What Is a Spectrum Analyzer? A Complete Guide - OneSDR

A spectrum analyzer is an essential tool used in radio frequency (RF) engineering, telecommunications, audio analysis, and electronic testing to measure and visualize signals across a range of frequencies.

🏷️ Spectrum Analyzers ⭐⭐⭐

It helps engineers and technicians analyze the strength, frequency, and quality of signals, making it a critical instrument for troubleshooting and optimizing electronic systems.

How Does a Spectrum Analyzer Work?

A spectrum analyzer works by capturing an input signal, breaking it down into its frequency components, and displaying the signal strength (amplitude) versus frequency. Unlike an oscilloscope, which shows signals over time, a spectrum analyzer visualizes signals in the frequency domain.

Key Functions of a Spectrum Analyzer

📊 Measures frequency components of a signal
💥 Identifies signal distortions, harmonics, and noise
⚡ Detects interference in communication systems
🛜 Analyzes RF transmissions from devices like WiFi, Bluetooth, and mobile phones
📡 Evaluates antenna and circuit performance

Siglent Spectrum Analyzer

Types of Spectrum Analyzers

Analog Spectrum Analyzers

Uses tunable filters and superheterodyne receivers to analyze signals.
Offers high accuracy but limited flexibility compared to digital models.
Mostly used in older RF measurement systems.

Analog Spectrum Analyzer made by Hewlett Packard

Digital Spectrum Analyzers

Uses Fast Fourier Transform (FFT) algorithms to analyze signals in real-time.
Allows for faster and more detailed frequency analysis.
Commonly used in modern RF and audio analysis applications.

Rigol Spectrum Analyzer

Real-Time Spectrum Analyzers

Continuously captures and processes signals without missing transient events.
Used for detecting fast or intermittent signals, such as WiFi and radar pulses.
Essential for security, military, and advanced RF testing.

Rigol Real Time Spectrum Analyzer

Portable and Handheld Spectrum Analyzers

Battery-operated and lightweight for field testing.
Used in RF interference detection, telecom maintenance, and spectrum monitoring.
Common brands include Keysight, Rohde & Schwarz, and Rigol.

TinySA Handheld Spectrum Analyzer

Common Applications of Spectrum Analyzers

✔ Radio Frequency (RF) Testing – Used to test WiFi, Bluetooth, cellular, and satellite signals.
✔ Audio Analysis – Helps measure sound frequencies and detect noise in audio systems.
✔ Wireless Network Optimization – Used by network engineers to analyze WiFi performance and detect interference.
✔ Antenna Testing – Ensures that antennas are operating at the correct frequencies.
✔ Electromagnetic Compatibility (EMC) Testing – Helps verify that electronic devices do not emit excessive RF interference.
✔ Security and Surveillance – Detects unauthorized transmissions and signal jamming.

How to Use a Spectrum Analyzer

Select the Frequency Range – Choose the range of frequencies you want to analyze.
Set the Resolution Bandwidth (RBW) – Adjust the RBW to balance frequency resolution and signal clarity.
Adjust the Sweep Time – A longer sweep time provides more detail, while a shorter sweep time gives a faster overview.
Analyze the Signal Peaks – Look for spikes or distortions that indicate signal strength and interference.
Use Markers and Traces – Identify specific frequency components within the signal.

Spectrum Analyzer vs. Oscilloscope

Feature	Spectrum Analyzer	Oscilloscope
Displays	Frequency vs. Amplitude	Time vs. Amplitude
Use Case	RF, audio, and signal analysis	Waveform analysis and troubleshooting
Ideal For	Wireless signals, interference detection	Measuring voltage, current, and time-domain signals

Popular Spectrum Analyzers

✔ Rigol DSA815-TG – Affordable and widely used for (benchtop) educational and RF projects.

✔ TinySA Handheld Spectrum Analyzer – Affordable and widely used for field work, portable R&D, education and professional applications.

✔ HackRF One (SDR) – A software-defined radio (SDR) that functions as a low-cost spectrum analyzer.

Final Thoughts

A spectrum analyzer is an invaluable tool for analyzing frequency signals, detecting interference, and optimizing communication systems.

Whether you’re working in RF engineering, audio processing, or telecommunications, understanding how to use a spectrum analyzer can greatly improve signal accuracy and system performance.