Johnson noise.In these three kinds of noises, flicker noise intensity and frequency f -1relevant, in order to reduce the impact of this noise, in real work, to select higher a little modulating frequency, now just between microprocessor and radio frequency frequency multiplier circuit, increase a modulating frequency amplifier, the modulation signal of the modulation signal output terminal output of microprocessor is amplified through modulating frequency amplifier, and then frequency modulating signal uprises, make light detecting signal frequency avoid f -1the region that noise is stronger.Johnson noise, thermonoise are all white audio-frequency noises, and Johnson noise is to affect the short steady principal element of frequency marking, will select suitable light intensity for this reason, increase the sensitive surface of transmitted light detector, and select appropriate bubble long, and bubble temperature, lamp temperature, to obtain preferably signal to noise ratio (S/N ratio).For a Rb atom frequency marking, certain at its quantized system noise, and given under the condition of line-width, its frequency discrimination slope is also closely related with depth of modulation, therefore in practical operation, think over this factor, suitably select the depth of modulation of microwave sounding signal.
The utility model by acting on physical system after adding a small interrogation signals in radio frequency frequency multiplier circuit, the quantum frequency discrimination signal being obtained by photoelectric cell is sent in phase sensitive detector, through the detection of locking phase, obtain frequency discrimination S curve, frequency discrimination S curve map as shown in Figure 2, the absorption curve of it and system is the relation of a derivation, and in figure, horizontal ordinate mark is the changing value of frequency f, and in fact it is recording digital to analog converter and change the process of voltage-controlled voltage.Because done the corresponding relation (being recorded in microprocessor with the form of showing) of digital to analog converter and VCXO device output frequency before scanning, and think that the voltage of being exported by digital to analog converter changes the frequency change causing within the scope of quantized system live width and the output of the frequency of VCXO is linear, therefore in this direct concrete magnitude of voltage from abscissa axis, the corresponding frequency of corresponding crystal oscillator.
By the S curve in Fig. 2, we can calculate live width and frequency discrimination slope.Its X-axis and Y-axis data are recorded in respectively in two column data hurdles under data pattern, the method of calculating live width is: under graphic model, X-axis to the indicated place of Point reading mouse and Y-axis value, in Fig. 2, the frequency interval between peak-to-peak value is f2-f1, being calculated as of live width , and cannot accurately obtain peak point in artificial operation, and what X-axis recorded is the voltage-controlled magnitude of voltage of analog to digital converter, while sexually revising voltage-controlled voltage online, the actual frequency variation of VCXO is being approximately 6Hz left and right between points.Just more difficult in the time of concrete calculating frequency discrimination slope, because first must find center origin (0, 0), in actual experiment, that selected amount subsystem frequency discrimination signal is put the process that level or the servo amplifier stage of rear class carry out phase-locked amplification front, according to each physical system and surveying instrument parameter, gains etc. are selected different, occur that sometimes line corresponding Y-axis magnitude of voltage in Ref center is not 0 situation, but a certain value (for example 0.024V), the definition of Ref will be watched the horizontal line under graphic model and obtain with people's naked eyes so, or look for middle point value under data pattern, these are all pretty troublesome things.
For solving the problem of calculating " live width " and " frequency discrimination slope " under practical situation, can adopt following methods: the voltage output value that the phase sensitive detection of microprocessor collection is obtained stores separately, and it is processed, draw the maximal value V of the Y-axis coordinate in the S curve in Fig. 2 hand minimum value V l, and record this moment corresponding X-axis frequency coordinate f 2and f 1, in the process of data acquisition, ensure the value of an X-axis of every change, record corresponding Y-axis magnitude of voltage of this moment simultaneously, they are relations one to one.By above-mentioned scheme, it is reliable that the calculating of live width just seems.At V l-V hin scope, select one close to 0 point, record the value of its X-axis simultaneously, this position is decided to be to initial point (0,0), according to this point respectively get to the left and right limit of X-axis respectively equal number point, for example 20 points are respectively got in left and right, and these 41 some data are carried out curve fitting, and show that corresponding slope value counts frequency discrimination slope.
The foregoing is only preferred embodiment of the present utility model, not in order to limit the utility model, all within spirit of the present utility model and principle, any amendment of doing, be equal to replacement, improvement etc., within all should being included in protection domain of the present utility model.

Claims (7)

1.一种基于光电池测量原子频标的线宽及鉴频斜率的装置，其特征在于：包括功率放大器、物理系统、光电池、前置放大器、相敏检波器、微处理器、数模转换器、压控晶体振荡器、调制频率放大器和射频倍频电路，所述功率放大器作用于所述物理系统上，所述物理系统、光电池、前置放大器和相敏检波器依次相连，所述微处理器上设有记录数据输入端，所述记录数据输入端与所述相敏检波器相连，所述微处理器上设有同步信号输出端、调制信号输出端和记录数据输出端，所述同步信号输出端与所述相敏检波器相连，所述记录数据输出端与所述数模转换器相连，所述数模转换器、压控晶体振荡器和射频倍频电路依次相连，所述微处理器通过调制频率放大器与所述射频倍频电路相连，所述射频倍频电路与所述物理系统相连。  1. A device based on photocell measurement of line width and frequency discrimination slope of atomic frequency standard, characterized in that: comprising power amplifier, physical system, photocell, preamplifier, phase-sensitive detector, microprocessor, digital-to-analog converter, A voltage-controlled crystal oscillator, a modulation frequency amplifier and a radio frequency multiplier circuit, the power amplifier acts on the physical system, the physical system, photocell, preamplifier and phase-sensitive detector are connected in sequence, and the microprocessor There is a recording data input terminal on it, and the recording data input terminal is connected with the phase-sensitive detector. The microprocessor is provided with a synchronous signal output terminal, a modulating signal output terminal and a recording data output terminal. The output terminal is connected to the phase-sensitive detector, the recorded data output terminal is connected to the digital-to-analog converter, the digital-to-analog converter, the voltage-controlled crystal oscillator and the radio frequency multiplication circuit are connected in sequence, and the microprocessing The device is connected to the radio frequency multiplication circuit through a modulation frequency amplifier, and the radio frequency multiplication circuit is connected to the physical system. the 2.根据权利要求1所述的一种基于光电池测量原子频标的线宽及鉴频斜率的装置，其特征在于：所述功率放大器作用在所述物理系统与所述光电池相连接的位置。  2. A photocell-based device for measuring the linewidth and frequency discrimination slope of an atomic frequency standard according to claim 1, wherein the power amplifier acts on a position where the physical system is connected to the photocell. the 3.根据权利要求1或2所述的一种基于光电池测量原子频标的线宽及鉴频斜率的装置，其特征在于：所述同步信号输出端输出同步信号，所述调制信号输出端输出调制信号，所述同步信号输出端输出的同步信号的相位与所述调制信号输出端输出的调制信号的相位相同。  3. according to claim 1 or 2, a kind of device based on photocell measurement atomic frequency standard line width and frequency discrimination slope, it is characterized in that: described synchronous signal output terminal outputs synchronous signal, and described modulation signal output terminal outputs modulation signal, the phase of the synchronization signal output from the synchronization signal output terminal is the same as the phase of the modulation signal output from the modulation signal output terminal. the 4.根据权利要求1或2所述的一种基于光电池测量原子频标的线宽及鉴频斜率的装置，其特征在于：所述记录数据输出端与所述数模转换器通过电压单步递增的方式相连。  4. The device for measuring the line width and frequency discrimination slope of an atomic frequency standard based on photocells according to claim 1 or 2, characterized in that: the recorded data output terminal and the digital-to-analog converter step by step increase the voltage connected in a way. the 5.根据权利要求1或2所述的一种基于光电池测量原子频标的线宽及鉴频斜率的装置，其特征在于：所述物理系统包括依次相连的光谱灯、集成滤光共振泡和谐振腔。  5. The device for measuring the line width and frequency discrimination slope of an atomic frequency standard based on photocells according to claim 1 or 2, wherein the physical system includes sequentially connected spectral lamps, integrated filter resonance bubbles and resonance cavity. the 6.根据权利要求5所述的一种基于光电池测量原子频标的线宽及鉴频斜率的装置，其特征在于：所述光电池贴附在所述物理系统的谐振腔的尾部。  6. A device for measuring the linewidth and frequency discrimination slope of an atomic frequency standard based on a photoelectric cell according to claim 5, wherein the photoelectric cell is attached to the tail of the resonant cavity of the physical system. the 7.根据权利要求1或2所述的一种基于光电池测量原子频标的线宽及鉴频斜率的装置，其特征在于：所述光电池为硅光电池。  7. A photocell-based device for measuring the line width and frequency discrimination slope of an atomic frequency standard according to claim 1 or 2, wherein the photocell is a silicon photocell. the
CN201420195153.1U 2014-04-21 2014-04-21 Device for measuring linewidth and frequency-discrimination gradient of atom frequency mark based on photocell Expired - Fee Related CN203881848U (en)

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104539289A (en) * 2014-11-26 2015-04-22 江汉大学 Estimation method and device for short-term stability of atomic frequency standard frequency
CN105572511A (en) * 2016-01-29 2016-05-11 江汉大学 Atomic clock performance evaluation device
CN105738709A (en) * 2016-02-01 2016-07-06 江汉大学 Measurement system based on phase sensitive detection, photoelectric equipment, measurement method and device

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104539289A (en) * 2014-11-26 2015-04-22 江汉大学 Estimation method and device for short-term stability of atomic frequency standard frequency
CN105572511A (en) * 2016-01-29 2016-05-11 江汉大学 Atomic clock performance evaluation device
CN105738709A (en) * 2016-02-01 2016-07-06 江汉大学 Measurement system based on phase sensitive detection, photoelectric equipment, measurement method and device

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