Issue link: https://iconnect007.uberflip.com/i/1534120
APRIL 2025 I DESIGN007 MAGAZINE 25 hybrid (mix of standard FR-4 and RF materi- als) and asymmetric stackups, but make sure you find a fabrication house that can process these materials. Another interesting type of RF stackup design involves multiple laminations with blind and buried vias, which are typically mechanically drilled, and there could even be backdrilling in each lamination. What are the most important things for PCB designers and design engineers to remember when working in the RF arena? In RF design, we deal with wavelengths and frequencies, not edge rate or rise time. e core concept that underlies all this is band- width, which is an idea that is applicable in both digital and RF. In terms of electrical per- formance, we only care about what happens in a narrow signal bandwidth. In RF design, the bandwidth where your system needs to operate is generally small, so you only need to have good performance in a narrow frequency range corresponding to your signal. is is why design practices like intentional placement of stubs and cascaded transmission lines actually do something useful in RF design, whereas you would never do this in a digital design. e design only needs to be good in your required frequency range. Is there anything else you'd like to add? Don't let yourself be scared away from RF design just because some people call it black magic. I think designers should know enough about RF materials, layout, and routing so that they can understand what's happening in a given layout. DESIGN007