CN201328110Y - Phase-locking frequency tracking device - Google Patents
Phase-locking frequency tracking device Download PDFInfo
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- CN201328110Y CN201328110Y CNU200820155143XU CN200820155143U CN201328110Y CN 201328110 Y CN201328110 Y CN 201328110Y CN U200820155143X U CNU200820155143X U CN U200820155143XU CN 200820155143 U CN200820155143 U CN 200820155143U CN 201328110 Y CN201328110 Y CN 201328110Y
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Abstract
The utility model discloses a phase-locking frequency tracking device, which comprises a reference frequency source, a sampling holding unit, a phase-frequency detector, a loop filter, a digital voltage controlled oscillator, a frequency meter, a variable frequency divider, a narrowband protection circuit, a jitter delay phase locking ring and a prescaler. The narrowband protection circuit is arranged between the variable frequency divider and the jitter delay phase locking ring to limit over-high component power of the signal itself or sub-harmonic thereof so as to protect the entire device and further eliminate spurious components. The phase-locking frequency tracking device is easy and feasible; can ensure the stability and the locking delay of the frequency tracking system; and has the advantages of high frequency tracking accuracy and easy integration.
Description
Technical field
The utility model relates to the frequency microwave communications field, and a kind of phase-locking type frequency-tracking device particularly is provided.
Background technology
Technology of frequency tracking is the key link in the modern communications, has obtained using widely.Frequency-tracking utilizes feedback technique to regulate the concussion frequency automatically exactly, and output frequency is changed along with original frequency change.In the frequent and violent application scenario of some frequency variations, often need have the circuit or the device of Automatic Frequency regulatory function, such as, supersonic generator, the harmonic analysis of electric power signal and processing and wireless communication transceiver etc.Existing frequency-tracking scheme mainly contains three kinds: (1) current scheme, promptly adopt the variation of electric current to follow the tracks of; (2) power scheme: the power to signal compares tracking; (3) phase place scheme: utilize phase error to remove to eliminate frequency error, when circuit reaches poised state, just can realize not having the frequency-tracking of frequency error.
But traditional frequency tracker has brought following two problems: 1) tracking frequency can only be that increment changes with the reference step frequency.Just must will reduce in order to improve tracking frequency resolution, yet this is conflicting with tracking length change-over time, is inversely proportional to change-over time because follow the tracks of resolution and follow the tracks of with reference to step frequency.Though adopted after the prescalar, permission is worked on higher frequency, but because the frequency dividing ratio of prescalar is fixed, output frequency can only be that increment changes with product with reference to step frequency with its frequency dividing ratio, like this, the resolution of synthesizer has just descended.2) another problem is that last output is directly to be added on the frequency divider, and just with reference to the integral multiple of tracking frequency scope, resolution is lower for output frequency, and the tracking frequency scope is less, will produce big frequency tracking error.
And because the variation of interference signal; the synthetic frequency component of some reference sources is just dropped within the loop bandwidth of phase-locked loop, and appear among the output spectrum of voltage controlled oscillator, just spectrum leakage; just caused output spuious, regular meeting causes bigger frequency tracking error.Spuious component can will make receiver sensitivity significantly descend with the desired signal mixing.
Summary of the invention
The utility model purpose is to solve the excessive problem of ubiquitous tracking error in the existing technology of frequency tracking, and then proposes a kind of phase-locking type frequency-tracking device that can obtain better frequency-tracking effect.Frequency tracking circuit in the utility model can effectively be avoided the generation of leakage effect, makes the fundamental frequency of sample frequency real-time tracking signal, thereby fundamentally solves the spectrum leakage effect.
The technical solution of the utility model is:
Described phase-locking type frequency-tracking device comprises reference frequency source, sample holding unit, phase frequency detector, loop filter, digital vco, frequency meter, variable frequency divider, shake time delay phase-locked loop, prescalar.Each part mentioned above is linked to be a loop successively.Described reference frequency source is connected the first input end of described sample holding unit, and prescalar is connected the 3rd input of described sample holding unit.Described phase frequency detector input is connected the output of described sample holding unit.Linkloop filter and digital vco successively again.First output output of described digital vco requires to follow the tracks of the frequency that obtains, and its second output is connected to described frequency meter.Described digital frequency meter output is connected to variable frequency divider, connects shake time delay phase-locked loop and prescalar more successively.An arrowband protective circuit that is used to eliminate spuious component is connected between described variable frequency divider and the shake time delay phase-locked loop.
Phase frequency detector is a phase frequency comparator, and it compares the phase place of output signal and reference signal, produces the error voltage that differs corresponding to two signals.Sample holding unit is equivalent to a sampling switch, and digital-to-analogue conversion is finished by it, and its sample frequency is the twice of reference frequency source.Signal after the sampling through after keeping, its endpoints thereof has trickle variation.Phase-samplomh error function after sampling keeps regarding nothing estimation partially as after the self adaptation adjustment repeatedly through phase-locked loop, just has two ends to equate when stable state.Can also significantly reduce phase noise and clutter noise in the loop behind the use sample holding unit.The height of sampling frequency need not satisfy Shannon's sampling theorem, also can not have aliasing effect, because only need take out the phase information of two signals, changes the step variation characteristic that also still can keep the same for the loop tracks beyond the sampling time.
Then, signal is by loop filter, filtering part radio-frequency component and the noise in the error voltage, to guarantee the desired performance of loop initial startup condition.The control of the controlled voltage of digital vco makes the frequency of voltage controlled oscillator close to the frequency of reference signal.When initial startup, the output frequency end of digital vco has bigger departing from, and its other end continues to deliver to frequency counter with offset signal.
The high speed bimodulus variable frequency divider and the frequency meter that design between prescalar and digital vco finally can obtain bigger total counting frequency dividing ratio.So also just improved the operating frequency of device greatly.Having prescalar and phase-locked loop member in the ring just provides a kind of and has obtained the method for a large amount of tracking frequencies from single reference frequency, also just is easy to change our needed acquisition tracking frequency by increment.When entering the frequency-tracking state, the just synthetic automatically and locking incoming carrier frequency of this device.On the whole, the frequency range of tracking has been expanded many times, has obtained frequency in a big way, and still remains less step frequency at interval.
Loop is when locking, and phase frequency detector has still been kept a fixed voltage output.This voltage is added on the voltage controlled oscillator by loop filter, adjusts to frequency input signal the frequency of oscillation of voltage controlled oscillator synchronous.If when the frequency of digital vco and phase place were constantly followed the tracks of the variation of frequency input signal and phase place, loop just was in tracking mode.If loop neither is in the lock state, be not in tracking mode again, then be in out-of-lock condition, the protection that this moment, device was just received the arrowband protective circuit.The arrowband protective circuit is a high-order capacitance resistance circuit, can further eliminate spuious component, and it comprises amplitude limiter, amplifier, resistance R 1, R2, R3, R4, R5, R6 and capacitor C 1, C2, C3, C4.The C2 of described circuit, C3 and R3, R5, R6 ground connection.Its resistance sizes parameter can be carried out the self adaptation adjustment in actual use.So, variable frequency divider also just cooperates phase-locked loop to continue the frequency of search needs.Prescalar and variable frequency divider all are used for carrying out frequency division, and the former is the coarse adjustment frequency, and its frequency dividing ratio can be 100, and the latter is fine tuning, can carry out the frequency conversion search.
Tracer action by phase-locked loop, output signal frequency can be locked on certain subharmonic or subharmonic component of input signal, can realize that output signal and reference signal are synchronous, there is not frequency difference between the two and only exists very little stable state to differ, and this phase error can be ignored after the compensation mechanism of shake time delay phase-locked loop, if the frequency of input signal and phase place are constantly changing, then can be by the automatic corrective action of loop, make frequency and phase place under voltage-controlled constantly follow the tracks of the variation of incoming frequency, thereby realize good tracking performance.So the difference of both frequencies is more and more littler, eliminate and locked until frequency difference, just can be used for realizing good frequency-tracking.
A kind of phase-locking type frequency-tracking device, described device is used at communication control processor, the carrier frequency that is used for is to the received signal followed the tracks of synchronously, it is characterized in that: sample holding unit (2) adopts the AD582SH of U.S. AD company, loop filter (4) adopts second order Bessel low pass filter, and shake time delay phase-locked loop (9) is selected general integrated digital phase-locked loop NE564 for use.Amplitude limiter (201) in the described arrowband protective circuit (8) adopts the N9356B of Agilent company, and amplifier (202) adopts the ICL7650 of Intersil company.
Compared with prior art, the utility model utilizes phase error to remove to eliminate frequency error, so when circuit reached poised state, though there is residual phase error to exist, frequency error can be reduced to zero, thereby realizes the frequency-tracking of no frequency error.Because its good adaptive performance and to the good filtration of noise can be widely used in communication, radio and signal processing etc., the frequency that is used for is to the received signal followed the tracks of synchronously.
The beneficial effects of the utility model are, and are simple in structure, can obtain better frequency-tracking effect.
Description of drawings
Fig. 1 is a structure drawing of device of the present utility model.
Fig. 2 is the arrowband protective circuit figure in the utility model device.
Embodiment
Below in conjunction with accompanying drawing and preferred embodiment the utility model is further specified:
Among the embodiment, the utility model comprises reference frequency source 1 as shown in Figure 1, sample holding unit 2, phase frequency detector 3; loop filter 4, digital vco 5, frequency meter 6, variable frequency divider 7; arrowband protective circuit 8, shake time delay phase-locked loop 9, prescalar 10.Each part mentioned above is linked to be a loop successively.Described reference frequency source 1 is connected the first input end of described sample holding unit 2, and prescalar 10 is connected the 3rd input of described sample holding unit 2.Described phase frequency detector 3 inputs are connected the output of described sample holding unit 2.Linkloop filter 4 and digital vco 5 successively again.First output output of described digital vco 5 requires to follow the tracks of the frequency that obtains, and its second output is connected to described frequency meter 6.Described digital frequency meter 6 outputs are connected to variable frequency divider 7, connect shake time delay phase-locked loop 9 and prescalar 10 more successively.An arrowband protective circuit 8 is connected between described variable frequency divider 7 and the shake time delay phase-locked loop 9.
When access needed tracked outer signal source to be connected second input of described sample holding unit 2, device just began to carry out the frequency-tracking running.Phase frequency detector 3 is phase frequency comparator, and it is the signal of being come by prescalar 10 outputs, and the phase place in reference frequency source 1 and outer signal source compares, and produces the error voltage that differs corresponding to signal, and transports to sample holding unit 2.Sample holding unit 2 is equivalent to a sampling switch, and its sample frequency is the twice of reference frequency source.After the signal of 2 pairs of inputs of sample holding unit was met the sampling maintenance, its input and output endpoints thereof had trickle variation.Can also significantly reduce phase noise and clutter noise in the loop behind the use sample holding unit 2.Then, signal is by loop filter 4, filtering part radio-frequency component and the noise in the error voltage.Pass through the control of digital vco 5 again, when initial startup, the other end of digital vco 5 continues to deliver to frequency meter 6 with offset signal.High speed bimodulus variable frequency divider 7 and frequency meter 6 between prescalar 10 and digital vco 5 can obtain bigger total counting frequency dividing ratio.Loop is when locking, and phase frequency detector 3 has still been kept a fixed voltage output.This voltage is added on the voltage controlled oscillator 5 by loop filter 4, adjusts to frequency input signal the frequency of oscillation of voltage controlled oscillator 5 synchronous.If when the frequency of digital vco 5 and phase place were constantly followed the tracks of the variation of frequency input signal and phase place, loop just was in tracking mode.If loop neither is in the lock state, be not in tracking mode again, then be in out-of-lock condition, the protection that this moment, device was just received arrowband protective circuit 8.Arrowband protective circuit 8 is high-order capacitance resistance circuit.This moment, variable frequency divider 7 also just cooperated shake time delay phase-locked loop 9 to continue the frequency that search needs.Error signal can be locked in output signal frequency on certain subharmonic or subharmonic component of input signal by the tracer action of phase-locked loop 9, can realize that output signal and reference signal are synchronous.The frequency dividing ratio of prescalar 10 is 100, the signal that the frequency departure of 10 pairs of inputs of prescalar is bigger carries out frequency division, and the signal after will handling delivers to the 3rd input of sample holding unit 2, and continues similarly to be handled by whole device circulation and do not have frequency difference and only exist very little stable state to differ between the device input/output terminal.If the frequency of input signal and phase place are constantly changing, then can make frequency and phase place constantly follow the tracks of the variation of incoming frequency, thereby realize good tracking performance by the automatic corrective action of loop.So the difference of two ends frequency is more and more littler, eliminate and locked until frequency difference, just can be used for realizing good frequency-tracking.
A kind of phase-locking type frequency-tracking device, described device is used at communication control processor, the carrier frequency that is used for is to the received signal followed the tracks of synchronously, its each module selects for use the device model to be: sample holding unit 2 adopts the AD582SH of U.S. AD company, loop filter 4 adopts second order Bessel low pass filter, and shake time delay phase-locked loop 9 is selected general integrated digital phase-locked loop NE564 for use.Amplitude limiter 201 in the described arrowband protective circuit 8 adopts the N9356B of Agilent company, and amplifier 202 adopts the ICL7650 of Intersil company.
Arrowband protective circuit in the utility model device comprises amplitude limiter 201 as shown in Figure 2, amplifier 202, resistance R 1, R2, R3, R4, R5, R6 and capacitor C 1, C2, C3, C4.Port one is the signal input port of circuit, and port 2 is an output port.The C2 of described circuit, C3 and R3, R5, R6 ground connection.Incorporated amplifier 202 and amplitude limiter 201 play the effect of protective device, also guarantee the inhibition to the high-order harmonic wave frequency component simultaneously.
In sum, the utility model is simple in structure, and noise is had good filtration, because high accuracy frequency-tracking performance of the present utility model can make frequency-tracking obtain using more widely.
Claims (5)
1, a kind of phase-locking type frequency-tracking device; comprise reference frequency source (1); sample holding unit (2), phase frequency detector (3), loop filter (4); digital vco (5); frequency meter (6), variable frequency divider (7), arrowband protective circuit (8); shake time delay phase-locked loop (9), prescalar (10).It is characterized in that each part mentioned above is linked to be a loop successively: described reference frequency source (1) is connected the first input end of described sample holding unit (2), and prescalar (10) is connected the 3rd input of described sample holding unit (2).Described phase frequency detector (3) input is connected the output of described sample holding unit (2).Linkloop filter (4) and digital vco (5) successively again.First output output of described digital vco (5) requires to follow the tracks of the frequency that obtains, and its second output is connected to described frequency meter (6).Described digital frequency meter (6) output is connected to variable frequency divider (7), connects shake time delay phase-locked loop (9) and prescalar (10) more successively.An arrowband protective circuit (8) is connected between described variable frequency divider (7) and the shake time delay phase-locked loop (9).
2, phase-locking type frequency-tracking device as claimed in claim 1; it is characterized in that: the arrowband protective circuit (8) that is used to eliminate spuious component is a high-order capacitance resistance circuit; comprise amplitude limiter (201), amplifier (202), resistance R 1, resistance R 2, resistance R 3, resistance R 4, resistance R 5, resistance R 6, capacitor C 1, capacitor C 2, capacitor C 3 and capacitor C 4, wherein capacitor C 2, capacitor C 3, resistance R 3, resistance R 5 and resistance R 6 ground connection.
3, phase-locking type frequency-tracking device as claimed in claim 1 is characterized in that: also comprise a sample holding unit (2) in this device, be equivalent to a sampling switch, digital-to-analogue conversion is finished by it, and its sample frequency is the twice of reference frequency source (1).
4, phase-locking type frequency-tracking device as claimed in claim 1 is characterized in that: prescalar (10) and variable frequency divider (7) all are used for carrying out frequency division, and the former is the coarse adjustment frequency, and its frequency dividing ratio is 100, and the latter carries out the frequency conversion search for fine tuning.
5, a kind of phase-locking type frequency-tracking device, described device is used at communication control processor, the carrier frequency that is used for is to the received signal followed the tracks of synchronously, it is characterized in that: sample holding unit (2) adopts the AD582SH of U.S. AD company, loop filter (4) adopts second order Bessel low pass filter, and shake time delay phase-locked loop (9) is selected general integrated digital phase-locked loop NE564 for use.Amplitude limiter (201) in the described arrowband protective circuit (8) adopts the N9356B of Agilent company, and amplifier (202) adopts the ICL7650 of Intersil company.
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| CNU200820155143XU CN201328110Y (en) | 2008-11-10 | 2008-11-10 | Phase-locking frequency tracking device |
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| CNU200820155143XU CN201328110Y (en) | 2008-11-10 | 2008-11-10 | Phase-locking frequency tracking device |
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| CN102130514A (en) * | 2011-03-30 | 2011-07-20 | 上海北京大学微电子研究院 | Wireless power supply device of diagnosis and treatment system |
| CN102510237A (en) * | 2011-11-15 | 2012-06-20 | 北京工商大学 | Frequency-tracking piezoelectric transducer type multi-point starting device |
| CN102664844A (en) * | 2012-04-11 | 2012-09-12 | 苏州英菲泰尔电子科技有限公司 | Method for timing recovering of chip and removing of carrier frequency offset in demodulator |
| CN102955175A (en) * | 2012-09-25 | 2013-03-06 | 北京华安奥特科技有限公司 | Self-adaption signal conditioning and sending device and method of wireless underground tunnel scenograph |
| CN103220246A (en) * | 2012-12-14 | 2013-07-24 | 西安英菲泰尔电子科技有限公司 | Method for timing recovery and combination carrier wave frequency offset elimination of chip in frequency shift keying (FSK) demodulator |
| CN107449414A (en) * | 2016-05-26 | 2017-12-08 | 中国科学院微电子研究所 | The closed loop phase lock drive circuit of MEMS gyroscope |
| CN108449742A (en) * | 2018-03-13 | 2018-08-24 | 北京邮电大学 | A kind of aid demodulation system and method for near-field communication |
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- 2008-11-10 CN CNU200820155143XU patent/CN201328110Y/en not_active Expired - Fee Related
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| CN102130514A (en) * | 2011-03-30 | 2011-07-20 | 上海北京大学微电子研究院 | Wireless power supply device of diagnosis and treatment system |
| CN102510237B (en) * | 2011-11-15 | 2014-08-20 | 北京工商大学 | Frequency-tracking piezoelectric transducer type multi-point starting device |
| CN102510237A (en) * | 2011-11-15 | 2012-06-20 | 北京工商大学 | Frequency-tracking piezoelectric transducer type multi-point starting device |
| CN102664844A (en) * | 2012-04-11 | 2012-09-12 | 苏州英菲泰尔电子科技有限公司 | Method for timing recovering of chip and removing of carrier frequency offset in demodulator |
| CN102664844B (en) * | 2012-04-11 | 2014-10-29 | 苏州英菲泰尔电子科技有限公司 | Method for timing recovering of chip and removing of carrier frequency offset in demodulator |
| CN102955175A (en) * | 2012-09-25 | 2013-03-06 | 北京华安奥特科技有限公司 | Self-adaption signal conditioning and sending device and method of wireless underground tunnel scenograph |
| CN103220246A (en) * | 2012-12-14 | 2013-07-24 | 西安英菲泰尔电子科技有限公司 | Method for timing recovery and combination carrier wave frequency offset elimination of chip in frequency shift keying (FSK) demodulator |
| CN107449414A (en) * | 2016-05-26 | 2017-12-08 | 中国科学院微电子研究所 | The closed loop phase lock drive circuit of MEMS gyroscope |
| CN108449742A (en) * | 2018-03-13 | 2018-08-24 | 北京邮电大学 | A kind of aid demodulation system and method for near-field communication |
| CN110207891A (en) * | 2019-05-10 | 2019-09-06 | 电子科技大学 | A kind of silicon micro resonance type pressure sensor closed loop detection system |
| CN110086489A (en) * | 2019-05-13 | 2019-08-02 | 福州大学 | Exempt from interrupt superregenerative receiver frequency calibration circuit and working method |
| CN110086489B (en) * | 2019-05-13 | 2020-06-12 | 福州大学 | Interruption-free super-regenerative receiver frequency calibration circuit and working method |
| CN110912637A (en) * | 2019-12-31 | 2020-03-24 | 广东大普通信技术有限公司 | Clock synchronization system and method |
| CN110912637B (en) * | 2019-12-31 | 2021-06-29 | 广东大普通信技术有限公司 | Clock synchronization system and method |
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