Y Units of spectrum analyzer

Hi, I'm using matlab 2011a (simulink). my model obtain the spectrum of an electric signal using the spectrum analyzer. I need to plot the spectrum in dB's. What is the amplitude units (y axis) that show this block (spectrum analyzer)?

Thanks, Néstor

Answer 1

[Shubham]

Hi Nestor,

In MATLAB 2011a, the Simulink Spectrum Analyzer block is part of the DSP System Toolbox, which allows you to visualize the frequency spectrum of signals. However, the specific features and settings available in MATLAB 2011a might differ slightly from newer versions. Here's how you can handle the amplitude units for the Spectrum Analyzer in your version:

Spectrum Analyzer Amplitude Units

1. Default Units: By default, the Spectrum Analyzer in MATLAB 2011a displays the amplitude in linear scale (often in volts or the same units as the input signal). To convert this to decibels (dB), you'll need to apply a manual conversion.
2. Converting to dB: If the Spectrum Analyzer does not have an option to display the amplitude in dB directly (as might be the case in older versions), you can convert the output manually using the formula:[ ]

Steps to Plot Spectrum in dB

To plot the spectrum in dB, you can follow these steps:

1. Use a block such as the "To Workspace" block to capture the output of the Spectrum Analyzer block.
2. After running your simulation, you can process the captured data in the MATLAB workspace to convert it to dB.
3. Use MATLAB plotting functions to display the spectrum in dB.