Application Note: A New Approach to Frequency Domain Analysis on Oscilloscopes

Traditional FFT workflows can make it hard to connect frequency-domain issues to time-domain events. Download the app note to see how Spectrum View helps debug clocks, EMI, PLL/VCO startup and RF-adjacent behavior faster to improve power supply stability measurements.
Sept. 16, 2026

Download the app note to learn why traditional oscilloscope FFT workflows can make it difficult to connect frequency-domain behavior to the exact time-domain event that caused it. The app note explains how Spectrum View uses patented hardware digital downconversion in Tektronix 4, 5 and 6 Series MSOs to provide synchronized waveform and spectrum views with independent controls. It also walks through examples showing how engineers can examine:

  • Spectrum Time and how spectral content changes across a captured acquisition 
  • RF vs. Time displays including magnitude, frequency, phase and spectrogram views 
  • Spread-spectrum clock startup, modulation activity and operating range 
  • PLL/VCO startup correlation with SPI commands, control signals and RF output stabilization 
  • Narrow-span, high-frequency analysis using hardware downconversion for improved frequency-domain resolution