Issue link: https://iconnect007.uberflip.com/i/1498723
34 DESIGN007 MAGAZINE I MAY 2023 density in conductors. As seen in Figure 1, the density of DC current at a sharp right-angle turn of a power strip will be very small at the outer point of the corner and could be very high at the inner corner. We know that high-speed traces with a sharp bend will suffer from the capacitive loading at the outer "unused" portion of the turning trace. We see in Figure 1 that, at DC, the outer corner is equally "unused" and does not cause problems; it is just not necessary to have cop- per there. Instead, the problem at DC shows up on the opposite side of the power strip, at the inner corner, where the current density may exceed the safe limit. Another example of complex 3D behavior at low frequencies was documented by mea- sured and simulated data 2 , where the conduc- tor geometry and the component placement interacted in a way that created a negative phase and negative slope of the magnitude of impedance. In Figure 2, the circuit in question Figure 1: Simulated DC current density of a power strip making a right-angle turn 1 . There is a total of 1A through a 1-ounce, half-inch-wide copper strip. Figure 2: Small fixture with two coaxial connectors and resistors is seen on the left, while measured and simulated impedances are seen on the right 2 .