WHITE PAPER

The Essential Signal

Generator Guide
Building a solid foundation in RF — Part 1
Eliminate Uncertainties from Your Test
Results with a Reliable Signal Source
Engineers designing consumer wireless, military communications, or radar devices face an ongoing
bandwidth crunch in spectrum filled with interference. An accurate signal generator offers precise
and stable test signals for characterizing your device under test (DUT). It also lets you apply
impairments to help you test your design within and beyond its limits.

Getting to market faster with test results you can trust starts with selecting the right test instrument
for the job. Our two-part series will help you better understand how signal generators work and
which key specifications are critical for your projects.

Part 1 introduces you to the inner workings of the signal generator. It provides a deeper look at basic
specifications such as power, accuracy, and speed. Part 2 covers more advanced features such as
modulation, spectral purity, and distortion.

The Essential Signal Generator Guide | 2

Contents
Section 1. What Is a Signal Generator?

Understand the basic functions of a signal generator, different types of signal generators, and
key specifications.

Section 2. Power

Learn about the difference between average power, envelope power, and peak envelope power, as
well as measurement applications for high or low output power.

Section 3. Accuracy

Gain confidence in your measurements. Take a deeper look at why accuracy matters and explore
specifications of interest.

Section 4. Speed

Learn about speed specifications and how to improve test throughput.

The Essential Signal Generator Guide | 3

Section 1. What Is a Signal Generator?
A signal generator is a source that outputs a signal. This signal can be a basic sinusoidal wave, a
pulse, or a modulated signal. Also called a signal source, this instrument enables you to output
signals at various frequencies, amplitudes, and times.

What does a signal generator do, and why is it important?

Engineers use signal generators to test components, receivers, and systems for various applications
throughout the product development cycle. The output signal can be as simple as a continuous wave
(CW) or as complex as a digitally modulated signal. The signal generator simulates signals at various
stages of communication systems. Figures 1-1 and 1-2 show common signal generator use cases for
component and receiver tests.

Component RF transceiver (Rx) System component

(stimulus-response)
RF Signal
I+, I-
RF / IF RF / IF
RF Rx
Q+, Q- RF / IF I Q
DUT
Baseband
BBIQ

Intermodulation (2-tone) RF transceiver (Tx) Component substitution

CW
CW #2
I+, I-
CW #1
∑ RF Tx RF / IF
RF / IF

X
DUT
Upconverter / downconverter

Figure 1-1. Signal generator use cases for component characteristic tests or a system component

The Essential Signal Generator Guide | 4

 Sensitivity CO-channel rejection CO-channel selectivity
In-band CW / modulated Adjacent / alternate channel
interfering interfering
Desired
signal Desired Desired
BERT
Rx signal ∑ signal ∑
DUT BERT BERT
Data / clock
Data / clock Rx Data / clock Rx
DUT DUT

Intermodulation immunity Spurious immunity Fading measurement

Out-of-band CW / modulated Out-of-band CW / modulated
Desired
interfering interfering signal

Desired Desired Channel

signal ∑ signal ∑ Simulator
BERT BERT
Data / clock Rx Data / clock Rx
DUT DUT Rx
DUT

Figure 1-2. Signal generator use cases for receiver sensitivity tests

Why is a signal generator important? Signal generators produce precise and stable test signals
for characterizing your DUT. They can simulate different kinds of signals, from digital IQ to high-
frequency signals. A signal generator can also apply impairments to characterize your device’s
behavior and test your design within and beyond its limits.

The Essential Signal Generator Guide | 5

Types of signal generators

Signal generators can be classified based on their form factor and capabilities.

Form factor: Benchtop or modular?

The most common signal generator form factor is benchtop. These instruments typically sit on
benches and in racks. Benchtop signal generators are well-suited for research and development
(R&D), where engineers use the front-panel controls to analyze and troubleshoot devices.

Portable signal generators are a popular subgroup in the benchtop category. R&D labs typically invest
in portable benchtop signal generators to maximize asset utilization while improving cost-effectiveness.
Because of their compact size, portable signal generators are easier to share among several benches.
R&D labs often use advanced benchtop units and portable units in tandem to minimize cost per port.

The PXIe modular form factor signal generators are compact instruments housed in a PXIe chassis
and controlled using a PC. Engineers can put several PXIe signal generators in a single chassis,
making them suitable for applications that require multichannel measurement capabilities, fast
measurement speed, and a small footprint. A PXIe signal generator often uses the same software
applications as a benchtop signal generator, providing measurement consistency and compatibility
from product development to manufacturing and support.

Figure 1-3. Benchtop and PXI modular signal generator

The Essential Signal Generator Guide | 6

Capabilities: Analog, vector, and agile signal generators

Analog signal generators supply sinusoidal CW signals and several types of analog modulation,
such as amplitude, frequency, and pulse modulation. Analog signal generators cover a frequency
range from RF to microwave. Most generators feature step / list sweep modes for passive device
characterization or calibration.

Vector signal generators add the ability to create digital modulation schemes. Traditional vector
signal generators have a built-in baseband IQ modulator to generate complex modulation formats,
such as quadrature phase-shift keying, quadrature amplitude modulation, or more complex
orthogonal frequency-division multiplexing signals. Some next-generation vector signal generators
replace the IQ modulator with direct digital synthesis technology to produce the same complex
formats with higher signal fidelity and better overall modulation quality. Combining the system with
an IQ baseband generator enables the emulation and transmission of virtually any signal within the
supported modulation bandwidth.

Optimized for speed, agile signal generators can quickly change the frequency, amplitude, and
phase of the signal. They also have the unique capability to be phase-coherent at all frequencies
at all times. This attribute, along with extensive pulse modulation and wideband chirp capabilities,
makes them ideal for electronic warfare (EW) and radar applications.

The Essential Signal Generator Guide | 7

Overview of key specifications

To select the right signal generator for your project, you need to understand its performance
specifications. Specifications tell you about the capability of your signal generator. Let’s explore the
major specifications: frequency, amplitude, and spectral purity performance.

Frequency specifications

The frequency specification defines the range, resolution, accuracy, and switching speed of your
signal generator.

• Range refers to the maximum and minimum frequencies your signal generator can output.

• Resolution is the smallest frequency change.

• Accuracy describes how close the source’s output frequency is to the set frequency.

• Switching explains how fast the output settles to the desired frequency.

Figure 1-4. Spectrum analysis with frequency and amplitude readouts

The Essential Signal Generator Guide | 8

Amplitude specifications

Amplitude specifications include range, resolution, and switching speed.

• Range is the difference between the maximum and minimum output power capability of the
signal generator. The signal generator’s output attenuator design determines its range. The
output attenuator enables the signal generator to produce extremely small signals used to test a
receiver’s sensitivity.

• Resolution is the smallest possible power increment.

• Switching speed describes how fast the source can change from one power level to another.

Pmax Accuracy
Power

Dynamic Output power

capability of the
range signal generator

Pmin

Frequency
Figure 1-5. Power output range and accuracy

The Essential Signal Generator Guide | 9

Spectral purity

Spectral purity is a signal’s inherent stability. A perfect signal generator creates a sinusoidal wave
at a single frequency without the presence of noise. However, signal generators consist of nonideal
components that introduce noise and distortion. The specifications associated with spectral purity
are often the most difficult to understand. These specifications include phase noise, harmonics, and
spurs, as shown in Figure 1-6.

• Phase noise is a frequency-domain view of the noise spectrum around the oscillator signal. It
describes the frequency stability of an oscillator.

• Harmonics refers to integer multiples of the sinusoidal fundamental frequency output. Nonlinear
characteristics of components used in the signal generator cause these harmonics.

• Spurs are nonrandom or deterministic signals created from mixing and dividing signals to get the
carrier frequency. These signals may be harmonically or nonharmonically related to the carrier.

Download our signal generator selection guide to learn more about Keysight’s
comprehensive portfolio of signal generators.

CW
output

Harmonic spur
Phase
~30dBc from
noise Non-harmonic spur
non-linear
Sub-harmonics (dBc/Hz) from power supplies
components
from multipliers used to from LO’s and other contributors
extend the frequency
output

Broadband noise floor

Thermal noise of source
0.5 f0 f0 2 f0

Figure 1-6. Various nonideal spectral components

The Essential Signal Generator Guide | 10

Section 2. Power
Signal generators provide precise and stable test signals for various component and system test
applications. An important specification of any signal generator is the output power range. Often,
signal generators need output signals as low as -120 dBm in receiver sensitivity testing and as high
as +20 dBm in RF power amplifier testing. They must also achieve this wide dynamic range while
meeting key specifications such as accuracy, spectral purity, and noise.

There are several types of power to consider, including average power, envelope power, and peak envelop
power (PEP). But before we look at each of these in detail, let’s first understand the basics of power.

What is power?

The International System of Units defines the watt (W) as a unit of power — 1 W is one joule per
second, used to quantify the rate of energy transfer. At direct current (DC) and low frequencies,
voltage and current measurements are simple and straightforward. Power (P) is the product of
voltage (V) and current (I).

For low-frequency signals, both voltage and current, vary with time. The energy transfer rate
(instantaneous power) also varies with time. In Figure 2-1, the blue curve represents instantaneous
power shifts around cycles. Calculate average power by integrating the area under the P curve.

DC

+ ZS
V +
– RL P = IV = V2/R
–

Low-frequency
AC
component
of power
Amplitude

P
V RL DC
component
of power
I
V

Figure 2-1. DC and low-frequency power measurements

The Essential Signal Generator Guide | 11

However, as frequency increases, voltage and current measurements become difficult and
impractical, so engineers measure power directly. Figure 2-2 represents three CWs with the same
voltage level but different frequencies. Pi (green curve) is instantaneous power that varies with time,
while Pavg (red line) is average power. Notice that average power remains constant and independent
of frequency, making it suitable for high-frequency signals. Let’s take a closer look at definitions of
power for RF measurements.

Figure 2-2. Low- and high-frequency power measurements

The Essential Signal Generator Guide | 12

Average power

As frequency increases, impedance varies. RF engineers commonly use the term average power to specify
all RF and microwave systems because instantaneous power variations are too fast to be meaningful.
Average power is the average energy transfer rate across many periods of the lowest frequency.

Envelope power and peak envelope power

For some applications, engineers examine the effects of modulation or transient conditions without
examining the details of the RF carrier waveform. Figure 2-3 illustrates high-frequency modulated
signal power measurements. The upper graph represents the voltage envelope of the modulated
signal. The lower left graph shows the instantaneous power of the signal in green and the average
power in red. You can measure the envelope power by averaging the power over a period that is
long compared to the highest modulation frequency but short compared to the carrier period. The
lower right graph shows the envelope power in red. The maximum envelope power, called PEP, is an
important parameter used to characterize the output power of a modulated signal.

Amplitude modulated signal

5
4
3
2
1
Voltage (V)

0
-1
-2
-3
-4
-5
0 .0001 0.0002 0.0003 0.0004 0.0005 0.0006

Amplitude modulated signal power Amplitude modulated signal power

0.45 0.45

0.4 0.4
0.35 0.35
0.3 0.3
Power (W)

0.25 0.25
0.2 0.2
0.15 0.15 Penv:
Pave: average power envelope
0.1 0.1
Pi: instantaneous power power
0.05 0.05
0 0
0 .0001 0.0002 0.0003 0.0004 0.0005 0.0006 0 .0001 0.0002 0.0003 0.0004 0.0005 0.0006
Time (s)
Time (s)

Figure 2-3. Voltage envelope and power envelope of a high-frequency modulated signal

The Essential Signal Generator Guide | 13

Understanding the power specifications

Regarding power specifications, many signal generators’ datasheets list the power output range,
resolution, and applicable frequency ranges. There are several points to be aware of:

• Frequency ranges and operating temperatures affect output amplitude.

• Options for higher output power needs are available.

• The step attenuator provides coarse power attenuation (in 5 dB steps) to achieve low power
levels. The automatic level control (ALC) in the attenuator hold range provides fine power-level
adjustment.

• Maximum output power generally applies to CW mode. Some datasheets list the maximum
output power for IQ modulation. The power specification for the Keysight CXG / EXG / MXG
signal generators refers to PEP.

Tip: Impedance match is important because a mismatch between the source and the
load impedance changes the effective signal input level to the DUT. If the mismatch is not
distinguished from the measurement result, it appears as degraded DUT performance.

The Keysight N5186A MXG signal generator features an embedded reflectometer built for convenient
match-corrected signal generation. It enables in situ generation of a match-corrected signal incident
to the current load with a single press of a button. Learn more about the benefits of match-corrected
measurements in this application note.

The Essential Signal Generator Guide | 14

Table 2.1. Amplitude specifications of Keysight CXG signal generator

Output parameters

Settable range +30 to –144 dBm

Resolution 0.01 dB

Step attenuator 0 to 130 dB in 5 dB steps electronic type

Connector Type N 50 Ω, nominal

Max output power 1 ( ) = typical

Frequency Standard

9 kHz to 10 MHz +13 dBm

> 10 MHz to 3 GHz +18 dBm

> 3 to 5 GHz +16 dBm

> 5 to 6.0 GHz +16 dBm

1. Quoted specifications between 20 °C and 30 °C. Maximum output power typically decreases by 0.01 dB / °C for
temperatures outside this range.

Why use decibels (dB) and decibel milliwatts (dBm)? They make expressing very
large or very small values more convenient. Using decibels also enables you to easily
calculate total system gain or loss. You just need to add for gain and subtract for loss.

The Essential Signal Generator Guide | 15

Characterize modulation signals

Many of the digitally modulated signals appear noise-like in the time and frequency domains, with
seemingly random peaks. How do you ensure that you are not driving your signal generator to
saturation during these peaks? The power complementary cumulative distribution function (CCDF)
curves tell us how high these peaks will go.

Figure 2-4 shows a CCDF curve with the highest peak-to-average ratio at 5.67 dB. In this example, the
maximum output power of the signal generator is 18 dBm, so the maximum power output you can
set your signal generator to is 12.33 dBm (18 dBm – 5.67 dB). Remember that the signal generator’s
power output is the average power output. Setting your signal generator’s output higher than 12.33
dBm leads to clipped peaks.

Looking for some tips on high-power applications? Get them here.

Figure 2-4. CCDF plot from Keysight E7608APPC PathWave Signal Generation for custom modulation

The Essential Signal Generator Guide | 16

Measurement applications

If you need to go beyond the specified output power range, you can use an amplifier to increase
the output power or an attenuator to decrease it. However, you need to take the amplifier’s gain
uncertainty and the attenuator’s flatness and accuracy into consideration. Here are some test
applications for high and low output power.

High-output-power test applications

• Overcome switching losses in automated test equipment (ATE) systems.

• Address the attenuation of signals in long cable runs.

• Conduct over-the-air tests.

• Test high-power amplifiers.

• Perform receiver blocking tests.

Low-output-power test applications

• Perform receiver sensitivity measurements.

• Measure interference signals.

The Essential Signal Generator Guide | 17

Section 3. Accuracy
People often confuse accuracy with precision. The accuracy of a signal generator measures
how close its output value is to the set value. Precision measures the degree to which the signal
generator’s output fluctuates. A high-precision generator has a stable output with little variation.
However, a high-precision generator may not necessarily have an accurate output. Figure 3-1 shows
the distinction between accuracy and precision.

Set
Value
Accuracy
Probability

value
Precision

Figure 3-1. Accuracy versus precision

Why accuracy matters

In research and development, you characterize your designs with high-accuracy measurement
instruments to ensure errors are from your DUT, not the instruments. In manufacturing, you test the RF
receiver to ensure that it meets specifications. However, you also want to be sure that you are not rejecting
perfectly good units. You can improve yield and product quality by improving the test accuracy.

Key accuracy specifications

There are two key accuracy specifications: amplitude accuracy and frequency accuracy. How much
accuracy you need depends on your application. If you are testing a wireless receiver’s sensitivity
with ± 4 dB accuracy, you need to use a source with ± 1 dB amplitude accuracy to achieve a test
accuracy ratio of 4.

The Essential Signal Generator Guide | 18

Amplitude accuracy

Amplitude accuracy tells you how close your signal generator’s output amplitude is to the set
amplitude. It is important to check the amplitude accuracy for the frequency and temperature range
of interest because a signal generator’s output accuracy degrades with temperature and at higher
frequencies. For example, the Keysight N5182B MXG signal generator’s absolute level accuracy
degrades by 0.01 dB / °C when the ambient temperature is outside the 20 °C to 30 °C range. Table
3-1 shows the amplitude accuracy specification of the Keysight N5166B CXG signal generator.

Download the white paper and learn how to improve amplitude accuracy with next-
generation signal generators.

Table 3.1. Accuracy specification of the Keysight N5166B CXG signal generator

Absolute level accuracy in CW mode (ALC on) ( ) = typical

Range Max power to -60 dBm < -60 to -110 dBm

9 to 100 kHz (± 0.6 dB) (± 0.9 dB)

100 kHz to 5 MHz ± 0.8 dB (± 0.3) ± 0.9 dB (± 0.3)

> 5 MHz to 3 GHz ± 0.6 dB (± 0.3) ± 0.8 dB (± 0.3)

> 3 to 6 GHz ± 0.6 dB (± 0.3) ± 1.1 dB (± 0.3)

Absolute level accuracy in CW mode (ALC off, power search run, relative to ALC on)

9 kHz to 6 GHz (± 0.15 dB)

(ALC on, relative to CW, W-CDMA 1 DPCH configuration < +10 dBm)

5 MHz to 6 GHz ± 0.25 dB (± 0.05)

The Essential Signal Generator Guide | 19

Amplitude flatness

Frequency sweeps can test the performance of filters and power amplifiers. Amplitude accuracy
affects the frequency-sweeping capability of a signal generator. The less the amplitude changes from
one frequency to another, the flatter the output. The change in amplitude when moving from one
frequency to another is known as flatness. While closely related to amplitude accuracy, the flatness
specification is tighter than the amplitude accuracy and usually referenced to the amplitude of the
starting frequency. Figure 3-2 illustrates this difference.

Frequency sweep - amplitude

Amplitude
accuracy spec
Output amplitude

Flatness spec

f1 Frequency f2

Figure 3-2. Comparison of amplitude accuracy and flatness

Improve accuracy to improve yield

Receiver sensitivity testing requires sources with accurate output power. This testing determines
whether a receiver can detect weak signals above a specified power level. For example, a 4G mobile
phone receiver has a specified sensitivity level of -110 dBm. If the receiver sensitivity test fails to
detect signals with a power level of 110 dBm or more, it will reject the DUT.

To illustrate the effects of poor accuracy on test yield, let’s use the 4G receiver example. Consider a
signal generator with an amplitude accuracy of ± 5 dB. To avoid overacceptances (or false positives),
the signal generator is set up to output -115 dBm. At -115 dBm, the signal generator’s output power
varies from -110 dBm to -120 dBm. As you can see in Figure 3-3, using this signal generator would
cause you to inadvertently reject four perfectly good receivers with borderline performance.

The Essential Signal Generator Guide | 20

  = Failed unit  = Failed unit
 = Passed unit  = Passed unit
Power out

Power out
 -110 dB specification  -110 dB specification
 Set source to -110 dBm 
      Actual output power= -114 dBm
 
Set source to -115 dBm
Frequency Frequency
Ideal signal generator Signal generator with ±5 dB
amplitude accuracy

Figure 3-3. Effects of poor amplitude accuracy on test yield

You can improve test yield by using a more accurate signal generator. Figure 3-4 shows the same
test using a signal generator with an amplitude accuracy specification of ± 1 dBm. Four of the same
six receivers tested earlier now pass the sensitivity test. We reduced false rejects by 75% just by
using a more accurate signal generator.

A more accurate signal generator may cost more. However, in the long run, the improved yield will
return the investment’s cost many times over.

 = Failed unit  = Failed unit

 = Passed unit  = Passed unit

 -110 dB specification  -110 dB specification

Power out

Power out

 Set source to -111 dBm


Actual output power = -112 dBm
 Actual output power = -114 dBm   
 Set source to -115 dBm 

Frequency Frequency
Signal generator with ±5 dB Signal generator with ±1 dB
amplitude accuracy amplitude accuracy

Figure 3-4. Effects of improved amplitude accuracy on test yield

The Essential Signal Generator Guide | 21

Frequency accuracy

Two main factors affect the frequency accuracy of a signal generator: the stability of the reference
oscillator and the amount of time that has passed since the signal generator underwent calibration.
Although temperature and line voltage also affect frequency stability, its effects are several orders of
magnitude less than the aging effect. Therefore, the key specification to look out for is the reference
oscillator aging rate.

A typical reference oscillator used in a signal generator has an aging rate of 0.152 ppm per year. A 10
GHz signal generator with this reference oscillator that has not undergone calibration for one year
will have a frequency accuracy of ± 1.52 kHz. Here is the calculation:

Frequency accuracy (Hz) = output frequency (Hz) x aging rate (ppm / year) x time since
last calibration = 10 GHz x 0.152 ppm / year x 1 (year) = 1.52 kHz

Table 3.2. Frequency reference of the Keysight N5172B EXG signal generator

Frequency reference

Accuracy ± (time since last adjustment x aging rate)

± temperature effects

± line voltage effects

± calibration accuracy

Internal time base reference oscillator aging rate 1 ≤ ± 5 ppm / 10 yrs, < ± 1 ppm / yr

Initial achievable calibration accuracy ± 4 x 10-8 or ± 40 ppb

Adjustment resolution < 1 x 10-10

Temperature effects ± 1 ppm (0 to 55 °C), nominal

Line voltage effects ± 0.1 ppm, nominal; 5% to 10%, nominal

1. Not verified by the Keysight N7800A TME calibration and adjustment software. Daily aging rate is available as a
supplementary service.

The Essential Signal Generator Guide | 22

Section 4. Speed
Reducing test time can reduce costs. So, the speed of your signal generator influences the cost
of test. A fast signal generator enables you to quickly switch from one frequency, amplitude, or
waveform to another. Speed specifications are in milliseconds. Table 4-1 shows the frequency
switching speed specification for the N5182B MXG signal generator.

Tip: Improve waveform switching speed by using the list / step sweep mode to preload
the waveforms into the nonvolatile memory.

Table 4.1. Switching speed specification of the Keysight N5182B MXG signal generator

Frequency switching speed 1, 2

Standard Option UNZ 3 Option UNZ, typical

CW mode ≤ 5 ms, typical ≤ 1.15 ms ≤ 950 µs

SCPI mode ≤ 5 ms, typical ≤ 900 µs ≤ 800 µs

Digital modulation on (N5182B only)

Standard Option UNZ 3 Option UNZ, typical

CW mode ≤ 5 ms, typical ≤ 1.15 ms ≤ 950 µs

List / step sweep mode ≤ 5 ms, typical ≤ 900 µs ≤ 800 µs

1. Time from receipt of SCPI command or trigger signal to within 0.1 ppm of final frequency or within 100 Hz, whichever is
greater.
2. With internal channel corrections on, the frequency switching speed is < 1.3 ms, measured for list mode and SCPI mode
cached frequency points. For the initial frequency point in SCPI mode, the time is < 3.3 ms, measured. The instrument
automatically caches the most recently used 1,024 frequencies. There is no speed degradation for amplitude-only changes.
3. Specifications apply when status register updates are off. For export-control purposes, CW switching speed calculations
are within 0.05% of the final frequency is 190 µs (measured).

The Essential Signal Generator Guide | 23

Factors affecting speed

The type of change and the source of commands affect switching speed. The time documented
in the specification indicates how long it takes for the signal generator’s output to stabilize once a
command is sent. Typical switching times can be up to 40% faster than speed specifications, which
are worst-case scenarios.

When you set the signal generator to a new frequency, the frequency synthesizer changes its output
to the desired frequency. The output amplifier then adjusts the power level so that the output power
stays the same at the new frequency. Essentially, frequency switching requires changes to both the
frequency synthesizer and the output amplifier, which is why frequency switching is often slower
than amplitude switching. During switching, command processing takes up the most time. Figure 4-1
shows each step to process a SCPI command request.

Figure 4-1. SCPI command processing time in a signal generator

The Essential Signal Generator Guide | 24

Faster switching speed

Using Step or List commands can improve a signal generator’s output in automatic test systems.
Typically, an operator sends commands to a signal generator to set frequency, amplitude, and
waveform when these states are not initially known. Using Standard Commands for Programmable
Instruments (SCPI) involves overhead time for sending, parsing, and processing commands before
switching can begin.

If the frequency, amplitude, and waveform combination is known in advance, using a step or list
sweep significantly improves speed. The signal generator can then sequence through the states in
rapid succession. Typical switching time in sweep mode is 600 µs to 800 µs compared to 2 ms in
SCPI mode.

Some signal generators offer high-speed switching options. The N5182B MXG signal generator, for
example, has a UNZ option that offers submillisecond switching speeds, perfect for high-volume
production. Keysight’s baseband tuning technology enables fast frequency and amplitude switching
speeds in list mode.

The Essential Signal Generator Guide | 25

Where switching speed matters

Wireless manufacturing

Test throughput is everything in manufacturing. Reducing test time leads to lower test costs. Using a
fast signal generator can help with higher bandwidth and advanced features in the latest chipsets.

Device characterization

Adding integrated functions in wireless systems impacts test demands and test costs. Introducing
communications standards, frequency bands, and multi-antenna techniques increases the device’s
complexity. This method requires switching frequencies for multiple bands, waveforms for multiple
formats, and amplitude levels to characterize the device’s performance.

Electronic warfare simulation

To simulate complex EW scenarios, you need a signal generator with capabilities such as fast
switching, phase repeatability, and pulse modulation. This process requires direct digital synthesis
technology to control frequency and phase and an agile attenuator to adjust amplitude levels.

The Essential Signal Generator Guide | 26

Summary
Wireless devices are incorporating more and
more functionalities, requiring more tests with
more setups under more conditions. They
include multiple standards, frequency bands, and
antennas, significantly increasing the challenges in
verification and production testing. Test engineers
are constantly looking for ways to improve test
throughput and cost. When equipped with the fast
switching capability, these signal generators can
switch frequency, amplitude, or waveform in less
than 1 ms in most cases.

End of Part 1
We have reached the end of Part 1 of our two-part white paper. We hope you have a better
understanding of the fundamental specifications of signal generators. In Part 2, we discuss more
advanced topics, such as modulation, spectral purity, distortions, and software.

Learn about the various types of modulation schemes and gain a more in-depth understanding of
harmonics and spurs. We share why distortions are not always bad and how you can improve your
productivity with the latest software. To stay updated with the most recent tutorials, techniques,
and best practices, check out Keysight Signal Generators and Sources online and follow the
Keysight RF Test and Measurement Facebook page and the Keysight RF & Microwave Instruments &
Measurements LinkedIn page.

Keysight enables innovators to push the boundaries of engineering by quickly

solving design, emulation, and test challenges to create the best product
experiences. Start your innovation journey at www.keysight.com.

This information is subject to change without notice. © Keysight Technologies, 2019 - 2024,
Published in USA, August 30, 2024, 5992-3253EN