Making the Channel Power Measurement | Agilent Technologies E4406A

Making the Channel Power Measurement

Making Measurements

Making the Channel Power Measurement

Making the Channel Power Measurement

Purpose

The Channel Power measurement is a common test used in the wireless industry to measure the total transmitted power of a radio within a defined frequency channel. This procedure measures the total power within the defined channel. This measurement is applied to design, characterize, evaluate, and verify transmitters and their components or devices for base stations and mobile stations.

Measurement Method

The Channel Power measurement reports the total transmitted power within the channel bandwidth. The measurement acquires a number of points representing the input signal in the time domain. It transforms this information into the frequency domain using FFT and then calculates the channel power. The effective resolution bandwidth of the frequency domain trace is proportional to the number of points acquired for FFT. The fastest FFT process is achieved using a number of acquired points that is a power of 2 (for example: 64, 128, 512).

Since the measurement is optimized for speed and accuracy, you are permitted to change only the number of acquired data points in powers of 2, not the actual resolution bandwidth which is shown in gray. However, if absolute sweep time is required, it can be changed to the user’s specific value at the expense of reduced speed. At no time will both sweep time and data points be set to manual because of conflicting parameter settings. This flexibility is available through the Advanced menu of the channel power measurement.

To improve repeatability, you can increase either the number of averages or the number of data points with longer time record length. The channel power graph is shown in the graph window, while the absolute channel power in dBm and the mean power spectral density in dBm/Hz are shown in the text window.

For channel power measurements using baseband I/Q inputs (available with Option B7C) see “Using Baseband I/Q Inputs (Option B7C)” on page 151.

Chapter 4

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Agilent Technologies E4406A manual Making the Channel Power Measurement, Purpose, Measurement Method, Making Measurements

Contents

Transmitter Tester User’s GuideAgilent Technologies E4406A VSA Series Safety Information EXCLUSIVE REMEDIES WarrantyLIMITATION OF WARRANTY Page Getting Started ContentsUsing System Features 4. Making Measurements Contents3.Setting the Mode Changing the Measurement Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 Changing the Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135 Using the Marker . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135 Troubleshooting Hints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135 Making the Power Stat CCDF Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136 Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136 Measurement Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136 Making the Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137 Changing the Measurement Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138 Changing the View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139 Changing the Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139 Using the Markers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140 Troubleshooting Hints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140 Service Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141 Timebase Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142 Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142 Measurement Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142 Test Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143 50 MHz Amplitude . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144 Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144 Measurement Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144 Test Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145 Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146 Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146 Measurement Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146 Test Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146 Front Panel Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148 Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148 Test Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149 Troubleshooting Hints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149 Service Power vs. Time Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150 Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150 Using Baseband I/Q Inputs Option B7C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151 What are Baseband I/Q Inputs? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152 What are Baseband I/Q Signals? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153 Why Make Measurements at Baseband?. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153 Making Measurements with Baseband I/Q Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154 Baseband I/Q Measurement Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155 Selecting Input Probes for Baseband Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156 Selecting Baseband I/Q Inputs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159 Selecting Baseband I/Q Input Connectors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159 Setting Up Baseband I/Q Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161 Baseband I/Q Measurement Views . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165 Baseband I/Q Measurement Result Examples Contents 6. Options and Accessories Contents5. If You Have a Problem List of Keys Front Panel Test List of Keys Reference List of Keys List of Keys Getting Started Topics include Part Description TableStandard Documentation Part Description TablePersonality Documentation Measurement Option Agilent Part URL for the Latest VSA Transmitter Tester UpdateUnderstanding Digital Communications Measurements Description Chapter Updating the FirmwareGetting Started Primary Key Making a MeasurementSetup Keys Step System Front Panel Keys Context Dependency MEASURESetup Service GSM cdmaOne Waveform Time DomainSpectrum Freq Domain Spurious Close Channel Power Meas View/Setup Trace Getting Started Channel PowerSetup Marker MEASURESetup Service GSM cdmaOne Waveform Time DomainSpectrum Freq Domain Spurious Close Channel Power Meas View/Setup Trace 2.Control keys Front Panel Description Chapter Getting Started Front Panel Description 6.Mode keys select the measurement mode and mode parameters See page 83 for more detail Chapter Getting Started Front Panel Description 12.Floppy Disk Drive. The floppy disk drive accepts 1.44 megabyte disks. For an explanation of the operation of the floppy disc drive see the Using Print Keys section on page be implemented with a future firmware update Chapter Rear Panel DescriptionGetting Started Rear Panel Description measurements. The external trigger accepts an 11. PARALLEL The PARALLEL connection supports remote printing Display Annotation Measurement Bar. Displays information about ESec even second clock - The green ESec Available Personality Options Installing Optional Measurement Personalities Available Personality Options Loading the Optional PersonalityRequired Information Key Path Viewing a License Key Using the Uninstall Key Installing a License KeyPage Figure 1-6HP F1047-80002Cable Cables for Connecting to the Serial Port RS-232Figure 1-5HP 24542U Cable HP 92219J Cable Cables for Connecting to the Serial Port RS-232Figure 1-7HP 24542G/H Cable Figure Figure 1-12Mouse Adapter typical Cables for Connecting to the Serial Port RS-232Figure 1-10HP 24542M Modem Cable Figure 1-11HP C2913A/C2914A Cable Figure 1-15HP 24542U Cable with 5181-6642Adapter Cables for Connecting to the Serial Port RS-232Figure 1-13HP 24542U Cable with 5181-6641Adapter Figure 1-14HP 24542U Cable with 5181-6640Adapter Figure 1-16HP 24542U Cable with 5181-6639Adapter Figure 1-19HP F1047-80002Cable with 5181-6642Adapter Instrument Installation Safety Considerations Instrument Operation and Maintenance Safety Considerations for Service Personnel Chapter Getting Started Safety Considerations Using System Features Install and Uninstall Using System Keys Table Key LocationsKey Access Locations Chapter Using System FeaturesKey Locations Key Access Path Key Access LocationsTable Using System Features Table Key Access LocationsUsing System Features Key Locations Key Access Path Table Key Access LocationsUsing System Features Key Locations Key Access Path Table Key Access LocationsUsing System Features Key Access Path Key Locations Key Access LocationsUsing System Features Key Access Path Chapter Using System FeaturesKey Locations Input/Input Port Chapter Using System Features Key Locations Key Locations Key Access LocationsUsing System Features Key Access Path Printing a Displayed Screen Using Print and Print Setup Functions Level language default towhen Color Print is set to Front Panel Key Chapter Using System FeaturesUsing Print and Print Setup Functions available only when selectedthe six screen files shown below are Saving a State Using File and Save KeysLoading a State Level Using the Alpha Editor KeysLevel Level Configuring I/O Using Input/Output Configuration Keys •SCPI LAN - Accesses the following keys Level File SystemReference Front Panel •10 MHz Out - Activates, or deactivates, the 10 MHz out signal on the rear panel of the instrument. The 10 MHz out can be used to lock other test equipment to the same frequency reference that is used by the transmitter tester. Once activated, the 10 MHz out feature is persistent, so if it is set to On it will remain on, even if the instrument has been preset, or powered off and then on Show Errors Using System Configuration and Alignment KeysRestore System Defaults Show System features are described in the service guide Chapter Using System FeaturesUsing System Configuration and Alignment Keys Show System Displays Chapter System LocalUsing System Features Using System Configuration and Alignment Keys Level AlignmentFront Level remains constant Chapter Using System FeaturesUsing System Configuration and Alignment Keys Chapter Using System FeaturesUsing System Configuration and Alignment Keys Setting the Mode Chapter Selecting a ModeSetting the Mode Selecting a Mode Input Keys Mode Setup Adjust the IF Align Signal Adjust Input Attenuation and Input Power •RF Burst Wideband •Video IF Envlp Trigger Keys •Sync Source key menu Selecting the Frequency/Channel 4 Making Measurements Basic Measurements Preparing for Measurements Initial SetupUsing Measure Keys Averaging Measurement SetupMeasurement Control Voltage Avg - The voltage is averaged Trigger Source Span / X Scale Keys Changing the View•Typical Measurement Windows •Trace Display •Amplitude / Y Scale Keys Markers Using MarkersTrace Search Marker Marker Functions Making the Measurement Making the Spectrum Frequency Domain MeasurementPurpose Measurement Method Results Making Measurements Changing the Measurement SetupSpectrum Frequency Domain Measurement Defaults Table measurement data Auto Auto Peak - Select this to set the ADC range automatically to the peak signal level. Auto peak is a compromise that works well for both CW and burst signals Chapter Changing the ViewMaking Measurements Making the Spectrum Frequency Domain Measurement Figure 4-4Spectrum Measurement - I/Q Polar View Changing the Linear Spectrum Display Changing the Display Changing the I or Q Waveform Window Making the Spectrum Frequency Domain Measurement Changing the I/Q Polar WindowSelecting Displayed Traces Within Windows Making Measurements Measuring Band Power Using the Markers Chapter Troubleshooting HintsMaking Measurements Making the Spectrum Frequency Domain Measurement Making the Measurement Making the Waveform Time Domain MeasurementPurpose Measurement Method Results Input signal: cdma2000 Rev 8, SR1, 9 Channel Chapter Making MeasurementsMaking the Waveform Time Domain Measurement Table Changing the Measurement SetupWaveform Time Domain Measurement Defaults In addition, the following parameters can be modified Chapter Making MeasurementsMaking the Waveform Time Domain Measurement Changing the View Meas Setup: View/Trace = I/Q Waveform View Figure 4-9Waveform Measurement - I/Q Polar View Changing the Display Chapter Making MeasurementsMaking the Waveform Time Domain Measurement •Off - Allows you to turn off the selected marker Using the Markers differing values for the maximum point Troubleshooting Hints Measurement Method Making the Adjacent Channel Power ACP MeasurementMaking the Adjacent Channel Power ACP Measurement Purpose Table ACP Setup RecommendationMaking the Measurement Results Figure 4-10ACP Measurement - Bar Graph View Changing the Measurement SetupAdjacent Channel Power Measurement Defaults Making the Adjacent Channel Power ACP Measurement Chapter Making the Adjacent Channel Power ACP MeasurementMaking Measurements Maximum Offset A 750.000 kHz Offset B 1.98000 MHz Chapter •Limit Test - Turns off the limit test function Changing the View Chapter Making the Adjacent Channel Power ACP MeasurementFigure 4-11ACP Measurement - Spectrum View Making Measurements This adjacent channel power ratio measurement can reveal degraded or defective parts in the transmitter section of the UUT. The following examples are those areas to be checked further Troubleshooting Hints Measurement Method Making the Channel Power MeasurementMaking the Channel Power Measurement Purpose Figure Channel Power MeasurementMaking the Measurement Results Table Changing the Measurement SetupChannel Power Measurement Defaults Page Changing the Display Using the MarkerTroubleshooting Hints Measurement Method Making the Power Stat CCDF MeasurementPurpose Figure Power Statistics CCDF MeasurementMaking the Measurement Results Table Changing the Measurement SetupPower Statistics CCDF Measurement Defaults Making Measurements Making the Power Stat CCDF MeasurementChanging the View Changing the Display •Off - Allows you to turn off the selected marker Using the MarkersTroubleshooting Hints Front Panel Test on page Pwr vs Time on page Service Measurements Measurement Method Test SetupTimebase Frequency Purpose Window Two Magnitude Window Three Freq ErrorResults Window One Time Record Measurement Method 50 MHz AmplitudeTest Setup Purpose Window Two Cal Magnitude Window Three ErrorResults Window One RF Magnitude Measurement Method SensorsTest Setup Purpose Chapter Making Measurements Sensors Purpose Front Panel TestTest Setup Chapter Troubleshooting HintsResults Making Measurements Front Panel Test Making Measurements Service Power vs. Time MeasurementService Power vs. Time Measurement Purpose Using Baseband I/Q Inputs Option B7C What are Baseband I/Q Inputs? Why Make Measurements at Baseband? What are Baseband I/Q Signals? Making Measurements with Baseband I/Q Inputs Chapter Baseband I/Q Measurement OverviewUsing Baseband I/Q Inputs Option B7C Making Measurements Selecting Input Probes for Baseband Measurements Chapter Using Baseband I/Q Inputs Option B7CMaking Measurements Agilent Probes - Balanced and Unbalanced Table Selecting Baseband I/Q Inputs Selecting Baseband I/Q Input Connectors •IF Align - Select to view the IF alignment signal. This signal is available as a diagnostic function, to check the operation of the alignment signal in the case of alignment failure. Once selected, a menu accessing the IF alignment signal parameters is available at the bottom of the Input menu. Either CW, comb, or pulse signals may be selected. Because the alignment signal is input at the IF frequency, it is displayed on any active Spectrum Freq Domain window, regardless of center frequency Table Setting Up Baseband I/Q InputsI/Q Range Settings by Displayed Unit of Measure I/Q Range TableI and Q Offset Increment vs. I/Q Range I and Q Chapter Using Baseband I/Q Inputs Option B7CMaking Measurements Selecting Baseband I/Q Input Impedance Spectrum Views and 0 Hz Center Frequency Baseband I/Q Measurement Views Waveform Views for Baseband I/Q Inputs Measurement Comparing RF and Baseband I/Q Measurement ViewsTable RF vs. Baseband I/Q Input Measurement Views, by Channel Power Measurement Baseband I/Q Measurement Result Examples Chapter Using Baseband I/Q Inputs Option B7CSpectrum Frequency Domain Measurement Making Measurements Figure 4-19Basic Mode Spectrum Linear View- Baseband I/Q Inputs Waveform Time Domain Measurement Table Baseband I/Q Key Access LocationsBaseband I/Q Key Access Locations Making Measurements Baseband I/Q Key Access LocationsUsing Baseband I/Q Inputs Option B7C Table Baseband I/Q - Waveform I/Q Marker Query BbIQ Programming CommandsCALCulate Subsystem Baseband I/Q - Spectrum I/Q Marker Query Spectrum - Y-AxisReference Level Baseband I/Q - IQ Offset CalibrationDISPlay Subsystem Spectrum - Y-AxisScale/Div Sets the amplitude reference level for the y-axis Baseband I/Q - Activate IQ Alignment INPut SubsystemBaseband I/Q - Select Input Impedance Baseband I/Q - Select Input Impedance Reference MEASure Subsystem Baseband I/Q - Select I/Q Voltage Range SENSe Subsystem Select the Input SignalBaseband I/Q - Select I/Q Power Range Instrument Messages and Functional Tests document 5 If You Have a Problem Key or Feature Does Not Appear in Menu Problem Symptoms and Solutions Problem Symptoms and Solutions LAN External Loopback Test Failed - Error MessageInstrument Fails Alignment - Error Message If You Have a Problem Instrument Keyboard is Locked Instrument Power-OnProblemLAN Communication Problem Chapter Support, Services, and AssistanceAgilent Technologies Test and Measurement Asia Call Center Numbers Returning Your Instrument to Agilent TechnologiesTable 5-1Contacting Agilent Options and Accessories Option BAE: NADC/PDC Measurement Personalities Options and Measurement PersonalitiesOption BAH: GSM Measurement Personality Option BAC: cdmaOne Measurement Personality Option B78: cdma2000 Measurement Personality Option HN1: iDEN Measurement PersonalityOption BAF W-CDMAMeasurement Personality Option 202: EDGE with GSM Measurement Personality Option B7C: Baseband IQ Measurement Personality Option 0B1: Additional Copy of Manuals Option 300: 321.4 MHz IF Output Option 1CN Handles Kit Option 0BV: Component-levelService DocumentationOption 0BW: Assembly-levelService Documentation Option 1CM Rack Mount Kit GPIB Cable AccessoriesBroadband Preamplifiers and Power Amplifiers AC Probe Description N2714A Calibration and Adjustment SoftwareRS-232Cables Model Number Numerics IndexIndex Index Index off, 140 select, 140 shape, 140 trace, IndexIndex Index Indexstate Index Index