The Hidden RF Loss: Why PCB-to-Connector Transitions Steal Your dB

RF systems rarely fail in obvious ways. More often, performance erodes quietly; a dB here, a little range there, until designs no longer match expectations. In this episode, we discuss one of the most overlooked sources of RF loss: the transition from a controlled‑impedance PCB trace to a connector and coaxial cable. You’ll learn why “50 ohms” is a wave property, not a component value, how small geometry changes at the PCB‑to‑connector interface can create impedance discontinuities, and why connectors and cables should be treated as part of the transmission line, not mechanical afterthoughts. We’ll also cover how cable selection, bend radius, mechanical stability, and prototype‑to‑production variability can quietly eat into your link budget, even when the radio and antenna are unchanged. Whether you’re designing your first RF system or chasing a few lost dB in a mature product, this episode breaks down the hidden risks and practical design considerations that help protect system margin before they show up in the field. To view datasheets or order samples, visit Würth Elektronik online or the MyWE customer portal. RELATED SOLUTIONS: Trilogy of Connectors Reference Guide: https://www.we-online.com/en/components/products/TRILOGY_OF_CONNECTORS_ENGLISH Coaxial Connectors: https://www.we-online.com/en/components/products/em/connectors/coax Coaxial Cable Assemblies: https://www.we-online.com/en/components/products/em/connectors/coax/coaxial_connectors_cable_assemblies Coaxial Cable Configurator: https://www.we-online.com/en/products/components/service/customized-solutions/cableconfigurator Listen to our PODCAST🎙️: https://www.we-online.com/en/news-center/podcast Follow us on LinkedIn: https://www.linkedin.com/company/wurth-elektronik (Americas) Follow us on LinkedIn: https://www.linkedin.com/company/wuerth-elektronik-group (Europe) Like us on Facebook: https://www.facebook.com/WurthElectronics/ (Americas) Like us on Facebook: https://www.facebook.com/Wuerth.Elektronik.Group/ (Europe) Follow us on X: https://x.com/WurthElectronic/ (Americas) Follow us on X: https://x.com/we_online (Europe) Follow us on Instagram: https://www.instagram.com/wurthelectronics (Americas) Timestamps 00:00 Introduction 02:30 Understand Radio Frequency 04:08 The most overlooked radio frequency risk is the PCB-to-connector transition 07:01 Cable selection is not a shopping decision, it's a margin decision 08:55 Most important factors in cable selection 11:03 The prototype-to-production trap, and where custom assemblies matter