It is pure common sense. Everyone knows that Si RFIC inductor loss is mostly due to inductive coupling with the substrate. The current inductively coupled into the substrate will flow parallel to and in the opposite direction of the current flowing in the turns of the spiral inductor. In this presentation, we EM analyze and visualize this substrate induced current and find out that…we are totally, absolutely, and completely wrong! It turns out that understanding why common sense is so wrong is important in understanding how patterned ground shields increase the Q of an inductor, and why in some cases, they don’t work. Join us and realize an in depth understanding of exactly what is going on, and to view some amazing visualizations. You can also read previously published guest columns on the topic of patterned ground shields for silicon RFICs by clicking any of the links below.