A Dose of Reality

摘要

In my january column, I offered a puzzle. In the measured TDR response from a seven-segment, closely coupled 50 Ω serpentine microstrip, it looks like we see the reflections from the six pairs of corners. FIGURE 1 shows the serpentine and FIGURE 2 the measured TDR response. But, is this measured TDR response really an example of reflections from corners? I asked for possible alternative explanations from you, and I had more than 30 e-mail responses. Half of you wrote, "I always knew corners could cause reflections and now you've demonstrated it." The other half wrote, "I've always heard corners don't cause reflections -it's a myth, so something else is going on." First, let me make it perfectly clear: 1. Corners can, absolutely, cause reflections. 2. The TDR response from this serpentine has nothing at all to do with the corners.