Keysight X Series Measurement Manual
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Keysight X Series Measurement Manual

Signal analyzer spectrum analyzer mode
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Keysight X-Series Signal Analyzers
This manual provides documentation for the following Analyzers:
PXA Signal Analyzer N9030A
EXA Signal Analyzer N9010A
MXE EMI Receiver N9038A
Notice: This document contains references to Agilent.
Please note that Agilent's Test and Measurement business
has become Keysight Technologies. For more information,
go to www.keysight.com.
MXA Signal Analyzer N9020A
CXA Signal Analyzer N9000A
Spectrum
Analyzer Mode
Measurement
Guide

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  • Page 1 EXA Signal Analyzer N9010A CXA Signal Analyzer N9000A MXE EMI Receiver N9038A Notice: This document contains references to Agilent. Please note that Agilent’s Test and Measurement business has become Keysight Technologies. For more information, go to www.keysight.com. Spectrum Analyzer Mode Measurement...
  • Page 2 CAUTION MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. A CAUTION notice denotes a hazard. It KEYSIGHT SHALL NOT BE LIABLE FOR calls attention to an operating ERRORS OR FOR INCIDENTAL OR procedure, practice, or the like that, if CONSEQUENTIAL DAMAGES IN...
  • Page 3 To receive the latest updates by email, subscribe to Keysight Email Updates at the following URL: http://www.keysight.com/find/emailupdates Information on preventing analyzer damage can be found at: http://www.keysight.com/find/tips Is your product software up-to-date? Periodically, Keysight releases software updates to fix known defects and incorporate product enhancements. To search for software updates for your product, go to the Keysight Technical Support website at: http://www.keysight.com/find/techsupport...

  • Page 5: Table Of Contents

    Contents Table of Contents 1 Getting Started with the Spectrum Analyzer Measurement Application Making a Basic Measurement Using the front panel Presetting the signal analyzer Viewing a signal Recommended Test Equipment Accessories Available 50 ohm load 50 ohm/75 ohm minimum loss pad 75 ohm matching transformer AC probe AC probe (low frequency)
  • Page 6 Contents Reducing Input Attenuation Decreasing the Resolution Bandwidth Using the Average Detector and Increased Sweep Time Trace Averaging 4 Improving Frequency Resolution and Accuracy Using a Frequency Counter to Improve Frequency Resolution and Accuracy 5 Tracking Drifting Signals Measuring a Source Frequency Drift Tracking a Signal 6 Making Distortion Measurements Identifying Analyzer Generated Distortion...
  • Page 7 12 Using Option BBA Baseband I/Q Inputs Baseband I/Q measurements available for X-Series Signal Analyzers Baseband I/Q measurement overview 13 Option EXM External Mixing Using Option EXM with the Keysight 11970 Series Mixers. Amplitude calibration Loading conversion loss data for the PXA Signal Analyzer Signal ID...
  • Page 8 Amplitude calibration LO adjustment Viewing the external mixer setup screen 14 Option Esc External Source Control Using Option ESC with the Keysight MXG Signal Sources. Loading conversion loss data for the PXA Signal Analyzer Signal ID Image shift Using the M1970 Series Mixers with X-Series Signal Analyzers (Option...
  • Page 9 Contents Measuring a complex/unknown signal “Quick Rules” for making time-gated measurements Using the Edge Mode or Level Mode for triggering Noise measurements using Time Gating AM and FM Demodulation Concepts Demodulating an AM signal using the analyzer as a fixed tuned receiver (Time-Domain) Demodulating an FM signal using the analyzer as a fixed tuned receiver (Time-Domain)
  • Page 10 Contents...
  • Page 11 Getting Started with the Spectrum Analyzer Measurement Application Getting Started with the Spectrum Analyzer Measurement Application This chapter provides some basic information about using the Spectrum Analyzer and IQ Analyzer Measurement Application Modes. It includes topics on: “Making a Basic Measurement” on page 12 •...

  • Page 12: Getting Started With The Spectrum Analyzer Measurement Application

    Making a Basic Measurement Making a Basic Measurement Refer to the description of the instrument front and rear panels to improve your understanding of the Keysight Signal Analyzer measurement platform. This knowledge will help you with the following measurement example. This section includes: “Using the front panel”...

  • Page 13: Presetting The Signal Analyzer

    Getting Started with the Spectrum Analyzer Measurement Application Making a Basic Measurement Example: A submenu key allows you to view a new menu of softkeys related to the submenu key category. Choice Allows you to make a selection from a list of values. Example: A choice key displays the currently selected submenu choice, in this example, dBm.

  • Page 14: Viewing A Signal

    Getting Started with the Spectrum Analyzer Measurement Application Making a Basic Measurement Viewing a signal Step Action Notes • Press Mode Preset. 4 Return the current mode settings to factory defaults. • Press Input/Output, 5 Route the internal 50 MHz signal to the RF Calibrator, 50, analyzer input.
  • Page 15 Getting Started with the Spectrum Analyzer Measurement Application Making a Basic Measurement Improving frequency accuracy NOTE When you use the frequency count function, if the ratio of the resolution bandwidth to the span is less than 0.002, you will get a display message that you need to reduce the Span/RBW ratio.
  • Page 16 Getting Started with the Spectrum Analyzer Measurement Application Making a Basic Measurement Valid marker count range NOTE Marker count functions properly only on CW signals or discrete peaks. For a valid reading, the marker must be ≥26 dB above the noise. Step Action Notes...

  • Page 17: Recommended Test Equipment

    The following table list the test equipment you will need to perform the example measurements describe in this manual. NOTE To find descriptions of specific analyzer functions, for the N9060A Spectrum Analyzer Measurement Application, refer to the Keysight Technologies X-Series User’s and Programmer’s Reference. Test Equipment Specifications...

  • Page 18: Accessories Available

    909D: DC to 26.5 GHz 50 ohm/75 ohm minimum loss pad The Keysight 11852B is a low VSWR minimum loss pad that allows you to make measurements on 75 Ohm devices using an analyzer with a 50 Ohm input. It is effective over a frequency range of dc to 2 GHz.

  • Page 19: Ac Probe (Low Frequency)

    Preamplifiers and power amplifiers can be used with your signal analyzer to enhance measurements of very low-level signals. • The Keysight 8447D preamplifier provides a minimum of 25 dB gain from 100 kHz to 1.3 GHz. • The Keysight 87405A preamplifier provides a minimum of 22 dB gain from 10 MHz to 3 GHz.

  • Page 20: Power Splitters

    Getting Started with the Spectrum Analyzer Measurement Application Accessories Available The Keysight 11947A Transient Limiter protects the analyzer input circuits from damage due to signal transients. It specifically is needed for use with a line impedance stabilization network (LISN). It operates over a frequency range of 9 kHz to 200 MHz, with 10 dB of insertion loss.

  • Page 21: Measuring Multiple Signals

    Measuring Multiple Signals Measuring Multiple Signals...

  • Page 22: Comparing Signals On The Same Screen Using Marker Delta

    Measuring Multiple Signals Comparing Signals on the Same Screen Using Marker Delta Comparing Signals on the Same Screen Using Marker Delta Using the analyzer, you can easily compare frequency and amplitude differences between signals, such as radio or television signal spectra. The analyzer delta marker function lets you compare two signals when both appear on the screen at one time.
  • Page 23 Measuring Multiple Signals Comparing Signals on the Same Screen Using Marker Delta Step Action Notes • Press Peak Search. The Next Pk Right and Next 5 Place a marker at the Pk Left softkeys are available highest peak on the display to move the marker from peak (10 MHz).
  • Page 24 Measuring Multiple Signals Comparing Signals on the Same Screen Using Marker Delta Step Action Notes Figure 2-2 Using the Delta Marker Function NOTE The frequency resolution of the marker readings can be increased by turning on the marker count function.

  • Page 25: Comparing Signals Not On The Same Screen Using Marker Delta

    Measuring Multiple Signals Comparing Signals not on the Same Screen Using Marker Delta Comparing Signals not on the Same Screen Using Marker Delta Measure the frequency and amplitude difference between two signals that do not appear on the screen at one time. (This technique is useful for harmonic distortion tests when narrow span and narrow bandwidth are necessary to measure the low level harmonics.) In this procedure, the analyzer 10 MHz signal is used to measure frequency and...
  • Page 26 Measuring Multiple Signals Comparing Signals not on the Same Screen Using Marker Delta Step Action Notes • Press Peak Search. 5 Place a marker at the highest peak on the display (10 MHz). • Press Marker →, Mkr → 6 Set the center frequency step size equal to the CF Step.
  • Page 27 Measuring Multiple Signals Comparing Signals not on the Same Screen Using Marker Delta Step Action Notes • Press Marker, Off. 10 Turn the markers off.

  • Page 28: Resolving Signals Of Equal Amplitude

    Measuring Multiple Signals Resolving Signals of Equal Amplitude Resolving Signals of Equal Amplitude In this procedure a decrease in resolution bandwidth is used in combination with a decrease in video bandwidth to resolve two signals of equal amplitude with a frequency separation of 100 kHz.
  • Page 29 Measuring Multiple Signals Resolving Signals of Equal Amplitude Step Action Notes Figure 2-5 Unresolved Signals of Equal Amplitude • Press BW, Res BW, 100, kHz. The RBW setting is less than or 6 Change the RBW. equal to the frequency separation of the two signals •...
  • Page 30 Measuring Multiple Signals Resolving Signals of Equal Amplitude Step Action Notes Figure 2-6 Unresolved Signals of Equal Amplitude • Press BW, Res BW, 10, kHz. Two signals are now visible, see 8 Decrease the RBW. Figure 2-7. You can use the front-panel knob or step keys to further reduce the resolution bandwidth and better resolve...
  • Page 31 Res BW in the lower-left corner of the screen, indicating that the resolution bandwidth is uncoupled. (For more information on coupling, refer to the Auto Couple key description in the Keysight Technologies X-Series User’s and Programmer’s Reference.)
  • Page 32 Measuring Multiple Signals Resolving Signals of Equal Amplitude Figure 2-8 Resolving Signals of Equal Amplitude...

  • Page 33: Resolving Small Signals Hidden By Large Signals

    Measuring Multiple Signals Resolving Small Signals Hidden by Large Signals Resolving Small Signals Hidden by Large Signals This procedure uses narrow resolution bandwidths to resolve two input signals with a frequency separation of 50 kHz and an amplitude difference of 60 dB. Step Action Notes...
  • Page 34 Measuring Multiple Signals Resolving Small Signals Hidden by Large Signals Step Action Notes • Press Peak Search, Mkr → Ref The Signal Analyzer 30 kHz 6 Set the 300 MHz signal filter shape factor of 4.1:1 has peak to the reference level. Lvl.
  • Page 35 Measuring Multiple Signals Resolving Small Signals Hidden by Large Signals Step Action Notes Figure 2-10 Unresolved Signals of Equal Amplitude • Press BW, 10, kHz. The Signal Analyzer 10 kHz 9 Decrease the RBW. filter shape factor of 4.1:1 has a bandwidth of 4.1 kHz at the 60 dB point.
  • Page 36 Measuring Multiple Signals Resolving Small Signals Hidden by Large Signals Step Action Notes Figure 2-11 Signal resolution with a 10 kHz RBW NOTE To make the separate signals more clear in the display, you may need to use averaging. To set the averaging to 10 averages: Press Meas Setup.

  • Page 37: Decreasing The Frequency Span Around The Signal

    Measuring Multiple Signals Decreasing the Frequency Span Around the Signal Decreasing the Frequency Span Around the Signal Using the analyzer signal track function, you can quickly decrease the span while keeping the signal at center frequency. This is a fast way to take a closer look at the area around the signal to identify signals that would otherwise not be resolved.
  • Page 38 Measuring Multiple Signals Decreasing the Frequency Span Around the Signal Step Action Notes • Press Mkr →, Mkr →Ref Lvl. Because the signal track 6 Set the calibration signal function automatically to the reference level. maintains the signal at the center of the screen, you can reduce the span quickly for a closer look.

  • Page 39: Easily Measure Varying Levels Of Modulated Power Compared To A Reference

    Measuring Multiple Signals Easily Measure Varying Levels of Modulated Power Compared to a Reference Easily Measure Varying Levels of Modulated Power Compared to a Reference This section demonstrates a method to measure the complex modulated power of a reference device or setup and then compare the result of adjustments and changes to that or other devices.
  • Page 40 Measuring Multiple Signals Easily Measure Varying Levels of Modulated Power Compared to a Reference Step Action Notes • Press Trace/Detector, Select 7 Enable trace averaging. Trace, Trace 1, Trace Average. • Press Marker Function, This measures the total power 8 Enable the Band/Interval of the reference 4-carrier Power Marker function.
  • Page 41 Measuring Multiple Signals Easily Measure Varying Levels of Modulated Power Compared to a Reference Step Action Notes • Press Marker, Select Marker, This will change the reference 11 Enable the Delta Band Band Power Marker into a fixed Power Marker Marker 1, Delta.
  • Page 42 Measuring Multiple Signals Easily Measure Varying Levels of Modulated Power Compared to a Reference...

  • Page 43: Measuring A Low−Level Signal

    Measuring a Low−Level Signal Measuring a Low−Level Signal...

  • Page 44: Reducing Input Attenuation

    Measuring a Low−Level Signal Reducing Input Attenuation Reducing Input Attenuation The ability to measure a low-level signal is limited by internally generated noise in the signal analyzer. The measurement setup can be changed in several ways to improve the analyzer sensitivity. The input attenuator affects the level of a signal passing through the instrument.
  • Page 45 Measuring a Low−Level Signal Reducing Input Attenuation Step Action Notes • Press Span, 1, MHz. If necessary re-center the 7 Reduce the span. peak. • Press AMPTD Y Scale, Increasing the attenuation 8 Set the attenuation. Attenuation, Mech Atten or Atten moves the noise floor closer to (Man), 20, dB.
  • Page 46 Measuring a Low−Level Signal Reducing Input Attenuation Step Action Notes Figure 3-2 Measuring a Low-Level Signal Using 0 dB Attenuation CAUTION When you finish this example, increase the attenuation to protect the analyzer RF input: Press AMPTD Y Scale, Attenuation, Mech Atten or Atten (Auto), or press Auto Couple.

  • Page 47: Decreasing The Resolution Bandwidth

    Measuring a Low−Level Signal Decreasing the Resolution Bandwidth Decreasing the Resolution Bandwidth Resolution bandwidth settings affect the level of internal noise without affecting the level of continuous wave (CW) signals. Decreasing the RBW by a decade reduces the noise floor by 10 dB. Step Action Notes...
  • Page 48 Measuring a Low−Level Signal Decreasing the Resolution Band width Step Action Notes Figure 3-3 Default resolution bandwidth • Press BW, 47, kHz. The low-level signal appears more 6 Decrease the RBW. clearly because the noise level is reduced. See Figure 3-4.
  • Page 49 Measuring a Low−Level Signal Decreasing the Resolution Bandwidth RBW Selections You can use the step keys to change the RBW in a 1−3−10 sequence. All the Signal Analyzer RBWs are digital and have a selectivity ratio of 4.1:1. Choosing the next lower RBW (in a 1−3−10 sequence) for better sensitivity increases the sweep time by about 10:1 for swept measurements, and about 3:1 for FFT measurements (within the limits of RBW).

  • Page 50: Using The Average Detector And Increased Sweep Time

    Measuring a Low−Level Signal Using the Average Detector and Increased Sweep Time Using the Average Detector and Increased Sweep Time When the analyzer noise masks low-level signals, changing to the average detector and increasing the sweep time smooths the noise and improves the signal visibility. Slower sweeps are required to average more noise variations.
  • Page 51 Measuring a Low−Level Signal Using the Average Detector and Increased Sweep Time Step Action Notes • The number 1 (Trace 1 indicator) in the 6 Select the average Press Trace/Detector, Trace/Detector panel (in the upper detector. More 1 of 2, Detector, right-hand corner of the display) Average (Log/RMS/V).

  • Page 52: Trace Averaging

    Measuring a Low−Level Signal Trace Averaging Trace Averaging Averaging is a digital process in which each trace point is averaged with the previous average for the same trace point. Selecting averaging, when the analyzer is autocoupled, changes the detection mode from normal to sample. Sample mode may not measure a signal amplitude as accurately as normal mode, because it may not find the true peak.
  • Page 53 Measuring a Low−Level Signal Trace Averaging Step Action Notes • As the averaging routine 6 Turn on Averaging. Press Trace/Detector, Trace smooths the trace, low level Average. signals become more visible. Avg/Hold >100 appears in the measurement bar near the top of the screen.
  • Page 54 Measuring a Low−Level Signal Trace Averaging...

  • Page 55: Improving Frequency Resolution And Accuracy

    Improving Frequency Resolution and Accuracy Improving Frequency Resolution and Accuracy...

  • Page 56: Using A Frequency Counter To Improve Frequency Resolution And Accuracy

    Improving Frequency Resolution and Accuracy Using a Frequency Counter to Improve Frequency Resolution and Accuracy Using a Frequency Counter to Improve Frequency Resolution and Accuracy This procedure uses the signal analyzer internal frequency counter to increase the resolution and accuracy of the frequency readout. Step Action Notes...

  • Page 57: Tracking Drifting Signals

    Tracking Drifting Signals Tracking Drifting Signals...

  • Page 58: Measuring A Source Frequency Drift

    Tracking Drifting Signals Measuring a Source Frequency Drift Measuring a Source Frequency Drift The analyzer can measure the short- and long-term stability of a source. The maximum amplitude level and the frequency drift of an input signal trace can be displayed and held by using the maximum-hold function.
  • Page 59 Tracking Drifting Signals Measuring a Source Frequency Drift Step Action Notes • Press SPAN X Scale, 7 Turn on the signal tracking function. Signal Track (On). • Press SPAN, 500, kHz. Notice that the signal is held in the 8 Reduce the span to center of the display.
  • Page 60 Tracking Drifting Signals Measuring a Source Frequency Drift Step Action Notes Figure 5-1 Viewing a Drifting Signal With Max Hold and Clear Write...

  • Page 61: Tracking A Signal

    Tracking Drifting Signals Tracking a Signal Tracking a Signal The signal track function is useful for tracking drifting signals that drift relatively slowly by keeping the signal centered on the display as the signal drifts. This procedure tracks a drifting signal. Note that the primary function of the signal track function is to track unstable signals, not to track a signal as the center frequency of the analyzer is changed.
  • Page 62 Tracking Drifting Signals Tracking a Signal Step Action Notes • Press SPAN X Scale, Signal Track Notice that signal tracking 7 Turn on the signal tracking places a marker on the function. (On). highest amplitude peak and then brings the selected peak to the center of the display.

  • Page 63: Making Distortion Measurements

    Making Distortion Measurements Making Distortion Measurements...

  • Page 64: Identifying Analyzer Generated Distortion

    Making Distortion Measurements Identifying Analyzer Generated Distortion Identifying Analyzer Generated Distortion High level input signals may cause internal analyzer distortion products that could mask the real distortion measured on the input signal. Using trace 2 and the RF attenuator, you can determine which signals, if any, are internally generated distortion products.
  • Page 65 Making Distortion Measurements Identifying Analyzer Generated Distortion Step Action Notes Figure 6-1 Harmonic Distortion • Press Peak Search, Next Peak, 5 Change the center frequency to the value Mkr→CF. of the second harmonic. 6 Change the span to a. Press SPAN X Scale, Span, 50, 50 MHz and re-center MHz.
  • Page 66 Making Distortion Measurements Identifying Analyzer Generated Distortion Step Action Notes • Press AMPTD Y Scale, Notice the ΔMkr1 amplitude 11 Increase the RF reading. This is the difference in attenuation to 10 dB. Attenuation, 10, dB. the distortion product amplitude readings between 0 dB and 10 dB input attenuation settings.

  • Page 67: Third-Order Intermodulation Distortion

    Making Distortion Measurements Third-Order Intermodulation Distortion Third-Order Intermodulation Distortion Two-tone, third-order intermodulation distortion is a common test in communication systems. When two signals are present in a non-linear system, they can interact and create third-order intermodulation distortion products that are located close to the original signals.
  • Page 68 Making Distortion Measurements Third-Order Intermodulation Distortion Step Action Notes • Press Mode, Spectrum Analyzer. 3 Select the mode. • Press Mode Preset. 4 Preset the analyzer. 5 Set the analyzer center a. Press FREQ Channel, Center frequency and span. Freq, 300.5, MHz. b.
  • Page 69 Making Distortion Measurements Third-Order Intermodulation Distortion Step Action Notes Figure 6-3 Measuring the Distortion Product...
  • Page 70 Making Distortion Measurements Third-Order Intermodulation Distortion...

  • Page 71: Measuring Noise

    Measuring Noise Measuring Noise...

  • Page 72: Measuring Signal-To-Noise

    Measuring Noise Measuring Signal-to-Noise Measuring Signal-to-Noise Signal-to-noise is a ratio used in many communication systems as an indication of noise in a system. Typically the more signals added to a system adds to the noise level, reducing the signal-to-noise ratio making it more difficult for modulated signals to be demodulated.
  • Page 73 Measuring Noise Measuring Signal-to-Noise Step Action Notes Figure 7-1 Measuring signal-to-noise Read the signal-to-noise in dB/Hz, that is with the noise value determined for a 1 Hz noise bandwidth. If you wish the noise value for a different bandwidth, decrease the .

  • Page 74: Measuring Noise Using The Noise Marker

    Measuring Noise Measuring Noise Using the Noise Marker Measuring Noise Using the Noise Marker This procedure uses the marker function, Marker Noise, to measure noise in a 1 Hz bandwidth. In this example the noise marker measurement is made near the 50 MHz reference signal to illustrate the use of Marker Noise.
  • Page 75 Measuring Noise Measuring Noise Using the Noise Marker Step Action Notes • Press Marker, 50, MHz. The noise marker value is based on the 7 Move the marker. mean of 5% of the total number of sweep points centered at the marker in the initially selected span.
  • Page 76 Measuring Noise Measuring Noise Using the Noise Marker Step Action Notes Figure 7-2 Noise marker Note that the marker amplitude value is 10 Set the analyzer to zero a. Press Mkr→, Mkr→CF. now correct since all points averaged are span at the marker b.
  • Page 77 Measuring Noise Measuring Noise Using the Noise Marker Step Action Notes Figure 7-3 Noise Marker with Zero Span...

  • Page 78: Measuring Noise-Like Signals Using Band/Interval Density Markers

    Measuring Noise Measuring Noise-Like Signals Using Band/Interval Density Markers Measuring Noise-Like Signals Using Band/Interval Density Markers Band/Interval Density Markers let you measure power over a frequency span. The markers allow you to easily and conveniently select any arbitrary portion of the displayed signal.
  • Page 79 Measuring Noise Measuring Noise-Like Signals Using Band/Interval Density Markers Step Action Notes Figure 7-4 Band/Interval Density Measurement • Press Marker Function, This allows you to move the 8 Set the Band/Interval markers (set at 40 kHz span) Density Markers. Band/Interval Density. around without changing the Band/Interval span.
  • Page 80 Measuring Noise Measuring Noise-Like Signals Using Band/Interval Density Markers Step Action Notes Figure 7-5 Band/Interval Density Measurement Band/Interval Density Markers can be changed to read the total absolute power by pressing NOTE Marker Function, Band/Interval Power.

  • Page 81: Measuring Noise-Like Signals Using The Channel Power Measurement

    Measuring Noise Measuring Noise-Like Signals Using the Channel Power Measurement Measuring Noise-Like Signals Using the Channel Power Measurement You may want to measure the total power of a noise-like signal that occupies some bandwidth. Typically, channel power measurements are used to measure the total (channel) power in a selected bandwidth for a modulated (noise-like) signal.
  • Page 82 Measuring Noise Measuring Noise-Like Signals Using the Channel Power Measurement Step Action Notes Figure 7-6 Measuring Channel Power The power reading is essentially that of the tone; that is, the total noise power is far enough below that of the tone that the noise power contributes very little to the total. The algorithm that computes the total power works equally well for signals of any statistical variant, whether tone-like, noise-like, or combination.

  • Page 83: Measuring Signal-To-Noise Of A Modulated Carrier

    Measuring Noise Measuring Signal-to-Noise of a Modulated Carrier Measuring Signal-to-Noise of a Modulated Carrier Signal-to-noise (or carrier-to-noise) is a ratio used in many communication systems as indication of the noise performance in the system. Typically, the more signals added to the system or an increase in the complexity of the modulation scheme can add to the noise level.
  • Page 84 Measuring Noise Measuring Signal-to-Noise of a Modulated Carrier Step Action Notes • Press FREQ Channel, Auto Tune. 5 Tune to the W-CDMA signal. • Press Marker Function, This measures the total 6 Enable the Band Power power of the 4 carrier Marker function.
  • Page 85 Measuring Noise Measuring Signal-to-Noise of a Modulated Carrier Step Action Notes Figure 7-8 Noise Marker Measuring System Noise Note the green “wings” of Marker 2 outlining the noise region to be included in the measurement and the resulting noise power expressed in dBm/Hz as shown in the Marker Results Block. •...
  • Page 86 Measuring Noise Measuring Signal-to-Noise of a Modulated Carrier Step Action Notes Figure 7-9 Signal-to-noise measurement Up to 11 are available. 13 Simultaneously measure a. Press Marker Function, Select carrier-to-noise on a second Marker, Marker 3, Marker Noise. region of the system by b.
  • Page 87 Measuring Noise Measuring Signal-to-Noise of a Modulated Carrier Step Action Notes Figure 7-10 Multiple Signal-to Noise Measurements with Marker Table...

  • Page 88: Improving Phase Noise Measurements By Subtracting Signal Analyzer Noise

    Measuring Noise Improving Phase Noise Measurements by Subtracting Signal Analyzer Noise Improving Phase Noise Measurements by Subtracting Signal Analyzer Noise Making noise power measurements (such as phase noise) near the noise floor of the signal analyzer can be challenging where every dB improvement is important. Utilizing the analyzer trace math function Power Diff and 3 separate traces allows measurement of the DUT phase noise in one trace, the analyzer noise floor in a second trace and then the resulting subtraction of those two traces displayed in a...
  • Page 89 Measuring Noise Improving Phase Noise Measurements by Subtracting Signal Analyzer Noise Step Action Notes Figure 7-11 Measurement of DUT and Analyzer Noise 7 Measure only the analyzer a. Turn off or remove the DUT signal to noise using trace 2 (blue the RF input of the analyzer.
  • Page 90 Measuring Noise Improving Phase Noise Measurements by Subtracting Signal Analyzer Noise Step Action Notes Figure 7-12 Measurement of Analyzer Noise Notice the phase noise 8 Subtract the noise from the a. Press Trace/Detector, Select Trace, improvement at 100 kHz DUT phase noise Trace 3, Clear Write.
  • Page 91 Measuring Noise Improving Phase Noise Measurements by Subtracting Signal Analyzer Noise Step Action Notes Figure 7-13 Improved Phase Noise Measurement Note the up to 6 dB 9 Measure the noise a. Press Marker, Select Marker, improvement in the Marker measurement improvement Marker 1, Normal.
  • Page 92 Measuring Noise Improving Phase Noise Measurements by Subtracting Signal Analyzer Noise Step Action Notes Figure 7-14 Improved Phase Noise Measurement with Delta Noise Markers...

  • Page 93: Making Time-Gated Measurements

    Making Time-Gated Measurements Making Time-Gated Measurements Traditional frequency-domain spectrum analysis provides only limited information for certain signals. Examples of these difficult-to-analyze signal include the following: • Pulsed-RF • Time multiplexed • Interleaved or intermittent • Time domain multiple access (TDMA) radio formats •...

  • Page 94: Generating A Pulsed-Rf Fm Signal

    When performing these measurements you can use a digitizing oscillascope or your Keysight X-Series Signal Analyzer (using Gate View) to set up the gated signal. Refer back to these first three steps to set up the pulse signal, the pulsed-RF FM...

  • Page 95: Analyzer Setup

    FM Rate 50 kHz RF On/Off Mod On/Off Analyzer setup If you are using an Keysight X-Series Signal Analyzer (using Gate View), set up the Figure 8-1 Figure 8-2 analyzer to view the gated RF signal (see for examples of the display).
  • Page 96 Making Time-Gated Measurements Generating a Pulsed-RF FM Signal Step Action Notes • Press Sweep/Control, Gate, More, 4 Set the gate source to the rear external Gate Source, External 1. trigger input. 5 Enable Gate View a. Press Sweep/Control, Gate, Gate and Gate.

  • Page 97: Digitizing Oscilloscope Setup

    If you are using a digitizing oscillascope, set up the oscilloscope to view the trigger, Figure 8-3 gate and RF signals (see for an example of the oscilloscope display): Table 8-4 Keysight Infiniium Oscilloscope with 3 or more input channels: Instrument Connections Timebase 1 ms/div Channel 1 ON, 2 V/div, OFFSET = 2 V, DC coupled, 1 M Ω...
  • Page 98 Making Time-Gated Measurements Generating a Pulsed-RF FM Signal Table 8-4 Keysight Infiniium Oscilloscope with 3 or more input channels: Instrument Connections Channel 2 ON, 500 mV/div, OFFSET = 2 V, DC coupled, 1 M Ω input, connect to the signal analyzer TRIGGER 2 OUT connector.

  • Page 99: Connecting The Instruments To Make Time-Gated Measurements

    Making Time-Gated Measurements Connecting the Instruments to Make Time-Gated Measurements Connecting the Instruments to Make Time-Gated Measurements Figure 8-4 shows a diagram of the test setup. ESG #1 produces a pulsed FM signal by using an external pulse signal. The external pulse signal is connected to the front of the ESG #1 to the EXT 2 INPUT to control the pulsing.

  • Page 100: Gated Lo Measurement

    Making Time-Gated Measurements Gated LO Measurement Gated LO Measurement This procedure utilizes gated LO to gate the FM signal. For concept and theory “How time gating works” on page 199. information about gated LO see Step Action Notes • Press Mode, Spectrum This enables the spectrum analyzer 1 Set the analyzer to the measurements.
  • Page 101 Making Time-Gated Measurements Gated LO Measurement Step Action Notes Figure 8-6 Viewing the Gate Settings with Gated LO The blue vertical line (the far left line outside of the RF envelope) represents the location equivalent to a zero gate delay. The vertical green parallel bars represent the gate settings.
  • Page 102 Making Time-Gated Measurements Gated LO Measurement Step Action Notes Figure 8-7 Pulsed RF FM Signal The moving signals are a result of the pulsed signal. Using delta markers with a time readout, notice that the period of the spikes is at 5 ms (the same period as the pulse signal). Using time gating, these signals well be blocked out, leaving the original FM signal.
  • Page 103 Making Time-Gated Measurements Gated LO Measurement Step Action Notes Figure 8-8 Pulsed and Gated Signal • Press Pulse, Pulse so Notice that the gated spectrum is much 9 Turn off the pulse that Off is selected. cleaner than the ungated spectrum (as seen modulation on ESG #1.

  • Page 104: Gated Video Measurement

    Making Time-Gated Measurements Gated Video Measurement Gated Video Measurement This procedure utilizes gated video to gate the FM signal. For concept and theory “How time gating works” on page 199. information about gated video see Step Action Notes • Press Mode, Spectrum This enables the spectrum analyzer 1 Set the analyzer to measurements.
  • Page 105 Making Time-Gated Measurements Gated Video Measurement Step Action Notes Figure 8-9 Viewing a Pulsed RF FM Signal (without gating) Ensure that the gate control is set to Edge. 6 Set the gate delay and a. Press Sweep/Control, gate length. Gate, More, Control (Edge).
  • Page 106 Making Time-Gated Measurements Gated Video Measurement Step Action Notes Figure 8-10 Viewing the FR Signal of a Pulsed RF Signal using Gated Video Notice that the gated spectrum is much cleaner than the ungated spectrum (as seen in Figure 8-9). The spectrum you see is the same as a frequency modulated signal without being pulsed.
  • Page 107 Making Time-Gated Measurements Gated Video Measurement Step Action Notes Figure 8-11 The Oscilloscope Display...

  • Page 108: Gated Fft Measurement

    Making Time-Gated Measurements Gated FFT Measurement Gated FFT Measurement This procedure utilizes gated FFT to gate the FM signal. For concept and theory “How time gating works” on page 199. information about gated FFT see Step Action Notes • Press Mode, Spectrum This enables the spectrum analyzer 1 Set the analyzer to the measurements.
  • Page 109 Making Time-Gated Measurements Gated FFT Measurement Step Action Notes Figure 8-12 Viewing the Gated FFT Measurement results The duration of the analysis required is determined by the RBW. Divide 1.83 by 4 ms to calculate the minimum RBW. The pulse width in our case is 4 ms so we need a minimum RBW of 458 Hz. In this case because the RBW is so narrow let the analyzer choose the RBW for the current analyzer settings (span).
  • Page 110 Making Time-Gated Measurements Gated FFT Measurement...

  • Page 111: Measuring Digital Communications Signals

    Measuring Digital Communications Signals Measuring Digital Communications Signals The Signal Analyzer makes power measurements on digital communication signals fast and repeatable by providing a comprehensive suite of power-based one-button automated measurements with pre-set standards-based format setups. The automated measurements also include pass/fail functionality that allow the user to quickly check if the signal passed the measurement.

  • Page 112: Channel Power Measurements

    Measuring Digital Communications Signals Channel Power Measurements Channel Power Measurements This section explains how to make a channel power measurement on a W-CDMA (3GPP) mobile station. (A signal generator is used to simulate a base station.) This test measures the total RF power present in the channel. The results are displayed graphically as well as in total power (dB) and power spectral density (dBm/Hz).
  • Page 113 Measuring Digital Communications Signals Channel Power Measurements Step Action Notes Figure 9-1 Channel Power Measurement Result. The graph window and the text window showing the absolute power and its mean power spectral density values over 5 MHz are displayed. To change the measurement parameters from their default condition: Press Meas Setup.

  • Page 114: Occupied Bandwidth Measurements

    Measuring Digital Communications Signals Occupied Bandwidth Measurements Occupied Bandwidth Measurements This section explains how to make the occupied bandwidth measurement on a W-CDMA (3GPP) mobile station. (A signal generator is used to simulate a base station.) The instrument measures power across the band, and then calculates its 99.0% power bandwidth.

  • Page 115: Troubleshooting Hints

    Measuring Digital Communications Signals Occupied Bandwidth Measurements Step Action Notes Figure 9-2 Occupied BW Measurement Result Troubleshooting hints Any distortion such as harmonics or intermodulation, for example, produces undesirable power outside the specified bandwidth. Shoulders on either side of the spectrum shape indicate spectral regrowth and intermodulation.

  • Page 116: Making Adjacent Channel Power (Acp) Measurements

    Measuring Digital Communications Signals Making Adjacent Channel Power (ACP) Measurements Making Adjacent Channel Power (ACP) Measurements The adjacent channel power (ACP) measurement is also referred to as the adjacent channel power ratio (ACPR) and adjacent channel leakage ratio (ACLR). We use the term ACP to refer to this measurement.
  • Page 117 Measuring Digital Communications Signals Making Adjacent Channel Power (ACP) Measurements Step Action Notes • Press FREQ Channel, 6 Set the center frequency. 1.920, GHz. • Press Meas, ACP. The Occupied BW measurement result 7 Initiate the adjacent should look like the following graphic. channel power measurement.
  • Page 118 Measuring Digital Communications Signals Making Adjacent Channel Power (ACP) Measurements Step Action Notes Figure 9-3 ACP Measurement on a Base Station W-CDMA Signal Two vertical white lines, in the center of the screen, indicate the bandwidth limits of the central channel being measured.
  • Page 119 Measuring Digital Communications Signals Making Adjacent Channel Power (ACP) Measurements Step Action Notes Figure 9-4 Measuring a Third Adjacent Channel • Press Meas Setup, 12 Set pass/fail limits for each offset. Offset/Limits, Offset, A, More, Rel Limit (Car), −55, dB, Offset, B, Rel Limit (Car), −75, dB, Offset, C, Rel Limit (Car), −60, dB.
  • Page 120 Measuring Digital Communications Signals Making Adjacent Channel Power (ACP) Measurements Step Action Notes Figure 9-5 Setting Offset Limits You may increase the repeatability by increasing the sweep time. NOTE...

  • Page 121: Making Statistical Power Measurements (Ccdf)

    Measuring Digital Communications Signals Making Statistical Power Measurements (CCDF) Making Statistical Power Measurements (CCDF) Complementary cumulative distribution function (CCDF) curves characterize a signal by providing information about how much time the signal spends at or above a given power level. The CCDF measurement shows the percentage of time a signal spends at a particular power level.
  • Page 122 Measuring Digital Communications Signals Making Statistical Power Measurements (CCDF) Step Action Notes • Press Mode Setup, Radio 5 Set the analyzer radio mode to W-CDMA as a Std, 3GPP W-CDMA, base station device. 3GPP W-CDMA, Device (BTS). • Press FREQ Channel, 1.98, 6 Set the center frequency.
  • Page 123 Measuring Digital Communications Signals Making Statistical Power Measurements (CCDF) Step Action Notes • Press Trace/Detector, Ref Press the Full Screen key again to 9 Display the stored trace. exit the full screen display without Trace (On). changing any parameter values. •...
  • Page 124 Measuring Digital Communications Signals Making Statistical Power Measurements (CCDF) Step Action Notes Figure 9-8 Reducing the Measurement Points to 1 kpt The number of points collected per sweep is dependent on the sampling rate and the NOTE measurement interval. The number of samples that have been processed are indicated at the top of the screen.
  • Page 125 Measuring Digital Communications Signals Making Statistical Power Measurements (CCDF) Step Action Notes Figure 9-9 Reducing the X Scale to 1 dB...

  • Page 126: Making Burst Power Measurements

    Measuring Digital Communications Signals Making Burst Power Measurements Making Burst Power Measurements The following example demonstrates how to make a burst power measurement on a Bluetooth signal broadcasting at 2.402 GHz. (A signal generator is used to simulate a Bluetooth signal.) Step Action Notes...
  • Page 127 Measuring Digital Communications Signals Making Burst Power Measurements Step Action Notes a. Press Meas, Burst Power. 7 Select the burst power measurement and b. Press AMPTD, optimize the attenuation Attenuation, Adjust Atten level. for Min Clip. • Press Full Screen. Figure 9-10.
  • Page 128 Measuring Digital Communications Signals Making Burst Power Measurements Step Action Notes Figure 9-11 Normal Screen Display of Burst Power Measurement Results • Press Trigger, RF Burst. For more information on trigger 9 Select one of the selections see “Trigger Concepts” on following three trigger page 194.
  • Page 129 Measuring Digital Communications Signals Making Burst Power Measurements Step Action Notes Figure 9-12 Burst Power Measurement Results with Threshold Level Set a. Press View/Display, Bar The burst width is indicated on the 11 Set the burst width to screen by two vertical white lines and a measure the central Graph (On).
  • Page 130 Measuring Digital Communications Signals Making Burst Power Measurements Step Action Notes Figure 9-13 Bar Graph Results with Measured Burst Width Set If you set the burst width manually to be wider than the screen's display, the vertical white lines NOTE move off the edges of the screen.
  • Page 131 Measuring Digital Communications Signals Making Burst Power Measurements Step Action Notes Figure 9-14 Displaying Multiple Bursts Although the burst power measurement still runs correctly when several bursts are displayed NOTE simultaneously, the timing accuracy of the measurement is degraded. For the best results (including the best trade-off between measurement variations and averaging time), it is recommended that the measurement be performed on a single burst.

  • Page 132: Spurious Emissions Measurements

    Measuring Digital Communications Signals Spurious Emissions Measurements Spurious Emissions Measurements The following example demonstrates how to make a spurious emissions measurement on a multitone signal used to simulate a spurious emission in a measured spectrum. Step Action Notes a. Setup a multitone signal with 1 Setup the signal source.
  • Page 133 Measuring Digital Communications Signals Spurious Emissions Measurements Step Action Notes a. Press Meas Setup, Spur, 1, The Spurious Emission result should 7 You may Focus the display Enter (or enter the number of look like Figure 9-15. The graph on a specific spurious the spur of interest) window and a text window are emissions signal.

  • Page 134: Troubleshooting Hints

    Measuring Digital Communications Signals Spurious Emissions Measurements Troubleshooting hints Spurious emissions measurements can reveal the presence of degraded or defective parts in the transmitter section of the UUT. The following are examples of problems which, once indicated by testing, may require further attention: •...

  • Page 135: Spectrum Emission Mask Measurements

    Measuring Digital Communications Signals Spectrum Emission Mask Measurements Spectrum Emission Mask Measurements This section explains how to make the spectrum emission mask measurement on a W-CDMA (3GPP) mobile station. (A signal generator is used to simulate a mobile station.) SEM compares the total power level within the defined carrier bandwidth and the given offset channels on both sides of the carrier frequency, to levels allowed by the standard.

  • Page 136: Troubleshooting Hints

    Measuring Digital Communications Signals Spectrum Emission Mask Measurements Step Action Notes • Press Meas, More, The Spectrum Emission Mask 7 Initiate the spectrum measurement result should look like emission mask Spectrum Emission Figure 9-16. The text window shows the measurement. Mask.
  • Page 137 Measuring Digital Communications Signals Spectrum Emission Mask Measurements Power amplifiers are one of the final stage elements of a base or mobile transmitter and are a critical part of meeting the important power and spectral efficiency specifications. Since spectrum emission mask measures the spectral response of the amplifier to a complex wideband signal, it is a key measurement linking amplifier linearity and other performance characteristics to the stringent system specifications.
  • Page 138 Measuring Digital Communications Signals Spectrum Emission Mask Measurements...

  • Page 139: 10 Demodulating Am Signals

    Demodulating AM Signals 10 Demodulating AM Signals...

  • Page 140: Measuring The Modulation Rate Of An Am Signal

    Set the source amplitudes to −10 dBm. c. Set the AM depth to 80%. d. Set the AM rate to 1 kHz. e. Turn AM on. 2 Connect an Keysight ESG RF signal source to the analyzer RF INPUT as shown. •...
  • Page 141 Demodulating AM Signals Measuring the Modulation Rate of an AM Signal Step Action Notes a. Press FREQ Channel, 5 Set the center frequency, span, RBW Center Freq, 300, MHz. and the sweep time. b. Press SPAN X Scale, Span, 500, kHz. c.
  • Page 142 Demodulating AM Signals Measuring the Modulation Rate of an AM Signal Step Action Notes Figure 10-1 Measuring Time Parameters Make sure the delta markers above are placed on adjacent peaks. See Figure 10-1 The frequency NOTE or the AM rate is 1 divided by the time between adjacent peaks: AM Rate = 1/1.0 ms = 1 kHz The signal analyzer can also make this rate calculation by changing the marker readout to inverse time.
  • Page 143 Demodulating AM Signals Measuring the Modulation Rate of an AM Signal Step Action Notes Figure 10-2 Measuring Time Parameters with Inverse Time Readout Another way to calculate the modulation rate would be to view the signal in the frequency domain and measure the delta frequency between the peak of the carrier and the first sideband.

  • Page 144: Measuring The Modulation Index Of An Am Signal

    Set the source amplitudes to −10 dBm. c. Set the AM depth to 80%. d. Set the AM rate to 1 kHz. e. Turn AM on. 2 Connect an Keysight ESG RF signal source to the analyzer RF INPUT as shown. •...
  • Page 145 Demodulating AM Signals Measuring the Modulation Index of an AM Signal Step Action Notes • Press AMPTD Y Scale, 6 Set the y-axis units to volts. More, Y-Axis Units, V (Volts). • Press AMPTD Y Scale, Ref 7 Position the signal peak Level, (rotate front-panel near the reference level.
  • Page 146 Demodulating AM Signals Measuring the Modulation Index of an AM Signal Step Action Notes Figure 10-3 AM Signal Measured in the Time Domain LEFT: 100% AM Signal (Modulation Index = 1) RIGHT: 80% AM Signal (Modulation Index = 0.8)

  • Page 147: 11 Iq Analyzer Measurement

    IQ Analyzer Measurement 11 IQ Analyzer Measurement...

  • Page 148: Capturing Wideband Signals For Further Analysis

    IQ Analyzer Measurement Capturing Wideband Signals for Further Analysis Capturing Wideband Signals for Further Analysis This section demonstrates how to capture complex time domain data from wide bandwidth RF signals. This mode preserves the instantaneous vector relationships of time, frequency, phase and amplitude contained within the selected digitizer span or analysis BW, at the analyzer's center frequency, for output as IQ data.

  • Page 149: Complex Spectrum Measurement

    IQ Analyzer Measurement Complex Spectrum Measurement Complex Spectrum Measurement This section explains how to make a waveform (time domain) measurement on a W-CDMA signal. (A signal generator is used to simulate a base station.) The measurement of I and Q modulated waveforms in the time domain disclose the voltages which comprise the complex modulated waveform of a digital signal.
  • Page 150 IQ Analyzer Measurement Complex Spectrum Measurement Step Action Notes Figure 11-1 Spectrum and I/Q Waveform (Span 10 MHz) Figure 11-2 Spectrum and I/Q Waveform (Span 25 MHz) A display with both an FFT derived spectrum in the upper window and an IQ Waveform in the lower NOTE window will appear when you activate a Complex Spectrum measurement.

  • Page 151: Iq Waveform (Time Domain) Measurement

    IQ Analyzer Measurement IQ Waveform (Time Domain) Measurement IQ Waveform (Time Domain) Measurement This section explains how to make a waveform (time domain) measurement on a W-CDMA signal. (A signal generator is used to simulate a base station.) The measurement of I and Q modulated waveforms in the time domain disclose the voltages which comprise the complex modulated waveform of a digital signal.
  • Page 152 IQ Analyzer Measurement IQ Waveform (Time Domain) Measurement Step Action Notes • Press BW, Info BW, 10, This view provides a waveform display of 9 Set the analysis MHz (25 MHz if option power versus time of the RF signal in the bandwidth.
  • Page 153 IQ Analyzer Measurement IQ Waveform (Time Domain) Measurement Step Action Notes • Press View/Display, IQ 10 View the IQ Waveform. Waveform. • Press Span X Scale, 11 Set the time scale. Scale/Div, 100, ns. • Press Marker, This view provides a display of voltage 12 Enable markers.
  • Page 154 IQ Analyzer Measurement IQ Waveform (Time Domain) Measurement...

  • Page 155: 12 Using Option Bba Baseband I/Q Inputs

    Using Option BBA Baseband I/Q Inputs 12 Using Option BBA Baseband I/Q Inputs...

  • Page 156: Baseband I/Q Measurements Available For X-Series Signal Analyzers

    Using Option BBA Baseband I/Q Inputs Baseband I/Q measurements available for X-Series Signal Analyzers Baseband I/Q measurements available for X-Series Signal Analyzers The following table shows the measurements that can be made using Baseband I/Q inputs: Table 12-1 BBIQ Supported Measurements vs. Mode Mode Measurements IQ Waveform...

  • Page 157: Baseband I/Q Measurement Overview

    Differential “On” from the I and Q Setup (balanced) softkey menus. The system supports a variety of input passive probes as well as the Keysight 1153A active differential probe using the InfiniMax probe interface. NOTE To avoid duplication, this section describes only the details unique to using the baseband I/Q inputs.
  • Page 158 Using Option BBA Baseband I/Q Inputs Baseband I/Q measurement overview Step Notes If you have set the I/Q Path to I+jQ or to I Only, press I 5 Set up the I Path (if required). Setup. a. Select whether Differential (Balanced) inputs is On or Off.

  • Page 159: 13 Option Exm External Mixing

    Option EXM External Mixing 13 Option EXM External Mixing...

  • Page 160: Using Option Exm With The Keysight 11970 Series Mixers

    Option EXM External Mixing Using Option EXM with the Keysight 11970 Series Mixers. Using Option EXM with the Keysight 11970 Series Mixers. The following examples explain how to, connect the external mixers to the signal analyzer using a diplexer, choose the band of interest, activate conversion loss correction data, and how to use the signal-identification functions.

  • Page 161: Amplitude Calibration

    Option EXM External Mixing Using Option EXM with the Keysight 11970 Series Mixers. Step Action Notes a. Press FREQ Channel. 7 Tune the analyzer to the input signal frequency b. Enter a center frequency or a start and stop frequency •...
  • Page 162 • The mixer ships with a printed copy of the conversion loss data. Find the printed copy conversion loss data that has the text "For Use with Keysight X-Series analyzers only". The conversion loss data will need to be manually entered as frequency and amplitude pairs into the analyzer corrections file.
  • Page 163 Option EXM External Mixing Using Option EXM with the Keysight 11970 Series Mixers. Down loading the conversion loss .csv files to the analyzer corrections array Action Notes You can view the contents of the CD. 1 Install the CD ROM provided with the mixer, into a PC.
  • Page 164 Option EXM External Mixing Using Option EXM with the Keysight 11970 Series Mixers. Action Notes 12 To view the contents of the corrections array in the conversion loss table, press Input/Output, More, Corrections, select the corrections array number, and press Edit.
  • Page 165 Option EXM External Mixing Using Option EXM with the Keysight 11970 Series Mixers. Manually entering conversion loss data Action Notes 1 Locate the printed copy of the conversion loss data that has the text "For use with Keysight X-Series analyzers only".

  • Page 166: Signal Id

    Option EXM External Mixing Using Option EXM with the Keysight 11970 Series Mixers. Signal ID Image Suppress The Image Suppress mode of Signal ID mathematically removes all image and multiple responses of signals present at the mixer input. Two hidden sweeps are taken in succession.
  • Page 167 Option EXM External Mixing Using Option EXM with the Keysight 11970 Series Mixers. Figure 13-1...

  • Page 168: Using The M1970 Series Mixers With X-Series Signal Analyzers

    Option EXM External Mixing Using the M1970 Series Mixers with X-Series Signal Analyzers (Option EXM) Using the M1970 Series Mixers with X-Series Signal Analyzers (Option EXM) Operating precautions WARNING Do not exceed the maximum ratings listed below or permanent damage to the mixer will result.

  • Page 169: Equipment Set Up

    Option EXM External Mixing Using the M1970 Series Mixers with X-Series Signal Analyzers (Option EXM) Avoiding waveguide flange damage Install the waveguide flange cap whenever the mixer is not connected to a device under test. This will protect the waveguide flange mating surface. Mixer waveguide connections Assure the shoulder of the mixer waveguide flange is properly aligned with the flange of the device under test.
  • Page 170 Option EXM External Mixing Using the M1970 Series Mixers with X-Series Signal Analyzers (Option EXM) The spectrum analyzer performs an LO alignment using a detector in the mixer to set the LO Power. During the alignment the yellow Busy LED turns on. Once the alignment completes, the mixer is ready to make calibrated measurements since the conversion loss values stored in the mixer are automatically loaded to the signal analyzer.

  • Page 171: Operation

    Option EXM External Mixing Using the M1970 Series Mixers with X-Series Signal Analyzers (Option EXM) Operation Step Action Notes a. Apply a signal to the mixer 1 Tune the analyzer input. b. Press FREQ Channel Multiple responses may appear on and enter a center screen.

  • Page 172: Amplitude Calibration

    Option EXM External Mixing Using the M1970 Series Mixers with X-Series Signal Analyzers (Option EXM) Step Action Notes a. Press Sweep/Control, 3 With wide spans, increasing Points, enter the number, the number of sweep points and press Enter. may improve the effectiveness of image suppressing.

  • Page 173: Viewing The External Mixer Setup Screen

    Option EXM External Mixing Using the M1970 Series Mixers with X-Series Signal Analyzers (Option EXM) Viewing the external mixer setup screen The mixer setup screen contains information such as mixer serial and model number, harmonic mixing used, and the status of the mixer connection. When the USB mixer is connected, the Mixer Preset, Mixer Bias and Edit Harmonic Table keys are grayed out since these keys do not apply.
  • Page 174 Option EXM External Mixing Using the M1970 Series Mixers with X-Series Signal Analyzers (Option EXM)

  • Page 175: 14 Option Esc External Source Control

    Option Esc External Source Control 14 Option Esc External Source Control...

  • Page 176: Using Option Esc With The Keysight Mxg Signal Sources

    Option Esc External Source Control Using Option ESC with the Keysight MXG Signal Sources. Using Option ESC with the Keysight MXG Signal Sources. The following examples explain how to connect the MXG signal source to the signal analyzer. Step Action Notes •...

  • Page 177: Lan

    Option Esc External Source Control Using Option ESC with the Keysight MXG Signal Sources. Step Action Notes • Press Input Output, External This enables you to identify true 8 Turn on the Signal ID signals from images and function Mixing, Signal ID Mode, Image harmonics.
  • Page 178 • The mixer ships with a printed copy of the conversion loss data. Find the printed copy conversion loss data that has the text "For Use with Keysight X-Series analyzers only". The conversion loss data will need to be manually entered as frequency and amplitude pairs into the analyzer corrections file.
  • Page 179 Option Esc External Source Control Using Option ESC with the Keysight MXG Signal Sources. Down loading the conversion loss .csv files to the analyzer corrections array Action Notes You can view the contents of the CD. 1 Install the CD ROM provided with the mixer, into a PC.
  • Page 180 Option Esc External Source Control Using Option ESC with the Keysight MXG Signal Sources. Action Notes 12 To view the contents of the corrections array in the conversion loss table, press Input/Output, More, Corrections, select the corrections array number, and press Edit.
  • Page 181 Option Esc External Source Control Using Option ESC with the Keysight MXG Signal Sources. Manually entering conversion loss data Action Notes 1 Locate the printed copy of the conversion loss data that has the text "For use with Keysight X-Series analyzers only".

  • Page 182: Signal Id

    Option Esc External Source Control Using Option ESC with the Keysight MXG Signal Sources. Signal ID Image Suppress The Image Suppress mode of Signal ID mathematically removes all image and multiple responses of signals present at the mixer input. Two hidden sweeps are taken in succession.
  • Page 183 Option Esc External Source Control Using Option ESC with the Keysight MXG Signal Sources. Figure 14-1...

  • Page 184: Using The M1970 Series Mixers With X-Series Signal Analyzers

    Option Esc External Source Control Using the M1970 Series Mixers with X-Series Signal Analyzers (Option EXM) Using the M1970 Series Mixers with X-Series Signal Analyzers (Option EXM) Operating precautions WARNING Do not exceed the maximum ratings listed below or permanent damage to the mixer will result.

  • Page 185: Equipment Set Up

    Option Esc External Source Control Using the M1970 Series Mixers with X-Series Signal Analyzers (Option EXM) Avoiding waveguide flange damage Install the waveguide flange cap whenever the mixer is not connected to a device under test. This will protect the waveguide flange mating surface. Mixer waveguide connections Assure the shoulder of the mixer waveguide flange is properly aligned with the flange of the device under test.
  • Page 186 Option Esc External Source Control Using the M1970 Series Mixers with X-Series Signal Analyzers (Option EXM) The spectrum analyzer performs an LO alignment using a detector in the mixer to set the LO Power. During the alignment the yellow Busy LED turns on. Once the alignment completes, the mixer is ready to make calibrated measurements since the conversion loss values stored in the mixer are automatically loaded to the signal analyzer.

  • Page 187: Operation

    Option Esc External Source Control Using the M1970 Series Mixers with X-Series Signal Analyzers (Option EXM) Operation Step Action Notes a. Apply a signal to the mixer 1 Tune the analyzer input. b. Press FREQ Channel Multiple responses may appear on and enter a center screen.

  • Page 188: Amplitude Calibration

    Option Esc External Source Control Using the M1970 Series Mixers with X-Series Signal Analyzers (Option EXM) Step Action Notes a. Press Sweep/Control, 3 With wide spans, increasing Points, enter the number, the number of sweep points and press Enter. may improve the effectiveness of image suppressing.

  • Page 189: Viewing The External Mixer Setup Screen

    Option Esc External Source Control Using the M1970 Series Mixers with X-Series Signal Analyzers (Option EXM) Viewing the external mixer setup screen The mixer setup screen contains information such as mixer serial and model number, harmonic mixing used, and the status of the mixer connection. When the USB mixer is connected, the Mixer Preset, Mixer Bias and Edit Harmonic Table keys are grayed out since these keys do not apply.
  • Page 190 Option Esc External Source Control Using the M1970 Series Mixers with X-Series Signal Analyzers (Option EXM)

  • Page 191: 15 Concepts

    Concepts 15 Concepts...

  • Page 192: Resolving Closely Spaced Signals

    Concepts Resolving Closely Spaced Signals Resolving Closely Spaced Signals Resolving signals of equal amplitude Two equal-amplitude input signals that are close in frequency can appear as a single signal trace on the analyzer display. Responding to a single-frequency signal, a swept-tuned analyzer traces out the shape of the selected internal IF (intermediate frequency) filter (typically referred to as the resolution bandwidth or RBW filter).
  • Page 193 Concepts Resolving Closely Spaced Signals To view the smaller signal, select a resolution bandwidth such that k is less than a Figure 15-1). The separation between the two signals (a) must be greater than (see half the filter width of the larger signal (k), measured at the amplitude level of the smaller signal.

  • Page 194: Trigger Concepts

    Concepts Trigger Concepts Trigger Concepts NOTE The trigger functions let you select the trigger settings for a sweep or measurement. When using a trigger source other than Free Run, the analyzer will begin a sweep only with the selected trigger conditions are met. A trigger event is defined as the point at which your trigger source signal meets the specified trigger level and polarity requirements (if any).
  • Page 195 Concepts Trigger Concepts Line triggering selects the line signal as the trigger. A new sweep/measurement will start synchronized with the next cycle of the line voltage. Pressing this key, when it is already selected, access the line trigger setup menu. Press Trigger, Line.
  • Page 196 Concepts Trigger Concepts Figure 15-2 Frame Triggering a. Period Sets the period of the internal periodic timer clock. For digital communications signals, this is usually set to the frame period of your current input signal. In the case that sync source is not set to OFF, and the external sync source rate is changed for some reason, the periodic timer is synchronized at the every external synchronization pulse by resetting the internal state of the timer circuit.

  • Page 197: Time Gating Concepts

    Concepts Time Gating Concepts Time Gating Concepts Introduction: Using Time Gating on a Simplified Digital Radio Signal This section shows you the concepts of using time gating on a simplified digital radio signal. The section on Making Time-Gated Measurements demonstrates time gating examples.
  • Page 198 Concepts Time Gating Concepts Time gating allows you to see the separate spectrum of radio 1 or radio 2 to Figure 15-5 determine the source of the spurious signal, as shown in Figure 15-5 Time-Gated Spectrum of Radio 1 Figure 15-6 Time-Gated Spectrum of Radio 2 Time gating lets you define a time window (or time gate) of when a measurement is performed.

  • Page 199: How Time Gating Works

    (level gating does not use gate length or gate delay parameters). Figure 15-7 Edge Trigger Timing Relationships With Keysight signal analyzers, there are three different implementations for time gating: gated LO, gated video and gated FFT.
  • Page 200 Concepts Time Gating Concepts Gated video concepts Gated video may be thought of as a simple gate switch, which connects the signal to the input of the signal analyzer. When the gate is “on” (under the Gate menu) the gate is passing a signal. When the gate is “off,” the gate is blocking the signal. Figure 15-8 Whenever the gate is passing a signal, the analyzer sees the signal.
  • Page 201 Concepts Time Gating Concepts Figure 15-9 Gated LO Signal Analyzer Block Diagram Gated FFT Concepts Gated FFT (Fast-Fourier Transform) is an FFT measurement which begins when the trigger conditions are satisfied. The process of making a spectrum measurement with FFTs is inherently a “gated” process, in that the spectrum is computed from a time record of short duration, much like a gate signal in swept-gated analysis.
  • Page 202 Concepts Time Gating Concepts Figure 15-10 Gated FFT Timing Diagram Time gating basics (Gated LO and Gated Video) The gate passes or blocks a signal with the following conditions: • Trigger condition - Usually an external transistor-transistor logic (TTL) periodic signal for edge triggering and a high/low TTL signal for level triggering.
  • Page 203 Concepts Time Gating Concepts • The gate signal. This TTL signal is low when the gate is “off” (blocking) and high when the gate is “on” (passing). The timing interactions between the three signals are best understood if you observe Figure 15-11).
  • Page 204 Concepts Time Gating Concepts Figure 15-12 Signal within pulse #1 (time-domain view) Figure 15-13 Using Time Gating to View Signal 1 (spectrum view) Moving the gate so that it is positioned over the middle of signal 2 produces a result Figure 15-15 as shown in Here, you see only the spectrum within the pulses of...

  • Page 205: Measuring A Complex/Unknown Signal

    Concepts Time Gating Concepts Figure 15-15 Using Time Gating to View Signal 2 (spectrum view) Measuring a complex/unknown signal NOTE The steps below help to determine the signal analyzer settings when using time gating. The steps apply to the time gating approaches using gated LO and gated video.
  • Page 206 Concepts Time Gating Concepts Figure 15-16 Time-domain Parameters Figure 15-16, the parameters are: • Pulse repetition interval (PRI) is 5 ms. • Pulse width (τ) is 3 ms. • Signal delay (SD) is 1 ms for positive edge trigger (0.6 ms for negative edge trigger).
  • Page 207 Concepts Time Gating Concepts which to display the signal of interest. If the signal is erratic or intermittent, you may want to hold the maximum value of the signal with Max Hold (located under the Trace/Detector menu) to determine the frequency of peak energy. To optimize measurement speed in the Gated LO case, set the span narrow enough so that the display will still show the signal characteristics you want to measure.
  • Page 208 Concepts Time Gating Concepts Figure 15-18 Best Position for Gate As a general rule, you will obtain the best measurement results if you position the gate relatively late within the signal of interest, but without extending the gate over the trailing pulse edge or signal transition. Doing so maximizes setup time and provides the resolution bandwidth filters of the signal analyzer the most time to settle before a gated measurement is made.
  • Page 209 Concepts Time Gating Concepts The resolution bandwidth you can choose is determined by the gate position, so you can trade off longer setup times for narrower resolution bandwidths. This trade-off is due to the time required for the resolution-bandwidth filters to fully charge before the gate comes on.

  • Page 210: Quick Rules" For Making Time-Gated Measurements

    Concepts Time Gating Concepts “Quick Rules” for making time-gated measurements This section summarizes the rules described in the previous sections. Table 15-1 Determining Signal Analyzer Settings for Viewing a Pulsed RF Signal Signal Analyzer Signal Analyzer Setting Comments Function Sweep Time Set the sweep time to be equal to or Because the gate must be on at least once (gated video...
  • Page 211 Concepts Time Gating Concepts Most control settings are determined by two key parameters of the signal under test: the pulse repetition interval (PRI) and the pulse width (τ). If you know these Table 15-2 parameters, you can begin by picking some standard settings. summarizes the parameters for a signal whose trigger event occurs at the same time as the beginning of the pulse (in other words, SD is 0).
  • Page 212 Concepts Time Gating Concepts Table 15-3 If You Have a Problem with the Time-Gated Measurement Symptom Possible Causes Suggested Solution Gate does not trigger. 1) Gate trigger voltage may be With external gate trigger: ensure that wrong. the trigger threshold is set near the 2) Gate may not be activated.

  • Page 213: Using The Edge Mode Or Level Mode For Triggering

    Concepts Time Gating Concepts Using the Edge Mode or Level Mode for triggering Depending on the trigger signal that you are working with, you can trigger the gate in one of two separate modes: edge or level. This gate-trigger function is separate from the normal external trigger capability of the signal analyzer, which initiates a sweep of a measurement trace based on an external signal.

  • Page 214: Noise Measurements Using Time Gating

    X-Series answer will be approximately correct, while the older analyzer will need a correction factor. That correction factor is discussed in Keysight Technologies Application Note 1303, Spectrum Analyzer Measurements and Noise, in the section on Peak-detected Noise and TDMA ACP Measurements.

  • Page 215: Am And Fm Demodulation Concepts

    Concepts AM and FM Demodulation Concepts AM and FM Demodulation Concepts Demodulating an AM signal using the analyzer as a fixed tuned receiver (Time-Domain) The zero span mode can be used to recover amplitude modulation on a carrier signal. The following functions establish a clear display of the waveform: •...

  • Page 216: Iq Analysis Concepts

    Concepts IQ Analysis Concepts IQ Analysis Concepts Purpose IQ Analysis (Basic) mode is used to capture complex time domain data from wide bandwidth RF signals. This mode preserves the instantaneous vector relationships of time, frequency, phase and amplitude contained within the selected digitizer span or analysis BW, at the analyzer's center frequency, for output as IQ data.

  • Page 217: Iq Waveform Measurement

    Concepts IQ Analysis Concepts IQ Waveform Measurement Purpose The IQ Waveform measurement provides a time domain view of the RF signal envelope with power versus time or an IQ waveform with the I and Q signal waveforms in parameters of voltage versus time. The RF Envelope view provides the power verses time display, and the I/Q Waveform view provides the voltage versus time display.

  • Page 218: Spurious Emissions Measurement Concepts

    Concepts Spurious Emissions Measurement Concepts Spurious Emissions Measurement Concepts Purpose Spurious signals can be caused by different combinations of signals in the transmitter. The spurious emissions from the transmitter should be minimized to guarantee minimum interference with other frequency channels in the system. Harmonics are distortion products caused by nonlinear behavior in the transmitter.

  • Page 219: Spectrum Emission Mask Measurement Concepts

    Concepts Spectrum Emission Mask Measurement Concepts Spectrum Emission Mask Measurement Concepts Purpose The Spectrum Emission Mask measurement includes the in-band and out-of-band spurious emissions. As it applies to W-CDMA (3GPP), this is the power contained in a specified frequency bandwidth at certain offsets relative to the total carrier power. It may also be expressed as a ratio of power spectral densities between the carrier and the specified offset frequency band.

  • Page 220: Occupied Bandwidth Measurement Concepts

    Concepts Occupied Bandwidth Measurement Concepts Occupied Bandwidth Measurement Concepts Purpose Occupied bandwidth measures the bandwidth containing 99.0 of the total transmission power. The spectrum shape of a signal can give useful qualitative insight into transmitter operation. Any distortion to the spectrum shape can indicate problems in transmitter performance.

  • Page 221: Baseband I/Q Inputs (Option Bba) Measurement Concepts

    Concepts Baseband I/Q Inputs (Option BBA) Measurement Concepts Baseband I/Q Inputs (Option BBA) Measurement Concepts The N9020A Option BBA Baseband I/Q Inputs provides the ability to analyze baseband I/Q signal characteristics of mobile and base station transmitters. This option may be used only in conjunction with the following modes: •...

  • Page 222: Why Make Measurements At Baseband

    Concepts Baseband I/Q Inputs (Option BBA) Measurement Concepts In receivers, baseband I/Q analysis may be used to test the I and Q products of I/Q demodulators, after an RF signal has been downconverted and demodulated. Why make measurements at baseband? Baseband I/Q measurements are a valuable means of making qualitative analyses of the following operating characteristics: •...

  • Page 223: Selecting Input Probes For Baseband Measurements

    The system supports a variety of 1 MΩ impedance input passive probes as well as the Keysight 1153A active differential probe using the InfiniMax probe interface. The Keysight 1153A active probe can be used for both single-ended and differential measurements. In either case a single connection is made for each channel (on either the I or Q input).

  • Page 224: Baseband I/Q Measurement Views

    Active probe, 2.5 GHz 1158A Active probe, 4 GHz Refer to the current Keysight probe data sheet for specific information regarding frequency of operation and power supply requirements. Baseband I/Q measurement views Measurement result views made in the IQ Analyzer (Basic) mode are available for baseband signals if they relate to the nature of the signal itself.
  • Page 225 Concepts Baseband I/Q Inputs (Option BBA) Measurement Concepts Waveform Signal Envelope views of I only or Q only To view the Signal Envelope display of I only or Q only signals, use the Waveform measurement capability in IQ Analyzer (Basic) Mode. The I and Q Waveform of an I/Q signal is very different from the complex signal displayed in the RF Envelope view.

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