Phase Noise 101: Basics, Applications And Measurements
Bob NelsonKeysight Technologies2018
Phase Noise Basics What is Phase Noise? Review: AM, PM and Phase Noise The Theory and Mathematics of Phase Noise Noise Sources that contribute to Phase Noise Phase Noise Applications Radar Digital Communications Phase Noise Measurements Phase Detector Techniques Reference Source/PLL Measurement Method Frequency Discriminator Measurement Method Cross-correlation Keysight Phase Noise Measurement Solutions Conclusion2
Phase Noise Basics What is Phase Noise? Review: AM, PM and Phase Noise The Theory and Mathematics of Phase Noise Noise Sources that contribute to Phase Noise Phase Noise Applications Radar Digital Communications Phase Noise Measurements Phase Detector Techniques Reference Source/PLL Measurement Method Frequency Discriminator Measurement Method Cross-correlation Keysight Phase Noise Measurement Solutions Conclusion3
F R E Q U E N C Y I N S TA B I L I T YLong-term Frequency Instabilityf Slow change in average ornominal center frequencytime(days, months, years)Short-term Frequency InstabilityfPhase noise is generallyconsidered the short-termphase/frequency instability of anoscillator or other RF/microwavecomponent Instantaneous frequencyfovariations around a nominalcenter frequencytime(seconds)4
IDEAL VERSUS REAL WORLD SIGNALSIdeal Sinusoidal SignalReal Sinusoidal SignalV(t) [Ao E(t)]sin[2ΟΖot ππ(t)]V(t) Aosin(2ΟΖot)wherewhereAo Nominal amplitudeΖo Nominal frequencyE(t) Random amplitude fluctuationsππ(t) Random phase οΏ½οΏ½(t)TimeΖoFrequency5
POWER SPECTRAL DENSITY OF NOISE SIDEBANDS Phase fluctuations of an oscillator produced bydifferent random noise sources is phase noiseP0 This is just phase modulation with noise as themessage signalSSB We concern ourselves mostly with the frequencydomain and in this realm, phase noise is simply thenoise sidebands/skirt around the delta functionrepresenting a perfect oscillator at a fixedfrequency that we would expect from theory Because phase modulation is symmetrical arounda center frequency, we can measure a single noisesideband (SSB)f06
HOW TO DEFINE PHASE NOISE MEASUREMENTSThree Elements: Upper sideband only, offset freq. (fm) from carrier freq. Power spectral density (in 1 Hz BW) Relative to carrier power in dBcP0SSB (ππ(ππ))dBc/Hz @ offset freq. fm1 Hz BWf0fm (offset freq.)7
A M P L I T U D E , F R E Q U E N C Y A N D P H A S E M O D U L AT I O N Phase noise is a modulation noise, so wewill quickly review the basics of modulation Amplitude Modulation (AM) varies theenvelope amplitude of the carrier frequencyin direct proportion to the message signal Phase Modulation (PM) and itβs timederivative Frequency Modulation (FM) varythe phase/frequency of the carrier in directproportion to the message signal On the right, we see phasor diagrams of theamplitude, phase and single sidebandmodulation (SSB). LSB is the lower sidebandand USB is the upper sideband. The grayvector indicates the resultant of the carrier*United States National Institute for Standards and Technology (NIST)8
BESSEL FUNCTIONS OF THE FIRST KIND Since phase noise is really phase modulation (PM)noise, it is prescient to review PM/FM In the frequency domain, PM has an infinite number ofsidebands and thus does not look like AM To determine the amplitude of these sidebands, one canuse Bessel functions, π±π±ππ (at bottom right) On the horizontal axis, is the peak phase deviation (ππππππalso called m and Beta, π·π·) of modulating signal and thevertical axis is the amplitude of the sidebands As an example, if we let ππππππ ππ ππ and draw a verticalline (in blue), the intersection of this line with all theBessel functions at that point will give us the amplitudesof the sidebands On the top screen capture, we can see these sidebandamplitudes as viewed on a spectrum analyzer9
We can use the Bessel functions to go the other way:measure the relative amplitude (power) of asideband to the power of the carrier in thefrequency domain and obtain rms phasedeviation Converting the peak phase deviation to a powerratio:π·π·πΊπΊπΊπΊπΊπΊ πΎπΎπ½π½πΊπΊπΊπΊπΊπΊ( ) π·π·ππ πΎπΎπ½π½ππππππππ ππππ ( ππππππ ) ππππππ (πππππ π ππ )ππππ1JCarrier Amplitude0Jπ½π½πΊπΊπΊπΊπΊπΊ ππ 5First Sideband Amplitude1J2nd Sideband Amplitude2J3rd Sideband Amplitude3J4th Sideband Amplitude4Linear Approximation for First SidebandAmplitude (V) At small ππππππ (narrowband PM), the first sideband(Bessel function J1) is almost linear with slope Β½ andthe carrier (J0) has a value of 1.0 and is constant. Theratio of the SSB voltage to the carrier voltage is equalto half the peak phase deviation:π½π½πΊπΊπΊπΊπΊπΊ π½π½ππ( ) ππππππ (ππππππ)π½π½ππ π½π½ππBessel Functions for Carrier and 4 Sideband Amplitudes (Linear Scale)0-0.5024ππππππ 68101214161820m Peak Phase Deviation (rad)10
ππ If ππ π·π· ππππππ ππππππ, weππactually have narrowband PMππππππ ππ. ππ ππππππ If we plot the Bessel functionsthat we just saw on a logscale, we can more easily seepeak phase deviations(ππ π·π· ππππππ ) this small If we draw a vertical blue lineat m 0.2, we see that only thecarrier and 1st sideband withhave appreciable amplitude βthe other sidebands are highlyattenuated more than -50 dBdown from the carrier11
R M S P H A S E F L U C T U AT I O N S & D E V I AT I O N From PM theory, we know the phase of the carrier will vary with amplitude of the sideband (message) signal Because we use a sinusoid as the sideband message (SSB) signal we can relate peak phase to rms phase:ππππππ πππππΉπΉπΉπΉπΉπΉ Now we can see that the rms phase fluctuationscan be obtained by just measuring the ratio of thepower of the sideband to the power of the carrier (atright a SA with a delta power οΏ½ππ ( ππππππ )ππ ( πππππΉπΉπΉπΉπΉπΉ )ππ πππππΉπΉπΉπΉπΉπΉ (πππππ π ππ ) Taking the square root and thus converting the powerratio to an RMS phase π·π·ππ πππΉπΉπΉπΉπΉπΉ (ππππππ)12
R M S P H A S E F L U C T U AT I O N S A N D P H A S E N O I S E Previously the message signal (with two sidebands) was a sinusoidal tone If we now replace the sinusoidal tone with a noise signal (and associated noiseBW) we get a continuous spectrum about the carrier with a spectral density inunits of power per unit of bandwidth (dBm/Hz)πΊπΊππ (ππ)ππ(ππ) We can convert the rms phase fluctuations into a spectral density by dividingby the bandwidth of the noise ))(πΊπΊππ (ππ) π―π―π―π―π©π©π©π© Phase modulation is a symmetric process so we only need to measure either the upper or lower sideband.The upper noise sideband is called phase noise or οΏ½πΉπΉ (ππ(ππ) πΊπΊππ ππππ πππππΉπΉπΉπΉπΉπΉ ππππππππππ( ) ( π―π―π―π― )πππ©π©π©π©13
I N T E G R AT E D P H A S E N O I S E We can integrate single sideband phase noise ππ ππ over the measurement bandwidthfrom ππππππππππππ to ππππππππππ (this is known as the single sideband integrated phase οΏ½ππππΉπΉπΉπΉπΉπΉππ ππ π π π π (ππππππππ ) οΏ½οΏ½π If we multiply this result by two (or integrate both phase noise skirts), we get the RMSphase fluctuations (πππππΉπΉπΉπΉπΉπΉ ) back (this is also known as double sideband integratedphase noise):πππππΉπΉπΉπΉπΉπΉ ππ οΏ½οΏ½πππππππππππ ππ π π π π (ππππππππ )We can now use the integrated single sideband phase noise to calculate the RMSphase deviation:πππΉπΉπΉπΉπΉπΉ ππππππ ππππππππππππ πππππππππππ ππ π π π π 14
PHASE NOISE & JITTER In the time domain, rms phase deviation is called jitter Frequently, people concerned about jitter deal with clocksignals, and thus are more concerned about measuringsquare wave type signals as opposed to the sinusoidsweβve been dealing with To relate rms phase deviation to jitter, we can use thefollowing mathematical relation: ππ οΏ½οΏ½οΏ½πππππ) οΏ½οΏ½οΏ½π οΏ½οΏ½οΏ½π)] rcentage of total angular periodaffected by rms phase noiseCarrier signal period(time) βsame as ππ/ππππ15
P H A S E N O I S E O N A S P E C T R U M A N A LY Z E R As we saw before, single sideband phase noise ππ ππ is arelative power measurement βwe measure the powerdensity of the noise sideband relative to the power of thecarrier:π·π·πΊπΊπΊπΊπΊπΊ (πΎπΎ/π―π―π―π―)π·π·ππ (πΎπΎ) πππππ π ππππ ππππππ ππππππ π―π―π―π― ππ οΏ½οΏ½π―ππ ππPcarrier (dBm) These ratios (relative power measurements) are suitedquite well to spectrum analyzers βwhich measure signalsusing a log-transformed power scale Context matters because ππ ππ is used for both linear unitsand log-transformed phase noise (in dBc/Hz)Pnoise (dBm/Hz)Ps (dBm)Pn (dBm/Hz) The log scale (dB) allows us to replace the division of thecarrier with subtraction and gives us units of dBc/Hzππ ππ Pnoise (dBm/Hz) - Pcarrier (dBm) -121.28 dBc/Hz1 kHz measurement bandwidthusing noise density marker(generally normalized to 1 Hz)16
M AT H E M AT I C A L D E R I VAT I O N O F N A R R O W B A N D P M Phase noise (ππ(ππ)) is a phase phenomenon βit is simply the phase modulation (PM) of a carrier signal with anoise message signal Deriving narrowband PM mathematically will show the extreme similarities between AM and PMππ ππ ππ ππππππππ οΏ½οΏ½π ππππππππππππ ππππππππππ ππππππππππππ ππππππππ οΏ½οΏ½πππ οΏ½οΏ½π οΏ½οΏ½πππππ & οΏ½οΏ½πππππππππππ ππππ ππ ππππππππππ οΏ½οΏ½π οΏ½οΏ½πππ ππππππππππππ ππππππππ πππ(ππππ ππ ππ ππ ) ππππππππ ππππππππππππ ππππππππ ππππππππππ ππππππππππ ππππ ππππRecall: ππππππ πΆπΆ π·π· ππππππ πΆπΆ)ππππππ(π·π· ππππππ πΆπΆ)ππππππ(π·π·Small Angle Approximations: ππ ππwhere: πΆπΆ ππππ ππ ππππππ π·π· ππ ππππππ ππππππ οΏ½οΏ½πππππππ οΏ½οΏ½πππππππ ππππ: ππππππ ππ οΏ½οΏ½π ππ ππ ππ ) ππππππ ππππ ππ ππ ππ ππππππ ππππ ππ ππ ππππππ ππππππ ππ ππ ππ ππnoise that modulatesthe phase of the carrierbecomes an amplitudemodulation of thecarrier!17
A M V S N A R R O W B A N D P M O N S P E C T R U M A N A LY Z E R Now we compare double sideband (DSB) AM with the narrowband PM signal with ππ ππ as themessage/modulating signal:Narrowband PM:DSB AM:ππππππ(ππππ ππ ππ ππ ) ππππππ ππππ ππ ππ ππ ππππππ ππππ ππππ ππ ππ ππππππ(ππππ ππ) ππππππ ππππ ππ ππ ππ ππππππ(ππππ ππ)The differencebetween the two isjust a phase shift!*DSB AM signal with 0.8% modulation index, AM Rate 10 kHzππππ*Narrowband PM signal with ππππππ ππππππ index, PM Rate 10 kHz Because a spectrum analyzer shows magnitude spectrum, AM and narrowband PM look identical βthereforewe need to remove the AM component to accurately measure only the phase noise component of total noise18
THERMAL NOISE (JOHNSON-NYQUIST NOISE)Ideal Thermal Noise Power Density @ Room Temperature (290K)-50-100Power (dBm)-174 010000Frequency (Hz)Thermal noise is βwhiteβ βthe same magnitude (-174 dBm/Hz)- at all frequenciesk Boltzmanβs constantFor T 290K:T Temperature (K)Np 204Displayed Average Noise Level (DANL) of a signal analyzer is thermal noiseplus the signal analyzerβs own internal noiseB Bandwidth (Hz)dB(Watts )dBm 174HzHzNp kTB19
A M A N D P M C O N T R I B U T E E Q U A L LY T O N O I S E P O W E R If we look at a signal in the complexdomain, we see that there are twodegrees of freedom: one for phase andone for amplitudePhase and amplitude componentsof noise vector together constitutetwo degrees of freedom Equipartition of power tells us that both ofthese degrees of freedom will contributeequally to our total noise power This means that although total thermalnoise is commonly known to be -174dBm/Hz, if we subtract out the amplitudenoise component, the phase noisecomponent of thermal noise is 3 dB lowerat -177 dBm/HzPhase0deg20
I N P U T S I G N A L L E V E L D I C TAT E S D Y N A M I C R A N G Eππ ππ Pnoise (dBm/Hz) - Pcarrier (dBm) As we can see above, phase noise is arelative measurement: a noise-tocarrier ratio in dBc/Hz This means that our sensitity is actuallydictated by the input power level of thecarrier (or input) signal For example, as we can see on the right,with a 30 dBm input signal, we canactually achieve a -207 dBc/Hzmeasurement until we are constrained bythe absolute level of the thermal phasenoise floor dictated by kTB (-177dBm/Hz)Theoretical kTB limits to phasenoise measurements for variousinput (carrier) signal levels 30ππ ππ dBc/Hz 20-197 10-1870-177-10-167-20-157Pcarrier (dBm)-207Total Noise Power (kTB) Pnoise (kTB) -174 dBm/HzPhase Noise and AM noise equally contributePhase Noise Power (kTB) -177 dBm/Hz21
1/F & THERMAL NOISE On a Bode plot (log scaled power and frequencyaxis), it has the easy to use property ofdecreasing by 10 dB/decade14201210-10 dB/decade1008Power (dBm)-10Power (W) In oscillators, 1/f is a βmodulationβ noise thatwouldnβt exist in absence of device electronics(unlike thermal noise)1/f Noise Log Scale1/f Noise in Linear Units In addition to a thermal noise floor that has anapproximately constant magnitude as a functionof frequency, nearly all electronic devices exhibita type of noise is inversely proportional tofrequency (1/f)64-20-302-40-50001234Frequency (Hz)5678910-110101021010Frequency (Hz) 1/f noise meets the thermal noise floor at the 1/fcorner frequency, beyond which point thermalnoise dominates (called broadband noise) Noise sources that are a higher order negativepower of frequency dominate closer to the carrierβBroadband noiseβ22
A L L P O W E R - L AW N O I S E P R O C E S S E S I N A N O S C I L L AT O RTheoretical Noise ProcessesReal Noise Processes in VCOππ ππ(ππππ)Frequency Offset from Carrier (Hz)*Dr. Sam Palermo, Texas A&M23
Phase Noise Basics What is Phase Noise? Review: AM, PM and Phase Noise The Theory and Mathematics of Phase Noise Noise Sources that contribute to Phase Noise Phase Noise Applications Radar Digital Communications Phase Noise Measurements Phase Detector Techniques Reference Source/PLL Measurement Method Frequency Discriminator Measurement Method Cross-correlation Keysight Phase Noise Measurement Solutions Conclusion24
Better PN lower skirtBetter chance to findDoppler reflection signalsHighest performance radar transceiverdesigns demand the best phase noise tofind moving targets, fast or slowSlowerV targetFaster25
QPSK EXAMPLEIIIRFQQLO90oQIdeal QPSK constellationDegraded phase noiseQPSK constellation26
64QAM EXAMPLEIQSymbols far fromthe origin on IQconstellation arespread more fora given amountof phase noiseon the LOIQ27
S I G N A L S O U R C E A S L O C A L O S C I L L AT O R 3 Keysight signal generatorsβ phasenoise performance is shown at right Phase noise comparison done at acenter frequency of 10 GHz We will see that using these signalgenerators (sources) as LOs for alarger system has a definite impact onEVM performanceE8257D - PSGN5173B - EXGN5183B - MXG*All sources have the best phase noise option (UNY) (applies to PSG & MXG)**Scale is 15 dB / div28
S I G N A L S O U R C E A S L O C A L O S C I L L AT O R For multicarrier modulation systems(OFDM), close-in phase noisematters most Close-in and far-out phase noiseperformance is one of the mainperformance metrics thatdifferentiates high-end signalgenerators from lower end signalgeneratorsE8257D - PSG The far out phase noise of a device isalso known as broadband noiseN5183B - MXG For extremely wideband single carriermodulation (e.g. 1 GHz BW forsatellite applications) this far outphase noise performance can affectthe EVM of the signal generatorE8257D PSGN5173B - EXGN5173B EXGN5183B MXGThis area is important for wideband single carrier*All sources have the best phase noise option (UNY) (applies to PSG & MXG)**Scale is 15 dB / div29
S I G N A L S O U R C E A S L O C A L O S C I L L AT O RPSG is LOEVM 1.8%MXG is LOEXG is LOEVM 2.1%EVM 2.1%Test configurationBasebandIFM8190AE8267D PSGInfiniium5 GHzTest SignalQPSKScopeUp converter60 GHzWARNING : Exi t 89 600 V SA So ftwar ebefore chang ing instr ument setu pLOPSG/MXG/EXG10 GHzx630
OFDM EXAMPLEPowerPower LTE uses OFDM with manysubcarriers βeach spaced at 15 kHz Lower (better) phase noise of the LOin a receiver or transmitter improveseach sub-carrierβs resolution andthus EVM performance Unlike our previous use case withwideband single carrier modulation,OFDM requires extremely goodclose-in phase noise performanceOFDM subcarriersFrequencyDown-convertedOFDM sub-carrierswith LO phase noiseaddedPowerFrequencyPhase noiseFrequencyLocal oscillatorwith phase noise31
Phase Noise Basics What is Phase Noise? Review: AM, PM and Phase Noise The Theory and Mathematics of Phase Noise Noise Sources that contribute to Phase Noise Phase Noise Applications Radar Digital Communications Phase Noise Measurements Phase Detector Techniques Reference Source/PLL Measurement Method Frequency Discriminator Measurement Method Cross-correlation Keysight Phase Noise Measurement Solutions Conclusion32
Direct Spectrum Method By sampling the carrier, the direct spectrum method(as employed in signal analyzers and some phasenoise systems) is able to immediately get amplitudeand phase information This method is far less sensitive (lowerperformance) than the carrier removal methodCarrier Removal Increased sensitivity is obtained by nulling the carrierand then measuring the phase noise of the resultingbaseband signal Both the frequency discriminator and thePLL/Reference Source methods discussed next usecarrier removal with phase detectors33
Both the frequency discriminator andreference source/PLL method use aphase detector as the heart of themeasurement system A phase detector takes two input signalsand compares their phase The output of the phase detector is just avoltage that is proportional to the phasedifference of the two signals (delta phase) The constant of proportionality, called K isin units of volts per radian (V/rad) andmust be measured ππ ππππ πͺπͺπͺπͺπͺπͺπͺ ("π·π·π·π·π·π·π·π·π·π· οΏ½οΏ½π«π«π«π«)34
T H E M AT H E M AT I C SProduct to Sum Identity: Double balanced mixers producesinusoids at the sum anddifference frequencies of twoinput signals π₯π₯ π‘π‘ and y π‘π‘ If both signals are at the samefrequency, we get 0 Hz (DC) anda high frequency term that goesaway via low pass filtering (LPF) After the LPF, we get only a DCterm that varies in amplitude as acosine function of the delta phaseof the two signals βthis is a deltaphase to voltage converter orphase detectorπ₯π₯ π‘π‘ π΄π΄π΄π΄π΄π΄π΄π΄[ππ0 π‘π‘ πππ₯π₯ π‘π‘ ] π¦π¦ π‘π‘ π΅π΅π π π π π π [ππ0 π‘π‘ πππ¦π¦ π‘π‘ οΏ½ππ₯π₯ π‘π‘ πππ¦π¦ π‘π‘ ] 0 πππ₯π₯ π‘π‘ πππ¦π¦ π‘π‘ ]221ππππππππ οΏ½οΏ½οΏ½π₯ π‘π‘ πππ¦π¦ π‘π‘ ]2 ππ ππ ππππ πͺπͺπͺπͺπͺπͺπͺ ("π·π·π·π·π·π·π·π·π·π· οΏ½οΏ½π«π«π«π«)35
I M P O R TA N C E O F Q U A D R AT U R EPhase Detector Output Voltage vs. Delta Phase The phase detectorβs cosine output voltage(cos ππ ) is non-linear and we would like tolinearize it so that we can get a linearlyproportional relationship between delta phaseand output voltage We notice that if both input signals to the phasedetector are 90 degrees offset, the outputvoltage is 0VSlope here is K180 ππππ As we increase or decrease the delta phaseabout 90 degrees (quadrature point), the outputvoltage is approximately linear We have now created a phase detector! Aftercharacterizing the proportionality constant, K, wenow get a an output voltage that linearly varieswith the delta οΏ½οΏ½οΏ½ππππππ π³π³ππππππππππ πΉπΉππππππππππ ππππππππππ οΏ½οΏ½πππππππ (ππππ )where π½π½ π²π² ππ36
An absolute phase noise measurementmeans that we are measuring the DUT(oscillator usually) phase noiseperformance directly βinclusive of thereference source used This is a 1-port measurement The Reference Source/PLL method is aphase detector technique tha uses aPhase Locked Loop System (PLL) to setand keep both our DUT and referencesources in phase lock at 90 degrees offset(quadrature) so that we keep the phasedetector in the linear region We are limited by the noise floor of thephase detector itself if we have a perfectreference37
This method is an absolute (1-port)measurement that also uses a phasedetector Signal from the DUT is split into twopaths The signal in one path is delayedrelative to the other path The delay line converts frequencyfluctuations into phase fluctuations The delay line or phase shifter isadjusted to put the inputs to the mixerin quadrature The phase detector converts phasefluctuations into voltage fluctuationswhich are analyzed on the basebandanalyzer38
With two phase detectorsand two references (2channels), we can furtherimprove our phase noisefloor There are now 2 channelsthat are uncorrelated, so wecan remove the noise addedby the references givenenough time (weβll quantifythis next) The DUT signal is commonto both channels and is thusperfectly correlated and keptas our measurement result39
TIME VERSUS PERFORMANCE IMPROVEMENTinternal system noise N1Signal-sourceUnder TestCH1DSPCross-correlation(Correlation# M)SplitterSourcenoise :NS.U.T.Measured noise : NmeasCH2internal system noise N2N meas N S .U .T . ( N1 N 2 ) / MAssuming N1 and N2 are uncorrelated.M (number of correlation)101001,00010,000Noise reduction on (N1 N2)-5dB-10dB-15dB-20dB40
RESIDUAL MEASUREMENTS USING A PHASE DETECTOR Can think of it as a completelydifferent class of measurement fromabsolute phase noise measurements Is the βadditiveβ or residual noise addedto an electronic signal and so is oftenperformed on a two port device like anamplifier Reference source doesnβt make adifference to residual measurementsbecause it is perfectly correlated atboth ports of the phase detector andwill cancel βleaving only the additionalphase noise added to the signal by theDUT41
Phase Noise Basics What is Phase Noise? Review: AM, PM and Phase Noise The Theory and Mathematics of Phase Noise Noise Sources that contribute to Phase Noise Phase Noise Applications Radar Digital Communications Phase Noise Measurements Phase Detector Techniques Reference Source/PLL Measurement Method Frequency Discriminator Measurement Method Cross-correlation Keysight Phase Noise Measurement Solutions Conclusion42
P H A S E N O I S E A P P O N X - S E R I E S A N A LY Z E R SPros: Easy to configure and use Quick phase noise check Log plot Spot frequency (PN change vs. time) rms PN, rms jitter, residual FM X-Series phase noise application automates PNmeasurementsDUTCons: Uses less sensitive direct spectrum method Limited by SA internal PN floor Caution: On vintage spectrum analyzers, AM noisecannot be separated from PM noise. In todayβsmodern signal analyzers, the AM component isremovedN9068C X-Series Phase Noise Application43
C R O S S C O R R E L AT I O N S Y S T E M W / B U I LT I N R E F E R E N C E S The Keysight E5052B incorporates A two-channel cross-correlation measurement system toreduce measurement noise Can be configured as: Two-channel normal phase noise (phase detector) PLL system Two-channel heterodyne digital discriminator system Provides excellent phase noise measurementperformance for many classes of sources and oscillators Well suited for free running oscillators44
G O L D S TA N D A R D P H A S E D E T E C T O R B A S E D S Y S T E M The E5500 system can be configured as: A reference source/PLL system A frequency discriminator system For absolute and residual phase noisemeasurements For pulsed phase noise measurements System is complex, but allows the mostmeasurement flexibility and best overallsystem performance Can use any reference sources for the bestpossible absolute phase noisemeasurements45
With the increased data requirements of todayβs digital radios in Satellite and 5G as well asincreased sensitivity requirements of modern radar systems, phase noise has taken on addedimportance to RF/microwave and systems engineers Understanding phase noise and its sources can be complicated and is a full-time profession forsome engineers Determining the best method of phase noise measurement can be bewildering, but all commontest solutions are well documented and Keysight applications experts are available to assist andanswer your questions In general, one solution does not fit all applications or all users Keysight provides a great breadth of phase noise measurement equipment that is tailored totodayβs demanding measurement requirements46
Becker, Randy, and Antonio Castro. βGenerating and Analyzing MmWave Signals for Imaging Radar and Wideband Communications.β Keysight AD Symposium2015. Worldwide , Worldwide . Gheen, Kay. βPhase Noise Measurement Methods and Techniques.β Agilent/Keysight AD Symposium 2012. Worldwide & Webcast, Worldwide & Webcast. Hewlett Packard/Keysight. Application Note 150-1: Spectrum Analysis Amplitude & Frequency Modulation. Application Note 150-1: Spectrum Analysis Amplitude &Frequency Modulation, Hewlett Packard, 1989. Hewlett Packard/Keysight Technologies. Phase Noise Characterization of Microwave Oscillators: Frequency Discriminator Method. Phase Noise Characterizationof Microwave Oscillators: Frequency Discriminator Method, Hewlett Packard, 1985. Hewlett Packard/Keysight Technologies. Phase Noise Characterization of Microwave Oscillators: Phase Detector Method. Phase Noise Characterization ofMicrowave Oscillators: Phase Detector Method, Hewlett Packard, 1984. βIEEE 1139-1999: IEEE Standard Definitions of Physical Quantities for Fundamental Frequency and Time Metrologyβ Random Instabilities.β IEEE Xplore, Instituteof Electrical and Electronics Engineers, 26 Mar. 1999, ieeexplore.ieee.org/stamp/stamp.jsp?arnumber 807679A. Kanemitsu, Rich. βPhase Noise Measurement Basics -An Overview .β Keysight Customer Training. 2018, USA, USA. Keysight Technologies . Phase Noise Measurement Solutions. Phase Noise Measurement Solutions, Keysight, 2018, pdf?id 1896487. Leeson, David B. βOscillator Phase Noise: A 50-Year Review.β IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, vol. 63, no. 8, 2016, pp.1208β1225., doi:10.1109/tuffc.2016.2562663. Nelson, Bob. βDemystify Integrated-Phase-Deviation Results In Phase-Noise Measurements.β Microwaves & RF, 2 Oct. 2012, measurements. Palermo, Sam. βECEN 620: Network Theory: Broadband Circuit Design.β Sam Palermo - ECEN 620, Texas A&M University ,ece.tamu.edu/ spalermo/ecen620.html. Prodanov, Vladamir. βLecture 25: Introduction to Phase Noise.β EE412: Advanced Analog Circuits. 2013, San Luis Obispo, California Polytechnic State University .47
Thank you!48
Thermal noise is "white" -the same magnitude (-174 dBm/Hz)- at all frequencies. Displayed Average Noise Level (DANL) of a signal analyzer is thermal noise plus the signal analyzer's own internal noise-174 dBm/Hz. 20 AM AND PM CONTRIBUTE EQUALLY TO NOISE POWER. Phas e. 0 deg.
to the problem we have observed in the ADS phase noise simulation where the pnmx phase noise goes flat below some small offset frequency.) The plot to the right shows the phase noise for Οf 2 c Ο 10 -3 osc. Note if we were to extrapolate from the phase noise at 100 kHz, we would get a phase noise of 30 dBc/Hz at an offset frequency of 1 Hz.
01.03 Rohde & Schwarz Mastering Phase Noise Measurements (Part 3) 3 2 Introduction Phase noise is unintentional phase modulation on a signal that spreads the spectrum and degrades performance in many RF applications. Whether you are new to phase noise or have been measuring phase noise for years it is important to get a good
Note: * The phase detector PLL loop filter calculator and phase noise estimator spreadsheet can be downloaded at www.psemi.com. Figure 3. Simulated Phase Noise Performance of the PE97420 at 100 MHz -180-170-160-150-140-130-120-110-100 0.1 1 10 100 1000 10000 Phase Noise (dBc/Hz) Frequency Offset (kHz) PE97240 PLL Phase Noise at VCO Output
Noise Figure Overview of Noise Measurement Methods 4 White Paper Noise Measurements The noise contribution from circuit elements is usually defined in terms of noise figure, noise factor or noise temperature. These are terms that quantify the amount of noise that a circuit element adds to a signal.
Jan 26, 2018Β Β· Adjusting the delay line or the phase shifter will determine the phase quadrature of the two inputs to the mixer (phase detector). Then, the phase detector converts phase fluctuations to voltage fluctuations, which can then be read on the baseband spectrum analyzer as frequency noise. The frequency noise is then converted for phase noise
phase noise separator are derived. A function scheme and a circuit structure for three-phase noise separators are proposed based on the theory developed. The technique to design a high-performance three-phase noise separator is explored. A three-phase noise sepa-rator pro
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In A-level Biology practical investigations, it is possible to show that many plants produce antimicrobial substances that can destroy or limit the growth of bacteria and fungi. A possible role of these substances in plants can be summarised by the following quotation: βThe function of these antibacterial substances may be to prevent or limit entry into the plant tissues where bacteria may .
