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Design and Verification for3G Wireless RFICs
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Requirements for the Power Amplifierof 3G Wireless Handsets
nBalance conflicting requirements
l Efficient battery usage
l Distortion in all its forms
n Include several alternative designs to choose best
nSatisfy specifications of communication format
nMinimize time to market
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Typical Development Design Flow
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IC Vendor to Customer Linkages
EquipmentManufacturer
ProductRequirements
PrototypeEvaluation
Boards
IC Design
Apps Engineering
Test Engineering
System Design
IC Vendor
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Design Challenges for 3G WirelessHandset Power Amplifiers –Synergism of Design and TestSystem RequirednMinimize the need for wafer design turn-arounds
l Include alternative designs on wafer
l Use accurate (validated) models with simulation tools
nAccount for module parasitics
nAccount for application board components
nTest the design with virtual test equipment
nSpeed up and automate actual testing
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The Many Tasks of TestingnAssemble test equipment
nDevelop procedures
nAssure procedures satisfy the latest format specifications
nPerform tests
l Test the different designs on the wafer
l Vary bias
l Vary temperature
l Test a statistically valid sample
n (This takes weeks and uses critical resources – especiallypeople.)
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Agilent’s Handset PA ValiFire System
3GPP Design LibraryEDGE Design Library
Advanced Design System
A to D Converter DigitalReceiver
RFICDownConverter
DATAInstrumentDriver
DATAInstrumentDriver
HP EEsof Signal Processing/System_level_example/Receiver
z- 1 z -1
Σ Σ
z- 1
z-1
Σ ΣM
M
P1 P2
E4406Vector Signal Analyzer
EDGE personality3GPP personality
E4433BRF Signal Generator
EDGE personality3GPP personality
DUT(EDGE/3GPP
PA RFIC)
ValiFire
PA Design Director(System software wrapper /application layer)
+
66319Bpower supply
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Test Automation
Sequence and automateyour prototype tests
l Built-in 3G test specs
l Guided user interface
l Data collection
l Spec checking
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ADS Switches Between Simulation(Virtual) & Measurement (Actual)
V1Mode=simulate
SweepTemp
PARAMETER SWEEP
SweepBias
PARAMETER SWEEP
SweepProbe
PARAMETER SWEEP
User_Defined_Variables
RF_Freq=1950 MHzNumSlotsMeasured=1DUT_Gain=25SignalPower=dbmtow(-10)
EqnVar
Controller
Device_To_Be_TestedGain=dbpolar(DUT_Gain,0)
Signal_Measurement
3GPPEVM
Simulation_Variables
EqnVar
Signal_Source
FCarrier=RF_FreqSignalPower=SignalPower
3GPPSource Test
Ref
Measurement_and_Specification_Information
3GPP EVMDesign Information
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Common Bottlenecks During Design
nWaiting for completed chips from the wafer
nSimulating and evaluating the package’s effect
nDesign of the application board and simulating andevaluating its effect
nTesting (each specification at varying bias & temperature)
nCorrelation of test results with customer needs & results
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A Design of a Power Amplifier Chip
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Verification of Module/PackageApplication Board
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Critical Tests for 3G Handset PowerAmplifier Design
nBoth Virtual & Actual
nPower addedefficiency (PAE)
nPower vs. frequency
nError VectorMagnitude (EVM)
nAdjacent channelleakage ratio (ACLR)
nActual Verification
nControlled by ADS withValiFire
lOperates test equipment
l Includes test specs
• Quick updates
lVaries bias
lCan control ovens
lCollects data
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ADS Design for Testing PAE vs. InputPower
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Data Showing PAE vs. Input Power
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ADS Design for Testing ComplexChannel Power
Controller
Device_To_Be_TestedGain=dbpolar(DUT_Gain,0)
User_Defined_Variables
RF_Freq=1950 MHzNumSlotsMeasured=10DUT_Gain=25PowerClass=3SignalPower=dbmtow(PowerPerClass-DUT_Gain)
EqnVar
Simulation_Variables
EqnVar
Signal_Source
FCarrier=RF_FreqSignalPower=SignalPower
3GPPSource
Test
Ref
Signal_MeasurementNumSlotsMeasured=NumSlotsMeasured
3GPPOutputPower
Measurement_and_Specification_Information
3GPP MaximumOutput PowerDesign Information
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Data Showing Complex ChannelPower
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ADS Design for Testing ACLRUser_Defined_Variables
RF_Freq=1950 MHzNumSlotsMeasured=1DUT_Gain=25SignalPower=dbmtow(24-DUT_Gain)
EqnVar
Controller
Device_To_Be_TestedGain=dbpolar(DUT_Gain,0)
Signal_Measurement
NumSlotsMeasured=NumSlotsMeasuredFCarrier=RF_Freq
3GPPACLR
Simulation_Variables
EqnVar
Signal_Source
FCarrier=RF_FreqSignalPower=SignalPower
3GPPSource Test
Ref
Measurement_and_Specification_Information
3GPP ACLRDesign Information
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Data Showing ACLR
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Simulated vs. Measured ACLR
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Measured ACLR vs Input Power
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ADS Design for Testing EVMUser_Defined_Variables
RF_Freq=1950 MHzNumSlotsMeasured=1DUT_Gain=25SignalPower=dbmtow(-10)
EqnVar
Controller
Device_To_Be_TestedGain=dbpolar(DUT_Gain,0)
Signal_Measurement
3GPPEVM
Simulation_Variables
EqnVar
Signal_Source
FCarrier=RF_FreqSignalPower=SignalPower
3GPPSource Test
Ref
Measurement_and_Specification_Information
3GPP EVMDesign Information
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Instruments Link to ADS via VEE
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Measurement system can bemodeled as mix of Dataflow andFSMs
GenerateSignal
MeasureResult
AdjustTemp
AdjustProbe
HandlerSet
PowerSupplies
Turn offPower
Supplies
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Data Showing EVM
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Data showing EVM
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There’s a Lot of Data. We Still Needto Vary Bias and Test Many Devices.Then What About Spec Changes?
nThat’s a LOT of documenteddata to be taken and processed
l ValiFire automates:
• Instrument operation
• Data collection
• Specification checking
l Agilent updates procedures for format spec changes
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These Techniques Provide theMechanism to Correlate RFICSupplier and NEM Results andRequirements.nThe NEMs cannot afford to be tied to a sole source
supplier.
nThey need to validate alternative suppliers to use when aspecific supplier has trouble.
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Reconcile Differences BetweenVirtual and Actual Performance forBetter Future DesignsnThis is the way to achieve accurate design models
l It helps reduce the number of design cycles
Model Simulate
Measure
OK ?
FixModel
Document
No
Yes
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Conclusion: Significant Time andTrouble Saved with Synergistic ChipDesign and Integrated TestnModule and application board
parasitics included.
nVirtual test for correlation of designwith actual test results and accuratemodeling.
nTest procedure updates readilyavailable as specs mature.
nTest procedures and specificationchecking are automatic.
nStatistically valid sample size needed.
