Figure 4. A snapshot, in time, of two complex numbers whose exponents, and thus their phase angles, change with time. The notion of negative frequency is often troubling to engineers who've spent so ...

This series is drawn from the course “DSP Made Simple for Engineers.” For more information, see Besser Associates. This article is also available as a PDF Part 2 introduces quadrature (complex) ...

Fig 1. In a typical PWM controller in which the active devices are driven by a simple square wave, a Fourier representation of the clock’s frequency spectrum consists of the fundamental switching ...