90度走线90 Degree Corners: The Final Turn Doug Brooks, President UltraCAD Design, Inc. needs to be fabricated; and then someone with the appropriate equipment and knowledge needs to do the testing and evaluation. See the acknowledgment at the end of this article for those who donated their time, effort, and resources for making this evaluation possible. Figure 1 illustrates the board that was designed and fabricated. Six traces provided various configurations for test. All traces were configured as microstrip, controlled impedance traces with identical dimensions (1.2 oz copper, 10 mils wide with 7 mils FR4 dielectric thickness between trace and underlying plane, Er = 4.6). Provision was made at one end of each trace for a 50 Ohm RF connector for mating with test equipment, and for pads at the oth……