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Agilent Technologies N9340A manual Making Distortion Measurements, Harmonic distortion

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Making Distortion Measurements

Making Measurements 3

Making Distortion Measurements

This section provides information on measuring and identifying signal distortion.

Identifying Analyzer Generated Distortion

High level input signals may cause analyzer distortion products that could mask the real distortion measured on the input signal. Use trace and the RF attenuator to determine which signals, if any, are internally generated distortion products. In this example, use a signal from a signal generator to determine whether the harmonic distortion products are generated by the analyzer.

1Input a signal (200 MHz, –10 dBm) to the analyzer RF IN connector.

2Set the analyzer center frequency and span:

•Press [PRESET]. (Factory Preset)

•Press [FREQ] > {Center Freq} > 400 > {MHz}.

•Press [SPAN] > 700 > {MHz}.

The signal produces harmonic distortion products (spaced 200 MHz from the original 200 MHz signal)

Figure 13 Harmonic distortion

3Change the center frequency to the value of the first harmonic:

N9340A User’s Guide

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Agilent Technologies N9340A Making Distortion Measurements, Identifying Analyzer Generated Distortion, Harmonic distortion

Contents

Agilent N9340A Handheld Spectrum Analyzer User’s GuideEdition WarrantyNotices Manual Part NumberEdition WarrantyNotices Manual Part Numberunderstood and met are fully understood and met1 N9340A Overview Viewing Battery Status2 Getting Started 3 Making MeasurementsShow Error 4 System SettingSetting Key Beep General system settingsNormal EnterESC/CLR MarkerSave Trace Save As Recall Trace Limit Limit Line Limit Pattern 6 SCPI Command ReferenceDefault unit of parameters ResetState Select One button measurementExt Input Tracking Generator SubsystemTrigger Source 139 UNIT Subsystem 7 Error Messages8 Menu Map Error Message ListAgilent Technologies N9340A OverviewAgilent N9340A Handheld Spectrum Analyzer 1 N9340A Overview IntroductionFunctionality N9340A User’s Guide Optimized UsabilityN9340A Overview MEAS, and MODE Front Panel OverviewCaption Function7. RF OUT Connector For future expansion 1. DC Connector2. Charging indicator 3. External power indicatorSYS Setting General Display AnnotationsDescription Associated Function KeyStep Installing a BatteryViewing Battery Status Working with BatteriesNever use a modified or damaged AC-DC adapter Charging a Battery1 N9340A Overview Agilent N9340A Handheld Spectrum Analyzer Getting StartedConventions 2 Getting Started Checking Shipment and Order ListN9340A User’s Guide Power RequirementsPlug a AC Power CordsPlug Type Cable PartN9340A User’s Guide Safety Considerationscase only Do NOT dispose of batteries in a fire 2 Getting StartedN9340A User’s Guide Electrostatic Discharge ESD PrecautionsEnvironmental Requirements Electrical Requirements2 Getting Started Instrument MarkingsN9340A User’s Guide Powering on the Analyzer for the First TimePower on your N9340A Preparation for Use Setting up your N9340ATesting buttons and screen pixel 1 Press SYS Setting General to set time and power saving modeN9340A User’s Guide 3 Press SYS More 1 of 3 Show Error to display the error informationChecking Instrument Information 2 Press SYS More 2 of 3 Option to display the option information4 Using Unit Softkeys 1 Using Knob2 Using Arrow Keys 3 Using Numeric Keypad5 Press FREQ Center Freq 1 GHz to set the center frequency to 1 GHz Viewing a Signal2 Press SYS More 1 0f 3 Preset and select Figure 1 View a signal 1 GHz, 0 dBmSome helpful tips Selecting a preset typeSaving a User-defined Preset DefaultN9340A User’s Guide Upgrading FirmwareAdding an option 2 Getting Started Contact Agilent TechnologiesAgilent N9340A Handheld Spectrum Analyzer Making MeasurementsPress FREQ Start Freq 40 MHz Press FREQ Stop Freq 110 MHz Measuring Multiple SignalsComparing Signals on the Same Screen 3 Making Measurementsscreen refer to “Improving Frequency Resolution andNext Left PK Accuracy on pagePress SPAN Span 2 MHz Press BW/SWP RBW 30 kHz Resolving Signals of Equal AmplitudeFigure 3 Setup for obtaining two signals Press PRESET Press FREQ Center Freq 300.05 MHzN9340A User’s Guide Making MeasurementsFigure 4 Resolving signals of equal amplitude Press MARKER Peak Search Next Right PK or Next Left PK Resolving Small Signals Hidden by Large SignalsPress SPAN 500 kHz Press BW/SWP RBW 300 Hz Press MARKER Peak Search Press MARKER DeltaPress FREQ Center Freq 1 GHz Press SPAN 5 MHz Measuring a Low-Level SignalFigure 6 A signal closer to the noise level Atten10 dB Reducing Input AttenuationPress AMPTD Attenuation 20 dB Figure 7 A signal closer to the noise level Atten 20 dBFigure 8 A signal closer to the noise level Atten 0 dB Press SPAN 1 MHzN9340A User’s Guide Decreasing the Resolution BandwidthFigure 9 Decreasing resolution bandwidth Making Measurements4 Press BW/SWP Avg Type to change the average type Using the Average Detector and Increased Sweep TimeFigure 10 Using the average detector 3 Press BW/SWP Sweep Time to set the sweep time to 500 msN9340A User’s Guide Trace AveragingFigure 11 Trace averaging Making Measurements3 Making Measurements Improving Frequency Resolution and AccuracyFigure 12 Using the frequency counter Figure 13 Harmonic distortion Making Distortion MeasurementsIdentifying Analyzer Generated Distortion Press FREQ Center Freq 400 MHz Press SPAN 700 MHzPress TRACE View Press MARKER Peak Search Press Marker Delta Press SPAN 50 MHz Press MARKER Peak SearchPress AMPTD Attenuation 0 dB Press MARKER Marker To To Ref Press TRACE Trace Press TRACE Clear WriteN9340A User’s Guide Figure 14 Identifying Analyzer Distortion O dB attenFigure 15 Identifying Analyzer Distortion 10 dB atten Making Measurements3 Making Measurements Third-Order Intermodulation DistortionPress MARKER Delta Press SPAN 5 MHzPress MARKER Peak Search Press MARKER Marker To To Ref3 Making Measurements Press MARKER Peak Search Next Left Right PeakPress Marker Normal Press MARKER Peak Search Next Left Right Peak Figure 16 TOI test screenMeasuring OBW One-button Power MeasurementSetting Percentage % Setting dBcKey Access MEAS ACPR Channel Space Key Access MEAS ACPR Center FreqKey Access MEAS ACPR Main Channel Key Access MEAS ACPR Adj ChannelIntegration Bandwidth Measuring Channel PowerKey Access MEAS Channel Power Center Freq Key Access MEAS Channel Power Int BWN9340A User’s Guide Channel Bandwidth3 Making Measurements Press FREQ Start Freq 100 MHz Press FREQ Stop Freq 1 GHz Figure 17 Transmission Measurement Test SetupPress Mode Track Generator Amplitude On -10 dBm Making a Stimulus Response Transmission MeasurementPress Marker Normal 370 MHz, Delta 130 MHz Press BW/SWP RBW 30 kHz Press BW/SWP VBW 30 kHzPress MEAS Normalize Store Ref 1 → 4 Normalize On Press MEAS Normalize Norm Ref Posn 8 ENTERPress Mode Track Generator Amplitude On -10 dBm 4 Press BW/SWP RBW 10 kHz to set the resolution bandwidth to 10 kHzMeasuring Stop Band Attenuation of a Low-pass Filter Press AMPTD Scale Type Log3 Making Measurements Press MARKER Normal 370 MHzPress Delta 37 MHz Figure 19 Minimum Stop Band AttenuationN9340A User’s Guide Figure 20 Reflection Measurement Short Calibration Test SetupMaking a Reflection Calibration Measurement Making MeasurementsPress BW/Avg RBW 1 MHz 10 dBmPress FREQ Start Freq 100 MHz Press FREQ Stop Freq 1 GHzN9340A User’s Guide Figure 21 Short Circuit NormalizedMaking Measurements 3 Making Measurements Measuring Return Loss Using the Reflection Calibration RoutineMeasuring the Return Loss of the Filter Agilent Technologies System SettingAgilent N9340A Handheld Spectrum Analyzer Setting Key Beep Visual and Audio AdjustmentQuick Display Adjustment Manual Display AdjustmentSystem Setting System SettingGeneral system settings Power ManagerExternal Trigger Trig Key Access SYS Setting Ext InputExt Input External Reference RefPress SYS Setting Save Setup to save the Quick saving or loading a system setupQuick saving a setup Quick recalling a setup4 System Setting FileFile Type Saving PathSystem Setting 1 Press SYS File File setup to select the save path and file typeSaving a file Quick saving a trace or a screen4 System Setting Press SYS File File setup File type to select a file typeViewing file list decide whether you need to delete the files 2 Press SYS File File setup File type to select a file typePress SYS File File setup File type to Loading a file4 System Setting Key Access SYS More 2 of 3 Show systemShow System N9340A User’s Guide Show ErrorKey Access SYS More 2 of 3 Show Error System Setting4 System Setting Key Access SYS More 2 of 3 CalibrationPerform a Time Base Calibration N9340A User’s Guide Factory Default SettingsDefault Setting ParameterN9340A User’s Guide 4 System SettingAgilent Technologies Key ReferenceAgilent N9340A Handheld Spectrum Analyzer 5 Key Reference AmplitudeRef level AttenuationScale Type Key access AMPTD Scale TypePreamp Scale/DIV5 Key Reference Key access AMPTD Y Axis UnitsRef Offset Y Axis UnitsN9340A User’s Guide BW/SWPKey Reference 5 Key Reference VBW/RBWAvg Type When preset is set to default, or VBW/RBW is set to AutoTrace averaging Key access BW/SWP Avg TypeLog Pwr Voltage5 Key Reference Sweep TimeIn non-zero spans In zero spanKey access BW/SWP Sweep In FFT ModeSweep Mode Key access BW/SWP Sweep Sweep ContKey access BW/SWP Sweep Sweep Mode Single SweepFast On, pressing BW/SWP Single Sweep haltsN9340A User’s Guide EnterKey Reference Terminate filename entries5 Key Reference ESC/CLRClear Association with other functionsStop Frequency FrequencyCenter Frequency Start Frequency5 Key Reference CF StepKey Reference MarkerMarker Normalsignal-to-noise/Hz DeltaThe delta marker function permits signal-to-noise measurements provided the signal is a single spectralNext RT Peak Peak SearchPeak Next LF PeakMode Key access MARKER To CenterKey access MARKER Marker To Marker ToKey access MARKER Marker Trace Activates a noise readout mode for evaluatingpower density Key access MARKER More 1 of 2 ModeN9340A User’s Guide Meas5 Key Reference Zero SpanSpan FullTrace of the selected trace, and updates each trace pointKey access TRACE TRACEDetector Minimum HoldView Blank5 Key Reference Key access TRACE More 1 of 2 Detector NormalKey access TRACE More 1 of 2 Detector Average Key access TRACE More 1 of 2 DetectorPos Peak Key access TRACE More 1 of 2 Detector SampleKey access TRACE More 1 of 2 Detector Neg Peak AverageKey access TRACE More 1 of 2 Recall trace Key access TRACE More 1 of 2 AverageKey access TRACE More 1 of 2 Save trace Key access TRACE More 1 of 2 Save asSet Pattern LimitLimit Line Limit Pattern5 Key Reference BeepSave Pattern Recall PatternAgilent Technologies SCPI Command ReferenceAgilent N9340A Handheld Spectrum Analyzer Terms Description 6 SCPI Command ReferenceSCPI Language Basics Common Terms used in this BookSCPI Command Reference Command CategoriesCommand Syntax Command Statement Rules Overview6 SCPI Command Reference Standard NotationsKeywords PunctuationN9340A User’s Guide Default unit of parametersSeparator SCPI Command ReferenceIdentification Query Common CommandsReset Clear StatusSelect the Type of Limit Line CALCulate SubsystemLimit Line Subsection Delete All Limit Lines in Memory6 SCPI Command Reference Control Limit Line TestingControl Limit line Buzzer Set Limit Line Y-axis valueN9340A User’s Guide Control Limit Pattern TestingSet Limit Pattern X-axis Units SCPI Command Reference6 SCPI Command Reference Define Limit Pattern ValuesFrequency Counter Marker CALCulateMARKer SubsectionMarkers All Off on All Traces Markers All OnMarker Peak Maximum Right Search Marker FunctionMarker Peak Maximum Search Marker Peak Maximum Left SearchN9340A User’s Guide Marker ModeSet center frequency to the marker value SCPI Command Reference6 SCPI Command Reference Set reference level to the marker valueMarker On/Off Marker to TraceN9340A User’s Guide Marker readout X ValueMarker readout Y Value SCPI Command Reference6 SCPI Command Reference DEMOdulation SubsystemAM Demodulation FM DemodulationSCPI Command Reference DISPlay SubsystemTurn the Entire Display On/Off Trace Y-Axis ScalingThis command sets the amplitude level offset for the Y- Axis Trace Y-Axis Reference LevelTrace Y-Axis Reference Level Offset 6 SCPI Command ReferenceDISPlayWINDowTRACeYSCALeSPACing? Display ModeVertical Axis Scaling DISPlayWINDowTRACeYSCALeSPACing LINearLOGarithmicThis command adjusts the contrast of the current screen display ContrastBrightness 6 SCPI Command ReferenceBW/SWP Sweep INITiate SubsystemContinuous or Single Sweep Initiate a single sweep6 SCPI Command Reference INSTrument SubsystemSelect One button measurement OBW Subsection Setting Percentage % method of OBWSetting dBc method of OBW MEASure SubsystemAdjacent channel Main Channel PowerLow Adjacent Channel Power Upper Adjacent Channel PowerMEASureACPRURATio? Low Adjacent Channel Power RatioUpper Adjacent Channel Power Ratio MEASureACPRLRATio?Power Density Channel Power SubsectionChannel Power and Power Density Channel PowerClear the current Average SENSe SubsystemSENSeAVERage Subsection Average TypeSENSeAVERageTRACe123456COUNt para SENSeAVERageTRACe 123456COUNt? Turn Averaging On/OffSet the Average Count SENSeAVERageTRACe 123456STATe?Video Bandwidth Resolution BandwidthResolution Bandwidth Automatic SENSeBANDwidth Subsection6 SCPI Command Reference Video to Resolution Bandwidth RatioVideo to Resolution Bandwidth Ratio Mode Select Video Bandwidth AutomaticN9340A User’s Guide SENSeDETector SubsectionAutomatic Detection Type Selected SCPI Command Reference6 SCPI Command Reference FREQuency SubsectionTypes of Dtection Center Frequency Step Size AutomaticSCPI Command Reference Center Frequency Step SizeFrequency Span Full Frequency SpanStop Frequency Zero Frequency SpanLast Frequency Span Start FrequencyInput Port Attenuator Auto SENSePOWer SubsectionInput Port Power Gain Input AttenuationAutomatic Sweep Time Sweep ModeSWEep Subsection Sweep TimeTime Query Error Information QuerySYSTem Subsystem Date Query6 SCPI Command Reference Select Trace Display ModeTRACe Subsystem SCPI Command Reference Tracking Generator SubsystemState Output Amplitude6 SCPI Command Reference Amplitude StepAmplitude Offset TGENeratorAMPLitudeOFFSet amptSCPI Command Reference Storing as referenceNormalization Normalization Reference Level6 SCPI Command Reference Normalization Reference PositionSCPI Command Reference TRIGer SubsystemExternal Trigger Slope Trigger SourceThis command specifies the video trigger level Video Trigger Level AmplitudeTRIGerSEQuenceVIDeoLEVel ampl TRIGerSEQuenceVIDeoLEVe? 6 SCPI Command ReferenceSelects a power unit for measurement UNITPOWer DBMDBMVDBUVVW UNITPOWer?UNIT Subsystem SCPI Command ReferenceN9340A User’s Guide 6 SCPI Command ReferenceAgilent Technologies Error MessagesAgilent N9340A Handheld Spectrum Analyzer 7 Error Messages Error Message ListN9340A User’s Guide Indicates no matchedFor example, currently in FFT 7 Error Messagescommunicate with Meas uncalRF Board Changed CannotN9340A User’s Guide 7 Error MessagesAgilent Technologies Menu MapAgilent N9340A Handheld Spectrum Analyzer AMPTD 8 Menu MapN9340A User’s Guide Menu MapBW/SWP Center Freq Start Freq Stop Freq CF Step Auto Man FREQ8 Menu Map FreqDelta MARKERMenu Map MarkerMEAS MEASMode 8 Menu MapN9340A User’s Guide SPANenable when Menu MapLight Show Error8 Menu Map SystemTrace TRACEMenu Map N9340A User’s Guide8 Menu Map LimitIndex Page N9340-90001 Agilent Technologies, Inc Printed in China AprilN9340-90001