CN108781057A - For reducing the mixting circuit of phase noise in local oscillator and frequency shift (FS) variance - Google Patents
For reducing the mixting circuit of phase noise in local oscillator and frequency shift (FS) variance Download PDFInfo
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- H—ELECTRICITY
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- H03B—GENERATION OF OSCILLATIONS, DIRECTLY OR BY FREQUENCY-CHANGING, BY CIRCUITS EMPLOYING ACTIVE ELEMENTS WHICH OPERATE IN A NON-SWITCHING MANNER; GENERATION OF NOISE BY SUCH CIRCUITS
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Abstract
The deviation of working frequency by average at least two oscillating input signals a kind of improves the device of the working frequency of oscillation output signal.The device includes that circuit is used for:(a) at least the first and second oscillating input signals are mixed by mixer.It is each that the oscillating input signal is with public input service frequency and mixed frequency signal is with synthetic work frequency.Each input service frequency is centered on public nominal frequency and has frequency departure, and synthetic work frequency is centered on the multiple of nominal frequency.(b) the synthetic work frequency of mixed frequency signal is divided to generate output signal by divider circuit, the output signal is with centered on nominal frequency and the working frequency with average frequency deviation, the average frequency deviation are the average value of the frequency departure of input signal.(c) output signal is exported.
Description
Background technology
The present invention is in the frequency departure effect for reducing oscillator signal involved in some embodiments, more specifically, but not arranging
Its ground is related to averagely reducing the frequency departure of oscillator signal by the deflection effect at least two oscillating input signals
Effect, especially oscillating input signal and the delay oscillator signal generated by postponing the oscillating input signal.
Oscillator signal is the basic structure block in the high application of various requirement, such as the reference signal for analog circuit
And/or the clock for digital circuit.Such application may usually need accurate low noise oscillator signal, the low noise sound and vibration
Swinging signal can be generated with minimum power consumption and keep accurate in certain frequency and time range.
In digital communication systems, especially in the wireless communication of multiple mobile transceivers and one or more base station communications
In system, the accuracy of oscillator signal may be very important.Each transceiver includes transmitters and receivers, the transmitter
With receiver may need to have the accurate and accurate reference frequency of low frequency wonder characteristic come with base station (one or more) into
Row communication.The reference of needs is provided usually using timing circuit and/or such as the component crystal oscillator, clock generator
Frequency, however, the frequency of the oscillator signal generated is easy to drift about with temperature at any time.
Invention content
One side according to some embodiments of the present invention provides a kind of by being inputted to two or more oscillations
The deviation of signal working frequency averagely improves the device of the working frequency of oscillation output signal.The device include one or
Multiple circuits, the circuit is for mixing at least the first and second oscillating input signals by the first mixer (M1)
For frequency to generate the mixed frequency signal with synthetic work frequency, each oscillating input signal has public input service frequency.
Each input service frequency is centered on public nominal frequency and has frequency departure, and synthetic work frequency is with nominal frequency
Multiple centered on.The one or more circuit is by dividing the synthetic work frequency of mixed frequency signal with divider circuit
To generate output signal, the output signal with centered on nominal frequency and the output services with average frequency deviation frequency
Rate, the average frequency deviation are the average value of at least frequency departure of the first and second oscillating input signals.Then, this
Or output signal described in multiple circuit outputs.
First mixer (M1) and/or the divider circuit are used to receive two additional oscillation input letters
Number to generate the output signal.
Optionally, which includes at least one delay circuit, is used to postpone received from oscillating circuit described first
Oscillator signal is inputted, the second oscillating input signal in the form of delay to generate as the first oscillating input signal.
Frequency departure includes frequency shift (FS) and/or the phase noise at the center relative to nominal frequency.The frequency shift (FS)
It is randomly distributed on around the nominal frequency of the oscillating input signal, and the phase noise is related to relative to described nominal
The random frequency change procedure of frequency in time.
At least one or more circuit further includes high-pass filter (high pass filter, HPF), and the HPF is used for
Remove at least one low frequency component of the mixed frequency signal.
Divider circuit includes the second frequency mixer (M2) and one or more low passes for generating the output signal
Filter (low pass filter, LPF), the LPF are used to remove one or more high fdrequency components from output signal.
Divider circuit further includes feedback path, which is used to generate feedback signal from the output signal.Instead
Feedback signal is fed back to second frequency mixer (M2), and second frequency mixer (M2) is used for the mixed frequency signal and described anti-
Feedback signal is mixed.
The feedback path also includes amplifier, and the amplifier is used for the signal amplitude level of the feedback signal is extensive
Again at equal with the signal amplitude level of the mixed frequency signal.
Optionally, the feedback path further includes frequency multiplier, work of the frequency multiplier for the feedback signal that doubles
Frequency is to match the working frequency of the mixed frequency signal.
Optionally, which includes one or more delay circuits, and one or more of delay circuits are for amplifying institute
It states output signal and is shaken with increasing the signal amplitude level of the output signal with compensating signal described in the mixing and scaling-down process
The decaying of width level.
One side according to some embodiments of the present invention provides a kind of by least two oscillating input signals
The method that the deviation of working frequency averagely improves the working frequency of oscillation output signal.This method includes:
Receive at least the first and second oscillating input signals, at least first and second oscillating input signals it is public
Input service frequency is centered on public nominal frequency and has frequency departure.
At least first and second oscillating input signals are mixed at the first frequency mixer (M1) to generate mixing
Signal, mixed frequency signal have the synthetic work frequency centered on the multiple of nominal frequency.
The synthetic work frequency of mixed frequency signal is divided to generate output signal at divider circuit, the output
The output services frequency of signal is centered on nominal frequency and to have average frequency deviation, the average frequency deviation be at least the
One and second oscillating input signal frequency departure average value.
The output output signal.
Divider circuit includes the second frequency mixer (M2) for generating the output signal and for from output letter
The feedback path of feedback signal number is generated, the feedback signal is fed back to the second frequency mixer (M2), second frequency mixer
(M2) it is used to be mixed mixed frequency signal and feedback signal.
Unless otherwise defined, otherwise all technologies used herein and/or scientific terminology have and fields of the present invention
The normally understood identical meaning of those of ordinary skill.Although can be used in the practice or test of the embodiment of the present invention
Similar or equivalent method and material with method described herein and material, but described hereafter is illustrative method and/
Or material.In case of conflict, then it is subject to including patent specification defined herein.In addition, these materials, method and example
It is merely illustrative, it is not necessary to be intended to limit.
Description of the drawings
Here some embodiments only by way of example with reference to the accompanying drawings to describe the present invention.Referring now particularly to attached drawing
It is described in detail, it is emphasized that shown details is as example and for the illustrative discussion to the embodiment of the present invention
Purpose.In this regard, the description carried out using attached drawing will make how can implement the embodiment of the present invention for this field skill
Art personnel become apparent.
In attached drawing:
Fig. 1 is the exemplary means for the frequency characteristic for being used to improve oscillation output signal according to some embodiments of the present invention
Schematic diagram;
Fig. 2 is the example process flow of the frequency characteristic of improvement oscillation output signal according to some embodiments of the present invention
Cheng Tu;
Fig. 3 is according to some embodiments of the present invention for improving oscillation output signal using two input signals
The schematic diagram of the exemplary means of frequency characteristic;
Fig. 4 is according to some embodiments of the present invention by carrying out the exemplary of average generation to two oscillating input signals
The schematic diagram of the power density diagram of the gain reduction of oscillation output signal;
Fig. 5 is to be used to improve the frequency of oscillation output signal using four input signals according to some embodiments of the present invention
The schematic diagram of the exemplary means of rate characteristic;And
Fig. 6 is to be used to improve oscillation output signal using the input signal of delay according to some embodiments of the present invention
The schematic diagram of the exemplary means of frequency characteristic.
Specific implementation mode
The present invention is in the frequency departure effect for reducing oscillator signal involved in some embodiments, more specifically, but not being
Uniquely, it is related to reducing the frequency departure effect of oscillator signal by the deflection effect of average at least two oscillating input signals
It answers, especially oscillating input signal and the delay oscillator signal generated by postponing oscillating input signal.
The present invention is proposed improves oscillation for one or more deflection effects by reducing oscillator signal working frequency
The device of one or more frequency characteristics (for example, about time and/or the precision of temperature, stability and/or variation) of signal,
System and method.Deflection effect may include such as frequency shift (FS) and/or phase noise (also referred to as phase drift).Frequency shift (FS)
The deviation at the center relative to nominal frequency can be shown as, and for multiple oscillator signals in practical application, usually frequency
Rate offset may be randomly distributed on around nominal frequency centre.In practical applications, phase noise usually can be with random phase
Position noise process is characterized, such as random, quick, the short-term fluctuation in the phase of oscillator signal.
It can be carried out by the deflection effect to two or more input oscillator signals with public nominal operating frequency
It is average to improve the frequency characteristic of oscillator signal to generate output signal.Due to the random nature of deflection effect, i.e. frequency shift (FS)
Random distribution and phase noise random process, so by deflection effect carry out averagely can it is significant improve output signal frequency
Characteristic.
By the deflection effect to two or more input signals averagely come improve the frequency characteristic of oscillator signal can
There can be significant benefit compared with being currently used in the existing method for improving frequency characteristic.One benefit is relative to using possibility
Expensive high-end oscillating circuit with the frequency characteristic (such as temperature-compensating and/or frequency-tracking) that one or more improves,
Source by using two or more low side oscillating circuits as oscillating input signal, can reduce cost.Another benefit is
By avoiding reducing circuit, such as phase tracking circuit using one or more phase noises, answering for oscillating circuit can be reduced
Polygamy (and may be decreased cost).
By being mixed first to input signal using the first mixting circuit to generate mixed frequency signal and use frequency divider
Circuit, which divides mixed frequency signal, to be come with restoring the nominal operating frequency of output signal to two or more oscillating input signals
Frequency characteristic be averaged.The synthetic work frequency of mixed frequency signal is the multiple of nominal operating frequency.It can make mixed frequency signal
By high-pass filter (HPF), which is used to remove one or more low frequency components, the mixing from mixed frequency signal
Signal is that the first mixting circuit is generated when being mixed to input signal.Then mixed frequency signal is made to enter divider circuit
In, divider circuit may include the second mixting circuit coupled with feedback path, and feedback path feedback loop output signal is with to
Two mixed frequency signals provide feedback signal.Second mixting circuit by being mixed to mixed frequency signal and feedback signal for being generated
Output signal.Divider circuit can also include low-pass filter (LPF), and the low-pass filter from output signal for removing
One or more high fdrequency components, the output signal are that the second mixting circuit is produced when being mixed to mixed frequency signal and feedback signal
Raw.Divider circuit can also include the amplifier on feedback path, which is used for the amplitude level of feedback signal
Revert to the nominal amplitude level of input signal.
Optionally, postpone one or more input signals using one or more delay circuits to generate as input to believe
Number delay form one or more postpones signals.Postpones signal can be used together with input signal to generate output letter
Number.
Optionally, divider circuit includes the frequency multiplier for making feedback signal double.If the quantity n of input signal is
2 power, when using more than two oscillating input signals come when generating output signal, it may be necessary to frequency multiplier.When to having public affairs
When n input signal of nominal frequency is mixed altogether, the synthetic work frequency of mixed frequency signal is that nominal frequency is multiplied by n.In order to
Feedback signal is suitably adjusted before feedback signal enters the second mixting circuit, feedback signal can be doubled to have and mix
The identical nominal frequency of frequency signal.
Optionally, output signal is amplified to increase the signal amplitude level of output signal, is being mixed and is being divided with compensation
The decaying of signal amplitude level described in period.
Before at least one embodiment of the present invention is explained in detail, it should be appreciated that the present invention in its application not
Be necessarily limited to described in being described below and/or the details of the construction of component and arrangement shown in attached drawing and/or example and/
Or method.The present invention can have other embodiment or be practiced or carried out in various ways.
The present invention can be system, method and/or computer program product.Computer program product may include having thereon
It is useful for making the computer readable storage medium that processor executes the computer-readable program instructions of each aspect of the present invention (or more
A medium).
Computer readable storage medium can be physical device, which can retain and store and be made by instruction execution equipment
Instruction.Computer readable storage medium can be (but are not limited to) for example:Electronic storage device, magnetic storage apparatus, light are deposited
Store up equipment, electromagnetism storage device, the suitable combination of semiconductor memory apparatus or any equipment above-mentioned.
Computer-readable program instructions described herein can be via such as internet, LAN, wide area network and/or nothing
The network of gauze network downloads to corresponding calculating/processing equipment or outer computer or outer from computer readable storage medium
Portion's storage device.
Computer-readable program instructions can be used as independent software package fully on the user computer, partly in user
It is executed on computer, partly on the user computer, partly on the remote computer, or completely in remote computer or service
It is executed on device.In the latter case, remote computer can be by including LAN (local area network, LAN)
Or any kind of network connection of wide area network (wide areanetwork, WAN) is to the computer of user, or can (example
Such as, pass through internet using Internet Service Provider) it is connected to outer computer.In some embodiments, in order to execute sheet
The various aspects of invention, including such as programmable logic circuit system, field programmable gate array (field-programmable
Gate arrays, FPGA) or the circuit system of programmable logic array (programmable logic arrays, PLA) can
Computer-readable program instructions are executed with the status information by using computer-readable program instructions so that electronic circuit system
System is personalized.
With reference to according to the method for the embodiment of the present invention, the flow chart and/or frame of device (system) and computer program product
Figure is described herein each aspect of the present invention.It should be understood that flowchart and or block diagram in each frame and flow chart and/
Or the combination of the frame in block diagram can be realized by computer-readable program instructions.
Flowcharts and block diagrams in the drawings show system according to various embodiments of the present invention, method and computer journey
The framework of sequence product, the possible embodiment of function and operation.This in this respect, each frame in flowchart or block diagram can be with
Expression includes the module of the instruction of one or more executable instructions for realizing specified logic function, section or part.?
In some alternate embodiments, the function of being pointed out in frame can not occur according to the sequence pointed out in attached drawing.For example, depending on institute
The function being related to, two frames continuously shown can essentially be executed substantially simultaneously or frame sometimes can be with opposite suitable
Sequence is performed.It is also noted that the combination of each frame and the frame in block diagram and or flow chart of block diagram and or flow chart
The system based on specialized hardware of function or action or the combination of execution specialized hardware and computer instruction can be specified by executing
It executes.
Referring now to figure 1, Fig. 1 is the frequency characteristic for improving oscillation output signal according to some embodiments of the invention
The schematic diagram of exemplary means.Exemplary means 100 include mixer 110 and divider circuit 120, mixer
110 receive multiple oscillating input signals (102A to 102N) with the working frequency centered on public nominal frequency, frequency dividing
The output of device circuit 120 has the oscillation output signal 106 of the working frequency centered on identical public nominal frequency.It is each defeated
Entering signal 102 can receive from such as pierce circuit.Mixting circuit 110 includes for two or more input signals 102
One or more frequency mixers (M1) 112 for being mixed and for being removed from the mixed frequency signal that frequency mixer (M1) 112 exports
One or more low frequency components are to generate the HPF 114 of mixed frequency signal 104.
Optionally, mixting circuit includes one or more delay circuits 116, is used to postpone one or more input signals
102 to generate one or more postpones signals, these postpones signals are (one or more in frequency mixer to be entered (M1) 112
It is a) the delay form of input signal 102.
Mixed frequency signal 104 is divided in divider circuit 120 using frequency mixer (M2) 122, frequency mixer (M2) 122
Mixed frequency signal 104 is mixed with feedback signal 108, by the feedback that output signal 106 is fed back to divider circuit 120
Path receives feedback signal 108.Feedback path includes for the amplitude level of feedback signal 108 to be restored to input signal 102
Nominal amplitude level amplifier 126.
Optionally, feedback path includes frequency multiplier 128, is used to make the working frequency of feedback signal 108 to double.Work as use
More than two input signal 102 is come when generating mixed frequency signal 104, it may be necessary to the work of the multiplication feedback signal 108 of frequency multiplier 128
Frequency is to make it equal to the working frequency of mixed frequency signal 104.Make the signal exported from frequency mixer (M2) 122 by LPF 124,
LPF 124 removes one or more high fdrequency components of mixed frequency signal to generate output signal 106.
Optionally, device 100 includes one or more output amplifiers 130, the amplitude electricity for restoring output signal 106
The flat output signal 107 with generation amplification.The amplitude level of output signal 106 may need to be resumed, because in frequency mixer electricity
The mixing executed in road 110 and/or divider circuit 120 and/or divide operation, the output signal 106 compared with input signal 102
It may decaying.
It is showing for the frequency characteristic of improvement oscillation output signal according to some embodiments of the present invention referring now to Fig. 2, Fig. 2
The flow chart of example property process.The process 200 of frequency characteristic for improving oscillation output signal 106 can be by using exemplary
Device 100 averagely completes the frequency characteristic of one or more oscillating input signals 102.
As shown in 210, process 200 starts from receiving two at least partly independent of each other at frequency mixer (M1) 112
Or multiple input signal 102.Oscillating input signal 102 all has the common operating frequency centered on nominal frequency, and every
A can include one or more deviations (deflection effect), such as frequency shift (FS) and/or phase noise.Each input signal
102 can indicate as described in following equation 1:
Equation 1:
Wherein, each input signal 102 is defined as si(t), with frequencies omegaOp, i, ωOp, iIt can be indicated as
The working frequency of input signal, and can also include being expressed as continuous time phase processPhase noise, wherein i tables
Show the label of input signal 102A to 102N.Frequencies omegaiBy being expressed as ωc=2 π fcNominal frequency constitute, and can also wrap
Include frequency shift (FS) ωi=2 π fi.Two oscillating input signals have public amplitude level A.
Assuming that the frequency shift (FS) ω of input signal 102iWith with finite variance σ2Nominal frequency ωc=2 π fcCentered on
Random distribution.It is assumed that the phase noise process of input signal 102It is random process, wherein the average value of the process isFrom
Correlation is R (t1, t2The π β min (t of)=21, t2).Wherein t1, t2Indicate different time points, and β is and each input signal
102 relevant auto-correlations it is expected parameter factors.Parameter beta is a feature of local oscillator, and different oscillators is had
Institute is different.Although present invention could apply to any kind of phase noise, above done in assume relevantly to represent typical case
Reality system, and the case where worst may further be presented, because the differentiation of input signal is uncertain.So
The phase noise process of definition is generated as:
Equation 2:
Wherein,It is around round Gauss (Gaussian) process so that i={ 1,2 } and δ () is dirac
(Dirac) trigonometric function.As discussed above, the characteristic for synthesizing random process can have following expectation and autocorrelation value
Wiener (Wiener) process:
Equation 3:
In mixting circuit, signal 102 is first mixed at filter (M1) 112 and is filtered to produce at HPF 114
Raw mixed frequency signal 104, the mixed frequency signal 104 have synthetic work frequency, which is all input signals 102
The summation of working frequency.Since the working frequency of all input signals 102 has public nominal frequency, so being expressed as sM(t)
Mixed frequency signal 104 synthetic work frequency be nfc(input signal 102si(t) multiple of working frequency), and with input
Signal 102 is directly related, as shown in following equation 4.
Equation 4:
As shown in 220, mixed frequency signal 104 is divided using divider circuit 120, it is such as following to generate
Output signal 106s ' (t) shown in formula 5.
Equation 5:
s′(t)∝cos(ω′t+θ′t)
Derived for 120 peer-to-peer 1 of divider circuit and equation 5, obtain following equation 6, mixed frequency signal with it is anti-
Feedback signal 108 (having the nominal amplitude level restored) is mixed in divider circuit 120.
Equation 6:
Obviously, output signal 106 is oscillator signal, and frequency is the frequencies omega with phase noise process1..., ωn's
Average frequency value, the noise process are the phase noise processes of input signal 102Average value.For common n
For rank (n input signal 102), it may be complicated to equation 6 to derive equation 1, and therefore, equation 1 hereinbefore arrives etc.
The derivation of formula 6 is recapitulative, is described in detail below for the embodiment of the low order of the present invention.
As shown in 230, output signal 106 is exported from device 100 for one or more of multiple applications,
Such as the reference clock for digital circuit, it is used for the modulating clock etc. of radio frequency (radio frequency, RF) transceiver.
It is averaged by the deviation (one or more) to input signal 102 to reduce deviation (one or more), it can
To significantly improve the operating frequency characteristics of output signal 106.Output signal 106 has with nominal frequency ωcCentered on work
Frequency, but may include due to the average of the deviation between two or more input signals 102 and reduce deviation (one or
It is multiple) (deflection effect).The random nature of deviation (one or more), i.e. 102 working frequency ω of input signalOp, iBetween frequency
The random distribution and phase noise process of rate offsetRandom nature allow carry out average operation statistically to reduce deviation
Effect.The deviation of reduction can have following characteristics.Each input signal 102si(t) frequency shift (FS) ωiVariance can be with table
It is shown as σ2.It is σ that output signal 106s ' (t), which will have variance,2The working frequency of/n.Similarly, the phase noise of output signal 106
The auto-correlation of process is also divided by n, is equal to R (t1, t2The π β min (t of)=21, t2)/n。
The deviation that output signal 106 reduces may increase amplitude noise to a certain extent, however, such as output amplifier
130 one or more amplifying circuits can be applied to output signal 106, for restore the amplitude level of output signal 106 with
Removal and/or reduction amplitude noise, so as to improve the signal-to-noise ratio of output signal 106.In addition, mixting circuit 110 and frequency divider electricity
Road 120 can cause at least some signal power losses, however noise level remains unchanged, to realize output signal 106
Higher signal-to-noise ratio.Output signal can be further magnified to restore the output that may be attenuated during mixing and frequency dividing
The amplitude level of signal 106.
Some embodiments of the present invention are provided by showing the example of possible embodiment and/or preferred embodiment.
It is according to some embodiments of the present invention for improving oscillation using two input signals referring now to Fig. 3, Fig. 3
The schematic diagram of the exemplary means of the frequency characteristic (one or more) of output signal.Device 100A is exemplary means 100
Specific variants receive two oscillating input signal 102A and 102B with the working frequency centered on public frequency and produce
Raw output signal 106A, the working frequency of output signal 106A is centered on nominal frequency, and the relatively described center has reduction
Deviation (one or more).Device 100A includes mixting circuit 110A and divider circuit 120A.Two input signals
102As1(t) and 102Bs2(t) as shown in following equation 7.
Equation 7:
ωOp, 1=2 π (fc+f1)
ωOp, 2=2 π (fc+f2)
To input signal 102As at frequency mixer (M1) 112A1(t) and 102Bs2(t) it is mixed, to generate as following
Pre-filtering mixed frequency signal 103As shown in equation 8M(t)。
Equation 8:
Pre-filtering mixed frequency signal 103As 'M(t) include two frequency components.First frequency component with input signal 102A and
The sum of the nominal frequency ω c of 102B (ωOp, 1+ωOp, 2) centered on.Second frequency component is with the mark of input signal 102A and 102B
Claim frequencies omegacDifference (ωOp, 1-ωOp, 2) centered on.
Then, pre-filtering mixed frequency signal 103A is input in HPF 114A, HPF 114A remove pre-filtering mixed frequency signal
The low frequency component of 103A, to generate the mixed frequency signal 104As shown in following equation 9M(t)。
Equation 9:
HPF 114A can be adapted for clearly distinguishing high fdrequency component ωOp, 1+ωOp, 2With low frequency component ω1-ω2.At this
It invents in interested typical practical applications, (ωOp, 1+ωOp, 2) and (ωOp, 1-ωOp, 2) difference may be very big, and allow
HPF suitably detaches two frequency components in the best way.
Then, mixed frequency signal 104A is output in divider circuit 120A, and divider circuit 120A is to mixed frequency signal
The working frequency of 104A is divided to generate output signal 106A.Divider circuit 120A includes frequency mixer (M2) 122A, is mixed
Frequency device (M2) 122A is mixed mixed signal 104A with feedback signal 108A to generate stable state output signal 106A.It is mixed
Frequency device (M2) 122A for reducing mixed signal 104A working frequency, to form the working frequency of output signal 106A with nominal
Centered on frequency.As shown in following equation 10, output signal 106A is represented as s ' (t).
Equation 10:
Output signal 106A is set to pass through the feedback path in the divider circuit 120A including amplifier 126A.Amplifier
126A restores the amplitude level of output signal 106A and is nominally shaken with equal with the amplitude level of mixed frequency signal 104A with generating
The feedback signal 108A of width level.Therefore, the amplification factor of amplifier 126A is set to 4/A2.Therefore, at steady state,
The intermediate output signal s (t) of frequency mixer (M2) 122A is the letter that mixed frequency signal 104A is mixed with feedback signal 108A
Number, as shown in following equation 11.
Equation 11:
Then, the signal exported from frequency mixer (M2) 122A is output in LPF 124A, and LPF 124A remove mixed frequency signal
High fdrequency component ω1+ω2+ ω ' is to generate output signal 106A.Therefore, output signal 106A can be such as following 12 institute of equation
Show to indicate.
Equation 12:
The expression formula in following equation 13 is generated in conjunction with equation 10 and 12.
Equation 13:
Equation 13 is converted into two items as represented by following equation 14.
Equation 14:
From equation 14 as can be seen that being averaged to the deviation of input signal 102A and 102B by using device 100A,
The deviation (deflection effect) of output signal 106 is reduced.
According to proposing before it is assumed that phase noise processAndIt is random process, such as they may be wiener
(Wiener) process, average value 0, auto-correlationWherein E [] indicates the phase
Hope operator, and β is a parameter.Since two phase noise processes are independent, so the synthesis of output signal 106A
Phase noise process θ 'tAuto-correlation indicated in following equation 15.
Equation 15:
This can be construed to the reduction of the noise variance of output signal 106A.By will be in input signal 104A and 102B
One power spectral density is compared with the power spectral density of average output signal 106A, shows that the gain reduces.
It is the schematic diagram of power density diagram according to some embodiments of the present invention, the power density referring now to Fig. 4, Fig. 4
The gain for showing the exemplary oscillation output signal generated by being averaged to two oscillating input signals reduces.Phase
Two oscillating input signals of device pair by using such as device 100A, which are averaged, and are produced is shown to power density diagram 400
The power density diagram of raw oscillation output signal.Curve graph 410 shows that such as described oscillation compared with curve graph 420 exports
The versus power density characteristic of the oscillation output signal of signal, curve graph 420 show such as oscillating input signal 102A and
The versus power density characteristic of the oscillating input signal of 102B.It is from Figure 40 0, it is evident that related to average output signal 106
The curve graph 410 of connection shows the noise of the 3dB compared with one of original input signal 102A and 102B associated curve graph 420
It reduces.
It is defeated for improving oscillation using four input signals according to some embodiments of the present invention referring now to Fig. 5, Fig. 5
Go out the schematic diagram of the exemplary means of the frequency characteristic (one or more) of signal.Although being described herein using 2 or 4
The device of input, it will be clear that 3 signals can also be configured as input.Device 100B is the specific change of exemplary means 100
Body receives four oscillating input signals 102A, 102B, 102C, the 102D with the working frequency centered on public frequency,
And output signal 106B is generated, the working frequency of output signal 106B is centered on nominal operating frequency and the relatively described center tool
There is the deviation (one or more) of reduction.The operation of described device 100B is similar to the operation of such as device 100A, and there are one examples
Be outside about multiplication feedback signal 108B working frequency to make it equal to the working frequency of mixed frequency signal 104B.Described device
100B includes mixting circuit 110B and divider circuit 120B.Using two level frequency mixer (M1) 112B to four input signals
102A-102D is mixed, and two level frequency mixer (M1) 112B first mixes each pair of 102A-102B and 120C-102D
Frequently, then the output of two frequency mixer (M1) 112B is mixed in frequency mixer (M1) 112C.Four output signals
102As1(t), 102Bs2(t), 103C s3(t) and 102D s4(t) as shown in following equation 16.
Equation 16:
ωOc, 1=2 π (fc+f1)
ωOc, 2=2 π (fc+f2)
ωOc, 3=2 π (fc+f3)
ωOc, 4=2 π (fc+f4)
Then pre-filtering mixed frequency signal 103B is output in HPF to remove the low frequency component of pre-filtering mixed frequency signal 103B
To generate mixed frequency signal 104B.Mixed frequency signal includes four with 2fcCentered on low frequency component and one with 4fcCentered on
High fdrequency component.Low frequency component is removed by HPF 114B, and mixed frequency signal 104A only includes that amplitude is equal to A4/ 8 high fdrequency component
[ω1+ω2+ω3+ω4].Signal 104B is fed into frequency mixer (M2) 112B in divider circuit 120B, frequency mixer (M2)
112B is mixed to generate intermediate output signal mixed frequency signal 104B with feedback signal 108B.Intermediate output signal passes through
The high fdrequency component of LPF 124B, LPF 124B removal output signals is to generate output signal 106B.Output signal 106B is fed back
To divider circuit 120B and enter amplifier, which is restored to the amplitude level of feedback signal 108B and mixed frequency signal
The equal nominal amplitude level of the amplitude level of 104B.Feedback signal 108B is output in frequency multiplier 128A, frequency multiplier 128A
The working frequency expansion of feedback signal 108B is four times greater, make it equal to the working frequency of mixed frequency signal 104B.Since two level is mixed
The working frequency of the effect of device (M1) 112B and 112C, mixed frequency signal 104B is the nominal operation frequency of input signal 102A-102B
4 times of rate.
After identical equation shown in for device 100A, institute's table in average output signal 106B such as following equation 17
Show.
Equation 17:
, it is evident that being averaged to the deviation of input signal 102A-102D by using device 100B from equation 17,
The deviation (deflection effect) of output signal 106 reduces.
Optionally, for the device of such as device 100, there are multiple embodiments, and device 100 is for receiving any exponent number n's
Oscillating input signal is to generate the output signal of such as output signal 106.Device 100 can be in mixting circuit (such as mixing electricity
Road 110) it is middle using multistage frequency mixer (M1) (such as frequency mixer (M1) 112), with divider circuit (such as divider circuit
120) frequency multiplier appropriate in is coupled (such as frequency multiplier 126).Output signal 106 can also be derived from amplifier 126 without
It is low-pass filter (LPF) 124.
It is according to some embodiments of the present invention for being shaken using the input signal of delay to improve referring now to Fig. 6, Fig. 6
Swing the schematic diagram of the exemplary means of the frequency characteristic of output signal.Device 100C is the specific variants of exemplary means 100,
Receive a concussion input signal 102A.By using single oscillator and especially by will be from the input of the oscillator
Signal 102A is mixed with the delay form of its own come to reduce phase noise be possible.In the case, it shakes with described
It is not independent to swing signal 102A and delay input relevant two processes of oscillator signal 102A1.Under this arrangement, phase
The reduction degree of noise depends on the delay.In addition, the reduction degree of phase noise might also depend on process itself.Device
100C includes delay circuit 116A, is configured to input signal 102A delay predetermined time periods (delay) to generate as defeated
Enter the postpones signal 102A1 of the delay form of signal 102A.Delay can have different values and can be based on shaking for generating
The local oscillator and desired phase noise for swinging input signal reduce to select to postpone.Additionally or alternatively, the amount of delay
It can depend on physical limit:The amount of delay veritably determines the size of delay circuit.Therefore, the available sky in described device
Between for the size of delay circuit set the upper limit, to set the upper limit for the amount of delay that may be implemented.The amount of delay is in phase
Noise reduces makees the result weighed between circuit size.To described defeated in (M1) frequency mixer of such as (M1) 112A frequency mixers
Enter signal 102A to be mixed with postpones signal 102A1, to generate pre-filtering mixed frequency signal 103C.Then, from frequency mixer (M1)
The signal that 112A flows through device 100C is similar with the signal for flowing through device 100A.
Although it is not independent to input oscillator signal 102A and delay input oscillator signal 102A1, will be shown below in phase
Position noise process is random, and especially in the case of wiener (Wiener) process, the device of the invention allows to reduce output letter
Number phase noise.
For example, it is assumed that the phase noise process in oscillating input signal 102A is wiener as described above (Wiener) process.
Consider that the phase noise process of two moment t and s, wherein t≤s, poor process verification are
The delay form (delaying τ) of shown process with itself is averagely obtained to new process W ', new process W 'tNo longer it is
Wiener-Hopf equation.The mean value of building-up process is 0, and the ladder increment between any time t and s has following characteristic:
Equation 18:
If (t-s)≤τ observations input oscillator signal 102A and delay input oscillator signal in a time interval
102A1, then the variance of new process is the half of original procedure, it means that the phase noise of input oscillator signal 102A reduces
1/2.For larger time interval, variance reduces constant, τ/2, the constant relative to 2 π β (t-s) of original variance at any time
Between become smaller.Under any circumstance, compared with the phase noise of input oscillator signal 102A, the phase noise of output signal reduces.
In more general terms, can should the statistically period of reduction or interested period with the variance of Kernel-based methods
To select delay τ.Specifically, delay can be set based on the quantity of the symbol during estimation phase noise.Particularly, if
Delay is set equal to the interested time, then the phase noise of output signal is θi'=θi/2.This interested time takes
Certainly in the application of the present invention.
It is τ=10, output signal by the delayed selection culture for example, in the system of phase noise of every 10 sign estimations
Phase noise process performance can be similar to every time estimation between variance be half Wiener-Hopf equation.
Therefore, the selection of delay needs the desired period of the variance reduced in the process depending on us.As existed
It is mentioned above, in practice, the value for postponing τ is bigger, and delay circuit just must be bigger.The selection of delay is related on circuit board
Free space and the degree that reduces of delay or, in other words, phase noise between tradeoff.
If oscillating input signal 102A delays to be more than to the time quantum of interested time, the device meeting described in Fig. 6
Generate the effect of desired reduction phase noise (especially variance noise).
Obviously, can be that the device of such as device 100 creates multiple additional embodiments, described device 100 include one or
The delay circuit of multiple such as delay circuits 116, it is defeated with the oscillation for postponing any number of such as oscillating input signal 102
Enter signal 102.In addition it is possible to use multilevel delay circuit 116 postpones any single input 102, with generate additional one or
The postpones signal of multiple such as postpones signal 102A1.For example, can be received by the device 100 including 3 delay circuits 116
Single input signal 102A.Input signal 102A can be input to the first delay circuit 116, to generate postpones signal 102A1.
It is then possible to postpones signal 102A1 is input to the second delay circuit 116, to generate postpones signal 102A2, it is then possible to will
The postpones signal 102A2 is input to third delay circuit 116 to generate postpones signal 102A3.Device 100 can be used for receiving
Fourth signal 102A, 102A1,102A2 and 102A3, to generate output signal 106.
Show the description to various embodiments of the present invention for purposes of illustration, but the description and unexpectedly
Figure is exhausted or is limited to the disclosed embodiments.In the case where not departing from the scope and spirit of described embodiment,
For those of ordinary skill in the art, many modifications and variations will be apparent.It is used herein by selection
Term be in order to best explained relative to the technology found in the market the principle of embodiment, practical application or technology into
Step, or make those skilled in the art it will be appreciated that embodiment disclosed herein.
Term " about " used herein refers to ± 10%.
Term " comprising ", " consist of ", " comprising ", " by ... constitute ", " having " and combination thereof mean " packet
It includes but is not limited to ".The term include term " by ... form " and " substantially by ... form ".
Phrase " substantially by ... form " refers to component or method may include additional ingredient and/or step, but only when
When other compositions and/or step will not substantially change the basic and novel features of claimed component or method.
As it is used herein, unless the context clearly indicates otherwise, otherwise singulative " one ", "one" and "the"
Including plural form.For example, term " a kind of compound " or " at least one compound " they may include multiple compounds, including its
Mixture.
This " exemplary " word used herein indicates " be used as example, example or explanation ".It is described as " exemplary "
Any embodiment be not necessarily to be construed as more more preferable than other embodiments or advantageously, and/or exclude to come from other implementations
The combination of the feature of example.
Term used herein refers to " optionally " " providing and not carrying in other embodiments in some embodiments
For ".Any specific embodiment of the present invention may include multiple " optional " features, unless these features mutually conflict.
In entire application, various embodiments of the present invention can be presented in the form of range.It should be understood that range
The description of form is not construed as inflexible limitation to the scope of the invention just for the sake of convenienct and succinct.Therefore,
The description of range is considered as specifically disclosing all possible subrange and the individual number within the scope of this.For example,
The description of range from 1 to 6 is considered as having specifically disclosed subrange, such as from 1 to 3,1 to 4,1 to 5,2 to 4,2
To 6,3 to 6 etc., and individual digital in the range, such as 1,2,3,4,5 and 6.Range regardless of the range, this
It is all suitable for.
Digital scope is pointed out whenever herein, is intended to the number for any reference being included in indicated range
Word (score or integer)." range/range " between the first designation number and the second designation number and " range/range from "
One the second designation number of designation number " to " " uses, and is intended to include the first and second instructions interchangeably herein
Number and all scores between them and integer number.
It is understood that for the sake of clarity, the present invention's described in the context of individual embodiment is certain
Feature can also combine offer in single embodiment.On the contrary, for simplicity, in the context of single embodiment
The various features of the present invention of description individually either can also be provided with any suitable sub-portfolio or be suitable in this hair
It is provided in the embodiment of any other bright description.Certain features described in the context of various embodiments are not considered
It is the essential feature of those embodiments, unless the embodiment does not work in the case of these no elements.
All publications referred in this specification, patents and patent applications are integrally incorporated this theory herein by reference
Bright book, degree are specifically and individually pointed out such as each individual publication, patent or patent application by quoting simultaneously
Enter herein.In addition, the reference of any bibliography in the application or mark are not necessarily to be construed as recognizing that this bibliography can
The prior art as the present invention.In the range of using chapter title, it should not be constructed as limiting.
Claims (15)
1. a kind of deviation by the working frequency at least two oscillating input signals averagely improves oscillation output letter
Number working frequency device, which is characterized in that including:
At least one circuit, is used for:
At least the first and second oscillating input signals are mixed by the first mixer (M1), each oscillation is defeated
Entering signal has public input service frequency, to generate the mixed frequency signal with synthetic work frequency, each input service
Frequency is centered on public nominal frequency and has frequency departure, and the synthetic work frequency is with times of the nominal frequency
Centered on number;
The synthetic work frequency of the mixed frequency signal is divided by divider circuit to generate output signal, the output
The output services frequency of signal centered on nominal frequency and have average frequency deviation, the average frequency deviation be it is described extremely
The average value of the frequency departure of few first and second oscillating input signals;And
Export the output signal.
2. the apparatus according to claim 1, wherein first mixer (M1) and/or the divider circuit
For receiving at least two additional oscillating input signals to generate the output signal.
3. device according to any one of claim 1 to 2 further includes at least one delay circuit, for postponing from shaking
Swing the first input oscillator signal of circuit reception, the institute in the form of delay to generate as first oscillating input signal
State the second oscillating input signal.
4. the apparatus according to claim 1, wherein the frequency departure include relative to the nominal frequency it is described in
The frequency shift (FS) of the heart and/or phase noise, wherein the frequency shift (FS) is randomly distributed on the described of the oscillating input signal
Around nominal frequency, and the phase noise is related to changing relative to the random frequency of the nominal frequency in time
Journey.
5. device according to any one of claim 1 to 4, wherein at least one circuit further includes high-pass filter
HPF, at least one low frequency component for removing the mixed frequency signal.
6. device according to any one of claim 1 to 5, wherein the divider circuit includes described defeated for generating
The second frequency mixer (M2) and at least one low-pass filter LPF, the LPF for going out signal are used for from the output signal
Except at least one high fdrequency component.
7. device according to claim 6, wherein the divider circuit further includes feedback path, the feedback path is used
In generating feedback signal from the output signal, the feedback signal is fed back to second frequency mixer (M2), and described second
Frequency mixer (M2) is for being mixed the mixed frequency signal and the feedback signal.
8. device according to claim 7 is used for wherein the feedback path also includes amplifier by the feedback signal
Signal amplitude level revert to it is equal with the signal amplitude level of the mixed frequency signal.
9. the device according to any one of claim 7 to 8, wherein the feedback path further includes frequency multiplier, for again
Increase the working frequency of the feedback signal to match the working frequency of the mixed frequency signal.
10. device according to any one of claim 1 to 9, wherein at least one circuit is described defeated for amplifying
Go out signal and compensates signal amplitude electricity described in the mixing and scaling-down process to increase the signal amplitude level of the output signal
Flat decaying.
11. a kind of deviation by the working frequency at least two oscillating input signals averagely improves oscillation output letter
Number working frequency method, including:
Receive at least the first and second oscillating input signals, the public input work of at least first and second oscillating input signals
Working frequency is centered on public nominal frequency and has frequency departure;
At least first and second oscillating input signals are mixed to generate mixed frequency signal at the first frequency mixer (M1),
The mixed frequency signal has the synthetic work frequency centered on the multiple of nominal frequency;
The synthetic work frequency of the mixed frequency signal is divided at divider circuit to generate output signal, the output
The output services frequency of signal is centered on nominal frequency and has an average frequency deviation, the average frequency deviation be it is described extremely
The average value of the frequency departure of few first and second oscillating input signals;And
Export the output signal.
12. further including according to the method for claim 11, making first mixer (M1) and/or the frequency divider
Circuit is adapted to receive at least two additional oscillating input signals to generate output signal.
13. the method according to any one of claim 11 to 12, which is characterized in that further include applying at least one delay
Circuit, the first input oscillator signal that the delay circuit is used to postpone to receive from oscillating circuit, to generate as institute
State second oscillating input signal of the delay form of the first oscillating input signal.
14. the method according to any one of claim 11 to 13, wherein the frequency departure includes relative to the mark
Frequency shift (FS) and/or the phase noise for claiming the center of frequency, wherein the frequency shift (FS) is randomly distributed on the oscillation
Around the nominal frequency of input signal, and the phase noise is related to the random frequency relative to the nominal frequency in time
Rate change procedure.
15. the method according to any one of claim 11 to 14, wherein the divider circuit includes for generating
State the second frequency mixer (M2) of output signal and the feedback path for generating feedback signal from the output signal, the feedback
Signal is fed back to second frequency mixer (M2), and second frequency mixer (M2) is used for the mixed frequency signal and the feedback
Signal is mixed.
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PCT/EP2016/054248 WO2017148505A1 (en) | 2016-02-29 | 2016-02-29 | Mixing circuit to reduce the phase noise and frequency offset variance in local oscillators |
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CN108781057B (en) | 2020-12-15 |
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