Case study of Near Field Signature Analysis (NFSA) as a diagnostic tool for high frequency circuits

A presentation of the method of Near Field Signature Analysis as a tool for diagnostic failure localization in high frequency circuit assemblies will be given. Traditional techniques of localizing faults in RF circuits rely heavily on manual methods and ATE approaches have limitations based on how much intelligence can be embedded into the software. Following the trends of robotic application, this method combines precise mechanical positioning and non-contact probing with local synthetic measurement technology. The technique can shorten the time to diagnosis by augmenting the ATE with more positional information and save manual labor by creating an automated parallel operation for failed RF assemblies. It also may generate data of a prognostic value. A case study will be used to demonstrate quantitatively the possibilities and limitations of the technology. Multiple units of a typical microwave circuit assembly will be examined with this method at several measurement points. A following set of measurements on failing assemblies will be then be presented and compared with the reference measurements and their respective known-good measurements.