Why does the rise time of the eye pattern as seen on the WFM700M show some differences as compared to TDS794D eye pattern display?. The WFM700 has 2-3 cycles on ringing on the rising edge before reaching peak level+ while the TDS794D looks smooth.
There are a couple of factors that contribute most the differences in the way the rising edge of the eye pattern is displayed on the WFM700M and the TDS794D. The first factor is the bandwidth of these two instruments. The TDS794D has a bandwidth of of 2 GHz at -3dB point while the WFM700M has a bandwidth of 2.5 GHz at -3 dB point. As result of the greater bandwidth the WFM700M displays an eye pattern with a faster rise time that increases the ringing. The second factor is that the WFM700M has a 3-6% undershoot which tends to make the ringing look more pronounced while the TDS794D has a 5-8% overshoot that tends to smooth out the ringing.
常見問答集 ID 57971