Testing Complex Circuits with Radio-Frequency Reflectometry

<div class="section abstract"><div class="htmlview paragraph">Driving automation systems rely heavily on sophisticated electronics to function effectively, and economic pressure poses new challenges in manufacturing. Tightly integrated sensors, processors, and communication modules monitor and control the vehicle's operation at any time. Size, weight, power, and cost constraints put pressure on manufactures to reduce stack electronics, miniaturize boards, and innovate over the traditional sequential assemble/test cycle. Consequently, designers and manufacturers reduce access to boards, remove test points, co-locate RF with other components, and break the sequential SMT line. Radio-frequency (RF) reflectometry is a mature and reliable technology essential for characterizing materials, components, and analog circuits. It provides precise insights into electromagnetic properties like impedance and permittivity, crucial for optimizing RF and microwave designs. Widely used in fields from material science to quantum computing, RF reflectometry is key to fine-tuning circuit performance and enhancing antenna design. Our technology provides fundamental innovation to test methods by leveraging RF reflectometry to identify hard-to-detect defects in highly integrated, critical electronics products at any point in the manufacturing line. The team demonstrated detecting critical and latent defects in systems with a just a few test points, and readiness to test at any state of manufacturing (i.e., bare boards, fully assembled, inaccessible regions) when traditional test methods such as in-circuit testing or optical inspection would be inapplicable. The team validated the technology on units under test of varying complexity, from sub-assemblies to even full control units. Furthermore, the team also demonstrated the capability to detect malicious alterations and thus the technology can significantly contribute to the verification of validation of safety and security of new driving automation solutions.</div></div>