Phase Noise measurement and Pulse stability measurement...Absolute measurement with Spectrum digitizer ı In FSWP for “absolute” measurements,wehave two digitizers: Spectrum digitizer

Frédéric Molina19.03.2018

Phase Noise measurementand Pulse stability measurement

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Agenda

ı Part 1 : Phase Noise measurement

ı Part 2 : Pulse stability measurement

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DUT


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What is Noise?Phase and Amplitude Noise

ı Ideal Signal (Noiseless)

V(t) = A . sin(2t)

A = nominal amplitude = nominal frequency

3

t

FFT

19/03/2018Phase Noise measurementand Pulse stability measurement

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What is Noise?Phase and Amplitude Noise

ı Real Signal

V(t) = [A + E(t)] . sin(2t + t)

E(t) = amplitude fluctuationst = phase fluctuations

4

t

)]1([)___

_1_____log(10)(0

HzdBcPPowerFrequencyCarrier

PHztorelatedPowerSidebandSinglefL SSBm

FFT


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Measurement MethodsPhase Detector

5

DUT

Reference Source

PDLPF


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FSWP : Digital Phase DemodulatorInternal structure

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ı PM signal has phase wraps at ±π. No filtering or FFT possibleı FM demodulator preferred to digital PLL due to its simplicity


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• Simultaneous measurement of AM Noise and Phase Noise with Total Noise

Phase Noise

AM Noise

FSWP

Total Noise (PN+AM)

AM Noise, Phase Noise, and Total Noise

19/03/2018 7Phase Noise measurementand Pulse stability measurement

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Special / Complex Measurement Setups1. Pulsed Phase Noise

ı Like a Spectrum Analyser phase noise measurement

ı Automatic PRI detection

ı What about Pulse Desensitisation? Improved dynamic due to… Gating on Pulse Cross Correlation

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DUT


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1/PW = 100kHz

A * 20 log(/T)(pulse desensitization)

PRF Lines

• PRF filter is narrow to pass center line and attenuate all other PRF lines• Center line is lower than pulse level due to pulse desensitization: 20*log(duty cycle)

PW ()10us

PRI (T)100us

Level (A)10dBm

Time

1/PRI = PRF = 10kHz

Pulsed Phase Noise – Pulse Spectrum


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Pulsed Phase Noise

Pulsed

~6dB

CW

• Max offset limited to PRF/2 for pulsed signals due to PRF lines• Pulsed phase noise ~6dB higher at PRF/2 due to coherent combining

0.5/PRI = 5kHz1/PRI = PRF = 10kHz


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Pulsed Phase Noise Measurement

Max offset automatically limited to PRF/2 (5kHz)

• Measurement truncated to max offset of PRF/2• Measurement time same as for CW


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Pulsed vs CW Phase Noise Measurement

Pulsed measurements same as CW for offsets << PRF/2

Pulsed measurement higher than CW at PRF/2

<< PRF/2PRF/2

CW

Pulsed


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R&S FSWP – FSWP-K4… and Show Everything on one Sight

l Phase Noisel AM Noisel Pulse in Time

Domainl Pulse in

FrequencyDomain


Additive Phase Noise – Digital Phase DemodulatorMeasurement Setup

DUT


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Additive Phase Noise – Digital Phase Demodulator• Internal hardware automatically reconfigures when “Additive” is selected• No phase detector or need for quadrature – no phase shifter• Greatly simplifies measurement setup and calibration• Internal Low Noise Synthesizer as DUT stimulus

FSWP Signal Source AnalyzerLow Noise Synthesizer

DUT

LPF

LPF

Digitizers+ FPGA

LNA

LNA

LPF

LPF LNA

LNA


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Additive Phase Noise – Digital Phase Demodulator• Internal Low Noise Synthesizer as DUT stimulus


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Agenda

ı Part 1 : Phase Noise measurement

ı Part 2 : Pulse stability measurement


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Option K6 : Pulse measurement

ı The K6 Pulse Measurement Application is available on Running on directly on signal analyzers (FSW, FSWP, FPS) Running on PC (VSE) connected to analyzers and scopes


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Measurement Process


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Measurement Process


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Measurement ProcessData Acquisitionl Segmented capture

l Capture more pulses, less noisel Support in HW for same timing accuracy as “normal” capture

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Measurement Process


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Measurement Process


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Measurement ProcessEnvelope Parameters

Ampl

itude

(% o

f Pul

se T

op)

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Measurement Process


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Measurement ProcessResult Display

ı Trend Plots column of table Visual recognition of „trends“ Multiple trends with different

parameters X-axis can be Timestamp or

Pulse Number


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ı Trend as “spectrum” Plots FFT of column of table Visual recognition of

periodicities Multiple plots with different

parameters


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ı Distribution Plots histogram of table column Visual recognition of „states“ Multiple distributions with different

parameters Y-axis can be Pulse Count or

Occurrence


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Measurement ProcessResult Displayı Linked markers – inter-pulse and intra-pulse

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K60 : Transient Analysis (Hop)

ı Automated measurement per hop Power measurements Frequency/phase Settling time Hop-hop changes

ı Statistics Numerical Trend Histogram


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K60 : Transient Analysis (Chirp)

ı Automated measurement per chirp Power measurements Frequency/phase Modulation linearity

ı Statistics Numerical Trend Histogram


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FSWP-K6P : Pulse stability measurement

ı Variability over time with respect to a reference value

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scusi @ 123RF.com scusi @ 123RF.com scusi @ 123RF.com

Time

Reference


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Stability – Pulsed Radar


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Time

Reference

60 dB

0.01 dB

RF Power


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Time

RF Power

Reference

3 GHz

0.001 rad


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ı In radar, moving targets cause “variability over time” in the radar return To discern a target, the transmit/receive hardware needs to be stable


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Measurement – Metrics

Standard deviation, normalized to the average power

Relative to average power,-60 dBc: average power deviation over all pulses is 60 dB smaller than average power level

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Pulse (n)

Pulse (n)

10 · log dBc

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Pulse-to-pulse deviation, normalized to the average power

Relative to average power,-60 dBc: average power deviation pulses-to-pulse is 60 dB smaller than average power level

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Pulse (n)

Pulse (n)

10 · log dBc


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Standard deviation

Relative to 1 radian,-60 dBc means RMS phase deviation over all pulses equals of 1 milli-radian (0.001rad)

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Pulse (n)

Pulse (n)

10 · log dBc


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Pulse-to-pulse deviation

Relative to 1 radian,-60 dBc means RMS phase deviation pulse-to-pulse equals of 1 milli-radian (0.001rad)

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Pulse (n)

Pulse (n)

10 · log dBc


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Measurement

ı We differentiate between two kinds of measurement:

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DUT Analyzer DUT Analyzer

“Absolute” “Additive”


DUT

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Absolute measurement with Spectrum digitizerı In FSWP for “absolute” measurements,we have two digitizers: Spectrum digitizer (digital I/Q)

Phase Noise digitizer (2x analog I/Q)

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DUT Analyzer

“Absolute”ATTENRF In

RefChan. 1

SynthChan. 1

LO 1

fADC

LO 1

fADC

PCFPGA

7680 MHz

1280 MHz

ATTEN ADC 0° 90° NCO

9 GHz

LO 1

< 8 GHz


ATTENRF In

0° 90°

0° 90°

ADC1,I

ADC1,Q

ADC2,I

ADC2,Q

I1

Q1

I2

Q2

RefChan. 1

SynthChan. 1

LO 1

LO 2

fADC1

fADC1

fADC2

fADC2

LO 1

fADC1

PCFPGA

RefChan. 2

SynthChan. 2

LO 2

fADC2 DUT

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Additive measurement with Phase Noise digitizer

ı In FSWP for “additive” measurements, only thePhase Noise digitizer (2nd analog I/Q mixer) is used

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DUT Analyzer

“Additive”

LO 2Pulse Switch

ATTENRF Out

ATTENRF In

0° 90°

ADC2,I

ADC2,Q

I2

Q2

LO 2 fADC2

fADC2

PCFPGARef

Chan. 2

SynthChan. 2

fADC2


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Measurement – Performance[test measurements: DUT bypass]ı Initial performance results for 3 GHz vs digitizer Pulse width: 5 us

WB for “wideband” SA path, “PN (Abs|Add)” for phase noise path (Absolute | Additive)

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-100

-80

-60

-40

-20

0

3 GHz Amplitude Stability, T: 10us

WB PN (Abs) PN (Add)

-100

-80

-60

-40

-20

0

3 GHz Phase Stability, T: 10us

WB PN (Abs) PN (Add)


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Measurement – Performance[test measurements: DUT bypass]ı Performance summary phase stability (median on pulse), 10 MHz I/Q bandwidth Pulse width: 5 us

WB for “wideband” SA path, “PN” for phase noise path (Absolute), , “PN+” for phase noise path (Additive)

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Interval 10 us 100 us 1 ms 10 msDigitizer WB PN PN+ WB PN PN+ WB PN PN+ WB PN PN+

3 GHz ‐67.4 ‐74.3 ‐81.6 ‐67.2 ‐73.9 ‐81.6 ‐63.4 ‐64.0 ‐81.5 ‐49.4 ‐47.8 ‐81.2

10 GHz ‐65.0 ‐64.5 ‐75.0 ‐64.5 ‐64.1 ‐74.9 ‐54.1 ‐55.1 ‐74.8 ‐37.6 ‐40.3 ‐74.7

18 GHz ‐60.6 ‐63.7 ‐74.2 ‐60.0 ‐62.6 ‐74.1 ‐49.9 ‐50.0 ‐73.8 ‐33.9 ‐34.2 ‐69.5


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Measurement – Performance[test measurements: DUT bypass]ı Performance summary amplitude stability (median on pulse), 10 MHz I/Q bandwidth Pulse width: 5 us

WB for “wideband” SA path, “PN” for phase noise path (Absolute), , “PN+” for phase noise path (Additive)

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Interval 10 us 100 us 1 ms 10 msDigitizer WB PN PN+ WB PN PN+ WB PN PN+ WB PN PN+

3 GHz ‐71.1 ‐84.7 ‐85.3 ‐70.8 ‐84.6 ‐85.1 ‐71.1 ‐84.4 ‐84.9 ‐71.0 ‐84.1 ‐84.5

10 GHz ‐68.4 ‐75.6 ‐78.2 ‐68.3 ‐75.5 ‐77.9 ‐68.3 ‐75.4 ‐77.7 ‐68.3 ‐75.2 ‐76.8

18 GHz ‐64.6 ‐72.1 ‐75.1 ‐64.6 ‐72.0 ‐75.0 ‐64.5 ‐71.9 ‐74.9 ‐64.4 ‐71.3 ‐74.0


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Measurement Application

ı The FSWP-K6P Pulse Stability Measurements extends the K6 application on FSWP

ı Multi-burst analysis Groups pulses in “bursts”

ı Burst averaging Focus on in-burst stability Control averaging range Compare positions in burst


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Documents

Phase Noise measurement and Pulse stability measurement...Absolute measurement with Spectrum digitizer ı In FSWP for “absolute” measurements,wehave two digitizers: Spectrum digitizer