Frequency Response Analysis (FRA) a critical measurement used to characterize the frequency response (gain and phase versus frequency) of a variety of today’s electronic designs including passive filters, amplifier circuits and negative feedback networks of switch mode power supplies (loop response). Engineers typically use network analyzers or standalone low-frequency FRAs to perform these types of measurements, but for the first time in an oscilloscope, automatic frequency response analysis is now available in Keysight’s InfiniiVision 4000 X-Series oscilloscopes. This frequency-domain measurement capability is achieved with a swept gain and phase measurement versus frequency (Bode plot). The FRA software uses the oscilloscope’s built-in waveform generator (WaveGen) to stimulate the circuit under test at various frequency settings and captures the input and output signals using two oscilloscope channels. At each test frequency, the oscilloscope measures, computes and plots gain (20LogVout/Vin) and phase logarithmically. To learn more about frequency response testing using a Keysight InfiniiVision oscilloscope, download the DSOXT3FRA/DSOX4FRA/DSOX6FRA data sheet.