Real-time spectrum analyzer including frequency mask gate and method of operating the same

A method executed by a real-time spectrum analyzer for providing a density histogram of sampled time domain data from an input signal in real-time, the method comprising:

• providing a continuous gap-free stream of a plurality of fast Fourier transform (FFT) spectra obtained by performing FFTs on the sampled time domain data;
• selecting FFT spectra of the plurality of FFT spectra that contain at least one FFT point that meets at least one trigger condition;
• and
• generating a density histogram using the selected FFT spectra.

A method executed by a real-time spectrum analyzer for providing a density histogram of sampled time domain data in real-time, the method comprising:

• performing fast Fourier transforms (FFTs) on the sampled time domain data to obtain a corresponding plurality of FFT spectra, each FFT spectrum containing a plurality of FFT points;
• determining whether FFT points within each FFT spectrum meet at least one trigger condition using a frequency mask detector;
• generating a plurality of gate control signals corresponding to the plurality of FFT spectra based on the determinations;
• gating the plurality of FFT spectra using a frequency mask gate in response to the plurality of gate control signals, respectively, to provide only select FFT spectra respectively containing at least one FFT point meeting the at least one trigger condition;
• and
• displaying a density histogram based on the gated FFT spectra.