2Agenda Basic concepts and measurement overview Dual source architecture and True Mode Stimulus measurementsDifferential component testingSignal Integrity testingDifferential PCB and on-wafer fixture de-embeddingDifferentialView user interfaceVectorStar performancemmWave True Mode Stimulus capabilitiesSystem configuration summary
3Differential devices and Measurements Differential Mode+_++__Common Mode+_+_Differential devices gaining popularity due to advantages in suppressing noise and EMI effects.Preferred driver in SI applicationsVNA needs to accurately modify stimulus conditions for complete analysis.
4Differential Applications For reasons of immunity, efficiency and raw performance, the number of balanced devices (both RF and high speed digital ) increasing.balancedbalancedRFIFfilterLOPCI Express Test CardTransmission Line
5Measurement Needs Insertion Loss Return Loss Gain Time domain Line ImpedanceRejectionBalanceCross talkAll these measurements can be performed with the 4 port VectorStar
6Measurements of Differential Devices Stimulus++ResponseResponse__ResponseResponseDerived from single ended S-parametersSignal is applied to one port and response is measured at all portsIncident signal is applied to each portDUT is assumed to be linearExcellent for passive devices and linear active devicesDoes not require an expensive second source or complex software corrections.Fastest measurement speed
7True Differential Measurements Both input ports are excited at onceEither balanced (in-phase) or differentially (180 degrees out of phase)Response is measured at both input and output ports balanced or differentiallyTechnique used for non-linear active devicesMust not use baluns (e.g. wafer probes)Baluns transform phase releationship at DUT plane and not validGenerally not valid for on-wafer measurementsOn-wafer measurements are non-50 ohm. Even if you were to ignore the balun error the DUT performance will change when a different impedance load is presented to the device after measurement.
8DifferentialViewTM for Signal Integrity Measurements Broadest frequency span: 70 kHz to 70/110 GHzBest time domain analysis capability4-port test set upgrades 2 port VectorStar to 4-port performance. 12-port configurations availableWidest range of calibration & de-embedding methodsChoice of TMS or SuperpositionPoor S-parameter DataGood S-parameter Data
9VectorStar Dual Source Option Dual Source VectorStarxN++a1b1a2b2__xNOption 031 Dual Source eliminates the need for a transfer switchProvides up to 7 dB of additional power at 70 GHzMS4640B series improves noise floor specification as much as 9 dBCombined, results in improved dynamic range performance up to 16 dB at 70 GHz!
10VectorStar 4-Port Solutions External test set offers easy upgrade capabilities – buy what you need when you need itBroadest frequency balanced/differential measurements in the marketMN4694B70 kHz* to 20/40 GHzK (2.92 mm)MN4697B70 kHz* to 50/70 GHzV (1.85 mm)Requires MS464xA VectorStar with Option 051, 061, or 062* Operational down to 40 kHz
11Connecting a 4-port Test Set Add a 4-port test set (MN4694B or MS4697B) for multiport measurementsWithout True Mode Stimulus Option (Opt 043) this configuration can be used to measure single ended multiport components (couplers, mixers, etc.)For passive or linear active devices use this configuration with standard super-position technique for differential analysisControl of the two sources without Opt 043 is via Multiple Source Control.
12Performing True Mode Stimulus Differential Measurements Option 043DifferentialView Option 043 Software provides the phase synchronization needed for True Mode Stimulus control.For independent amplitude and phase control driving ports are configured in a 1:3 or 1:4 and 2:4 or 2:3 arrangement.
13DifferentialViewTM and Dual Source Differential, common and mixed mode S-parametersTrue Mode Stimulus capabilityAdjust differential phase & amplitudeInstant view of results during parameter change+_+_+_Differential ModeCommon ModeMixed Mode
14VectorStar TMS SetupDifferentialView menu provides easy access to all key parametersNo need to activate numerous configuration panels to edit setup
15DifferentialView provides easy access to TMS parameter modification DifferentialView software provides easy to configure menus and stimulus controls for accurate TMS measurementsDifferentialView quickly sets up VectorStar for specific differential stimulus needs of the DUT while continuously displaying the setup parameters
16Differential View provides TMS mode measurements of non-linear device Performance differences of a compressed device can clearly be seen between single ended and TMS mode.
17Dual Source Multiple Source Control Multiple source control provides advanced independent controls of the two internal sourcesAlso controls up to 4 external sources for a total of 6 sources.
18Measuring Linear Differential Devices Single ended, super-positioning measurements often preferred over TMS method due to faster measurement speed and less error correction processingComparing single-ended and TMS mode measurements of linear differential amplifier reveals minimal differences.Mode-converting match measurements of the linear amplifier in SE and TMS modes also shows minimal difference.
19Comparing Superposition and TMS mode measurements of non-linear device SD2D1 values of a compressed amplifier (for single-ended and true-mode stimulus drive) are shown here.In this case, performance differences can clearly be seen
20Measurements of Nonlinear Differential Devices Dual Source VectorStarxN++a1b1a2b2__xNNon-1800 Phase Offset at DUT Input1800 Phase Offset at Test PortNo TMS correction applied.Measuring nonlinear differential devices with a 1800 offset is preferable for more realistic characterization.Nonlinear devices are sensitive to source mismatchSource mismatch will shift stimulus signals to non-ideal offset
21Measurements of Nonlinear Differential Devices Dual Source VectorStarxN++a1b1a3b3__xN1800 Phase Offset at DUT Input1800 Phase Offset at Test PortOpt 043 TMS: Measure mismatch and apply correction during measurementApplying TMS correction within DifferentialView corrects offset shiftMonitoring the applied signals (a3/a1) will provide an indication on the success of correction
22TMS Differential Phase Stability Sweep to sweep phase variations from 1800 differential while driving nonlinear DUT at -12 dBmAccurate DDS architecture combined with optimized algorithms offer up to 5 times improvement in true mode accuracy
23Nonlinear DUT Measurement at Non-1800 Offset Measuring nonlinear differential devices with a 1800 offset is preferable for more realistic characterization.Without proper offset correction performance of device will varyExample demonstrates variance in DUT performance when stimulated by 1800 and 1350 offsetSD2D1 performance of example device changes by as much as 2 dB at 3 GHzAnritsu white paper discusses this issue in more detail
24VNA measurement uncertainty when operating in TMS mode All VNAs operating in the TMS mode must add an additional layer of corrections for proper analysisExample comparisons of uncertainties for single-ended vs. true-mode stimulus mode when performing linear S-parameter measurementsNot included are differences in stability due to drift from thermal changes or cable flexingAdditionally, the increase in sensitivities to source match interactions when operating in a compressed state will add yet another layer of correctionsConsequently, the common approach is to use single ended (super-positioning) when measuring passive devices or linear active devices and use TMS when measurement of a compressed device demands
25Measuring Differential Devices Through Baluns and Fixtures DUT test port planePort 1 path to DUTPort 3 path to DUTCalibrated test port planeVNA test port cablesFixtures often used to transition from single ended VNA test ports to the input of differential devicesChallenging to extract directly from measurement. If not de-embedded properly, will contribute to overall error of predictive model.VectorStar’s extensive de-embedding capabilities help reduce the complexity of fixture and transition removal
26Embedding/De-embedding Useful to add and remove networks to/from a given result.EmbedDUTMatchnetwkDUTMatchNetwkDe-embedfixtureDUTfixtureDUTVectorStar provides the most advanced E/DE functions available on a VNAMultiple network E/DE also availableApplies to 2, 3 and 4 port DUTs
27VectorStar Fixture De-embedding VectorStar provides an extensive array of network extraction tools for enhanced de-embedding capabilities.Calibration menus generate characterization files (SnP) for fixture and probe de-embedding.
28DifferentialViewTM True Mode Stimulus Interface DifferentialView offers easy configuration for differential and mixed mode measurements for thorough analysis
29Differential Measurements +_SweptPhaseMeasure device performance in an unbalanced state:Set amplitude or phase to an offset relationshipSweep phase to find device anomaliesUse data to:Verify operating performance over wide input rangeAnalyze non-linear boundariesOptimize input matching circuit to maximize performanceSpecify better device performance
30VectorStar DifferentialView Phase Sweep DifferentialView menu provides real time display of measurement parametersImmediately observe DUT performance changes with changes in setupExample of modifying phase sweep parameters while observing effects
31VectorStar Dual Source Using Multiple Source Control to configure VectorStar for mixer measurementsUp-converters or Down-converters can be configuredUse external loop options (051, 061, or 062) for direct access to VNA converters
32DifferentialViewTM for Broadband and mmWave Measurements Compact size and high performance make the Anritsu mmWave modules ideal for 2 port or 4 port configurationEnables Broadband differential analysis on small platen
33True Mode Stimulus Broadband Measurements Excellent stability due to excellent raw directivity and close positioning of the mmwave test and reference couplersImprove device models due to high-quality low frequency dataRemove RF/microwave concatenation issuesSpend more time measuring (& less time calibrating)Easy positioning of small modules on probe stationShort cables conveniently connect to probes for best performance & stability
34VectorStar mmWave True Mode Stimulus Measurements VectorStar supports Anritsu mmwave modules to 125 GHz in coax or mmwave OML or VDI modules in waveguide bands up to 1.1 THzmmWave modules used in single ended or TMS mode differential measurement configuration
35Multiport CONFIGURATIONS Passive Device MeasurementsRecommended:MS464xB Vector Network Analyzer 10 MHz to 20, 40, 50, 70 GHzOpt 051 Direct Access LoopsOpt 007 Frequency Offset. Multiple source control software.MN469xB 4-port test setAdd options as desired:Option 002 Time DomainOpt kHz Low-end extensionOpt 031 Dual SourceActive Device MeasurementsRecommended:MS464xB Vector Network Analyzer 10 MHz to 20, 40, 50, 70 GHzOpt 061 Active Device Measurements SuiteOpt 007 Frequency Offset. Multiple source control software.MN469xB 4-port test setAdd options as desired:Opt 031 Dual SourceOpt kHz Low-End Extension See datasheet for full list
36Differential Device CONFIGURATIONS Linear Device MeasurementsRecommended:MS4647B Vector Network Analyzer 10 MHz to 70 GHzOpt 002 Time DomainOpt 061 Active Device Measurements SuiteMN4697B 4-port test setAdd other options as desired.Opt kHz Low-End Extension See datasheet for full listNon-linear Device MeasurementsRecommended:MS4647B Vector Network Analyzer 10 MHz to 70 GHzOpt kHz Low-End ExtensionOpt 031 Dual SourceOpt 043 DifferentialViewTMOpt 061 Active Device Measurements SuiteMN4697B 4-port test setAdd other options as desired. See datasheet for full list
37Signal Integrity CONFIGURATIONS Backplane/Interconnect MeasurementsMS4647B Vector Network Analyzer 10 MHz to 70 GHzOpt 002 Time DomainOpt 051 Direct Access LoopsOpt kHz Low-End ExtensionMN4697B 4-port test setActive Device MeasurementsMS4647B Vector Network Analyzer 10 MHz to 70 GHzOpt kHz Low-End ExtensionOpt 031 Dual SourceOpt 043 DifferentialViewTMOpt 061 Active Device Measurements SuiteMN4697B 4-port test setAdd other options as required. See datasheet for full list
38SummaryOption 031 Dual Source offers improved power output for high power measurement requirements.Improved MS4640B noise floor further improves dynamic range performanceUse standard 4-port configurations with super-positioning for passive and linear device customersInclude Option 043 TMS mode when measuring non-linear differential devices.VNAs using TMS mode double the sweep count for additional stimulus corrections. Use TMS mode only when a must.If must use TMS mode then use a VNA offering the optimum TMS mode performance.VectorStar offers improved TMS mode performance using DDS architecture and enhanced performance algorithms.