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Aerospace and Defense Symposium 2007EuMw 2007 Agilent Workshop
Signal Generation Back to BasicsSignal Generation Back to Basics
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Page M6- 1
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopAgenda
The need for creating test signals– Aerospace Defense to Communications
From Generating Signals… No modulation– No modulation
– Analog Modulation– Composite Modulation
T Si l ti Si l…To Simulating Signals– Simulating real-life signals
Signal GeneratorsSignal GeneratorsSignal Simulation Solutions
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopFrom Movies ….
Nov. 1940 - News Flash
Disney releases Fantasia withDisney releases Fantasia with “Fantasound”, a new audio stereophonic sound system
Walt Disney orders eight audio oscillators (HP 200B) for the sound production of the movie Fantasia.
The 200B was used to calibrate the breakthrough sound system of Walt Disney's celebrated animated film, Fantasia
Stimulus/Response Testing
OutputInput Output
PowerTone/volumeEqualizer
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopAerospace Defense ….
ANTENNA
RF SignalInjection
TESTING RADAR TRANSMITTERS and RECEIVERs
ANTENNA
IF Signal
LNA
IF SignalInjection
1st LO
IFBPF
SignalProcessor
(range and Doppler) 1stIFA
IFBPF
2nd
IFA
2nd
LOLOSubstitution
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopTo Mobile Communications….
TESTING DIGITAL TRANSMITTERS and RECEIVERs
1011001110001010001 1011001110001010001
RF Signal injectionIF Signal Injection
Baseband Signal Injection
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopAgenda
The need for creating test signals– Aerospace Defense to Communications
From Generating Signals… No modulation– No modulation
– Analog Modulation– Composite Modulation
T Si l ti Si l…To Simulating Signals– Simulating real-life signals
Signal GeneratorsSignal GeneratorsSignal Simulation SolutionsSummaryy
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopGenerating Signals – No Modulation
Continuous Wave (CW)ag
e
Ti age
F
Volta Time
Volta Frequency
Spectrum AnalyzerOscilloscopeThe sine wave is the basic, non-modulated signal: It is useful for stimulus/response testing of linear components and for Local Oscillator substitution Available frequencies range from
Spectrum AnalyzerOscilloscope
Local Oscillator substitution. Available frequencies range from low RF to Millimeter.
RF Microwave MillimeterRF Microwave Millimeter
20-70 GHz 300 GHz6 GHz
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopGenerating Signals – Analog Modulation
Modulation: Where the Information Resides
V = V(t) sin[2p fc(t) + f(t)]
AM, Pulse FM PM
V = V(t) sin[q(t)]V = V(t) sin[q(t)]
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopGenerating Signals - Analog Modulation
Important Characteristics for Modulation
Amplitude ModulationpAmplitude ModulationCarrier
Modulation frequency (rate)Depth of modulation (Mod Index)
Modulation depth %,dB
Volta
ge
Time
Depth of modulation (Mod Index)Linear AM (%)Log AM (dB)Sensitivity (depth/volt)
Modulation frequency
Sensitivity (depth/volt)Distortion %
Where are AM signals used?
AM RadioAM RadioAntenna scanASK (early digital 100101)
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopGenerating Signals – Analog Modulation
Amplitude Modulation
Where are AM signals used?eCarrier
Volta
ge
TimeAM RadioA t
ModulationAntenna scanASK (early digital 100101)
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopGenerating Signals – Analog Modulation
I t t Ch t i ti f
Frequency Modulationge
Important Characteristics for Frequency Modulation
Frequency Deviation
Volta
g
Time
Frequency DeviationModulation FrequencydcFMAccuracyAccuracyResolutionDistortionSensitivity (dev/volt)Wh FM i l d? Sensitivity (dev/volt)Where are FM signals used?
FM RadioAviation Flight systemsAviation Flight systemsRadarFSK (early digital 1011)
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopGenerating Signals – Analog Modulation
V A i [2 f t (t)]
Frequency Modulation
Important Characteristics for
V= A sin[2pfct + m(t)]b
Important Characteristics for Frequency ModulationF /F
dev modb = D
Frequency Deviation
ge
Frequency DeviationModulation FrequencydcFMAccuracy
Volta Time
AccuracyResolutionDistortionSensitivity (dev/volt)Sensitivity (dev/volt)
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopGenerating Signals – Analog Modulation
Important Characteristics for Phase Modulation
Phase Modulation
Phase deviationModulation Rateol
tage
AccuracyResolutionDistortion
Vo Time
DistortionSensitivity
Where are Phase Modulated signals used?
PSK (early digital 1010)PSK (early digital 1010)Radar(pulse coding)
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopGenerating Signals – Analog Modulation
Phase Modulation
Where are Phase Modulated signals used?
PSK (early digital 1010)Radar(pulse coding)Vo
ltage
TimeRadar(pulse coding)
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopGenerating Signals – Analog Modulation
RiseRate=1/T T
Pulse Modulation
On/Off ratio
Risetime
wer
Important Characteristics for Pulse Modulation
TimePulseWidth
t
Po
Pulse widthPulse periodOn/Off ratioOn/Off ratioRise time
Where are Pulse Modulated
1/t
1/Tsignals used?
RadarHigh Power
Pow
erg
Stimulus/ResponseCommunications
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopGenerating Signals – Analog ModulationPulse Modulation
RiRate=1/T T
Where are Pulse Modulated
On/Off ratio
Risetime
wer
Where are Pulse Modulated signals used?
RadarHigh Po er
TimePulseWidth
t
Pow High Power
Stimulus/ResponseCommunications
Width
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopGenerating Signals – Composite Modulation
Independent Amplitude and
Simultaneous modulation of two Mod Types
Independent Amplitude and Phase
Modulation QIntegrated IQ Modulator
IIndependent pFM and Pulse
Modulation
32 QAM Constellation DiagramFM during the pulse = chirp
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopGenerating Signals – Composite Modulation
P l Di l
Vector Signals (Amplitude and Phase)Polar Display
Phase
0 d0 deg
• Magnitude is an absolute value• Phase is relative to a reference signal (0 degrees)
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopGenerating Signals – Composite Modulation
Vector Signal Changes or Modifications
Phase
0 deg Phase0 deg
Magnitude Change Phase Change
0 deg
Frequency ChangeBoth Change
0 deg
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopGenerating Signals – Composite ModulationPolar Versus I-Q Format
Q
Project Signals to “I” and “Q” Axes
Q
Polar to Rectangular Conversion
IQ Pl Sh 2 ThiQ-Value
Phase 0 deg IQ Plane Shows 2 ThingsWhat the modulated carrier is doing relative to the
d l t d i
Iunmodulated carrier.What baseband I and Q inputs are required to produce the modulated carrier
I-Value
modulated carrier
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopGenerating Signals – Composite ModulationTransmitting Digital Data -- Bits vs Symbols
f 1Transmitting Digital Bits (f 1 = 0, f 2 = 1 ) Transmission Bandwidth Required
Binary Data bit = 0,1
f (t) =f 1f 2
T 0101010102/ T
Symbol = Groups/blocks of Bits2 bits/symbol (00 01 10 11) 3 bit / b l (000 001 )
Main lobe width is 2 × Sample rate2/ T
Symbol Rate = Bit rate3 bits/symbol (000 001 …..) 4 bits/symbol (0000 0001 ..)
Symbol 1 (00)
S b l 2 (01)
Symbol Rate = Bit rate# bits per symbol
2/ SMain lobe width is 2 × Symbol rate
Symbol 2 (01)Symbol 3 (10)Symbol 4 (11)
S
f (t) =
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Main lobe width is 2 × Symbol rateS
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopGenerating Signals – Composite Modulation
Number of bits per symbol
Transmission bandwidth
Modulation format
Constellation
Digital Modulation Characteristics
BPSK 1 I
Q
01
F
I
Q 0001
QPSK 2
F/2
I1011 F/2
Q 0000
Symbol Rate = #symbols/sec. (Hz)
16 QAM 4
F/4
I
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopGenerating Signals – Composite Modulation
Vector Modulation - Important CharacteristicsQ
IQ Modulation BandwidthFrequency Response/flatness
Q
Frequency Response/flatnessIQ quadrature skewIQ gain balance
Phase 0 degI flatness
Fbw
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopGenerating Signals – Composite ModulationVector Modulation - Where Used
Q
Mobile Digital CommunicationsMobile Digital CommunicationsModern Radars I
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopAgenda
The need for creating test signals– Aerospace Defense to Communications
From Generating Signals… No modulation– No modulation
– Analog Modulation– Composite Modulation
T Si l ti Si l…To Simulating Signals– Simulating real-life signals
Signal GeneratorsSignal GeneratorsSignal Simulation Solutions
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopSimulating SignalsAdd interference/impairments to user data
Multipath signals
Multi-path Fading
1011001110001010001 1011001110001010001
Add i l i i tAdd signal impairments Streaming data
Recovering User Data Removing test signal imperfections
Beyond S-Parameters© Agilent Technologies, Inc. 2007
g g
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopSimulating Signals
Record/playback real signals scenariosRF Signal
ANTENNA
RF SignalInjection
LNA
1st LO
SignalProcessor
(range and Doppler)IF
BPF
(range and Doppler)1stIFA
2nd
LO
IFBPF
2nd
IFA
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopAgenda
The need for creating test signals– Aerospace Defense to Communications
From Generating Signals… No modulation– No modulation
– Analog Modulation– Composite Modulation
T Si l ti Si l…To Simulating Signals– Simulating real-life signals
Signal GeneratorsSignal GeneratorsSignal Simulation Solutions
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopSignal Generators
• Basic CW Signals• Block Diagram (RF and Microwave)• Specifications• ApplicationsApplications
• Analog Signals• Block Diagram (AM, FM, PM, Pulse)• Applications
• Vector Signals • Block Diagram (IQ)• Applications
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopBasic CW Signals – Block Diagram
Synthesizer Section
RF Source
Frac-N
ALC OutputOutput Section
Phase
ALC Modulator
OutputAttenuator
VCODetector
Reference
divideby X
ALCDriver
ReferenceOscillator ALC Detector
ALC = automatic level controlReference Section
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopBasic CW Signals – Block Diagram Reference Section
To synthesizer section
PhaseDetector
sectionDivideby X
Optional External Reference Input Reference Oscillator (TCXO or OCXO)
TCXO OCXOC OAging Rate +/- 2ppm/year +/- 0.1 ppm /year
Temp. +/- 1ppm +/- 0.01 ppm
Line Voltage +/- 0.5ppm +/- 0.001 ppm
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopBasic CW Signals – Block Diagram
Front
Synthesizer Section
panelcontrol
N = 93.1
Frac-N
5MHz
Error signal
PhaseDetector
To output sectionX 2
931 MHzVCO
From reference
Multiplier
465 5 MHz
931 MHz
5MHz
From reference section
465.5 MHz
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopBasic CW Signals – Block Diagram
PLL/Fractional-N…suppress phase noise
Overall phase noise of signal Phase-locked-loop (PLL) bandwidth selected for optimum
Referenceoscillator Phase
detector
noise performance
detector noise Broadband
noise floor
20logN
VCO iVCO noise frequency
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopBasic CW Signals – Block DiagramOutput Section
ALC Output• ALC
•maintains level output Modulator Attenuator
From synthesizer section
S
power by adding/subtracting power as needed
Source output• Output Attenuator
•mechanical or electronic•provides attenuation to
ALCDriver
pachieve wide output range (e.g. -136dBm to +17dBm)
ALC Detector
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopBasic CW Signals – Block Diagram
Reference Section
Microwave Source
ALC Output
Reference Section
Phase
FracN
Modulatorp
Attenuator
Sampler
VCO
PhaseDet
ALC
Ref Osc
Phase
YIGOscillator
ALC D t t
ALCDriver
SynthesizerFrac-N
PhaseDetector
ALC DetectorSynthesizer Section
Output Section
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopBasic CW Signals – Specifications
R F t F
Frequency
Range -- Fmin to FmaxResolution – smallest frequency incrementAccuracy – is it where it says it isy y
r
UncertaintyAccuracy = +_ fCW t aging calt* *
f
Pow
er
Frequency
= CW frequency = 1 GHz= aging rate = 0.152 ppm/year= time since last calibrated = 1 year
fCWt aging
caltq y
Accuracy = 152 Hz+_
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopBasic CW Signals – Specifications
• Range ( 136dBm to +17dBm)
Amplitude
• Range (-136dBm to +17dBm)• Accuracy (+/- 0.5dB)• Resolution (0.02dB)• Switching Speed (19ms)• Reverse Power Protection
DUTSource protected from accidental transmission from
How accurate is this number?What is P out?max
DUTaccidental transmission from DUT
Volta
ge
minWhat is P out?
Frequency
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopBasic CW Signals – Specifications Frequency Sweep
Ramp sweep• accuracy• sweep time
f2
• sweep time• resolution
t2f1
Step sweep• accuracy
timet2t1
f• accuracy• number of points• switching time
f4f3f2
t4t3t1 t2
f1
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopBasic CW Signals – Specifications level accuracy spec
Frequency Sweep - Amplitude
Frequency Sweep• Level Accuracy flatness specpo
wer
• Flatness• Source Match (SWR)
flatness spec
f1 f2frequency
Power Sweep• Power Sweep Range
P2• Power Slope Range• Source Match (SWR)
ower
P2
power sweep range
po
P1
g
t1 t2
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopBasic CW Signals – Specifications
Spectral Purity
• Phase Noise• Spurious
CW output
H i
CW output
Non-harmonic spur~65dBc
Harmonic spur~30dBcPhase
noise
Sub-harmonics
0 5 f0 f0 2f0
Beyond S-Parameters© Agilent Technologies, Inc. 2007
0.5 f0 f0 2f0
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopBasic CW Signals – Specifications
Spectral Purity – Phase Noise
CW output
Measured as
Frequency
Measured as dBc/Hz
Frequency
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopBasic CW Signals – ApplicationsAs a Local Oscillator
IF signal transmitter outputP f
DUT
Poor frequency accuracy and/or resolution will cause the transmitter output to be at the wrong frequency
LO signal
poor phase noise spreads energy into adjacent • Frequency Range
• Accuracy
Key Specs:
channels• Accuracy• Resolution• Output Power• Phase Noise
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopBasic CW Signals – Applications In-Channel Receiver Testing
IF
Receiver SensitivityThe smallest RF signal that will produce a desired baseband output from the
receiver
signal
DUT
in-channel signal(cw signal)
IF Rejection Curvesource output• Range (-136dBm to +17dBm)
Key Specs:
dBm
)
jp
116 dB t
Range ( 136dBm to 17dBm)• Accuracy (+/- 0.5dB)• Resolution (0.02dB)
Frequency
Leve
l (d -116 dBm to –
126 dBm
IF Channel
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopBasic CW Signals – Applications
Receiver SelectivitySpurious Response
Out-of-channel Receiver Testing
IF
Spurious Response Immunity
signalout-of-channel signal(CW and/or modulated signal) DUT
IF Rejection Curvesource output
Key Specs:(d
Bm
)
spur from source and/or high levels of phase noise can cause a good receiver to fail
• Frequency Range • Output Power• Phase Noise
Key Specs:Le
vel (• Phase Noise
• Broadband noise• Non-harmonic spurious
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Frequency
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopBasic CW Signals – Applications
f1
Non-linear Amplifier Testing - TOI
output RF
f1DUT
isolatof2 r
Two-tone IntermodulationK Sf2f
1test system third order products will also fall here
Two tone Intermodulation Distortion• Frequency Range
• Frequency Accuracy• Frequency Resolution
Key Specs:
spurious signals from source can corrupt measurement
q y• Output Power• Non-harmonic spurious
fU = 2f2 - f1fL = 2f1 - f2frequency
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopBasic CW Signals – Applications Out-of-channel Receiver Testing - IMD
IF
Intermodulation immunity
isolator
f1
signal
DUT
isolator
Fmod = nF1 + mF2
n= -1,2
f2
out-of-channel signals IF Rejection Curve
sources output
,m= 2,-1
• Frequency Range • Frequency Accuracy
Key Specs:dB
m)
spur from source
F1 F2 Intermodulation product Fmod = 2F2 – F1
• Frequency Accuracy• Frequency Resolution• Output Power• Non-harmonic spurious
Leve
l (d source
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Frequency
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopBasic CW Signals – Applications Stimulus-Response Testing
Detector
Detector
DUTSweeper Input
Fin Fout
Fin Fout
Fin Fout
Key Specs:• Frequency Range • Frequency Accuracy• Frequency Ramp/step sweep
P
Key Specs:
LO
• Power sweep• Sweep speed• Output Power accuracy• Residual FM
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopSignal Generators
• Basic CW Signals• Block Diagram (RF and Microwave)• Specifications• Applications• Applications
• Analog Signals• Block Diagram (AM, FM, PM, Pulse)Block Diagram (AM, FM, PM, Pulse)• Applications
• Vector Signals • Block Diagram (IQ)• Applications
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopAnalog Signals – Block DiagramAdd AM, FM, PM, and Pulse Modulation
ALC Modulator
Pulse
OutputAttenuatorVCO
Freq
PulseMod.
Freq.Control ALC
Driver
ReferenceOscillator
FM, PM input AM input Pulse Mod input
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopAnalog Signals – Block Diagram
ALC Output
Add internal modulation generator
ALC Modulator
PulseMod.
AttenuatorVCO
Freq.Control
Mod.
ALCD iDriver
FM, PM inputAM input Pulse Mod input
FMSource
AMSource
PulseSourceReference
Oscillator
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopAnalog Signals – Applications
Receiver
Receiver Baseband Distortion
Receiver
In-channel signalIn channel signal(modulated signal)
Non-linear distortion is characterized by• Frequency RangeKey Specs:
Non-linear distortion is characterized by the appearance of harmonics other than
the fundamental component in the baseband output
Frequency Range • Modulation rate/deviation• Modulation Distortion
Required SG M d l ti Receiver ( i (dB)/20)
vel (
dBm
) Distortion
Modulation distortion
= Receiver Distortion % x 10-(margin(dB)/20)
Example:For a receiver distortion of 5% and
Frequency
LevFor a receiver distortion of 5% and
a 10 dB test margin, the SG must have < 1.58% mod distortion
Beyond S-Parameters© Agilent Technologies, Inc. 2007
q y
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopAnalog Signals – Applications
RF Si l
Pulsed Radar Testing with Chirps
ANTENNA
RF SignalInjection
FM during the pulse = chirp
LNA• Frequency Range • FM Modulation rate/deviation
Key Specs:
LNA
1st LO
FM Modulation rate/deviation• Pulse rate, width, rise time
SignalProcessor
(range and Doppler)IF
BPF
(range and Doppler)1stIFA
2nd
LO
IFBPF
2nd
IFA
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopSignal Generators
• Basic CW Signals• Block Diagram (RF and Microwave)
Specifications• Specifications• Applications
• Analog Signalsa og S g a s• Block Diagram (AM, FM, PM, Pulse)• Applications
• Vector Signals • Block Diagram (IQ)• Applications• Applications
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopVector Signals – Block Diagram
IQ Modulation
I:
Q 0001
p/Carrier
:
I2
Q 1011:
Good Interface with Digital Signals and CircuitsCan be Implemented with Simple CircuitsF t t t t hFast, accurate state change
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopVector Signals – Block Diagram
OutputI-Q Modulator
Adding the IQ modulator
VCO
SynthesizerOutputI-Q Modulator
p/2
Freq.C t l
ALCControl Driver
Reference
Q
Reference I
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopVector Signals – Block Diagram
Analog Reconstruction Filters
Baseband IQ signal generation
Symbol DAC
Filters
IPattern RAM
yMapping and
Baseband Filters
DAC Q
00 -> 1+j1
1100010110101001011100
00 1 j1
01 -> -1+j1
10 -> -1-j110101010 11 -> 1-j1
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopVector Signals – Block DiagramBaseband Generator: Baseband Filters
Fast Transitions Require Wide Bandwidths
Frequency
Frequency
Filtering Slows Down Transitions and Narrows the Bandwidth
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopVector Signals – Block Diagram
OutputI-Q Modulator
Adding an internal Baseband Generator
VCO
SynthesizerOutputI-Q Modulator
p/2
Freq.C t l
ALCControl Driver
QPattern RAM and SymbolReference
DACI
Symbol MappingReference
Baseband Generator
DAC
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopVector Signals – Applications
F t S ifi Si l G ti• Format Specific Signal Generation• Receiver Sensitivity• Receiver Selectivity• Receiver Selectivity• Component Distortion
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopVector Signals – Applications
Digital Format Access SchemesDifferent time - different Users
One User
FDMA Differ channel different UsersFDMA TDMADiffer channel - different Users Different time - different Users
CDMA OFDMSame channel – many users
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopVector Signals – Applications
Format Specific Modulation
GSM: multiple users, same frequency, different time slots
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopVector Signals – Applications
The smallest modulated RF signal that will
Digital Receiver Sensitivity
BasebandRF
DUTThe smallest modulated RF signal that will produce a specified BER from the receiver
Baseband
DSPDAC
RF LO
Payload Data
plitu
deA
mp
BER Spec Line
BER
Beyond S-Parameters© Agilent Technologies, Inc. 2007
frequency
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopVector Signals – Applications
T ti 110 dB iti it di it l i
Digital Receiver Sensitivity
Testing a -110 dB sensitivity digital receiver:X= Failed unitO=Passed unit
-110 dB specification-110 dB specification
Set source to 115 dBmActual output power= -114 dBm
XX
X XX
O
-110 dB specificationSet source to -111 dBm
Actual output power= -112 dBm
XX
O OOSet source to -115 dBmO
O
Frequency Frequency
Case 1: Source has +/-5 dB ofoutput power accuracy at-100 to -120 dBm output power.
Case 2: Source has +/-1 dB ofoutput power accuracy at-100 to -120 dBm output power.
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopVector Signals – Applications
• Simulated portionReceiver Sensitivity – Connected Solutions
Demodulator
RF IF
BasebandDe-Coding
A/DConverter
I
RF/IF BER
DUT
Signal GeneratorSignal
AnalyzerSimulation Software
Beyond S-Parameters© Agilent Technologies, Inc. 2007
ySimulation Software
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopVector Signals – Applications
In-channel signal
Receiver Selectivity (Blocking Tests)g
(modulated signal)
BasebandRF
O t f h l i l
DSP
RF LO
DAC
IF Rejection Curve
Out-of-channel signal(CW or modulated signal)
Payload
vel (
dBm
)
Spur from source and/or high levels of phase noise can cause a good receiver to fail
Data
F
Lev
Sensitivity specification
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Frequency
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopVector Signals – Applications
Component Distortion – Adjacent Channel Power Ratio
Spectral Output from amplifier
DUT
Input from VSG
p p p
ACPR
Spectral regrowth
ACP Margin
Margin (dB) 0 1 2 3 4 5 10 15Error contribution (dB) 3.0 2.5 2.1 1.8 1.5 1.2 0.4 0.2
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopVector Signals – Applications
OFDM Si l
Component Distortion – Error Vector Magnitude
OFDM Signal -400 MHz Bandwidth
DAC
QQ QQ
Q Magnitude Error (IQ error mag)
II
Error Vector MagnitudeTest
Signal
Ideal (Reference) Signal
Phase Error (IQ error phase)
f
Beyond S-Parameters© Agilent Technologies, Inc. 2007
I
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopVector Signals – Applications
Measured EVM = -30 dB, 3.3%Component Distortion – EVM
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopAgenda
The need for creating test signals– Aerospace Defense to Communications
From Generating Signals… No modulation– No modulation
– Analog Modulation– Composite Modulation
T Si l ti Si l…To Simulating Signals– Simulating real-life signals
Signal GeneratorsSignal GeneratorsSignal Simulation Solutions
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopSignal Simulation Solutions
Simulating real signal environmentsSignal CreationSignal Creation
Import/export Custom Digital Data User
H d
Create Impairments
Digital
Fading Baseband
SWHardware
RF/Microwave SignalsI t l BBGStream Data
Waveform Capture and
Playback Baseband
Digital Signal
Interface
Si l
RF/Microwave SignalsInternal BBGStream Data
External BBG
Baseband SW Baseband IQ generation
Vector Signal
Generator
Remove test signal imperfections
Signal Creation
SWCreate Standard
Signals
pe ect o sVector Signal
Analyzer
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopSignal Simulation Solutions
Remove Test Signal Imperfections
BBG
Add
Signal LAN/GPIB
Add Predistortion (corrections)
VSGSoftware LAN/GPIB
Measure Measurement
Results
VSA
Modulated Signal
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopSignal Simulation Solutions
Remove Test Signal Imperfections – IQ Flatness
Source of error – I/Q modulator, RF chain, IQ pathResult passband tilt ripple and roll offResult – passband tilt, ripple, and roll off
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopSignal Simulation SolutionsRemove Test Signal imperfections – IQ flatness
Solution – measure vector signal generator and apply predistortionTradeoff – calculation time, valid cal time Typical application – wideband, multitone, and multicarrier
500 MHz UWB32 tones - 80 MHz
Before2.4 dB 6-8 dB
0.1 dB < 3 dBAfter
0.1 dB < 3 dB
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopSignal Simulation Solutions
Removing Test Signal Imperfections - IMD
Before Predistortion After PredistortionBefore PredistortionMeasured in-band IMD = -40 dBc
After PredistortionMeasured in-band IMD = -84 dBc
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopSignal Simulation Solutions
Removing Test Signal Imperfections – Group Delay Before Predistortion
EVM -30 dB, 3.3%After Predistortion
EVM –34 dB, 2%
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopSignal Simulation Solutions
DUT
Non-linear Amplifier Testing
output RFDUT
Intermodulation Di t tiDistortion
• Improved IMD suppression (typically > 80 dBc) Correct generator with additional devices in the loop
Signal Studio – Enhanced Multitone
• Correct generator with additional devices in the loop• Lower overall cost-of-test for large # tones• Same hardware for ACPR/NPR distortion tests
Up to 1024 tones Set relative tone powerSet relative tone phase 80 MHz correction BWCCDF plot
Beyond S-Parameters© Agilent Technologies, Inc. 2007
p
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopSignal Simulation Solutions
Adding Impairments to Signals – Fading
R i
Faded signal
Receiver
��
BER/PER analysis
transmission channel
Interferersanalysis
SW and interface hw Faded analog RF, IF, or IQ for receiver testFaded digital IQ baseband for digital
subsystem test
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopSignal Simulation Solutions
RF Signal
RF Capture & Playback
ANTENNA
RF SignalInjection
LNA
1st LO
Record signals off the airTransfer files to a PC equipped with Baseband Studio and re-formatSt th i t th V t PSG i l t f l b k
IF
SignalProcessor
(range and Doppler)1stIF2nd
Stream them into the Vector PSG signal generator for playback
IFBPF
1stIFA
2nd
LO
IFBPF
2nd
IFA
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopSignal Simulation Solutions
Digital Capture & PlaybackCapture data from the digital
Digital bus
Capture digital I/Q signals
p gsection of a transmitter
DUT
Test stimulus to the digital section of a receiver
Digital bus
Playback digital I/Q signals
section of a receiver
DUT
Beyond S-Parameters© Agilent Technologies, Inc. 2007
Aerospace and Defense Symposium 2007EuMw 2007 Agilent Workshop
THANK YOU!THANK YOU!
Beyond S-Parameters© Agilent Technologies, Inc. 2007