Unwanted levels of PIM can result from several different factors, including the amplitudes and frequencies of the multiple transmitted tones, the configuration of a circuit’s transmission lines, and the current density and power level of the application. Multiple signal tones are usually denoted by their fundamental frequencies, such as f1 and f2, with the frequencies of their PIM spurious signals resulting from the differences between different harmonics of the fundamental tones. Learn about how PCB designs can reduce PIM.