Signal Generator Guide: What Is It and How to Use It Properly

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Are you tired of wrestling with unreliable signal generators that fail to meet your expectations? You're not alone. Many engineers face the frustrating challenge of finding a signal generator that delivers accurate results while still being easy to use.

But what if we told you there's a way to overcome these obstacles and master the art of signal generation?

This guide will unveil the secrets behind selecting the perfect signal generator, setting it up correctly, and using it effectively to ensure precise and dependable measurements every time.

Say goodbye to guesswork and hello to confidence as we take you on a journey through the world of signal generators. Keep reading to unlock your full potential as an engineer and make your projects shine.

What Is a Signal Generator?

A signal generator is an electronic device that generates repeating or non-repeating waveforms used to test and evaluate electronic test equipment. It simulates real-world signals and conditions, enabling you to test the performance and behavior of electronic systems.

They come in a variety of shapes and sizes, from handheld devices with basic waveforms to sophisticated benchtop models capable of generating complex signals over a wide frequency range.

Signal generators are essential for testing circuits, verifying designs, troubleshooting equipment, characterizing components, and more.

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How Does a Signal Generator Work?

A signal generator has several key components, including an oscillator, modulator, amplifier, and output stage. The signal generation process starts with the oscillator, whichgenerates a stable and repetitive waveform, such as a sine wave.

Typical block diagram of a signal generator — Simplified block diagram of a signal generator – Source: Keysight

The waveform passes through the modulator, which shapes the waveform into the desired signal type, such as a square wave or triangle wave. It adds any modulation, such as amplitude, frequency, or phase modulation. It then amplifies the output signal to the desired level and sends it to the DUT (device under test).

A signal generator can generate various waveforms, including sine, square, triangle, sawtooth, and arbitrary. Sine wave signals are commonly used for testing and evaluating audio systems, while square and triangle signals test digital circuits. Sawtooth and arbitrary signals test various electronic systems, as they can simulate real-world signals and conditions.

Types of Signal Generators

Signal generators come in various forms with unique features, advantages, and limitations. Understanding these differences can help you choose the right signal generator for your specific needs.

Function Generators

A function generator is a versatile type of signal generator that produces standard waveforms such as sine, square, triangle, and sawtooth waves. It allows you to adjust various parameters, including amplitude, frequency, and duty cycle, to meet specific testing requirements.

Function generators offer several advantages, such as

Simplicity of operation
A wide range of frequency capabilities
Flexibility to work with multiple waveform types

These features make them suitable for various applications, including testing filters, amplifiers, and oscillators and characterizing the frequency response of circuits.

Function generators also have some limitations. They may not offer the highest precision or the ability to generate complex, user-defined waveforms. Additionally, they might not support advanced modulation schemes, limiting their usefulness in certain applications.

Used function generators are an affordable option if you want to save on costs while getting reliable test results. Used and premium used models from reputable manufacturers like Keysight can deliver excellent performance and quality at a fraction of the price of new equipment, making them an attractive choice for budget-conscious engineers!

A function noise generator — A Keysight 81160A-002 pulse function arbitrary noise generator- Source: Keysight

Arbitrary Waveform Generators

Arbitrary waveform generators (AWGs) are advanced signal generators that allow you to create and output complex, user-defined waveforms with high precision and accuracy.

These devices offer greater flexibility compared to traditional function generators, enabling the generation of arbitrary waveforms, including those with intricate shapes, varying amplitudes, and irregular timing.

The advantages of using AWGs include

The ability to produce custom waveforms for specific applications
Higher precision and accuracy
Support for advanced modulation schemes

Typical uses for AWGs involve simulating real-world electronic signals, such as those found in communication systems, sensors, and control systems. They are also valuable in applications requiring the generation of non-standard or mathematically defined waveforms.

However, AWGs have limitations, such as a generally higher cost than function generators and a potentially narrower frequency range. Additionally, they may have a steeper learning curve due to their advanced features and software requirements.

High-end AWGs from many manufacturers can be expensive and have long wait times for shipping. However, used and premium used models from Keysight offer a more budget-friendly alternative with fast shipping, and you don't sacrifice quality or performance in the process.

An arbitrary waveform generator — A Keysight M8199A arbitrary waveform generator – Source: Keysight

Pulse Generators

Pulse generators are specialized signal generators designed to produce precisely timed, repeating pulses with adjustable parameters such as pulse width, repetition rate, and amplitude. These devices are essential for applications requiring the generation of digital signals, trigger signals, or precise timing events.

The advantages of using pulse generators include their ability to produce clean, sharp-edged pulses with high timing accuracy and the flexibility to adjust key pulse parameters to meet specific requirements. Pulse generators are commonly used to test and characterize digital circuits, clock and timing systems, and components such as counters, shift registers, and flip-flops.

Pulse generators also have limitations, including a restricted frequency range compared to other signal generator types and the inability to produce analog or complex waveforms. They may also be less versatile in terms of modulation capabilities.

Since pulse generators are used in more specialized applications, they can be costly when looking to purchase. Used and premium used Keysight pulse generators offer an excellent solution for those looking to save on costs.

Used models are often significantly cheaper than their brand-new counterparts. Some used pulse generators offer up to 60% off, a significant advantage for anyone with limited funds.

A pulse generator — A Keysight 81134A Pulse Pattern Generator – Source: Keysight

RF Signal Generators

A radio frequency (RF) generator generates high-frequency signals in the radio frequency spectrum, typically ranging from a few kilohertz to several gigahertz. These generators are crucial for various applications in wireless communication systems, RF component testing, and electromagnetic compatibility (EMC) testing.

The advantages of using RF signal generators include

The ability to generate high-frequency signals
A wide range of modulation options
Support for multiple wireless communication standards

RF signal generators are typically used in testing and characterizing RF components such as filters, amplifiers, and antennas, as well as simulating wireless signals for receiver testing and system calibration.

RF signal generators also come with some limitations, including a potentially narrower frequency range compared to other types of signal generators, the need for external modulation sources for some models, and variations in output power capabilities. They may also be more expensive than other types of signal generators due to their specialized functions.

Buying a used RF signal generator through Keysight helps you save on costs, and since they come with a warranty, you get the peace of mind that you are getting a quality product.

A radio frequency signal generator — A Keysight N5166B CXG X-Series RF signal generator – Source: Keysight

Vector Signal Generators

Vector signal generators (VSGs) are advanced signal generators capable of producing complex modulated signals used in modern wireless communication standards, such as 5G, 4G LTE, and Wi-Fi.

These devices generate signals that can closely emulate real-world communication system conditions, making them essential for designing, testing, and validating modern wireless devices and systems.

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The advantages of using VSGs include

The ability to generate complex, digitally modulated signals with high accuracy and precision
Support for a wide range of wireless communication standards
Flexibility to adapt to new and emerging technologies

A vector signal generator is used in testing and validating wireless devices, such as smartphones, base stations, and IoT devices, as well as evaluating the performance of communication systems under various conditions. They are also used to develop adaptive radio frequency (RF) systems and cognitive radio applications.

VSGs come with some limitations, including potentially higher costs than other types of signal generators, wider bandwidths for higher-end models, and more complex user interfaces compared to other types of signal generators.

Features of Signal Generators

Signal generators are versatile tools with various essential features that engineers can use to produce different signals. Understanding these features can help you make the most of your signal generator and ensure accurate application results. Here, we'll discuss the key features, including frequency range, waveform type, amplitude, and modulation.

The frequency range of a signal generator determines the span of frequencies it can generate, from the lowest to the highest. Different applications require specific frequency ranges, so selecting a signal generator that covers the frequencies needed for your project is crucial. The frequency range also affects the signal generator's ability to work with various components, such as filters, oscillators, and antennas.
The waveform type refers to the shape of the signal the device generates. Common types of waveforms include sine, square, triangular, and custom or arbitrary waveforms. Different waveforms are suitable for various applications, and the choice of a waveform can impact the performance of the circuits and systems you're testing.
Amplitude is the measure of a signal's strength or voltage level. Adjustable amplitude allows engineers to simulate various signal conditions and test the performance of devices and systems under different voltage levels. Accurate amplitude control is essential for obtaining precise test results and ensuring the proper operation of electronic components.
Modulation is modifying a signal's properties, such as frequency, amplitude, or phase, to encode information. Signal generators often include modulation capabilities, enabling the generation of modulated signals used in communication systems, radar applications, and other advanced testing scenarios. The type and quality of modulation can significantly impact the performance of the devices and systems under test.

By understanding and properly utilizing these key features, you can generate signals that accurately represent the conditions you need to simulate, ensuring reliable and precise results in your testing and development processes

Setting Up Your Signal Generator

Setting up a signal generator is crucial for obtaining accurate and reliable measurements in your testing and development processes. A well-configured signal generator ensures that the generated signals meet the desired parameters and specifications, allowing you to effectively simulate the required conditions for your project.

This section will cover the essential steps and considerations for setting up your signal generator, helping you achieve the best results in your testing and development activities.

Choosing the Right Signal Generator

Selecting the right signal generator is important for achieving accurate and reliable test results. Plus, they are a considerable investment, so it pays to choose carefully. To make the best decision, consider the following factors while considering your specific project requirements.

Required frequency range. Determine the frequency range needed for your project. Ensure that the signal generator you choose can cover the full range of frequencies you intend to work with, from the lowest to the highest.
Waveform types. Identify the type of waveform necessary for your project, such as sine, square, triangular, or custom waveforms. Make sure the signal generator supports the generation of these waveforms.
Output power. Consider the output power requirements for your testing needs. The signal generator should be capable of providing the desired output levels without distortion or excessive noise.
Modulation capabilities. If your project involves modulated signals, ensure that the signal generator offers the required modulation types, such as amplitude, frequency, or phase modulation.

To prioritize features based on your project requirements, identify the most critical aspects of your testing needs, and focus on the signal generator specifications that directly impact those aspects. This tip will help you balance the cost and performance of the equipment.

When comparing different models and brands of signal generators, consider cost, performance, and reliability. Evaluate each option based on its ability to meet your project requirements while staying within your budget. Read reviews, consult peers, or get advice from experts to gather insights into the performance and reliability of various models.

Essential Accessories

You will need to choose the right accessories to maximize the performance and get the most out of your signal generator. Here's a list of essential accessories to use with your signal generator.

High-quality cables and connectors are critical for maintaining signal integrity and minimizing signal loss or distortion. Choose cables with appropriate impedance and shielding properties to match your signal generator's specifications. Also, ensure that connectors are compatible and provide a secure connection.
Attenuators are essential to reduce the signal amplitude without altering other characteristics, such as frequency or waveform shape. They help protect sensitive devices under test from excessive signal levels and prevent distortion or damage.
An oscilloscope is an indispensable tool for visualizing and analyzing the signals generated by your signal generator. It allows you to verify the waveform shape, frequency, amplitude, and other parameters, ensuring that the generated signals meet your project requirements.
A frequency counter is a useful accessory for measuring the frequency of the generated signals with high accuracy. It helps verify that the signal generator operates within the specified tolerances and provides additional confidence in your measurements.
A stable and reliable power supply is essential for maintaining consistent performance from your signal generator. Ensure your power supply can deliver your equipment's required voltage and current levels without introducing unwanted noise or fluctuations.

Each of these accessories is vital to your signal generator setup's overall functionality and effectiveness. Investing in the right accessories ensures accurate, reliable, and efficient testing and measurement processes!

Safety Precautions

When working with electronic equipment like signal generators, following general safety precautions to protect the equipment and yourself is best. Here are some key safety measures to keep in mind.

Wear personal protective equipment (PPE). Wearing appropriate PPE, such as safety glasses, gloves, and closed-toe shoes, can help protect you from potential injuries while working with electronic devices.
Avoid live circuits. Always ensure that the equipment is powered off and disconnected from the power source before making any adjustments or modifications. This step reduces the risk of electrical shock and potential damage to the device.
Maintain a clean workspace. A clutter-free workspace minimizes the chances of accidents, such as tripping over cables or knocking over equipment. Keep your work area clean and organized to promote a safe working environment.
Proper earth grounding. Ensuring that your signal generator and other equipment are correctly grounded prevents electrical damage and protects you from electrical hazards. Grounding helps dissipate any excess electrical energy, reducing the risk of electrical shock and ensuring the stability of your measurements.

By closely following these safety precautions, you will create a safer work environment while minimizing the risk of damage to your signal generator and other equipment. Always prioritize safety when working with electronic devices to ensure accurate and reliable results without putting yourself at risk.

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Using Your Signal Generator

Effectively using your signal generator is a primary way to make sure you get accurate test results. A thorough understanding of the device's capabilities, features, and limitations is vital to maximizing its potential in your projects.

By learning how to operate your signal generator and configure its various settings, you will ensure that it works as intended and produces accurate results.

Basic Operations

Operating a signal generator involves several fundamental steps, which we will outline below. Following these simple instructions, you can easily set up your signal generator and generate the desired signals for your specific applications.

Powering on and off. To power up the signal generator, connect it to a power source and press the power button located on the front panel. Once you have completed your testing, press the power button again to turn off the device.
Adjusting frequency and amplitude settings. Locate the frequency control knob or keypad on the front panel to set the output frequency. Turn the knob or input the desired frequency value using the keypad. Similarly, you can adjust the amplitude of the output signal by turning the amplitude control knob or inputting the desired amplitude value using the keypad.
Selecting waveform types. Signal generators offer various waveform types. Press the corresponding button on the front panel to select the desired waveform or navigate to the waveform selection menu using the device's user interface.

Familiarizing yourself with these fundamental steps will help you take full advantage of your signal generator's capabilities and ensure accurate and reliable project results.

Advanced Features

Signal generators also have more advanced features, allowing greater precision in testing and measurement applications. Here's a brief overview of some key advanced features and how to access and use them.

Many signal generators support various modulation types, such as amplitude modulation (AM), frequency modulation (FM), and phase modulation (PM). To access these features, locate the modulation menu on the front panel or device interface, and select the desired modulation type. Adjust the modulation depth, rate, or deviation according to your requirements.
Arbitrary waveform generators (AWGs) enable the creation of user-defined waveforms for more complex testing scenarios. To generate an arbitrary waveform, use the device's dedicated software to design the custom waveform or import a pre-existing waveform file. Upload the waveform to the AWG, and configure the output settings as needed.
Frequency sweeping helps characterize frequency-dependent components or systems, such as filters and amplifiers. To perform a frequency sweep, access the sweep menu on the device interface or front panel, and set the start and stop frequencies, sweep time, and type (linear or logarithmic). Initiate the sweep, and monitor the response of the component or system under test using an oscilloscope or spectrum analyzer.

Real-World Applications

Everything we have spoken about so far is more than just theory. Signal generators play an important role in real-world engineering applications, enabling engineers to perform various tasks such as troubleshooting circuits, simulating sensor signals, and testing filters and amplifiers. Here are some examples of how signal generators are used in these scenarios.

Troubleshooting circuits. You can use signal generators to inject known signals into a circuit, allowing them to identify faulty components or connections. By using both basic and advanced features, such as frequency sweeping and modulation, you can effectively analyze and diagnose issues within the circuit.
Simulating sensor signals. Signal generators can replicate the output of various sensors, such as temperature, pressure, or acceleration sensors, to validate and test the performance of sensor-based systems. By using arbitrary waveform generators to produce complex, user-defined waveforms, you can accurately simulate a wide range of sensor outputs.
Testing filters and amplifiers. Signal generators are great for characterizing the performance of filters and amplifiers across a range of frequencies. You can evaluate these components' frequency response, gain, and linearity using frequency sweeps and various waveform types.

Tips and Tricks

Optimizing signal generator performance and maintaining the equipment is crucial for ensuring the quality of your measurements. The following tips and tricks can help you achieve maximum efficiency, accuracy, and reliability in testing and troubleshooting.

Optimizing Signal Generator Performance

To reduce phase noise and improve output accuracy, follow these practical tips to increase your signal generator's performance.

Always select quality, shielded cables to ensure minimal signal loss and reduce interference chances. Remember to inspect and replace them as needed.
A good grounding setup minimizes the risk of electrical noise and enhances the stability of your measurements. Check for secure connections and ground your equipment according to the manufacturer's guidelines.
To minimize environmental interference, keep your signal generator away from sources of electromagnetic interference, such as power supplies, transformers, and other electronic devices. Also, maintain a stable temperature to prevent thermal drift in your measurements.

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Signal Generator Maintenance

If you want your signal generator to keep operating as it should, you must maintain it, whether a new or used device. Here are some key steps to keep your equipment in excellent condition.

Regularly clean the signal generator and its accessories to prevent dust and debris buildup. Inspect cables, connectors, and other components for signs of wear or damage, replacing them when they show signs of wear.
Periodic calibration ensures the accuracy and consistency of your measurements. Follow the manufacturer's guidelines regarding calibration intervals, and use only qualified calibration services to guarantee reliable results.
For more complex issues or when in doubt, consult professional repair services to diagnose and fix any problems. Experienced technicians have the necessary tools and knowledge to address various issues.

Remember, regular maintenance is crucial for new and used signal generators, ensuring they perform at their best throughout their lifespan. One way to achieve this is through Keysight Care, a comprehensive support plan designed to help you get the best performance from your Keysight equipment.

To learn more about Keysight Care or to discuss your specific needs, talk to your account manager or call our support team at 1 800 829-4444.

The Importance of Signal Generator Accuracy and Precision in Test and Measurement

Accuracy and precision are paramount in test and measurement applications, as they play a critical role in ensuring the validity and reliability of your results. Using a signal generator with low accuracy or precision can lead to incorrect conclusions, poor design decisions, and even product failures.

That's why investing in a high-quality signal generator that delivers accurate and precise signals is essential.

When evaluating the accuracy and precision of a signal generator, consider the following factors.

The stability of the generated frequency over time is crucial, as it determines the consistency of your measurements. Look for signal generators with low drift and excellent short-term stability.
Accurate amplitude settings are essential for consistent output levels. Review the signal generator's specifications for amplitude accuracy, which should be within acceptable limits for your application.
Low-phase noise is crucial for applications involving high-quality signals, such as communication systems and radar. Examine the signal generator's phase noise performance to ensure it meets your requirements.

Keysight signal generators are designed with these factors in mind, offering exceptional accuracy and precision to help you achieve the best possible test results. Their advanced technology, such as high-performance oscillators, digital modulation techniques, and low-noise amplifiers, enable them to produce highly accurate and precise signals.

Investing in a high-quality signal generator like those offered by Keysight will ensure that your test and measurement applications are as accurate and precise as possible!

Frequently Asked Questions (FAQs)

Are there any benefits to purchasing used signal generators?
Yes, purchasing used signal generators can save you money without sacrificing quality. As long as the equipment is maintained correctly, used signal generators can provide reliable and accurate results.

What should I look for when buying a used signal generator?
When buying a used signal generator, consider its overall condition, calibration status, and maintenance history. Also, ensure it has the required frequency range, waveform types, and modulation capabilities for your needs.

How do I ensure the quality of a used signal generator?
To ensure the quality of a used signal generator, purchase from a reputable seller, verify its performance and accuracy and check if it has been calibrated recently. Regular maintenance and proper care are essential to maintain the quality of the equipment.

Can I use a signal generator to test speakers?
Yes, signal generators can test speakers by generating audio signals. You can analyze the speakers' responses to various frequencies and determine their performance characteristics.

What is the difference between a signal generator and an oscilloscope?
A signal generator produces electrical signals with various waveform types, frequencies, and amplitudes. An oscilloscope is an instrument used to visualize and analyze electrical signals, allowing you to measure and observe their characteristics.

How do I choose the right cable for my signal generator?
Choose cables with low attenuation, proper impedance matching, and quality connectors compatible with your signal generator and the device under test. High-quality cables are essential for minimizing signal loss and preserving signal integrity.

Can I create my own custom waveforms with a signal generator?
Yes, with an arbitrary waveform generator (AWG), you can create custom waveforms by defining each sample point's shape, amplitude, and duration. This feature is helpful in simulating complex signals in various applications.

What is the difference between a function generator and an arbitrary waveform generator?
A function generator produces standard waveforms, such as sine, square, and triangle waves, with adjustable frequency, amplitude, and other parameters. An arbitrary waveform generator (AWG) can create custom, user-defined waveforms with high precision and accuracy, allowing for more complex signal generation.

Buy a Premium Refurbished Keysight Signal Generator And Get it Shipped Fast/With 2 Weeks Shipping

As any engineer knows, a signal generator is an essential piece of equipment used to create signals of all shapes and sizes, making it an essential tool for testing and debugging circuits.

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Keysight premium used test equipment — Buying premium used equipment through Keysight is a great way to get a “like new” signal generator at a fraction of the cost – Source: Keysight

Closing Thoughts From Keysight

Signal generators play a crucial role in electronic testing in various industries. From sine and square signals to RF and vector signals, the right signal generator can greatly impact the success of an engineer's project.

Keysight's reliable signal generators offer a variety of features and capabilities, making them some of the best on the market. Whether you need a basic unit for simple tasks or an advanced model for sophisticated applications, our team of experts can help you find the perfect signal generator.

See Keysights Used Equipment to find the widest selection of discounted, high-quality signal generators to fit your needs.

Keysight Premium Used banner — Keysight Premium Used gives you peace of mind when purchasing – Source: Keysight

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