understanding new pulse-analysis techniques · 2015-05-12 · – this presentation will apply both...

2015 Aerospace Defense Symposium

Understanding New Pulse-analysis Techniques

Giuseppe Savoia

Keysight Technologies

Page

Agenda

– Concept for Radar/Pulse signal analysis

• Vector signal analyzers and oscilloscopes to be compared

• Characteristics of Radar/Pulse signal

• Measurement considerations

– Overcome challenges of complex pulse analysis

• How to identify the signal immediately?

• How to acquire wideband signal with best fidelity?

• How to improve acquisition efficiency?

• How to characterize pulse modulation?

– Summary

2015

AD Symposium 2

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Vector Signal Analyzers and Oscilloscopes to be Compared

Which platform should I choose?

– Will see that new vector signal analyzers have

increased their analysis bandwidth and they offer the

best dynamic range

– Will see that new oscilloscopes offer bandwidths

typically wider than a vector signal analyzer, with

good amplitude and phase linearity, and useful, but

lower dynamic range

– This presentation will apply both platforms to pulsed

RF analysis measurement challenges and compare

results

UXA Signal Analyzer

510 MHz BW, 14 bits

S-Series Oscilloscopes

8 GHz BW, 10 bits

2015

AD Symposium 3

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Concept for Radar/Pulse Signal Analysis

– Pulse modulation is basic format for

Military Radar

– Complex modulation is often used for in-

pulse modulation

- CW Pulse, LFM, NLFM

- Binary Phase Coded (Barker)

- Poly Phase Coded (ZC Code,

Frank)

- Poly Time, PRN…

– Frequency hopping

– Variable Pulse Repetition Interval (PRI )

– High dynamic range

Characteristics of Radar/Pulse signal

2015

AD Symposium 4

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20 and 40 GHz optionsFor high-speed, low phase noise, multi-port applications

− 200 ns update rate

− Phase repeatable or phase continuous frequency switching

− Two Amplitude Ranges

− 10 dBm LO

− -120 to 0 dBm (90 dB agile)

− 10-25% Linear Chirp Widths

− Arbitrary Chirp Profiles

− Pulse ~6 nS Rise/ Fall Pulses, 90 dB on/off

− -70 dBc spurious @18 GHz

− Industry leading phase noise -126 dBc @10 kHz @10 GHz

− Multiple Instrument Coherence

− Lower cost of ownership

− Industry’s best reliability with a target MTBF of 75k hours

UXG Agile Signal Generator

Frequency Range 0.01 to 20/40 GHz

Output Power + 10 dBm

Agile Amplitude

Switching Range

80 dB < 0 dBM

20 GHz Model Only

Agile Amplitude

Switching Range10 dB >0 dBM

Phase Noise (10

GHz @ 20 kHz

offset (typical)

-126 dBc/Hz

Non-harmonic

Spurious-70 dBc

Digital word control Frequency, FM/PM

Compatibility mode Comstron

Pulse On/Off 90 db

Minimum Pulse

Width5nS

Size 3U

2015

AD Symposium 5

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nanoFET MMIC

switches & attenuatorsProprietary DAC

200 ns Update Rate

Phase Coherent Switching

UXG Agile Signal Generator

UXG - Enabling Technologies

2015

AD Symposium 6

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Numerically

Controlled

Oscillator

Electronic &

Mechanical

Attenuators

Analog Out

0.01 – 40 GHz

Digital to

Analog

Converter

x2n

FreqDoublers

LowpassFilter Bands

Amplifier

Pulse Parameter List & External Digital PDW Interface

FrequencyPhaseLFM

PulsePulse TimePulse Width

Amplitude

N5193A UXG Agile Signal Generator

PDWs from simulation

computer 2015

AD Symposium 7

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Pulse Interleaving

t-Time

Emitter Priority

Big Bird 1

Big Bird 2

Big Bird 3

Collisions

Output

2015

AD Symposium 8

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− Simulate AoA

− Exercise direction finding

receivers

− Play any pulse out of any

emitter on any channel to

increase pulse density

UXG

UXG

UXG

UXG

Multiple Instrument Synchronization

2015

AD Symposium 9

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Concept for Radar/Pulse Signal Analysis

– Frequency Band

– Signal Bandwidth

– Dynamic Range

– Measurements

- Power

- Spectrum

- Modulation

Characteristics(Frequency/Phase/Time)

– Analysis Length (Memory Size)

- Long scenario with variable pulse parameters

- Low duty cycle pulses

Measurement considerations

2015

AD Symposium 10

Creating-Multi-Emitter-Signal-Scenarios.mpeg


Page

Agenda









– Summary

2015

AD Symposium 11

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Overcome Challenges of Complex Pulse Analysis

2015

AD Symposium 12

General procedure for pulse signal analysis

ComplexPulse Signals

Trigger&

AcquisitionResults ShownMeasurement

Processed

Streaming for Post

Analysis

Live Measurement

Real-Time Analysis

Acquisition HW Analysis AlgorithmDUT

Display

Data Storage

Trigger

Page

IF Mag Trigger

– Trigger happens when input signal

is varying in amplitude and Mag

conditions are met.

– A good start to trigger pulse

measurement

– Could be used with Holdoff to get a

stable measurement

– No frequency selectivity, can’t

trigger specific frequency event

Real-time trigger used for pulse signal identification

Question: How to avoid triggering by unwanted signals?

How to Identify the Signal Immediately? Real-time Trigger

2015

AD Symposium 13

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Frequency-Mask Trigger (FMT)

– Based on RTSA HW

– Various criteria for Trigger: Enter,

Leave, Inside, Outside, Enter →

Leave, Leave → Enter

– Identify specific frequency pulse

from complex environment

– Can be recalled in VSA for

seamless pulse analysis

Real-time trigger in signal analyzer used for pulse signal identification

Question: How to identify a pulse in presence

of other signals with similar frequency?


2015

AD Symposium 14

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Time Qualified Triggering(TQT)

Use case: To trigger on a pulsed signal in presence of other similar

signals that lasts for either longer or shorter durationsA

mp

litu

de

Time

Am

plit

ud

e

FrequencyFrequency

Am

plit

ud

e

5 GHz band

FMT (?)

FMT does not work if equal

amplitude signals overlap in

the frequency domain

BUT, overlapping signals in

the frequency domain can

be resolved by time domain

trigger.

Real-time trigger used for pulse signal identification


2015

AD Symposium 15

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Time Qualified Triggering(TQT)

– Qualifying a trigger by using a time criteria

– Available with FMT and IF Mag triggers

– Trigger point definition

• Data acquisition happens AFTER time criteria has been applied

• Use pre-trigger to capture the entire event

>T1 (trigger on blue pulse)Overlap in frequency

resolved!

T1

Time

Am

plit

ud

e

Am

plit

ud

e

Frequency

Trigger Point


2015

AD Symposium 16

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“I Can’t See My Pulse from Others!!”

Two pulses at similar frequency

TQ>20us

FM Chirp

TQ<20us

CW Pulse

Demo video available on DVD

2015

AD Symposium 17

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“I Can’t Trigger On My Signal from Environment!!”

FMT without TQT – cannot separate signals

TQ>300uS

Isolate ZigBee

TQ<300uS

Isolate Wifi

Demo video available on DVD

2015

AD Symposium 18

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Oscilloscope Has Time “Holdoff” or “Zone” Trigger for Stable Trace

Basic Trigger in VSA

– Trigger happens when input signal

crosses a voltage threshold

– Slope specified

– Holdoff set to be a longer time than

the longest pulse

– Alternative is to use “Zone”

triggering --- define area where

signal trace ignored if the trace

passes through

Holdoff set > widest pulse; Or Zone drawn and defined where unstable

Trigger limited compared to the vector signal analyzer

Time holdoff trigger set in scope or VSA

Zone trigger

Scope capture in VSA

2015

AD Symposium 19

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Agenda









– Summary

2015

AD Symposium 20

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How to Acquire a Wideband Signal with the Best Fidelity?

Wideband Acquisition Requirement

– UWB Radar bandwidth greater than

500 MHz

– Frequency hopping happens in wide

range

– Wideband acquisition for EW/SIGINT

2015

AD Symposium 21



Page

Dynamic Range in Wideband Acquisition

– Dynamic range is critical in:

- Out-band distortion search

- Dynamic environment with large

and small signals

– Dynamic range is limited in wideband

acquisition due to:

- Noise level increase as BW

increase

- ADC effective bits limited for

high sample rate

– Trade-off between BW & DR


2015

AD Symposium 22

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How to Acquire Wideband Signal with the Best Fidelity?

Signal Analyzers pursuing wider BW with high DR

– Signal analyzer was narrow BW

instrument with high DR

- Spectrum monitoring in

sweep mode

- Too narrow for wideband

vector analysis

– Signal analyzer is now increasing

BW with high DR

- 510 MHz BW with 2.4 GSa/s

sample rate

- >78 dBc SFDR with 14 bit

ADC 510 MHz span and analysis BW

>78

dB

c

New proprietary ADC

2.4G Sa/s 14 bit

1.8 GHz fundamental

UXA FFT with 1.8 GHz sine input.

2015

AD Symposium 23

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Oscilloscopes pursue high DR with wide BW

– Oscilloscopes increase frequency

and BW coverage to 63 GHz

– A view of 500 MHz analysis

bandwidth measurement with

S-Series 8 GHz BW scope

• 500 MHz span selected in VSA

as in previous UXA example

• 30 kHz resolution bandwidth

• 10 averages

– See a 72 dB SFDR with 10-bit A/D

– May have to navigate around

oscilloscope spursS-Series FFT Response- 1.8 GHz sine input.

>70

dB

c

1.8 GHz fundamental

500 MHz span


2015

AD Symposium 24

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Oscilloscopes pursue high DR with wide BW

– 8 GHz BW S-Series SFDR shown

at 72 dB in 100 kHz ResBW

across 5 GHz span / analysis BW

– Noise density is optimized to mid-

range signal analyzer level

• ~ -160 dBm/Hz at 2mV/div

• ~ – 136 dBm/Hz at 100

mV/div)

S-Series Spurious Response- 1 GHz sine input

>7

0 d

Bc

5 GHz span


2015

AD Symposium 25

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Pulses with 60 dB power difference seen with UXA signal analyzer

Center 3.7GHz

Span 500 MHz

ResBW 200 kHz

200 MHz chirp

on large pulse

+6 dBm range

100 averages


2015

AD Symposium 26

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Pulses with 50 dB power difference seen with S-series oscilloscope

Center 3.7 GHz

Span 500 MHz

ResBW 200 kHz

200 MHz chirp

6 dBm range

100 averages

(same conditions

as UXA)


2015

AD Symposium 27

Page

Oscilloscope SNR is a function of the measurement bandwidth

0

20

40

60

80

100

120

140

1.00E+00 1.00E+02 1.00E+04 1.00E+06 1.00E+08 1.00E+10

SN

R i

n d

B

VSA Span/Inst BW in Hz

S Series SNR vs. Inst. BW @ 0dBm Range

7 ENOB

~= 42 dB SNR

@ 8 GHz

~= 80dB SNR @ 1 MHz

This is an example graph of expected SNR for the scope

0 dBm sensitivity range (63 mV/div)

Ignoring spurs


2015

AD Symposium 28

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Getting Noise Density from Data Sheet Vrms Noise

V/div dBm Ref Level dBm/Hz Noise

1mV/div -28 dBm -158 dBm/Hz **

2mV/div -28 dBm -158 dBm/Hz





100mV/div +2 dBm -136 dBm/Hz



1V/div +22 dBm -118 dBm/Hz

http://www.coretechgroup.com/dBm_Calculator.php

50 mV/div and 8 GHz BW

1.4 mV rms noise =

-44 dBm @ 8 GHz =

-44 dBm – 10 log (8E09) =

-143 dBm/Hz noise density

From S-Series Data (8 GHz model)

2015

AD Symposium 29

AD Symposium 30

Oscilloscope typical RF performance affecting fidelity

Stated oscilloscope typical values not guaranteed, subject to change. Oscilloscope measurement conditions and UXA DANL measurement conditions below.

S-Series Typical Values (tested to 8 GHz BW on a test

oscilloscope unless noted)

V-Series Typical Values (tested to 30 GHz on a test oscilloscope unless noted)

UXA Signal Analyzer (Typical values)

Sensitivity / Noise Density (1 mV/div; -38 dBm range) Power Spectral Density measurement at 1.0001 GHz, 1.0001 GHz center frequency, 500 kHz span, and 3 kHz RBW

DANL (UXA log average 0 dB input attenuation, 1 Hz RBW, preamp on)

-160 dBm/Hz -159 dBm/Hz

-166 dBm (w/ NFE off)-171 dBm (w/ NFE on)

Noise Figure (derived from measurement above) 14 dB 15 dB 10.3 dB / 5.3 dB

Signal to Noise Ratio / Dynamic Range (0 dBm 1 GHz input carrier, 0 dBm scope input range)1 GHz center frequency, 100 MHz span, 1 kHz RBW, measurement at +20 MHz from center

108 dB 111 dB 118 dB (1.8 GHz input sine, 1kHz RBW)

Absolute amplitude accuracy (5 oscilloscopes, 4 channels each, data points referenced to leveled RF source at each frequency point, 0-7.5 GHz S-Series, 0-30 GHz V-Series)

+/- 1 dB (0 to 7.5 GHz) +/- 0.5 dB (0 to 30 GHz) +/- 0.16 dB (10 MHz to 3.6 GHz, attenuation 10 dB, 95th percentile, 2 sigma)

Deviation from linear phase (fast step input to oscilloscope, phase FFT calculated from derivative of the step response) +/- 7 deg +/- 3 deg

3.4 deg (pk-pk 510 MHzBW)

Phase noise (@ 1 GHz)

10 KHz offset -121 dBc/Hz -125 dBc/Hz -136 dBc/Hz

100 KHz offset -122 dBc/Hz -131 dBc/Hz -142 dBc/Hz

Spur Free Dynamic Range (SFDR)1 GHz, 0 dBm signal present at input, FFT =5 GHz span, 3 GHz center, 100 kHz RBW; ignoring 2

nd– 5

thharmonics

72 dB 67 dB >78 dBc for 510 MHz BW

Input Match (S11)(< 50 mV/div 0-7 GHz S-Series, 0-30 GHz V-Series)(> =50mV/div 0 – 7 GHz S-Series, 0-30 GHz V-Series)

-15 dB; 1.4 VSWR-21 dB; 1.2 VSWR

-15 dB; 1.4 VSWR-19 dB; 1.25 VSWR

(10 dB input attenuator)1.1 VSWR (up to 3.6 GHz)1.28 VSWR (3.6 – 8.4 GHz)


Page

Which platform should I choose?

– For BW less than 510 MHz, signal

analyzer should be a good choice

- Frequency coverage from RF to MW

- Best dynamic range and noise level

– For BW greater than 510 MHz,

oscilloscope is the major platform

- Also good for < 510 MHz, low cost,

but watch throughput

– Signal analyzer could be combined with

oscilloscope as economy solution for

higher carrier and wide BW

Bandwidth scalable for pulse analysis UXA signal analyzer

510 MHz BW, 14 bits

S-Series oscilloscopes

8 GHz BW, 10 bits

+signal analyzer + oscilloscope

1.2 GHz BW, 10 bits


2015

AD Symposium 31

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Agenda









– Summary

2015

AD Symposium 32

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How to Improve Acquisition Efficiency?

Capture length with wideband signal

– For gapless capture, the time length

depends on

- Memory size

- Sample rate

– Captured data could be streaming to

external storage

– Captured data could also be stored inside

instruments for playback and post analysis

Start Time Analysis Position Stop Time2015

AD Symposium 33

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Capture Length with UXA

– UXA down-converted signal to IF

and digitized:

- Sample Rate:

500 M*1.28=640 MSa/s

- Memory Size: 536 MSa

- Max Capture Length:

536 M/640 M = 0.8375s

– Number of pulses included:

0.8375s/50us = 16,750 pulses

– Capture length is acceptable for

most cases

Example 1: Chirp signal at 4.9 GHz CF, 500 MHz BW, 1 µs pulse width, 50 µs PRI

Capture Length with S-Series Scope

– Oscilloscopes digitize signal at RF

directly:

- Sample Rate: 20 GSa/s

- Memory Size: 500 MSa used

in VSA

- Max Capture Length:

500 M/20 G = 0.025s

– Number of pulses included:

0.025 s/50 µs = 500 pulses

– Capture length is not sufficient for

some cases

Question: How can I capture more pulses with scopes?


2015

AD Symposium 34

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Segmented Capture Length with S-Series Scope

– Segment definition:

- Segment Length: 1.2µs

- Sample Rate: 20G Sa/s

- Size Per Segment: (20G Sa/s) * (1.2µs) = 24,000 samples

- Number of Segment: (400M Sa) / (24k Sa) = 16,666 segments

- Max Capture Length: 50µs * 16,666 =0.8 s

- Number of pulses included: 0.8s / 50µs = 16,662 pulses

– Capture Length is much longer than gapless capture with scopes

– The Lower duty cycle the pulse has, the more benefit we get

Answer: Segmented Capture!!

Example: Chirp signal at 4.9 GHz CF, 500 MHz BW, 1 µs pulse width, 50 µs PRI

Segmented Capture

• Capture pulse “ON” period only and ignore

“OFF” period

• Memory is fully used especially for low duty

cycle pulses, without losing information

2015

AD Symposium 35

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Oscilloscope Segmented Memory RF Pulse Capture

2015

AD Symposium 37

Video Demo can be found at: http://youtu.be/4ZPzBY_LNns

http://youtu.be/4ZPzBY_LNns

Page

• “Meas Trend” of Clock TIE to

see inverse of phase shift

• Time view of single RF pulse

in pulse train

• “Meas Trend” of Frequency

to see frequency shift across

the RF pulse (1 GHz linear

shift)

• 2 GHz FFT of an RF pulse

(variety of FFT window

options)

• Can also make RF pulse

envelope measurementsExample: 1 usec wide RF pulses, linear FM

3.5 GHz to 4.5 GHz, 10 usec PRI

1 GHz wide chirp example using 5 scope functions

Envelope, Frequency Trend, and Wide FFT Measurements

Video

demo

on

DVD

2015

AD Symposium 38

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Agenda









– Summary

2015

AD Symposium 39

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How to Characterize Pulse Modulation?

We already have several helpful tools….

Spectrum monitoring with 510 MHz RTSA

Basic vector Measurement in

Scope (above) and VSA (below)

2015

AD Symposium 40

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– Pulse analysis features in VSA

• Multiple HW support with scalable

analysis bandwidth & dynamic

range

• Measures all relevant parameters

including time, level and

modulations

• Trend and histogram analysis over

many pulses

• Works with scope segmented

memory!

But still need powerful weapon for in-depth characterizing…

2015

AD Symposium 41

Page


Level measurement

– Pulse detection threshold definition

- Isolate pulses from noise and

interfering

– Pulse Level Results

- Top Power/Base Power

- Droop

- Overshoot

- Ripple

2015

AD Symposium 42

AD Symposium 43


Time domain measurement

– Pulse width detection

threshold definition

- Specify pulse width

detection range

– Time domain results

- Pulse Width

- PRI/Duty Cycle

- Rise Time/Fall Time

- Ripple

Page


Frequency/phase measurement

– Graphical trace for Frequency

vs. Time, Phase vs. Time

– Overlay display of traces

2015

AD Symposium 44

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In-pulse modulation measurement

– CW/LFM supported now

– FM Dev, Slope and In-linearity

measurement for LFM

FM Error Peak (Hz)

Measured FM

LFM Best-fit

Pk-Pk

Deviation (Hz)


2015

AD Symposium 45

Page

Trend and histogram analysis

– Pulse cumulative statistics table

– Graphical histogram

– Trend Line Trace Plots

Measurement pause enable

– Perform conditional logic test

on a supported metrics in Pulse

Table

Pulse modulation histogram


2015

AD Symposium 46

Page

Multi-Channel or Multi-Format Analysis in Parallel

Chirp Pulse at 2.3 GHz + LTE signal at 2.36 GHz


2015

AD Symposium 47

Minute Video of VSA Version 19 Pulse Option BHG

2015

AD Symposium 48

Video Demo can be found at http://youtu.be/BPHfYiRgJtE

Using oscilloscope segmented memory for long capture time

http://youtu.be/BPHfYiRgJtE

Page

• Testing Tx and components

• Pulse modulation stability

• Characterizing threats (SIGINT)

• Verifying threat simulations

• Verifying EW jamming responses

The Pulse Analysis feature in VSA is helpful for ALL Pulse Designers

Target with EW

Jamming or

DeceptionClutter

InterferenceTransmitter

ReceiverEW

Target

Radar


2015

AD Symposium 49

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Agenda









– Summary

2015

AD Symposium 50

Page

Summary

– Real-time trigger in Magnitude, Frequency and Time domain is the first

step for successful pulse analysis (in SA)

– Although lacking such triggers, new oscilloscopes offer impressive RF

performance useful for in-band measurements

– Complex Radar/EW environment requires wider acquisition bandwidth

with higher dynamic range

– Acquisition efficiency could be improved significantly with segmented

capture

– Pulse analysis feature in VSA can provide complete pulse

measurements in multiple views

2015

AD Symposium 51

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Demo Videos Available on the AD Symposium DVD

– Basic oscilloscope FFT measurements on a sine wave input

– Oscilloscope wideband RF pulse time domain analysis on pulse envelope,

display of linear FM chirp across pulse, and use of segmented memory for long

capture time

– Oscilloscope wideband RF pulse frequency domain analysis with FFTs, gated

FFTs, and segmented memory

– Oscilloscope + 89600 wideband RF pulse analysis on envelope, display of linear

FM chirp across pulse and unwrapped phase across pulse

– Oscilloscope + 89600 VSA pulse option for automated RF pulse time and

frequency domain analysis – adjust number of segments and statistical

measurements

– Oscilloscope + 89600 VSA pulse option for automated RF pulse time and

frequency domain analysis with segmented memory

– Oscilloscope + 89600 VSA for wideband communications signal analysis

2015

AD Symposium 52

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Questions?

2015

AD Symposium 53

understanding new pulse-analysis techniques · 2015-05-12 · – this presentation will apply both...

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