CN109406876A - A kind of pulse carrier frequency detecting device and method based on TDC - Google Patents
A kind of pulse carrier frequency detecting device and method based on TDC Download PDFInfo
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- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R23/00—Arrangements for measuring frequencies; Arrangements for analysing frequency spectra
- G01R23/02—Arrangements for measuring frequency, e.g. pulse repetition rate; Arrangements for measuring period of current or voltage
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Abstract
The invention discloses a kind of pulse carrier frequency detecting device and method based on TDC, including signal conditioning unit, wave band frequency unit, power and pulse envelope detection unit, TDC unit, power processing unit, signal processing unit, the signal conditioning unit, wave band frequency unit, TDC unit, signal processing unit are sequentially connected, the signal conditioning unit, power and pulse envelope detection unit, power processing unit, signal processing unit are sequentially connected, and the wave band frequency unit is connect with signal processing unit.Present invention reduces pulse-modulated signal frequency test costs, and improve the precision of frequency test；Also achieve simultaneously the pulsewidth to pulse-modulated signal, the rise time, fall time isopulse parameter and continuous radiofrequency signal frequency measurement ability, and the power measurement of pulse-modulated signal and continuous radiofrequency signal can be provided.
Description
Technical field
It is specifically a kind of pulse carrier frequency detecting based on TDC the present invention relates to measurement, Radar Technology field
Device and method.
Background technique
Most basic three test volume in frequency microwave field of measuring technique is field distribution (standing wave), power and frequency,
Other parameters, which can be passed through to calculate by these three fundamental quantities, derive, therefore to the accurate measuring technique of signal power and frequency
Have become the key link of communication measurement.
Existing universal frequency measurement method there are several types of: direct counting method frequency measurement, analog interpolation counter with
And Equal-precision digital frequency measure method.The core of these frequency measuring methods be logic-based device realize can to input signal or
The universal counter that reference clock is counted, but be limited to the working frequency of device its numerical ability be only capable of reaching 10 nanoseconds or
Nanosecond rank, thus its measurement range is subject to certain restrictions, and is usually used in lower than the frequency measurement of 1GHz once.If measuring radio frequency
Or signal, it is necessary to high-frequency signal be become by the signal that universal counter assessing method can measure using frequency expanding method, so
Frequency is measured with universal counter Measuring Frequency Method afterwards.
The method of frequency expansion there are several types of: divide three kinds of method, heterodyne down converter technique and displacement method etc. in advance commonly
Frequency expanding method.In the selection process, mainly consider because being known as measurement accuracy, time of measuring, dynamic range and cost.
Input signal can be changed to lower frequency thus have higher resolution ratio by heterodyne down converter technique, but need a volume
It is relatively complicated that outer tuning local oscillator and input pre-selection, frequency mixer, intermediate frequency device such as improve at circuits, the circuit.In displacement method
Gate time needs to extend, therefore when time of measuring is identical, and resolution ratio does not have heterodyne down method of changing height, but due to lock
The application of circuitry phase does not use the method generally in rf frequency measurement so that it has very high sensitivity and loop gain
The main reason for be displacement method circuit structure it is especially complex so that cost becomes very high.Pre- frequency dividing method passes through input signal
It crosses directly by counter technique after frequency divider divides in advance, frequency measurement, sensitivity and dynamic range are all by institute in circuit
For the frequency divider of use come what is determined, required component is fewer, also there is very big advantage, circuit structure letter in cost
Single and higher cost performance is widely used it.
In pulsed radar applications, when measured signal is into after impulse modulation, impulse modulation width directly limit be sent to it is logical
With the number of the available counting input signal of counter, seriously affected to be generated to the direct measurement accuracy of frequency.When setting
Input signal is directly counted in gate time (effective measurement count time is less than or equal to pulsewidth T, and optimal cases are equal to pulsewidth T)
When, the corresponding frequency error of one count difference value of universal counter is 1/T, and pulsewidth is narrower, and T is smaller, and frequency error is bigger；When with
When modulation pulsewidth T is that gate counts the reference pulse of period t, the corresponding frequency error t/ of one technology difference of universal counter
T, in the case where pulsewidth T is certain, the period, t was smaller, and frequency error is smaller.Current radar pulse width can it is narrow to 2 it is delicate with
In the case where interior, universal counter single frequency measurement accuracy is difficult to be guaranteed, and it is tired to generally use repeatedly measurement progress result
Meter or average method improve measurement accuracy.
Summary of the invention
The purpose of the present invention is to provide a kind of pulse carrier frequency detecting device and method based on TDC, is a kind of base
In the time to the novel pulse modulated RF frequency test method of number conversion TDC technology, solve existing in the prior art
The low problem complicated with realization of pulse frequency detection accuracy.
The present invention is achieved through the following technical solutions: a kind of pulse carrier frequency detecting device based on TDC, including signal
Conditioning unit, wave band frequency unit, power and pulse envelope detection unit, TDC unit, power processing unit, signal processing list
Member, the signal conditioning unit, wave band frequency unit, TDC unit, signal processing unit are sequentially connected, the signal condition list
Member, power and pulse envelope detection unit, power processing unit, signal processing unit are sequentially connected, the wave band frequency unit
It is connect with signal processing unit.
Further, in order to preferably realize the present invention, the wave band frequency unit includes low band frequency unit, Gao Bo
Section frequency unit, the output end of signal conditioning unit are connect with the low band frequency unit, high band frequency unit respectively, institute
The output end for stating low band frequency unit is connect with TDC unit and signal processing unit respectively, the high band frequency unit
Output end is connect with TDC unit and signal processing unit respectively.
It further, further include comparator unit, power and pulse envelope detection unit in order to preferably realize the present invention
Output end connect with comparator unit, the comparator unit output end is connect with signal processing unit.
Further, further include external trigger unit in order to preferably realize the present invention, further include external trigger unit, clock
And calibration signal generates unit, the external trigger unit is connect with signal processing unit, and the clock and calibration signal generate list
Member is connect with signal conditioning unit and signal processing unit respectively.
Further, in order to preferably realize the present invention, specifically includes the following steps:
Step F1: initial measured signal input signal conditioning unit, signal conditioning unit is according to the frequency of initial measured signal
After rate judges automatically high band or low band, high band measured signal is sent to high band frequency unit, low band is tested
Signal is sent to low band unit under test；
Step F2: low band frequency unit and high band frequency unit will be initially tested according to the rule of wave band frequency unit
Signal is sent into TDC unit and signal processing unit simultaneously and is measured to initial measured signal, and according to signal processing unit
Initial measurement decides whether to carry out rapid Optimum to the frequency dividing ratio of wave band frequency unit；
Step F3: mono- by TDC after measured signal is sent into TDC unit by low band frequency unit and high band frequency unit
Member accurately measures the measured signal divided, and the temporal information of measurement is then sent to signal processing unit and is computed
Obtain frequency information；
Step F4: measured signal is sent to power and pulse envelope detection unit, power and pulse by signal conditioning unit
The logarithmic detector module of envelope detected unit carries out accurately logarithmic detector, inspection to the measured signal that signal conditioning unit is coupled out
Wave signal send to comparator unit and power processing unit handled simultaneously, and signal processing unit is respectively fed to after processing to mention
For the measurement start-stop of TDC unit；
Step F5: signal processing unit calculates and obtains the pulse characteristics of measured signal.
Further, further comprising the steps of in order to preferably realize the present invention:
Step F6: clock and calibration signal are generated unit and are generated at signal using internal timebase signal or external timing signal
Power calibration signal needed for reference clock needed for managing unit and signal conditioning unit.
Further, in order to preferably realize the present invention, the step F1 is specifically referred to:
External trigger unit access signal conditioning unit can be realized that measurement is synchronous with measured signal manually by staff, or by
Signal conditioning unit receives measured signal automatically.
Further, in order to preferably realize the present invention, the step F4 is specifically referred to:
Logarithmic detector module will not change the envelope characteristic of measured signal to guarantee the pulse width and edge of measured signal
Feature；Power processing unit carries out peak holding to rectified signal, then by the accurate ADC of power processing unit to peak holding
Signal is sampled and is converted, and sampling and transformation result reflect the input power of current measured signal, then measured signal is sent
To signal processing unit；
The envelope signal that detection exports is compared by comparator unit with the voltage value of setting, is sent more afterwards to signal
Reason unit is handled, and signal processing unit obtains the pulse characteristics of measured signal；
The pulse characteristics include rise time, fall time, duty ratio, pulse-recurrence time and the frequency of measured signal
Rate.
Further, in order to preferably realize the present invention, the step F5 is specifically referred to:
Signal processing unit controls signal conditioning unit according to the pulse characteristics and power of measured signal, control
The power distribution of each link of whole system guarantees that measured signal is entered in the state of undistorted with suitable watt level and divides
Frequency unit simultaneously works normally.
Further, in order to preferably realize the present invention, when the measured signal of input is continuous wave signal, power and arteries and veins
It rushes after the logarithmic detector module of envelope detected unit carries out logarithmic detector to measured signal, the rectified signal of formation is detecting circuit
Signal；When input signal is pulse-modulated signal, the logarithmic detector module of power and pulse envelope detection unit is to tested letter
After number carrying out logarithmic detector, the rectified signal of formation is envelope signal；
Rectified signal enters comparator unit and power processing unit simultaneously, when comparator unit only carries out envelope signal
Between parameter handle, power processing unit only detecting circuit signal is handled.
Working principle:
Present apparatus acceptable measured signal be relatively high power range (about 65dB) in continuous radiofrequency signal or
Pulse-modulated signal, when measured signal enters test equipment, signal conditioning unit is automatically selected according to the frequency of measured signal
Wave band frequency unit.Measured signal be sent to before frequency unit can according to input power size by signal conditioning unit as far as possible
Measured signal is improved under the premise of the local edge for not influencing pulse-modulated signal, to guarantee measured signal with suitable
Power enters wave band frequency unit, so that wave band frequency unit works in Optimal State.The output of wave band frequency unit according to
Rule enters TDC unit and signal processing unit measures measured signal, and according to the measurement knot of signal processing unit
Fruit judges whether that the frequency dividing ratio to wave band frequency unit optimizes.The measured signal of wave band frequency unit output frequency division enters
After TDC unit, the measured signal of frequency dividing is accurately measured by TDC unit, measurement accuracy by TDC unit resolution ratio and
The systematic error of signal processing unit determines.The logarithmic detector module of power and pulse envelope detection unit is to signal conditioning unit
The measured signal being coupled out carries out accurately logarithmic detector and obtains rectified signal, for the pulse width and edge for keeping measured signal
Characteristic, logarithmic detector module cannot change the envelope characteristic of measured signal.Rectified signal is sent into signal processing unit, processing unit
Obtain the frequency and power measurement of pulse-modulated signal and continuous radiofrequency signal, and modules to whole device or unit into
Row regulation.
Compared with prior art, the present invention have the following advantages that and the utility model has the advantages that
(1) present invention reduces pulse-modulated signal frequency test costs, and improve the precision of frequency test；Simultaneously
Realize the frequency of the pulsewidth to pulse-modulated signal, rise time, fall time isopulse parameter and continuous radiofrequency signal
The ability of measurement, and the power measurement of pulse-modulated signal and continuous radiofrequency signal can be provided；
(2) signal processing unit of the present invention realizes the communication with conversion chip TDC unit and the control to TDC unit,
And it carries out the calculating of frequency measurement and reports.Signal processing unit is the control core of whole device, receives external survey
Amount instruction initiates measurement movement, reads measurement result, report measurement results；
(3) present invention supports pulse envelope rise and fall time to survey along detection, pulse width measuring, pulse repetition period
Amount, pulse train detection measurement.Comparator unit detects pulse envelope signal and 10% level, 50% level and 90% electricity
It is flat compare after signal, by 10% level of pulse envelope, 50% level and 90% level position, signal processing unit can be with
Calculate rise and fall time, pulse width, pulse repetition period and pulse train；
(4) present invention can count multiple measurement results when modulated pulse trains are repeatable or number of pulses is more
It averagely can further promote frequency measurement accuracy.
Detailed description of the invention
Fig. 1 is detection device system block diagram of the present invention；
Fig. 2 is TDC unit pulse period waveform diagram of the present invention；
Fig. 3 is signal conditioning unit partial circuit schematic diagram of the present invention；
Fig. 4 is signal conditioning unit partial circuit schematic diagram of the present invention；
Fig. 5 is power processing unit partial circuit schematic diagram of the present invention；
Fig. 6 is power processing unit partial circuit schematic diagram of the present invention；
Fig. 7 is comparator unit circuit diagram of the present invention；
Fig. 8 is high band frequency unit circuit diagram of the present invention；
Fig. 9 is low band frequency unit circuit diagram of the present invention；
Figure 10 is TDC element circuit schematic diagram of the present invention；
Figure 11 is signal processing unit schematic diagram of the present invention.
Specific embodiment
The present invention is described in further detail below with reference to embodiment, embodiments of the present invention are not limited thereto.
Embodiment 1:
The present invention is achieved through the following technical solutions, as Figure 1-Figure 2, a kind of pulse carrier frequency inspection based on TDC
Survey device, including signal conditioning unit, wave band frequency unit, power and pulse envelope detection unit, TDC unit, Power Processing
Unit, signal processing unit, the signal conditioning unit, wave band frequency unit, TDC unit, signal processing unit are sequentially connected,
The signal conditioning unit, power and pulse envelope detection unit, power processing unit, signal processing unit are sequentially connected, institute
Wave band frequency unit is stated to connect with signal processing unit.
It should be noted that the present invention proposes a kind of pulse carrier frequency detecting device based on TDC by above-mentioned improvement
And method, the device include signal conditioning unit, wave band frequency unit, power and pulse envelope detection unit, TDC unit, when
Clock and calibration signal generate unit and signal processing unit, and present apparatus acceptable measured signal is relatively high power range
Continuous radiofrequency signal or pulse-modulated signal in (about 65dB), when measured signal enters test equipment, signal condition
Unit automatically selects wave band frequency unit according to the frequency of measured signal.Measured signal can be according to defeated before being sent to frequency unit
Enter watt level by signal conditioning unit under the premise of not influencing the local edge of pulse-modulated signal as far as possible to measured signal
It is improved, to guarantee that measured signal enters wave band frequency unit with suitable power, so that wave band frequency unit works in
Optimal State.The output of wave band frequency unit enters TDC unit and signal processing unit according to rule and carries out to measured signal
Measurement, and judge whether that the frequency dividing ratio to wave band frequency unit optimizes according to the measurement result of signal processing unit.Wave band
After the measured signal of frequency unit output frequency division enters TDC unit, the measured signal of frequency dividing is precisely surveyed by TDC unit
Amount, measurement accuracy are determined by the resolution ratio of TDC unit and the systematic error of signal processing unit.Power and pulse envelope detection
The logarithmic detector module of unit carries out accurately logarithmic detector to the measured signal that signal conditioning unit is coupled out and obtains detection letter
Number, for the pulse width and edge characteristics for keeping measured signal, logarithmic detector module cannot change the envelope characteristic of measured signal.
Rectified signal is sent into signal processing unit, and processing unit obtains the frequency of pulse-modulated signal and continuous radiofrequency signal and power is surveyed
Amount, and the modules or unit of whole device are regulated and controled.
Present invention reduces pulse-modulated signal frequency test costs, and improve the precision of frequency test；Also real simultaneously
The frequency for having showed the pulsewidth to pulse-modulated signal, rise time, fall time isopulse parameter and continuous radiofrequency signal is surveyed
The ability of amount, and the power measurement of pulse-modulated signal and continuous radiofrequency signal can be provided.
The other parts of the present embodiment are same as the previously described embodiments, and so it will not be repeated.
Embodiment 2:
The present embodiment advanced optimizes on the basis of the above embodiments, as shown in Figure 1, the wave band frequency unit packet
Include low band frequency unit, high band frequency unit, the output end of signal conditioning unit respectively with the low band frequency unit,
The connection of high band frequency unit, the output end of the low band frequency unit are connect with TDC unit and signal processing unit respectively,
The output end of the high band frequency unit is connect with TDC unit and signal processing unit respectively.
It should be noted that the wave band frequency unit includes high band frequency unit and low band by above-mentioned improvement
Frequency unit, and high band frequency unit and low band frequency unit are connect with signal processing unit and TDC unit respectively.Letter
Number conditioning unit automatically selects high band or low band according to the frequency of input measured signal, and high band measured signal is sent to
Low band measured signal is sent to high band fractional frequency signal by high band frequency unit.
Initial measured signal is sent into signal processing unit according to rule by wave band frequency unit, by signal processing unit pair
Initial measured signal measures, then signal processing unit according to initial measurement to the frequency dividing ratio of wave band frequency unit into
Row rapid Optimum is tested frequency dividing by TDC unit after the measured signal to TDC unit after wave band frequency unit output frequency division
Signal is accurately measured, and measurement accuracy is determined by the resolution ratio of TDC unit and the systematic error of signal processing unit.
The other parts of the present embodiment are same as the previously described embodiments, and so it will not be repeated.
Embodiment 3:
The present embodiment advanced optimizes on the basis of the above embodiments, as shown in Figure 1, further include comparator unit,
Power and the output end of pulse envelope detection unit are connect with comparator unit, the comparator unit output end and signal processing
Unit connection.
It should be noted that power and pulse envelope detection unit are coupled out signal conditioning unit by above-mentioned improvement
Measured signal carry out accurately logarithmic detector, rectified signal are sent in power processing unit and comparator unit simultaneously.Input
The measured signal of signal conditioning unit is pulse-modulated signal or continuous radiofrequency signal, and rectified signal is sent to Power Processing list simultaneously
After member and comparator unit.When the measured signal of input is continuous radiofrequency signal, rectified signal is detecting circuit signal；When defeated
When the measured signal entered is pulse-modulated signal, rectified signal is envelope signal.Comparator unit only to pulse-modulated signal into
The processing of row time parameter, power processing unit only carry out voltage (power) measurement to rectified signal.
Power processing unit carries out peak holding to rectified signal, then by the accurate ADC of power processing unit to peak value
Signal is kept to be sampled and sent after being converted to signal processing unit, sampled result reflects the input work of current measured signal
Then rate controls signal conditioning unit by signal processing unit, and adjust the power distribution of entire link, guarantees tested
Signal enters wave band frequency unit in the state of undistorted with suitable watt level, and makes modules or the normal work of unit
Make.
The envelope signal that detection exports is compared by comparator unit with the voltage value of setting, and comparator is sent out tested
Signal is handled to signal processing unit and is obtained pulse signal feature, signal characteristic include the rise time, fall time,
Duty ratio, pulse width, pulse-recurrence time and frequency etc., the parameters such as the propagation delay of comparator and up and down time
It will affect measurement result.
The other parts of the present embodiment are same as the previously described embodiments, and so it will not be repeated.
Embodiment 4:
The present embodiment advanced optimizes on the basis of the above embodiments, as shown in Figure 1, further include external trigger unit,
Clock and calibration signal generate unit, and the external trigger unit is connect with signal processing unit, and the clock and calibration signal produce
Raw unit is connect with signal conditioning unit and signal processing unit respectively.
It should be noted that clock and calibration signal generate unit and internal when base production can be used by above-mentioned improvement
Reference clock needed for raw digital processing element, also can be used external timing signal.When using external timing signal, it can default
Measured signal is synchronous with the clock of signal processing unit, helps to improve power and frequency measurement accuracy.Clock and calibration signal
The calibration signal generation circuit for generating unit generates known to frequency, power and accurate calibration signal is for TDC unit timing essence
Degree and the calibration of envelope level detection precision, to guarantee the real-time performance of device.
When the present apparatus and external equipment composition system, the trigger signal starting present apparatus can be generated by external trigger unit and is completed
The frequency of measured signal, power measurement can also make the present apparatus receive measured signal automatically and be handled and measured.
The other parts of the present embodiment are same as the previously described embodiments, and so it will not be repeated.
Embodiment 5:
The present embodiment advanced optimizes on the basis of the above embodiments, as shown in Figure 1, specifically includes the following steps:
Step F1: initial measured signal input signal conditioning unit, signal conditioning unit is according to the frequency of initial measured signal
After rate judges automatically high band or low band, high band measured signal is sent to high band frequency unit, low band is tested
Signal is sent to low band unit under test；
The step F1 is specifically referred to:
External trigger unit access signal conditioning unit can be realized that measurement is synchronous with measured signal manually by staff, or by
Signal conditioning unit receives measured signal automatically；
Step F2: low band frequency unit and high band frequency unit will be initially tested according to the rule of wave band frequency unit
Signal is sent into TDC unit and signal processing unit simultaneously and is measured to initial measured signal, and according to signal processing unit
Initial measurement decides whether to carry out rapid Optimum to the frequency dividing ratio of wave band frequency unit；
Step F3: mono- by TDC after measured signal is sent into TDC unit by low band frequency unit and high band frequency unit
Member accurately measures the measured signal divided, and the temporal information of measurement is then sent to signal processing unit and is computed
Obtain frequency information；
Step F4: measured signal is sent to power and pulse envelope detection unit, power and pulse by signal conditioning unit
The logarithmic detector module of envelope detected unit carries out accurately logarithmic detector, inspection to the measured signal that signal conditioning unit is coupled out
Wave signal send to comparator unit and power processing unit handled simultaneously, and signal processing unit is respectively fed to after processing to mention
For the measurement start-stop of TDC unit；
The step F4 is specifically referred to:
Logarithmic detector module will not change the envelope characteristic of measured signal to guarantee the pulse width and edge of measured signal
Feature；Power processing unit carries out peak holding to rectified signal, then by the accurate ADC of power processing unit to peak holding
Signal is sampled and is converted, and sampling and transformation result reflect the input power of current measured signal, then measured signal is sent
To signal processing unit；
The envelope signal that detection exports is compared by comparator unit with the voltage value of setting, is sent more afterwards to signal
Reason unit is handled, and signal processing unit obtains the pulse characteristics of measured signal；
The pulse characteristics include rise time, fall time, duty ratio, pulse-recurrence time and the frequency of measured signal
Rate；
Step F5: signal processing unit calculates and obtains the pulse characteristics of measured signal；
The step F5 is specifically referred to:
Signal processing unit controls signal conditioning unit according to the pulse characteristics and power of measured signal, control
The power distribution of each link of whole system guarantees that measured signal is entered in the state of undistorted with suitable watt level and divides
Frequency unit simultaneously works normally；
It is further comprising the steps of:
Step F6: clock and calibration signal are generated unit and are generated at signal using internal timebase signal or external timing signal
Power calibration signal needed for reference clock needed for managing unit and signal conditioning unit.
When the measured signal of input is continuous wave signal, the logarithmic detector module pair of power and pulse envelope detection unit
After measured signal carries out logarithmic detector, the rectified signal of formation is detecting circuit signal；When input signal is pulse-modulated signal
When, after the logarithmic detector module of power and pulse envelope detection unit carries out logarithmic detector to measured signal, the detection of formation is believed
Number be envelope signal；
Rectified signal enters comparator unit and power processing unit simultaneously, when comparator unit only carries out envelope signal
Between parameter handle, power processing unit only detecting circuit signal is handled.
It should be noted that signal processing unit processes are all mono- from wave band frequency unit, TDC by above-mentioned improvement
Member, comparator unit, power processing unit, clock and calibration signal generate the signal of unit, external trigger unit, and according to than
Required gate time, beginning and ending time are constructed compared with the output signal of device unit, the output of fractional frequency signal or TDC unit is believed
Number the preparation feature of measured signal is analyzed and obtained, contains carrier frequency signaling, envelope characteristic information etc., and the present apparatus
It can be with the continuous radiofrequency signal of adaptive measuring or pulse-modulated signal.
Signal processing unit controls all unit or module according to initial measured signal, such as signal condition mould
RF switch, frequency division coefficient and the clock and calibration signal of block generate the phaselocked loop of unit, and there are also the essences of power processing unit
Close ADC or DAC etc..Signal processing unit receives or sends single-ended 3.3.V LVTTL signal, high speed SPI signal, difference
2.5V PECL signal etc..
The other parts of the present embodiment are same as the previously described embodiments, and so it will not be repeated.
Embodiment 6:
The present embodiment advanced optimizes on the basis of the above embodiments, as shown in Figure 1, in the present apparatus before use, head
The factory calibration and system calibration work, factory calibration that first carry out power and frequency measurement use external perimysium reference model and power
Meter, using 10MHz as stepping, is distinguished from 50MHz~6GHz when calibration inputs standard signal power -10dBm, 0dBm and 10dBm
Highly attenuating channel and low attenuation path are calibrated, calibration value is stored in the non-volatile memory medium of equipment.
System calibration uses internal standard power source and standard frequency source, and measurement result is stored in by when first system calibration
In the non-volatile memory medium of equipment, when next system calibration, the deviation when time measurement result and storage measurement result is calculated, by
Drift correction is into the calculation processing of frequency and power.
Pulse envelope signal is inputted into after frequency measuring equipment, by the highly attenuating channel of default, at the beginning of carrying out input power
It surveys.Signal processing unit judges thresholding according to preset height decay power, according to the range of first power scale, strobe pulse frequency
Measurement channel is measured using highly attenuating channel measurement and low attenuation path.
By the signal after high-low-range channel selecting, while entering high and low wave band frequency unit and carrying out signal frequency split
Processing, the division of basis signal frequency range, selection are handled using high band processing or low band.Signal processing unit is according to passing through
Signal power size after internal low pass filter, the selection of automatic identification and confirmation measured signal height frequency range.High low band
Signal due to frequency it is higher, require carry out scaling down processing.According to the width of pulse envelope, signal processing software adjust automatically
The frequency division coefficient of input signal in pulse envelope width, detects no more than 5 input signal rising edges, it is believed that signal point
Frequency is in optimum state.
The other parts of the present embodiment are same as the previously described embodiments, and so it will not be repeated.
Embodiment 7:
The present embodiment advanced optimizes on the basis of the above embodiments, and as Figure 1-Figure 2, the present apparatus is supported continuous
The automatic identification of wave and pulse-modulated signal, the frequency measurement for supporting continuous radiofrequency signal and pulse-modulated signal.Continuous radio frequency
Signal and pulse-modulated signal are distinguished by the shape of pulse envelope.The envelope detection output of continuous radiofrequency signal is fixation
Level signal, and the envelope detection of pulse-modulated signal output is the pulse signal with rise and fall edge.
Pulse envelope detects the effective range for determining time conversion work, uses the envelope detection of wideband segment limit
The envelope waveform of pulse-modulated signal is measured in device, school.10% level of envelope waveform, 50% level are found by signal processing unit
And 90% level.By the comparator unit of high speed, detect pulse envelope signal and 10% level, 50% level and
90% level relatively after signal, be sent into signal processing unit handled.Signal processing unit is according to the secondary of this three groups of signals
Order relation judges the effective rising edge and failing edge of pulse envelope.Section between the rising edge and failing edge of pulse envelope
The valid interval of time interval measurement is carried out for TDC unit.Signal after the completion of high low band frequency unit processing, into conversion
The measurement of pulse period is carried out in chip TDC unit.
As shown in Fig. 2, START signal is defined as: generated by envelope signal, when comparator unit successively sends out 10%,
50%, 90% decision signal is regarded as primary effective START signal；Believe when generating START using outer triggering signal
Number when, need to shield the START signal generated by envelope at this time；When carrying out the measurement of continuous radio frequency signal frequency, envelope is examined at this time
Wave is direct voltage output, actively generates START signal by signal processing unit, can construct 1ms, 1s signal strobe substitution envelope
Signal.
STOP signal is defined as: STOP signal is obtained by pulse-modulated signal is divided, to avoid pulse frequency division head and the tail
Unstability, discard each clock edge of head and the tail.
Frequency measurement is defined as: calculate the time difference of two STOP signals of arbitrary neighborhood, it is inverted to can be obtained point
The frequency of signal after frequency；When first measurement, it is contemplated that full frequency band input covering, frequency dividing ratio can be arranged very little to guarantee full frequency band
Input generates the above STOP signal of at least two, when the input of frequency low side 50MHz, 800MHz generate 2 STOP signals, then
High-frequency certainly will generate more than 5 STOP signals when inputting, but not influence TDC cell operation, and only precision reduces；For the first time
After measuring input signal frequency range, frequency dividing ratio can be optimized to improve measurement accuracy, to include 2~4 in each pulse envelope
Divided pulse is advisable；The time difference between two STOP signals is calculated, and pulse modulation frequency is calculated according to frequency dividing ratio.
If measured radio frequency signal frequency is fc, modulation pulsewidth is tpw, frequency dividing ratio m, each envelope includes n frequency dividing arteries and veins
When punching, measured signal and the present apparatus share reference clock, the resolution ratio of TDC unit is tacc, consider the error of TDC unit measurement
Precision, the error of final frequency measurement is by being estimated asDivided pulse in frequency error and envelope
Square directly proportional, wherein minimum 2 n of quantity, when frequency input signal is unknown, m can be set to minimum value, very so as to cause n
Greatly, therefore frequency error is larger, so needing to distribute m and n rationally according to first measured value；Frequency error and taccIt is directly proportional, by TDC
The performance of unit is determining, taccSmaller, frequency error is smaller；Frequency error and modulation pulsewidth tpwSquare be inversely proportional, pulse width
Wider, frequency error is smaller；By signal processing software adjust automatically frequency division coefficient, available optimal frequency measurement essence
Degree.By actual test, pulse-width is the impulse modulation rf frequency of 950MHz~1150MHz frequency range of 20us,
Measurement accuracy is within 10kHz.If measured signal uses different reference clocks from the present apparatus, frequency error measurement is being calculated
When clock reference error should be taken into account.
The other parts of the present embodiment are same as the previously described embodiments, and so it will not be repeated.
Embodiment 8:
The present embodiment advanced optimizes on the basis of the above embodiments, and as Figure 1-Figure 2, signal processing unit is real
The now control with the communication of conversion chip TDC unit and to TDC unit, and carry out the calculating of frequency measurement with it is upper
Report.Signal processing unit is the control core of whole device, receives externally measured instruction, initiates measurement movement, reads measurement knot
Fruit, report measurement results.
Support pulse envelope rise and fall time along detection, pulse width measuring, pulse repetition period measurement, pulse train
Detection measurement.After comparator unit detects pulse envelope signal compared with 10% level, 50% level and 90% level
Signal can calculate rising by 10% level of pulse envelope, 50% level and 90% level position, signal processing unit
Fall time, pulse width, pulse repetition period and pulse train.
Can multiple measurement results be carried out with statistical average when modulated pulse trains are repeatable or number of pulses is more can be into
One step promotes frequency measurement accuracy.
The other parts of the present embodiment are same as the previously described embodiments, and so it will not be repeated.
Embodiment 8:
The present embodiment advanced optimizes on the basis of the above embodiments, and the signal conditioning unit includes two poles of protection
Pipe, broadband SPDT switch, attenuator, RF switch, coupler, power divider；The protection diode, broadband SPDT are opened
Pass, attenuator, RF switch are sequentially connected, and the broadband SPDT switch is connect with RF switch, the RF switch, coupling
Device, power divider are sequentially connected；The model 0402ESDA of the protection diode, the model of the broadband SPDT switch
MASW-002103-13630G, the model FAC0606P of the attenuator, the model PE42540 of the RF switch.
The power processing unit include logarithmic detector, minimum peak detector, maximum peak detector, triode,
Analog switch, the logarithmic detector are connect with minimum peak detector and maximum peak detector respectively, the minimum peak
Detector and maximum peak detector are connect with triode respectively, and the analog switch is connect with logarithmic detector, the logarithm
Wave detector is connect with power divider.
Comparator unit includes the chip of model AD5623RBRMZ-3；The input terminal of the AD5623RBRMZ-3 with it is right
Number wave detector connection, output end are connect with signal processing unit.The TDC unit uses the core of model TDC7201TOF
Piece.The signal processing unit uses the fpga chip of model XC7A200T-AFBG484I；The fpga chip with
TDC7201TOF is connected with AD5623RBRMZ-3.
As shown in Fig. 3-11, for the simple circuit schematic diagram between each module of the present invention or unit.
The above is only presently preferred embodiments of the present invention, not does limitation in any form to the present invention, it is all according to
According to technical spirit any simple modification to the above embodiments of the invention, equivalent variations, protection of the invention is each fallen within
Within the scope of.
Claims (10)
1. a kind of pulse carrier frequency detecting device based on TDC, it is characterised in that: divided including signal conditioning unit, wave band
Unit, power and pulse envelope detection unit, TDC unit, power processing unit, signal processing unit, the signal condition list
Member, wave band frequency unit, TDC unit, signal processing unit are sequentially connected, the signal conditioning unit, power and pulse envelope
Detection unit, power processing unit, signal processing unit are sequentially connected, and the wave band frequency unit and signal processing unit connect
It connects.
2. a kind of pulse carrier frequency detecting device based on TDC according to claim 1, it is characterised in that: the wave
Section frequency unit includes low band frequency unit, high band frequency unit, the output end of signal conditioning unit respectively with it is described low
Wave band frequency unit, high band frequency unit connection, the output end of the low band frequency unit respectively with TDC unit and signal
Processing unit connection, the output end of the high band frequency unit are connect with TDC unit and signal processing unit respectively.
3. a kind of pulse carrier frequency detecting device based on TDC according to claim 1 or 2, it is characterised in that: also wrap
Include comparator unit, the output end of power and pulse envelope detection unit is connect with comparator unit, and the comparator unit is defeated
Outlet is connect with signal processing unit.
4. a kind of pulse carrier frequency detecting device based on TDC according to claim 3, it is characterised in that: further include
External trigger unit, clock and calibration signal generate unit, and the external trigger unit is connect with signal processing unit, the clock and
Calibration signal generates unit and connect respectively with signal conditioning unit and signal processing unit.
5. a kind of pulse carrier frequency detecting method based on TDC according to claim 1, it is characterised in that: specific packet
Include following steps:
Step F1: initial measured signal input signal conditioning unit, signal conditioning unit according to the frequency of initial measured signal from
It moves after judging high band or low band, high band measured signal is sent to high band frequency unit, by low band measured signal
It is sent to low band unit under test；
Step F2: low band frequency unit and high band frequency unit are according to the rule of wave band frequency unit by initial measured signal
It is sent into TDC unit and signal processing unit simultaneously to measure initial measured signal, and according to the initial of signal processing unit
Measurement result decides whether to carry out rapid Optimum to the frequency dividing ratio of wave band frequency unit；
Step F3: after measured signal is sent into TDC unit by low band frequency unit and high band frequency unit, by TDC unit pair
The measured signal divided is accurately measured, and the temporal information of measurement is then sent to signal processing unit and is calculated
Frequency information；
Step F4: measured signal is sent to power and pulse envelope detection unit, power and pulse envelope by signal conditioning unit
The logarithmic detector module of detection unit carries out accurately logarithmic detector, detection letter to the measured signal that signal conditioning unit is coupled out
It number send to comparator unit and power processing unit and is handled simultaneously, signal processing unit is respectively fed to after processing to provide
The measurement start-stop of TDC unit；
Step F5: signal processing unit calculates and obtains the pulse characteristics of measured signal.
6. a kind of pulse carrier frequency detecting method based on TDC according to claim 5, it is characterised in that: further include
Following steps:
Step F6: clock and calibration signal generate unit and generate signal processing list using internal timebase signal or external timing signal
Power calibration signal needed for member required reference clock and signal conditioning unit.
7. a kind of pulse carrier frequency detecting method based on TDC according to claim 5, it is characterised in that: the step
Rapid F1 is specifically referred to:
External trigger unit access signal conditioning unit can be realized that measurement is synchronous with measured signal manually by staff, or by signal
Conditioning unit receives measured signal automatically.
8. a kind of pulse carrier frequency detecting method based on TDC according to claim 5, it is characterised in that: the step
Rapid F4 is specifically referred to:
Logarithmic detector module will not change the envelope characteristic of measured signal to guarantee the pulse width and edge features of measured signal；
Power processing unit carries out peak holding to rectified signal, then by the accurate ADC of power processing unit to peak hold signal
It is sampled and is converted, sampling and transformation result reflect the input power of current measured signal, then measured signal is sent to letter
Number processing unit；
The envelope signal that detection exports is compared by comparator unit with the voltage value of setting, is sent more afterwards to signal processing list
Member is handled, and signal processing unit obtains the pulse characteristics of measured signal；
The pulse characteristics include rise time, fall time, duty ratio, pulse-recurrence time and the frequency of measured signal.
9. a kind of pulse carrier frequency detecting method based on TDC according to claim 8, it is characterised in that: the step
Rapid F5 is specifically referred to:
Signal processing unit controls signal conditioning unit according to the pulse characteristics and power of measured signal, and control is entire
It is single to guarantee that measured signal enters frequency dividing in the state of undistorted with suitable watt level for the power distribution of each link of system
Member simultaneously works normally.
10. a kind of pulse carrier frequency detecting method based on TDC according to claim 8, it is characterised in that: work as input
Measured signal when being continuous wave signal, the logarithmic detector module of power and pulse envelope detection unit carries out pair measured signal
After number detection, the rectified signal of formation is detecting circuit signal；When input signal is pulse-modulated signal, power and pulse packet
After the logarithmic detector module of network detection unit carries out logarithmic detector to measured signal, the rectified signal of formation is envelope signal；
Rectified signal enters comparator unit and power processing unit simultaneously, and comparator unit only carries out time ginseng to envelope signal
Amount processing, power processing unit are only handled detecting circuit signal.
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| CN112327075A (en) * | 2020-10-20 | 2021-02-05 | 云南电网有限责任公司电力科学研究院 | Debugging method for power module of frequency modulation test platform of new energy unit |
| CN113093510A (en) * | 2021-02-26 | 2021-07-09 | 山东师范大学 | Clock frequency signal error measuring instrument and method |
| WO2023036090A1 (en) * | 2021-09-13 | 2023-03-16 | 北京车和家信息技术有限公司 | Pulse width modulation signal acquisition method and apparatus, computer device, and storage medium |
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