Solve EMI problems in time and frequency domains using RTO digital oscilloscopes
RTO digital oscilloscopes can help development engineers analyze EMI problems in the time domain and frequency domain when designing electronics, and can help locate the causes of EMI. The RTO digital oscilloscope has extremely low input noise, and its sensitivity can reach 1mv/div within the full bandwidth range of 0-4GHz. RTO's real-time FFT spectrum analysis capability can be used with near-field probe analysis to diagnose EMI problems.
Fig: R&S RTO digital oscilloscope – low-noise front-end/high-performance FFT creates a powerful EMI diagnostic tool
The key to EMI diagnosis is FFT technology. With the FFT function of traditional oscilloscopes, it is difficult to set parameters in the frequency domain, and spectrum analysis takes a long time. Since the FFT operating interface of the R&S RTO oscilloscope is based on a spectrum analyzer, users can directly set parameters, including start frequency, cutoff frequency, bandwidth resolution and detector type, just like using a spectrum analyzer.
The powerful FFT technology combined with the large memory depth of the RTO oscilloscope allows users to independently set time domain and frequency domain parameters and flexibly conduct analysis in the time domain and frequency domain. These features allow users to detect sources of radiated interference as quickly as possible.
The R&S RTO oscilloscope uses Overlap FFT for frequency domain analysis. Overlapping FFT technology can achieve high sensitivity to spurious radiation and capture occasional spurious frequency points. The oscilloscope first divides the captured time domain signal into several time segments, and then performs FFT calculations to obtain the spectrum of each time segment, so that low-energy occasional spurious signals can be captured in the spectrum.
Then, signals with different frequencies are marked with different colors, and the FFT analysis spectrum of all time periods is combined into a complete spectrum.
Radiation and incidental radiation are marked with different colors. Spectrum analysis using different color marking techniques can perfectly demonstrate the type and frequency of EMI radiation.
Windowed FFT technology allows users to customize a time window on the captured signal, perform FFT analysis on only the signal within the time window, and analyze the corresponding relationship between each time domain signal and the spectrum by sliding this window. For example, this technique can be used to analyze EMI problems caused by transistor overshoot in switching power supplies. After confirming the problem point, the user can quickly verify the effect of the rectification.
Template tools are also very effective when analyzing stray radiation problems. Users define templates in the frequency domain and make corresponding settings for the violating signals, so that they can accurately determine which signals cause spectrum violations. Even for signals that have been captured, users can adjust FFT parameters, such as window size and frequency resolution. Such powerful functions allow users to conduct careful analysis of EMI radiation that is difficult to capture.
The R&S RTO oscilloscope sets a new benchmark for oscilloscopes with its rich acquisition and analysis features. At the same time, combined with a wide range of accessories, such as the R&S HZ-15 near-field probe, it provides a complete set of EMI diagnostic solutions.
