Issue link: https://iconnect007.uberflip.com/i/1496727
42 DESIGN007 MAGAZINE I APRIL 2023 • Radiation patterns don't overlap in the same frequency bands • Isolation and separation amongst antennas • Alignment with polarization of these sig- nals (e.g., right-hand circular, vertical, or horizontal) Add lumped or printed filters along signal paths for these different signals to reject inter- ference outside of their carrier frequencies and bandwidths. Route and shield RF transmission lines to minimize interference with these signals. Sim- ulate the above structures at various operat- ing signal frequency bands to verify and tweak until they "play nice together" with minimal interference prior to prototyping. What do "traditional" PCB designers and EEs need to know about measurement and analy- sis of RF circuits? How is this different from analysis at lower speeds? Measurements and simulation analysis always go together in the design of RF PCBs, because designers need to understand how physical layout and 3D packaging affects RF perfor- mance and then account for these effects. Designers can use simulation analysis to reproduce the non-ideal effects seen in mea- surements in order to prescribe corrective design tweaks for the next prototype. At lower speeds, the usual measurements will be based on connectivity checks. Shaughnessy: What are some of the consid- erations that PCB designers should take into account when selecting RF materials? Some of the most important considerations when choosing RF materials are: • Cost • Signal loss at the intended frequency of operation • Tolerance of electrical and mechanical properties • Stability of electrical and mechanical properties over a range of temperature and humidity • Manufacturer's availability schedule and risk of delays or discontinuation • Risk mitigation from second source availability or replacement What advice would you give to designers who find themselves in the RF world now? Learn how to use the latest RF circuit and EM simulators. is is critical. Learn how to use EM and circuit simulators together in co-sim- ulation and co-optimization of electrical and physical layout parameters to preserve given RF specs. is will help reduce the number of design iterations. Thanks for your time. ank you. I appreciate it. DESIGN007 How-Siang Yap