CN107576879A - Sweep measurement device and the method for estimating cable attribute - Google Patents
Sweep measurement device and the method for estimating cable attribute Download PDFInfo
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Abstract
The invention discloses a kind of sweep measurement device and the method for estimating cable attribute, the present invention is by setting dual directional coupler module, it is configured as transmission signal and reflected signal being oriented coupling sampling output respectively, and the sampled signal being coupled out is input to corresponding power measurement module, power measurement module, it is configured as that the signal power of dual directional coupler module different output port output is measured and gathered, only the amplitude information of reflected signal can be measured, reduce the complexity of measurement apparatus and improve the antijamming capability of measurement apparatus, cable length is relatively accurately estimated by the way that the analysis to frequency domain data is comparable, and judge whether cable properties impedance changes, and then judge whether cable is damaged.
Description
Technical field
The present invention relates to a kind of sweep measurement device and the method for estimating cable attribute.
Background technology
Communication cable refers to for closely voice communication and the electricity of the communication of remote high frequency carrier digital and signal transmission
Cable, it is widely used in the key areas such as communication line, instrument and meter, electric power.It is same mainly to include local call communication cable, high frequency
Axle communication cable etc.；Because a variety of external factor can cause communication cable that the failures such as short circuit, open circuit occur.Therefore a kind of letter is passed through
Single device and simple effective method estimation cable attribute are very necessary, and main to include estimation cable length, cable is special
Whether property impedance occurs exception.
The attribute information of communication cable is estimated to realize, reduces the artificial investigation workload of cable fault, this hair
The frequency domain characteristic of a kind of bright sweep measurement device for proposing simplification and the cable reflection coefficient measured by analyzing the device
The method for estimating cable attribute, realizes the estimation to communication cable length and to judge whether communication cable characteristic impedance occurs different
Often.
In common sweep-frequency measurement system, such as Network Analyzer, portable radio-frequency analyzer, function is very powerful,
The amplitude information (reflectance factor, return loss, voltage standing wave ratio) of tested load can be not only measured by way of frequency sweep, simultaneously
The phase information (phase difference of incoming signal and reflected signal) of reflected signal can be measured.Although said apparatus measuring system is smart
Degree is high, supports wide frequency range, but equipment is larger and complicated, and cost is very high, and it is contour to be mainly used in accurate radio-frequency cable, antenna
The measurement and assessment of precision device, are unsuitable for low-cost popularization and use.
" the dress based on radio frequency reflection power monitoring and the breakage of positioning cable screen layer of Application No. 2016110399356
Put and method " patent provide and a kind of real time and on line monitoring only carried out to cable shield layer state by measuring reflection power
Device and method, but its cable status analysis method too complex and need the branch of platform and database by complicated algorithm
Support could realize that cable length measurement and accident analysis, daemon software development difficulty are larger；The frequency sweep of a small amount of number can not be passed through
Measurement obtains the attribute information of cable.
Patent No. 102879703A patent " one kind ground connection performance monitoring system and communication cable shielding layer dynamic monitoring
Method " provide one kind by measuring screen layer to core electric capacity, the integrality of dynamic surveillance wired communication cable screen layer
Method.But because capacitance signal is excessively single, carrying cable status information content is limited, it is difficult to the electricity under complex environment
Cable carries out positioning analysis.Simultaneously because singal source resistance mismatches with transmission line input impedance, so measurement accuracy is low, error
Greatly.The attribute informations such as this method also more accurate can not estimate cable length, whether cable properties impedance changes in addition.
The content of the invention
The present invention is in order to solve the above problems, it is proposed that a kind of sweep measurement device and the method for estimating cable attribute, this
Invention only measures to the amplitude information of reflected signal, reduces the complexity of measurement apparatus and improves the anti-of measurement apparatus
Interference performance, cable length is relatively accurately estimated by the way that the analysis to frequency domain data is comparable, and judge that cable properties impedance is
It is no to change, and then judge whether cable is damaged.
To achieve these goals, the present invention adopts the following technical scheme that：
A kind of sweep measurement device, including：
Module occurs for sine wave signal, and the sinusoidal signal for being configured as producing Frequency Adjustable by DDS technologies is used as transmitting letter
Number source；
Power-adjustable amplification module, it is configured as adjusting sine wave swept-frequency signal generation module according to actual conditions demand
Transmission power size；
Impedance matching module, the transformer and build-out resistor for being configured to, with different no-load voltage ratios form outlet side impedance
Adjustable circuit network, impedance matching can be carried out to the cable of different impedance varieties；
Dual directional coupler module, it is configured as transmission signal and reflected signal being oriented coupling sampling respectively defeated
Go out, and the sampled signal being coupled out is input to corresponding power measurement module；
The power measurement module, it is configured as the signal power to the output of dual directional coupler module different output port
Measure and gather；
MCU control module, it is configured as connecting sine wave signal generation module, power-adjustable amplification module, power measurement
Module and impedance matching module, above-mentioned module is scheduled, coordinates control, to monitor the shape of communication cable shielding layer
State.
The dual directional coupler module includes input port, straight-through port, the first coupling port and the second coupling port
And isolated port；The directional coupler is used to sample frequency sweep reflected signal, and frequency sweep transmission signal is by the directional coupler
Input port input, the first coupling port and the second coupling port, which are used to exporting the directional coupler, launches frequency sweep
The sampled signal of signal and reflected signal, the straight-through port are used to export the frequency sweep transmission signal by the directional coupler
Or input reflection signal, the isolated port are hanging.
The MCU control module is also associated with display module, shows the LCD display of chart, can be by sweep measurement result
Shown.
Further, the first coupling port of the dual directional coupler module and the second coupling port pass through RF switching moldings
Block connects MCU control module and power measurement module, is realized and switched by RF switch modules.
Preferably, the RF switch modules are single-pole double-throw switch (SPDT), it is allowed to which high frequency analog signals pass through.
Further, the power measurement module includes two, connects the first coupling port and the second coupling port respectively.
The loaded cable, refer to communication cable to be measured, connect the measurement apparatus.
Frequency Sweeping Method based on said apparatus, comprises the following steps：
(1) loaded cable and impedance matching module are connected, impedance matching module is adjusted, makes the defeated of detection means
Go out the input resistant matching with loaded cable；
(2) sinusoidal signal of a certain fixed frequency of module generation occurs for MCU control module control sine wave signal, and inputs
To power-adjustable amplification module；
(3) MCU control module control power-adjustable amplification module adjusts sinusoidal signal to setting power, is input to amphiorentation
Coupler Module, dual directional coupler module carry out coupling sampling to transmission signal, and switch RF switch modules be connected to it is double fixed
To the first coupling port of Coupler Module, sampled signal is input to power measurement module；The main energy of transmission signal is by double
Directional coupler module and impedance matching module, are coupled in loaded cable；
(4) MCU control module control power measurement module measures to the signal power of input, waits measurement result steady
After fixed, transmission signal power data that recording power measurement module measures simultaneously preserves；After the completion of, MCU control module control RF
Switch module is switched to the coupling port of dual directional coupler module second；
(5) after sinusoidal signal is coupled in loaded cable, in communication cable end or the locus of impedance discontinuity
Reflection can be produced；Reflected signal is along original path reverse transfer, by impedance matching module；
(6) reflected signal continues to be transferred to dual directional coupler module, and the module is sampled and coupled to reflected signal
Output, and power measurement module is coupled to by RF switch modules again；
(7) MCU control module control power measurement module measures to the signal power of input, waits measurement result steady
After fixed, reflection signal power data that recording power measurement module measures simultaneously preserve；
(8) sinusoidal signal that module produces next Frequency point, and repeat step occur for MCU module control sine wave signal
(3)~(7)；After all predeterminated frequency point datas have been measured, perform (9)；
(9) MCU module is calculated and counted to sweep measurement result, calculates and loaded cable is tested under each Frequency point
Return loss, reflectance factor and voltage standing wave ratio, and shown in graphical form in display module；
In the step (1), impedance matching module output difference pin, for different types of cable and the different electricity of measurement
Cable attribute, connected mode are different；For the property measurement of certain a pair of twisted-pair feeder in communication cable, directly by differential pin and this pair
Twisted wire connects；, it is necessary to which one in differential pin is connect into cable screens in the case of communication cable shielding layer attribute is measured
Layer is covered, one connects any one cored wire；For coaxial communications cable, then differential pin connects with screen layer and central axis respectively
Connect.
In the step (5), after signal is coupled in loaded cable, the impedance between cable shield and cored wire has
The place of change, impedance mismatch produce reflection, and reflected signal can be transferred to impedance matching module along loaded cable, so
After be transferred to dual directional coupler module, be transferred to power measurement module finally by RF switch modules, carry out power measurement.
In the step (8), measurement apparatus is directed to the communication cable of the different model under varying environment, can set different
Swept frequency range and swept frequency interval, and these configuration informations are saved in MCU control module, to carry out automatic frequency sweep measurement.
In the step (9), corresponding reflection system can be calculated by the transmission signal and the power of reflected signal that measure
Three number, voltage standing wave ratio and return loss conventional reflection parameters, sweep measurement result is calculated and counted to realize.
Specifically, the method for cable attribute is estimated by frequency sweep reflectance factor, including：
(I) sweep measurement is carried out to the communication cable of known length first, obtains the return loss frequency spectrum of the cable, recorded
The length cables correspond to the number of completed wave in return loss frequency spectrum, and return loss corresponding to the cable of unit of account length
The number that curve fluctuates in frequency spectrum, is designated as N0；
(II) sweep measurement is carried out to the cable of other unknown lengths, the frequency spectrum of return loss is similarly obtained, in frequency spectrum
The number that curve fluctuates is counted, and is designated as N, calculates the length estimated value L=N/N0 of the cable；
(III) to after having disposed intact communication cable carry out sweep measurement, and record standard measurement data be used as after
Face judges whether cable resistance characteristic occurs abnormal contrast benchmark；
(IV) sweep measurement periodically is carried out to operating communication cable, if the return loss frequency spectrum and benchmark that measure
Frequency spectrum difference exceedes setting value, then shows that communication cable impedance operator is changed, and cable is likely to occur damaged or abnormal.
In the step (I), institute's frequency sweep reflection parameters include three reflectance factor, voltage standing wave ratio and return loss ginsengs
Number.
In the step (I), for signal measurement angle, the changing rule of return loss frequency spectrum is the phase of swept-frequency signal
Position information is due to the embodiment being superimposed upon in amplitude value information of ripple, equivalent to being surveyed indirectly to the phase information of swept-frequency signal
Amount.
Fluctuating change is presented in return loss frequency spectrum, and transmission signal is in communication cable in transmitting procedure, due to cable distribution
The presence of inductance and electric capacity, the phase of transmission signal can be made gradually to postpone；Because cable space structure is relatively fixed, distributed inductance
Cable build-in attribute is also may be regarded as with electric capacity, therefore the speed of signal phase delay is also fixed for the construction of cable of the same race；
When being transferred to cable end piece and reflecting, reflections letters identical from emission signal frequency, that phase is different can be formed
Number；In transmitting procedure with transmission signal being superimposed for ripple occurs for reflected signal, because phase is different, forms part standing wave, finally
Cause transmitting and reflection electromagnetic wave energy-flux density uneven, energy coupling efficiency reduces, and as transmission signal and reflection are believed
The difference of number phase difference and change, ultimately result in the frequency spectrum presentation fluctuating change of return loss.
Compared with prior art, beneficial effects of the present invention are：
(1) by the implementation of the present invention, cable attribute can be measured and estimated by fairly simple cheap device
Calculate, including cable length, the change of cable resistance characteristic；
(2) by the present invention implementation, can make engineering staff in a short period of time the measurement of complete paired cable attribute and
Estimation, is easy to the state analysis to cable and maintenance；
(3) present invention is only acquired to the amplitude Value Data of reflected signal, stronger to the electromagnetic environment adaptability of complexity,
Device is simple, and cost is low；Robustness in function and structure is stronger, with more practicality.
Brief description of the drawings
The Figure of description for forming the part of the application is used for providing further understanding of the present application, and the application's shows
Meaning property example and its illustrate be used for explain the application, do not form the improper restriction to the application.
Fig. 1 is apparatus of the present invention hardware composition schematic diagram；
Another optional measurement structures of Fig. 2；
Fig. 3 is 35m coaxial lines A (thinner) measurement result；
Fig. 4 is 35m coaxial lines B (thicker) measurement result；
Fig. 5 is the measurement result of 200m (A) coaxial cable；
Fig. 6 is the measurement result of the overall plastic local call communication cable of 200m5*2*0.5 specifications；
Fig. 7 is the measurement result of the overall plastic local call communication cable of 100m5*2*0.5 specifications；
Fig. 8 is the measurement result of the overall plastic local call communication cable of 400m5*2*0.5 specifications.
Embodiment：
The invention will be further described with embodiment below in conjunction with the accompanying drawings.
It is noted that described further below is all exemplary, it is intended to provides further instruction to the application.It is unless another
Indicate, all technologies used herein and scientific terminology are with usual with the application person of an ordinary skill in the technical field
The identical meanings of understanding.
It should be noted that term used herein above is merely to describe embodiment, and be not intended to restricted root
According to the illustrative embodiments of the application.As used herein, unless the context clearly indicates otherwise, otherwise singulative
It is also intended to include plural form, additionally, it should be understood that, when in this manual using term "comprising" and/or " bag
Include " when, it indicates existing characteristics, step, operation, device, component and/or combinations thereof.
Term explains part：Including self-defined term, generic term, needs are not explained and limit clear term, citation
Offer and be related to content etc..
As background technology is introduced, cable status analysis method too complex in the prior art be present and need platform
Fault location could be realized by the support of complicated algorithm with database, daemon software development difficulty is larger, can not be more accurate
Estimate cable length, the deficiency for the attribute information such as whether cable properties impedance changes, in order to solve technical problem as above, this
Application proposes a kind of sweep measurement device of simplification and the frequency domain spy of the cable reflection coefficient measured by analyzing the device
Property estimation cable attribute method, the present invention only measures to the amplitude information of reflected signal, reduces answering for measurement apparatus
Polygamy and the antijamming capability for improving measurement apparatus, grown by the analysis to frequency domain data than cable is relatively accurately estimated
Degree, and judge whether cable properties impedance changes, and then judge whether cable is damaged.
A kind of sweep measurement device of simplification, behind abbreviation measurement apparatus, including：
Module occurs for sine wave signal, and the sinusoidal signal for being configured as producing Frequency Adjustable by DDS technologies is used as transmitting letter
Number source；
Power-adjustable amplification module, it is configured as adjusting sine wave swept-frequency signal generation module according to actual conditions demand
Transmission power size；
Dual directional coupler module, it is configured as transmission signal and reflected signal being oriented coupling sampling respectively defeated
Go out, and the sampled signal being coupled out is input to corresponding power measurement module；
The power measurement module, it is configured as that the signal power of RF switch modules output is measured and gathered；
Impedance matching module, the transformer and build-out resistor for being configured to, with different no-load voltage ratios form outlet side impedance
Adjustable circuit network, impedance matching can be carried out to the cable of different impedance varieties；
The MCU control module, it is configured as connecting sine wave signal generation module, power-adjustable amplification module and joint
Impedance matching module, above-mentioned module is scheduled, coordinates control, to monitor the state of communication cable shielding layer.
The dual directional coupler module includes input port, straight-through port, coupling port 1, coupling port 2 and isolation
Port；
The directional coupler is used to sample frequency sweep reflected signal, and frequency sweep transmission signal is as described in the directional coupler
Input port inputs, and the coupling port is used to export sampling of the directional coupler to frequency sweep transmission signal and reflected signal
Signal, the straight-through port is used to export the frequency sweep transmission signal or input reflection signal by the directional coupler, described
Isolated port is hanging.
The display module, it is configured as showing the LCD display of chart, sweep measurement result can be shown.
The RF switch modules, the High Frequency Analog Switch device of the type of SPDT × 1, i.e. single-pole double-throw switch (SPDT) are configured as, permitted
Perhaps high frequency analog signals pass through.
The loaded cable, refer to communication cable to be measured, connect the measurement apparatus.
Frequency Sweeping Method based on said apparatus, comprises the following steps
(1) loaded cable and impedance matching module are connected, impedance matching module is adjusted, makes the defeated of detection means
Go out the input resistant matching with loaded cable；
(2) sinusoidal signal of a certain fixed frequency of module generation occurs for MCU control module control sine wave signal, and inputs
To power-adjustable amplification module；
(3) MCU control module control power-adjustable amplification module adjusts sinusoidal signal to setting power (setting power work
MCU module is saved in for the transmission power of sinusoidal signal), it is then input to dual directional coupler module, dual directional coupler mould
Block carries out coupling sampling to transmission signal, and switches the coupling port 1 that RF switch modules are connected to dual directional coupler module, will
Sampled signal is input to power measurement module；The main energy of transmission signal is by dual directional coupler module and impedance matching mould
Block, it is coupled in loaded cable；
(4) MCU control module control power measurement module measures to the signal power of input, waits measurement result steady
After fixed, transmission signal power data that recording power measurement module measures simultaneously preserves；After the completion of, MCU control module control RF
Switch module is switched to the coupling port 2 of dual directional coupler module.
(5) after sinusoidal signal is coupled in loaded cable, in communication cable end or the locus of impedance discontinuity
Reflection can be produced；Reflected signal is along original path reverse transfer, by impedance matching module, impedance matching mould
The impedance matching effect of block ensure that the normal transmission of signal, and it is (general in the module and impedance mismatching point to effectively prevent signal
In the case of be cable shield breaking point) between multiple reflections occur or produce stronger concussion, it is accurate to influence measurement result
Property；
(6) reflected signal continues to be transferred to dual directional coupler module, and the module is sampled and coupled to reflected signal
Output, and power measurement module is coupled to by RF switch modules again；
(7) MCU control module control power measurement module measures to the signal power of input, waits measurement result steady
After fixed, reflection signal power data that recording power measurement module measures simultaneously preserve；
(8) sinusoidal signal that module produces next Frequency point, and repeat step occur for MCU module control sine wave signal
(3)~(7)；After the data of all predeterminated frequency points have been measured, perform (9)；
(9) MCU module is calculated and counted to sweep measurement result, calculates and loaded cable is tested under each Frequency point
Return loss, reflectance factor and voltage standing wave ratio, and shown in graphical form in display module；
In the step (1), impedance matching module output difference pin, for different types of cable and the different electricity of measurement
Cable attribute, connected mode are different；For the property measurement of certain a pair of twisted-pair feeder in local call communication cable, directly by differential pin with
The twisted pair line connection；In the case of local call communication cable screen layer attribute is measured, it is necessary to by one in differential pin
Cable shield is connect, one connects any one cored wire；For coaxial communications cable, then differential pin is respectively with screen layer with
Mandrel line connects；
In the step (5), after signal is coupled in loaded cable, the impedance between cable shield and cored wire has
The place (including cable end piece) of change, can be because impedance mismatch produces reflection, and reflected signal can transmit along loaded cable
To impedance matching module, dual directional coupler module is then communicated to, being transferred to power finally by RF switch modules surveys
Module is measured, carries out power measurement.
In the step (8), measurement apparatus is directed to the communication cable of the different model under varying environment, can set different
Swept frequency range and swept frequency interval, and these configuration informations are saved in MCU control module, it is convenient for measuring device and carries out automatically
Sweep measurement；
It is described that sweep measurement result is calculated and counted in the step (9), refer to the transmission signal by measuring
With the power of reflected signal, with reference to the parameter of directional coupler, corresponding reflectance factor, voltage standing wave ratio and echo can be calculated
Three conventional reflection parameters are lost；Specific reduction formula refers to associated radio frequency textbook.
A kind of method that cable attribute is estimated by frequency sweep reflectance factor, is mainly included the following steps that：
(1) sweep measurement is carried out to the communication cable of known length first, obtains return loss frequency spectrum (Fig. 3 of the cable
And Fig. 4)；The frequency spectrum of return loss is not straight line it can be seen from measurement result, but " waveform " change is presented, and
As frequency increase is gradual, the increase of return loss general trend；In the spectrum, the length cables are recorded and correspond to return loss frequency
The number (can retain decimal place) of completed wave in spectrum, and " wave " number corresponding to the cable of unit of account length, are designated as N0；
(2) sweep measurement is carried out to the cable of other unknown lengths, the frequency spectrum of return loss is similarly obtained, in frequency spectrum
The number of " wave " is counted and (is designated as N), then the length estimation of the cable is：L=N/N0 (unit length)；Such as Fig. 3 and
Fig. 5, Fig. 4 and Fig. 6；
(3) sweep measurement is carried out to the intact communication cable after having disposed, and records standard measurement data as below
Judge whether cable resistance characteristic occurs abnormal contrast benchmark；
(4) sweep measurement periodically is carried out to operating communication cable, if the return loss frequency spectrum and benchmark that measure
Frequency spectrum difference is excessive, then shows that communication cable impedance operator is changed, and cable is likely to occur damaged or abnormal；Need and
Shi Jinhang is overhauled；
In the step (1), institute's frequency sweep reflection parameters include three reflectance factor, voltage standing wave ratio, return loss parameters,
It is sweeping to the return loss of following several communication cables using sweep measurement device such as Fig. 3~Fig. 8 by taking return loss as an example
Frequency measurement result；
In the step (1), " waveform " change is presented in return loss frequency spectrum, is explained as follows in macroscopic perspective：Transmitting letter
Number in transmitting procedure, due to the presence of cable distribution inductance and electric capacity, the phase of transmission signal can be made gradual in communication cable
Delay；Because cable space structure is relatively fixed, distributed inductance and electric capacity also may be regarded as cable build-in attribute, therefore signal phase
The speed of delay is also fixed for the construction of cable of the same race；
When being transferred to cable end piece and reflecting, reflections letters identical from emission signal frequency, that phase is different can be formed
Number；In transmitting procedure with transmission signal being superimposed for ripple occurs for reflected signal, because phase is different, forms part standing wave, finally
Cause transmitting and reflection electromagnetic wave energy-flux density uneven, energy coupling efficiency reduces, and as transmission signal and reflection are believed
The difference of number phase difference and change, the frequency spectrum for ultimately resulting in return loss is presented " waveform " and changed；
For signal measurement angle, the changing rule of return loss frequency spectrum is the phase information of swept-frequency signal due to ripple
The embodiment being superimposed upon in signal amplitude information, equivalent to being measured indirectly the phase information of swept-frequency signal；This is also this
The theoretical foundation that method can be estimated cable length.
In a kind of typical embodiment of the application, as shown in figure 1, a kind of status monitoring of communication cable shielding layer
Module, power-adjustable amplification module, joint resistance occur for detection means, including MCU control module, display module, sine wave signal
Anti- matching module, dual directional coupler module, RF switch modules and power measurement module.
Module occurs for sine wave signal, using the CMOS whole number frequency synthesizers of Highgrade integration, main composition portion
Point：High-speed DDS module, frequency setting registers, high-speed A/D converter (DAC)；With reference to model：The AD9851 of ADI companies.
Power-adjustable amplification module, mainly by variable gain amplifier (VGA), power amplifier (HPA) and its periphery electricity
Road forms, and VGA refers to model：The AD8338 of ADI companies；HPA refers to model：The ADA4870 of ADI companies；
Impedance matching module, formed using matching transformer and its peripheral build-out resistor, electric capacity, inductance original paper.
With transformer basic parameter：Primary side and secondary side no-load voltage ratio 1-16 are adjustable, primary side input impedance in 300Hz-10MHz frequency ranges
For 50 Ω, transimission power upper limit threshold is 5W；
Dual directional coupler module, formed using bidirectional oriented coupler, attenuator network.Directional coupler is joined substantially
Number：Insertion loss<0.5dB, support frequency range 300K-10MHz, interface impedance：50Ω；
Power measurement module, it is high using the AD8310 of ADI companies, wide dynamic range, measurement accuracy, support bandwidth.
RF switch modules, RF switch, for the input signal channel of power switched measurement module, pass through the behaviour of the module
Make, the function that a power measurement module is sampled to transmission signal and reflection signal power respectively can be achieved.With reference to model：
ADG918、ADG919；Support that bandwidth, isolation are high, crosstalk is small；
Display module, it is low in energy consumption using conventional technical grade display screen, facilitate portable set to operate；
Apparatus control method (as shown in Figure 1)：
1. device itself can complete simple closed-loop control；
1) detection means initializes：MCU module reads default swept frequency range minimum value A, maximum B, and frequency interval
x；；MCU control module sends upper electricity instruction to sine wave signal generating module, then sends original sine wave frequency rate control letter
Breath, control module enter state to be output；MCU control module sends upper electricity instruction to power-adjustable amplification module, then sends
Initial signal power amplification multiple is minimum multiplication factor, and control module, which enters, treats working condition；MCU control module control joint
Impedance matching module carries out initial impedance matching and set；Electricity and initialization in MCU control module control power measurement module, are allowed to
Into treating working condition；Electricity and initialization on MCU control module control display module, feed them into initial interface；RF is switched
Electricity and initialization, acquiescence are switched to connection transmission signal (coupling port 1) and power measurement module in module；
2) delay a period of time, after treating that each module running status of device is stable, MCU module controls sine wave signal
Module, power-adjustable amplification module start to export, and control power measurement module to start working simultaneously, receive RF switches and transmit
Come signal and measure power, send the result to MCU control module；
3) for a period of time, after signal to be transmitted power measurement, MCU module control RF switch modules are switched to company for delay
Reflected signal (coupling port 2) and power measurement module are connect,；And control what power measurement module passed over to RF switch modules
Signal carries out power measurement, sends the result to MCU control module；
4) power information received is carried out analysis calculating by MCU control module, draw under the frequency return loss (or
Person's reflectance factor, voltage standing wave ratio), then by the measuring condition of this measurement, including emission signal frequency, power, reflection letter
Number power, return loss value are preserved；
5) judge：When the frequency f of this measurement is less than B, then module adjustment output frequency occurs for MCU module control sinusoidal signal
Rate is f+x；Repeat (2)-(5)；Work as f=B, then perform (6)；
6) MCU control module control display module shows the return loss frequency spectrum of this measurement；
2. device can complete the opened loop control of external hand input with display module；
1) the transmittable fixed frequency measuring command being manually entered of display module is to MCU control module, MCU control module root
According to the frequency information in the order, the frequency of module adjustment sinusoidal signal occurs for control sine wave signal, then performs controlling party
(2)-(4) step in method 1；
The constant power multiplication factor order that display module can be manually entered to MCU control module, MCU control module according to
Power output multiplication factor information in the order, the power amplification times of control power-adjustable amplification module adjustment sinusoidal signal
Number, then perform (2)-(4) step in control method 1.
Case verification：
Such as Fig. 3, Fig. 4, the coaxial communications cable of two equal lengths, in the return loss frequency spectrum that similar frequency bands measurement obtains
In " wave " number be about 2.5, parameter can be calculated：N0=2.5/35=0.0714/m；
Such as Fig. 5, " wave " number is about 14, and corresponding cable length L ≈ 14/N0 ≈ 196m are calculated；With actual electricity
Cable length is consistent substantially；
By the above method, Fig. 6~Fig. 8 can be verified successively, result of calculation in error range with actual electricity
Cable length is consistent.
The preferred embodiment of the application is the foregoing is only, is not limited to the application, for the skill of this area
For art personnel, the application can have various modifications and variations.It is all within spirit herein and principle, made any repair
Change, equivalent substitution, improvement etc., should be included within the protection domain of the application.
Although above-mentioned the embodiment of the present invention is described with reference to accompanying drawing, model not is protected to the present invention
The limitation enclosed, one of ordinary skill in the art should be understood that on the basis of technical scheme those skilled in the art are not
Need to pay various modifications or deformation that creative work can make still within protection scope of the present invention.
Claims (10)
1. a kind of sweep measurement device, including：
Module occurs for sine wave signal, and the sinusoidal signal for being configured as producing Frequency Adjustable by DDS technologies is used as transmiting signal source；
Power-adjustable amplification module, it is configured as the transmitting for adjusting sine wave swept-frequency signal according to actual conditions demand and module occurring
Watt level；
Impedance matching module, the transformer and build-out resistor for being configured to, with different no-load voltage ratios form outlet side impedance adjustable
Circuit network, impedance matching can be carried out to the cables of different impedance varieties；
It is characterized in that in addition to：Dual directional coupler module, it is configured as transmission signal and reflected signal being oriented respectively
Coupling sampling output, and the sampled signal being coupled out is input to corresponding power measurement module；
The power measurement module, it is configured as carrying out the signal power of dual directional coupler module different output port output
Measurement and collection；
MCU control module, it is configured as connecting sine wave signal generation module, power-adjustable amplification module, power measurement module
With impedance matching module, above-mentioned module is scheduled, coordinates control, to monitor the state of communication cable shielding layer.
2. a kind of sweep measurement device as claimed in claim 1, it is characterized in that：The dual directional coupler module includes input
Port, straight-through port, the first coupling port and the second coupling port and isolated port；The directional coupler is swept for sampling
Frequency reflected signal, frequency sweep transmission signal are inputted by the input port of the directional coupler, the first coupling port and second
Coupling port is used to export the directional coupler to frequency sweep transmission signal and the sampled signal of reflected signal, the straight-through port
For exporting frequency sweep transmission signal or input reflection signal by the directional coupler, the isolated port is hanging.
3. a kind of sweep measurement device as claimed in claim 1, it is characterized in that：First coupling of the dual directional coupler module
Close port and MCU control module and power measurement module are connected by RF switch modules with the second coupling port, pass through RF switching moldings
Block realizes that switching, or, the power measurement module include two, connects the first coupling port and the second coupling port respectively.
4. based on the Frequency Sweeping Method of the device as any one of claim 1-3, it is characterized in that：Including following step
Suddenly：
(1) loaded cable and impedance matching module are connected, adjusts impedance matching module, make the output of detection means with
The input resistant matching of loaded cable；
(2) MCU control module control sine wave signal occurs module and produces the sinusoidal signal of a certain fixed frequency, and be input to can
Adjusting power amplification module；
(3) MCU control module control power-adjustable amplification module adjusts sinusoidal signal to setting power, is input to amphiorentation coupling
Device module, dual directional coupler module carry out coupling sampling to transmission signal, and switch RF switch modules and be connected to amphiorentation coupling
First coupling port of clutch module, power measurement module is input to by sampled signal；The main energy of transmission signal passes through amphiorentation
Coupler Module and impedance matching module, are coupled in loaded cable；
(4) MCU control module control power measurement module measures to the signal power of input, waits measurement result to stablize it
Afterwards, recording power measurement module measures transmission signal power data simultaneously preserves；After the completion of, MCU control module control RF switches
Module is switched to the coupling port of dual directional coupler module second
(5) after sinusoidal signal is coupled in loaded cable, can be produced in communication cable end or the locus of impedance discontinuity
Raw reflection；Reflected signal is along original path reverse transfer, by impedance matching module；
(6) reflected signal continues to be transferred to dual directional coupler module, and the module is sampled and coupled output to reflected signal,
And power measurement module is coupled to by RF switch modules again；
(7) MCU control module control power measurement module measures to the signal power of input, waits measurement result to stablize it
Afterwards, recording power measurement module measures reflection signal power data simultaneously preserve；
(8) sinusoidal signal that module produces next Frequency point, and repeat step (3) occur for MCU module control sine wave signal
~(7)；After all predeterminated frequency point datas have been measured, perform (9)；
(9) MCU module is calculated and counted to sweep measurement result, calculates and returning for loaded cable is tested under each Frequency point
Ripple loss, reflectance factor and voltage standing wave ratio, and shown in graphical form in display module.
5. Frequency Sweeping Method as claimed in claim 4, it is characterized in that：In the step (1), impedance matching module output difference
Pin is separated, it is different for different types of cable cable attribute different with measurement, connected mode；For certain a pair in communication cable
The property measurement of twisted-pair feeder, directly by differential pin and the twisted pair line connection；For measuring communication cable shielding layer attribute
Situation, it is necessary to which one in differential pin is connect into cable shield, one connects any one cored wire；For coaxial telecommunications electricity
Cable, then differential pin connected respectively with screen layer with central axis.
6. Frequency Sweeping Method as claimed in claim 4, it is characterized in that：In the step (5), signal is coupled to loaded cable
In after, place that the impedance between cable shield and cored wire changes, impedance mismatch produces reflection, reflected signal meeting
Impedance matching module is transferred to along loaded cable, dual directional coupler module is then communicated to, is switched finally by RF
Module transfer carries out power measurement to power measurement module.
7. Frequency Sweeping Method as claimed in claim 4, it is characterized in that：In the step (8), measurement apparatus is directed to different rings
The communication cable of different model under border, can set different swept frequency ranges and swept frequency interval, and by these configuration informations
MCU control module is saved in, to carry out automatic frequency sweep measurement.
8. Frequency Sweeping Method as claimed in claim 4, it is characterized in that：In the step (9), pass through the transmission signal measured
With the power of reflected signal can calculate corresponding reflectance factor, voltage standing wave ratio and return loss three it is conventional reflection ginseng
Number, sweep measurement result is calculated and counted to realize.
9. Frequency Sweeping Method as claimed in claim 4, it is characterized in that：The side of cable attribute is estimated by frequency sweep reflectance factor
Method, including：
(I) sweep measurement is carried out to the communication cable of known length first, obtains the return loss frequency spectrum of the cable, record the length
Degree cable corresponds to the number of completed wave in return loss frequency spectrum, and the frequency spectrum of return loss corresponding to the cable of unit of account length
The number that middle curve fluctuates, is designated as N0；
(II) sweep measurement is carried out to the cable of other unknown lengths, the frequency spectrum of return loss is similarly obtained, to curve in frequency spectrum
The number fluctuated is counted, and is designated as N, calculates the length estimated value L=N/N0 of the cable；
(III) sweep measurement is carried out to the intact communication cable after having disposed, and records standard measurement data and be used as and sentence below
Whether power-off cable impedance operator occurs abnormal contrast benchmark；
(IV) sweep measurement periodically is carried out to operating communication cable, if the return loss frequency spectrum and reference spectral that measure
Difference exceedes setting value, then shows that communication cable impedance operator is changed, and cable is likely to occur damaged or abnormal.
10. Frequency Sweeping Method as claimed in claim 9, it is characterized in that：
In the step (I), for signal measurement angle, the changing rule of return loss frequency spectrum is the phase letter of swept-frequency signal
Breath is due to the embodiment being superimposed upon in amplitude value information of ripple, equivalent to being measured indirectly the phase information of swept-frequency signal.
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| CN109541391A (en) * | 2018-10-10 | 2019-03-29 | 山东康威通信技术股份有限公司 | A kind of low-power consumption cable shield on-Line Monitor Device, monitoring system and method |
| CN110161333A (en) * | 2019-05-23 | 2019-08-23 | 上海微小卫星工程中心 | Isolator reverse power withstand test system and method |
| CN110261739A (en) * | 2019-07-29 | 2019-09-20 | 哈尔滨工业大学 | A kind of cable soft fault positioning device and localization method |
| CN111521911A (en) * | 2020-05-21 | 2020-08-11 | 山东信通电子股份有限公司 | Intelligent monitoring method and equipment for power transmission line |
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| CN108445291A (en) * | 2018-03-14 | 2018-08-24 | 哈尔滨工业大学 | A kind of cable quality of production control method based on back scattering inversion technique |
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| CN109541391A (en) * | 2018-10-10 | 2019-03-29 | 山东康威通信技术股份有限公司 | A kind of low-power consumption cable shield on-Line Monitor Device, monitoring system and method |
| CN110161333A (en) * | 2019-05-23 | 2019-08-23 | 上海微小卫星工程中心 | Isolator reverse power withstand test system and method |
| CN111610370A (en) * | 2019-05-23 | 2020-09-01 | 青岛鼎信通讯股份有限公司 | 10kV line impedance detection device |
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| CN111521911A (en) * | 2020-05-21 | 2020-08-11 | 山东信通电子股份有限公司 | Intelligent monitoring method and equipment for power transmission line |
| CN113805101A (en) * | 2021-07-14 | 2021-12-17 | 国网江苏省电力有限公司电力科学研究院 | Cable cross interconnection system connection state testing method and testing device |
| CN116742432A (en) * | 2023-08-15 | 2023-09-12 | 西安普用电子科技有限公司 | Interface universality adapting method and system for realizing cable assembly based on negative feedback |
| CN116742432B (en) * | 2023-08-15 | 2023-10-24 | 西安普用电子科技有限公司 | Interface universality adapting method and system for realizing cable assembly based on negative feedback |
| CN117517783A (en) * | 2024-01-02 | 2024-02-06 | 成都迅翼卫通科技有限公司 | Single-port impedance detection device and method and electronic equipment |
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