Keysight N9340B User manual

Keysight Technologies
N9340B Handheld Spectrum Analyzer
Demo Guide

This demo guide is a tool for the new user to gain familiarity with the basic functions and features of
the Keysight Technologies, Inc. N9340B handheld spectrum analyzer.
Almost all exercises utilize a signal from an external signal generator with amplitude of –10 dBm and
frequency of 100 MHz.
Key names surrounded by [ ] indicate hardkeys located on the front panel, while key names surrounded
by { } indicate softkeys located on the right of the display.
Demos
1. Panel Tour
2. File Operation
3. Measurement Basics
4. Peak Search and Makers
5. Measuring Signal to Noise with Delta Markers
6. Improving Signal to Noise
7. Limit Lines and Pass/Fail Testing
8. Spectrogram
9. Tracking Generator
10. Power Meter Measurements
11. Field Strength Measurements
12. AM/FM, ASK/FSK Demodulation
13. Spectrum Emission Mask
14. Automation
2
Introduction

3
Section 1
Panel Tour
Caption Function
1Power switch Toggles the analyzer between on and off
2 Function keys Includes hardkeys: SYS, FREQ, SPAN, AMPTD, BW/SWP, TRACE, MEAS, and MODE
3 Preset Returns the analyzer to a known state, also turns on/off power save feature (press for 1 sec.)
4Enter Confirms a parameter selection or configuration
5ESC/CLR Exits and closes the dialog box or clears the character input
6MARKER Activates the marker functions
7LIMIT Sets limit lines for quick pass/fail testing
8 Save Quickly saves the current trace
9 Arrow keys Increases or decreases a parameter step by step
10 Knob Selects an option item or edits a numerical parameter
11 Softkeys Indicate current menu functions
12 Built-in light sensor Adjusts the display brightness automatically
13 Speaker Active when in demodulation mode
14 Screen Displays measured traces and status
14 12 10
9
7
6
5
4
1 2 3
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Caption Function
1 External DC power connector Provides input for the DC power source via an AC-DC adapter or automotive type DC adapter.
2 LED indicator (charging) Light is {On} when the battery is charging
3 LED indicator Light is {On} when external DC power is connected to the tester
4USB interface (device) Connects the analyzer to a PC
5 USB interface (host) Connects the analyzer to a USB memory stick or disk
6Headphone Connects the analyzer to a headphone
7LAN interface Connects the analyzer to a PC for SCPI remote control
8 RF OUT connector The output for the built-in tracking generator. Enabled with Option TG3.
9 EXT TRIG IN/REF IN
(BNC, female)
Connects to an external TTL signal or a 10 MHz reference signal. The TTL signal is used to
trigger the analyzer’s internal sweep.
10 RF IN connector (50 Ω) Accepts an external input with a frequency range from 100 kHz to 3 GHz, tunable to 9 kHz
Section 1
Top Panel Overview
10 9 8
71 2 3 4 5 6

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1. Adjust the display brightness
Instruction Key strokes
Switch the screen brightness state from
automatic to manual.
[SYS], {Brightness Man}
Rotate the knob to adjust the display
brightness.
Switch the screen brightness state back to
automatic.
[SYS], {Brightness Auto}
Cover the light sensor with your finger and
watch as the display brightness adjusts
automatically.
2. Backlit key demo
Instruction Key strokes
Switch the backlit key state to auto. [SYS], {KeyBackLight}
Cover the light sensor with your finger and
watch as the back lights come on.
Switch the backlit key state to manual,
and adjust the backlit keys’ brightness.
[SYS], {KeyBackLight}, {BackLight Man},
{Brightness}, {High} {Off} {Brightness},
{Med}
Set the automatic turn-off time interval so
the backlit keys will shut off when not in
operation.
[SYS], {KeyBackLight}, {AutoOffTimer}, {5
Sec}, {10 Sec}
Communication system maintenance and repair often requires a technician to
troubleshoot in bright daylight or in the dark. There is a light sensor on the front
panel of the N9340B that measures the ambient light and automatically adjusts
the brightness of the display and its backlit keys.
You can also manually set the brightness of the display, and the backlit keys, so
they can be seen clearly in any light. The duration of the key light can also be
set to maximize battery life.
Section 1
Auto-Brightness and Backlit Keys

6
A key feature of the Keysight N9340B Handheld spectrum analyzer is the
easy-to-use file system.
In addition to the 16 MB internal memory, the Keysight N9340B also allows you
to save files to an external USB memory device, such as a USB memory stick.
The analyzer has seven file types:
– CSV (*.CSV) Records the trace data as comma separated
variables.
– Pattern (*.PTN) Records the limit-line settings.
– Screen (*.JPG) Records the current screen.
– Setup (*.SET) Records the current system setting information.
– Spectrum Mask (*.MSK) Records spectrum mask settings.
– State (*.STA) Records the current controls and settings of the
analyzer.
– Trace (*.DAT) Records the data of the current trace and controls.
In this section, the state of the instrument is saved to a filename of your choice
so that it can be recalled for use in later sections.
Section 2
Save/Recall Setups and Results
1. Save a state file to the local memory
Instruction Key strokes
Call up the file save menu. [SYS]
Select the internal memory. [File], {File Setup}, {Save Path}, {Local}
Select the file type. {File Setup}, {File Type}, {State}
Enter the file name using numeric keypad. Enter a file name.
Save to the internal memory. {Save}

7
Keep the USB stick connected for the following operation.
Recalling a file from either the local memory or an external USB memory stick
is a simple task.
Here is an example:
3. Recall the state file you just saved in the USB memory stick.
Instruction Key strokes
Call up the file save menu. [SYS]
Select the load path. {File}, {View}, {USB}
Select the file type. {File Setup}, {File Type}, {State}
Rotate the knob to highlight the file.
Load the file. {Load now}
2. Save the state file to an external USB memory stick.
Instruction Key strokes
Insert a USB memory stick into the USB port
on the top panel of the analyzer.
Call up the file save menu. [SYS]
Select the save path. {File}, {File Setup} {Save Path}, {USB}
Select the file type. {File Setup}, {File Type}, {State}
Enter the file name using the numeric keypad
(using alphabet and/or number keys).
Enter a file name.
Save to the USB memory stick. {Save}
Section 2
Save/Recall Setups and Results (continued)

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Section 3
Measurement Basics: Frequency, Span, Amplitude
The key measurement setup parameters of a spectrum analyzer are:
– Frequency: Adjusts the frequency.
– Span: Adjusts the difference between the start and stop
frequencies of the displayed spectrum.
– Amplitude: Adjusts the view of the signal level.
A typical spectrum analyzer measurement procedure contains the following
three steps:
1. First, the center frequency of the analyzer is tuned to the signal of interest.
2. Next, the span is adjusted to zoom in on the signal of interest.
3. Finally, the amplitude is adjusted to give the optimum view of the signal.
In this section, you will set an external signal generator to 100 MHz at –10 dBm
and connect an RF cable from its output port to the input port of the N9340B.
Software
If you do not have a signal generator, you can connect an antenna to the input
port of the N9340B and perform this demonstration using an ambient signal
such as from a local radio station. In this case you may need to jump ahead
to Section 6 to learn how to lower the noise floor by reducing the resolution
bandwidth (RBW).
Instruction Key strokes
Connect a Type-N RF cable from an external
signal generator’s RF output port to the RF
input connector of the N9340B.
Tune the center frequency to 100 MHz. [FREQ], [100], {MHz}
Adjust the span to zoom in on the signal on
the screen.
[Span], [10], {MHz}
Set the reference level so that the signal peak
is at the top graticule line.
[AMPTD], then rotate the knob.

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Section 4
Peak Searching and Markers
The peak auto search feature of the analyzer allows you to measure multiple
peaks simultaneously. Not only does this save time, it also provides a clear
printout of frequency and amplitude data.
If you do not have a signal generator or this signal generator only generates one
peak, you can connect an antenna to the input port of the N9340B and perform
this demonstration using ambient signals, such as from several local radio
stations. In this case you may need to jump ahead to Section 6 to learn how to
lower the noise.
Instruction Key strokes
Connect the 100 MHz signal to the RF
IN connector. Set start frequency and
stop frequency.
[Preset], [FREQ] {Start Freq}, [90],
{MHz}, {Stop Freq}, [320], {MHz}
Activate auto peak search. [MARKER], {Peak Search}, {6 Peaks
Search {On}}
Figure 1. Marker peak search function

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Section 5
Measuring Signal to Noise with Delta Markers
Harmonic distortion is present in any electronic system where a signal travels
through an active device. Communication engineers are extremely concerned
with harmonic distortion. For example, cellular radio systems must be checked
for harmonics of the carrier signal that might interfere with other systems
operating at the same frequencies as the harmonics.
In this section, the 100 MHz signal’s harmonics will be located using marker
delta. The marker delta function allows you to easily compare the frequency
and amplitude differences between two signals.
Note: Besides harmonics, you can also measure the amplitude ratio of any two signals present in dBc
using delta markers. The Marker Normal function lets you enter the exact frequency you want the
marker to go. The Delta Marker function lets you enter the exact frequency difference desired and
places the second marker at that point. The amplitude difference is shown in the upper right corner
of the display.
Instruction Key strokes
Set center frequency and span. [FREQ], {Center Freq}, [290], {MHz},
{SPAN}, [420], {MHz}
Place a marker at the highest peak on the
display (100 MHz).
[MARKER], {Peak Search}, {Return}
Anchor the first marker and activate a second
marker.
[MARKER], {Delta}
Move the second marker to another signal
peak by rotating the knob or entering the
frequency offset.
Rotate the knob, or press [100], {MHz}
Figure 2. Delta markers

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Section 6
Improving Signal to Noise:
RBW, Input Attenuation, Preamplifier and Video Average
One of the primary uses of a spectrum analyzer is searching for and measur-
ing low-level signals (such as the 3rd harmonic of an oscillator). Sensitivity
optimization of the analyzer is absolutely crucial when trying to characterize
signals of this nature. The input attenuator and bandwidth settings affect the
level of signals that can be seen on the display. The attenuator affects the level
of a signal passing through the instrument. Narrowing the resolution bandwidth
(RBW) fi lter allows you to resolve two or more signals that are close
together in frequency, and lowers the noise fl oor of the analyzer so you can
detect very small signals.
The Keysight N9340B provides a 1-dB step attenuator to allow maximum
flexibility when setting the analyzer’s dynamic range.
If after adjusting the attenuation and RBW, a signal is still near the noise,
visibility can be improved by using the video bandwidth (VBW) or averaging
functions. VBW filter smoothes small signal variations. Averaging function
simply averages the traces on screen as the sweep is made. Turning on the
internal preamplifier also reduces the effective noise floor.
Instruction Key strokes
Connect the 100 MHz signal to RF IN
connector.
[Preset]
Zoom in on the 3rd harmonic “=
(150 kHz span).
[Frequency] [300], {MHz}, [Span],
[150], {kHz}
Turn preamp on. [AMPTD], {preamp off on} {On}
Bring the peak of the harmonic to top
graticule line.
[AMPTD], then rotate the knob.
Reduce the resolution bandwidth to
1 kHz.
[BW/SWP] {RBW} {Man} reduce to
100 Hz
Manually reduce the attenuation. [AMPTD], {Attenuation} {Man}, [0]
{dB}
Smooth out the noise using averaging
function.
[TRACE], {More} {Average {On}}
Figure 3. Improved signal to noise

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Section 7
Limit Lines and Pass/Fail Testing: Creating a Mask with Limit Lines
In many onsite test situations, it is necessary to quickly test a signal to see
whether or not it meets a specifi cation for frequency and amplitude. For
example, during radio transmitter service and maintenance, the technician
would want to make sure that the center frequency of a carrier and its harmonic
fall within a certain frequency and amplitude mask.
Limit lines make it easy to set up pass/fail testing. The analyzer compares
trace data to a set of amplitude and frequency parameters while the analyzer is
sweeping the measurement range.
Instruction Key strokes
Connect the signal to the RF IN connec-
tor. Set center frequency and span.
[Preset], [FREQ], {Center Freq},
[100], {MHz}, [Span], [1], {MHz}
Quit digital edit state. [ESC/CLR]
Open the limit menu. [Limit]
Activate the limit lines. {Limit {On}}
Open the limit lines edit menu. {Edit Limits}
There are two ways to edit limit lines:
limit points and limits table.
{Limits Table}
Edit the point 0. {Frequency}, [99.5] {MHz}, {Ampli-
tude}, [48], {–dBm}
Note: For other points, you only need to press {Add} and enter the frequency and amplitude.
Firmware above A.01.02 will support 100 limit points.
Figure 4. FM signal with limit lines

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Section 8
Spectrogram
The Spectrogram shows a three-dimensional display of the spectrum with
power over frequency and time. This allows you to locate intermittent interfer-
ing signals and identify spurious signals that cause dropped calls and poor
service quality in communications systems.
The X-axis represents frequency as in a normal spectrum display, but amplitude
is now represented by color, red for a strong signal and blue for noise floor. The
Y-axis now represents time, with the trace from the newest sweep displayed
at the bottom of the screen. Earlier traces move up toward the top with each
new sweep. Two coupled markers allow you to place a marker on any trace in
the spectrogram and view the normal spectrum for the time of that sweep. The
time interval between sweeps can be adjusted, and up to 1500 traces can be
displayed and saved.
In the following demo, an Omni Antenna with a frequency range from 1.8 GHz to
1.9 GHz is needed.
Instruction Key strokes
Connect the omni antenna to the RF IN
connector.
Set HSA to high sensitivity mode. [AMPTD], {HiSensitivity}, {On}
Set the center frequency and span.1[FREQ], {Center Freq}, [1.8052], {GHz},
[SPAN], [5], {MHz}
Turn on the spectrogram function. [MEAS], {Spectrogram}
Set the update interval time between two
frames.
{Update Int. {On}}, rotate the knob or
pres the numeric keypads to set the
update interval time.
Turn on Marker 1 and Marker 2. [MARKER], {State {On}}, {Marker (2)},
{State {On}}
Change the frequency of marker. {Frequency}, rotate the knob to change
the marker to the frequency you want.
View trace. [MEAS], {Disp Mode} {Trace}
Save spectrogram data. {Save&Load}, {Save RAM As}, type a
name for the trace and press [ENTER}
Recall the saved spectrogram file. {Load Spctrg}, select trace name with
the knob, {Load Now}
1. The frequency selected for this demo depends on the cellular signals present. In the USA,
use: [FREQ], {Center Freq}, [877.13], {MHz}, [SPAN], [10], {MHz}

14
Figure 5. Spectrogram screenshot
Figure 6. Spectrogram trace mode
Trace display shows the trace from the spectrogram for the time selected.
Section 8
Spectrogram (continued)

15
Section 9
Tracking Generator: Transmission and Reflection Measurements
A spectrum analyzer with tracking generator can be used to perform compo-
nent tests such as frequency response and gain and loss on components and
subsystems. The tracking generator is a signal source whose RF output follows
(tracks) the tuning of the spectrum analyzer. The N9340B spectrum analyzer
has an optional high-performance, built-in tracking generator (Option TG3),
operating from 5 MHz to 3 GHz. A tuned receiver architecture and narrow IF
bandwidths provide high dynamic range for scalar component test.
The N9340B spectrum analyzer can be used to characterize measure transmis-
sion parameters, such as fl atness and rejection, or refl ection parameters,
such as return loss on devices under test (DUTs). Return loss is an a reflection
measurement requiring a directional coupler or bridge.
Transmission measurements
In the following demo, the rejection of a bandpass fi lter is measured.
In the following demo, a 300 MHz bandpass fi lter is used as a DUT.
The marker readout displays the rejection of the fi lter at 90 MHz above the
center frequency of the band pass.
Figure 7. Transmission measurement setup
DUT
N9340B
HANDHELD SPECTRU M ANALYZER
100kHz - 3.0 GHz
SYS MODE MEAS TRACE BW/
SWP AMPTD SPAN FREQ
ENTER
MARKER ESC/CLR
1ABC 2DEF 3GHI
4JKL 5MNO 6PQR
7STU 8VWX 9YZ_
0SAVE LIMIT
PRESET

16
Instruction Key strokes
Preset the analyzer. [PRESET]
Set the start and stop frequencies and the
resolution bandwidth.
[FREQ] {Start Freq}, [100] {MHz}, {Stop
Freq}, [1] {GHz}, [BW/SWP], {RBW}, [1]
{MHz}
Turn on tracking generator, and set its output
level to –10 dBm.
[MODE], {Tracking Generator}, {Amplitude
{On}}, [–10] {dBm}
Make sure the sweep time is auto coupled. [BW/SWP], {Sweep Time {Auto}}
Increase measurement sensitivity and smooth
the noise.
{RBW} [30] {kHz}, {VBW} [30] {kHz}
Disconnect the DUT, and directly connect the
cable from the tracking generator output to
the analyzer input.
Store the frequency response of the cable in
trace 4 by performing normalization.
[MEAS] {Normalize}, {Store Ref
(1 → 4), {Normalize {On}}
Reconnect the DUT.
Change the normalized reference position. {Norm Ref Posn}, [8], [ENTER]
Measure the rejection of the low-pass filter. [300] {MHz}, {Delta} [130] {MHz}
Figure 8. Transmission measurement
Section 9
Tracking Generator: Transmission and Reflection Measurements (continued)

17
This demo shows a return loss measurement on a 300 MHz bandpass fi lter.
You will need a directional bridge such as the Keysight 86205A to perform this
measurement. Before making the measurement, calibrate the test setup using
a calibration standard with a known reflection coefficient.
The calibration standard for refl ection measurements is usually a short circuit
connected at the reference plane (the point at which the DUT is connected).
A short circuit has a refl ection coeffi cient of 1 (0 dB return loss); it refl ects
all incident power and provides a convenient 0 dB reference.
Figure 9. Reflection measurement setup
If possible, use a coupler or bridge with the correct test port connector for
both calibrating and measuring. Any adapter between the test port and DUT
degrades coupler/bridge directivity and system source match. Ideally, you
should use the same adapter for the calibration and the measurement. Be sure
to terminate the second port of a two port device.
Please refer to the following procedures when connecting the DUT to the
instrument:
1. Connect the DUT to the directional bridge as shown in Figure 9 and
terminate
the unconnected port of the DUT.
2. Connect the RF OUT port of the analyzer to the directional bridge.
3. Connect the RF IN port to the coupled port of the directional bridge.
CAUTION:
Excessive signal input may damage the DUT. Do not exceed the maximum power
that the DUT can tolerate.
Section 9
Reflection measurements
Coupled port
or
Short
circuit
DUT
N9340B
HANDHELD SPECTRU M ANALYZER
100kHz - 3.0 GHz
SYS MODE MEAS TRACE BW/
SWP AMPTD SPAN FREQ
ENTER
MARKER ESC/CLR
1ABC 2DEF 3GHI
4JKL 5MNO 6PQR
7STU 8VWX 9YZ_
0SAVE LIMIT
PRESET

18
Instruction Key strokes
Preset the analyzer. [PRESET]
Turn on tracking generator, set the output
level to –10 dBm.
[MODE], {Tracking Generator}, [ENTER],
{Amplitude {On}}, –10, dBm
Set the start and stop frequencies for your
DUT. (Frequencies shown here are for example
only.)
[FREQ], {Start Freq}, [100], {MHz} {Stop
Freq}, [500], {MHz}
Disconnect the DUT, and connect a cable from
the input connector to the directional bridge
output connector.
Normalize to eliminate the test system
response error.
[MEAS], {Normalize}, {Store Ref (1 to 4),
{Normalize {On}}
Change the normalized reference position. {Norm Ref Posn}, 8, [ENTER]
Reconnect the DUT without changing any
analyzer settings and terminate the uncon-
nected port of the DUT.
Use a marker to read the return loss. Position a marker and rotate the knob
to find the highest peak; this is the
maximum return loss.
Figure 10. Short circuit normalized
Section 9
Reflection measurements (continued)
Figure 11. Return loss of the bandpass filter

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Section 10
Power Meter
The N9340B spectrum analyzer can be used with the Keysight U2000 Series
USB power sensor to make average power measurements. It can make true
average power measurements for all types of signals with a frequency range
of 9 kHz to 24 GHz, power levels from –60 dBm to +20 dBm, and with measure-
ment speed of up to 1000 readings per second in buffered mode. The N9340B
controls the power sensor, and retrieves measurement results over the
USB port.
The N9340B displays measurement results and provides pass/fail testing with
user-defined upper and lower limits. The results are displayed in dBm and W for
absolute power measurements and in dB and percentage for relative measure-
ments. Results can be displayed in power meter mode with fast display update
rates or on a chart of power versus time.
In this demo, the N9340B is used with a U2000A USB power sensor to measure
the output power of an external signal generator.
Instruction Key strokes
Connect the U2000A power sensor to the
USB interface of the N9340B.
[PRESET]
Turn on the power meter function. [MODE], Rotate the knob to highlight
PowerMeter, [ENTER]
Zero and the zero type is INT {Zeroing}, {Zeroing}
Connect the USB power sensor’s RF IN port to
the signal generator’s output and turn on the
generator.
Turn on the limit function.
If sound warning when power is beyond limit
value, {Limit Beep {On}}.
[MEAS], [Meas Setup], {Limits}, {Limits
{On}}, {Return}
Change the display mode from meter to chart. [MEAS], {Meas Disp}, {Chart View}
Save the chart (400 points) [SYS], {File}, Enter the file name, {Save}

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The N9340B can display power measurement results in meter mode
or chart mode.
Figure 12. Power meter mode
Figure 13. Chart mode
Section 10
Power Meter (continued)