Uploaded January 2025 | Updated September 2026, 2 weeks ago
Spectrum analyzers are one of the mainstays of RF design - they're essential for looking at RF and many other signals. These analyzers come in many shapes, sizes and formats.
But what do they really do?
We are all used to seeing how a varying voltage appears on an oscilloscope. Voltage is plotted on the vertical axis against time on the horizontal axis, so it's possible to see how the waveform varies over time, and we may see the familiar sine waves or other waveforms.
But spectrum analyzers are different. They plot amplitude on the vertical axis, but instead of time on the horizontal axis, it's frequency. It's a bit like tuning a radio over a certain band and noting the amplitude of the signals for each frequency.
Although there is some noise, we see the main signals rising above this - we see the noise because spectrum analyzers generally use a logarithmic amplitude scale.
More information can be found at: electronics-notes.com/articles/test-methods/spectrum-analyzer/spectrum-analyser-overview.php
Website homepage: electronics-notes.com
Please don't forget to subscribe to our YouTube channel: youtube.com/electronicsnotes?sub_confirmation=1
Spectrum analyzers are one of the mainstays of RF design - they're essential for looking at RF and many other signals. These analyzers come in many shapes, sizes and formats.
But what do they really do?
We are all used to seeing how a varying voltage appears on an oscilloscope. Voltage is plotted on the vertical axis against time on the horizontal axis, so it's possible to see how the waveform varies over time, and we may see the familiar sine waves or other waveforms.
But spectrum analyzers are different. They plot amplitude on the vertical axis, but instead of time on the horizontal axis, it's frequency. It's a bit like tuning a radio over a certain band and noting the amplitude of the signals for each frequency.
Although there is some noise, we see the main signals rising above this - we see the noise because spectrum analyzers generally use a logarithmic amplitude scale.
More information can be found at: electronics-notes.com/articles/test-methods/spectrum-analyzer/spectrum-analyser-overview.php
Website homepage: electronics-notes.com
Please don't forget to subscribe to our YouTube channel: youtube.com/electronicsnotes?sub_confirmation=1
