ABSTRACT
We perform measurements during the prototype board bring-up phase for diagnosing bugs, during the design validation to collect data, during transceiver tuning as a feedback, and sometimes in production for debugging failing units. We also measure SI test boards to obtain material data that we can use in later design projects. With oscilloscopes (scopes) we measure signals as voltage versus time diagrams, with vector network analyzers (VNAs) we measure PCB traces as frequency-domain S-parameters, with signal analyzers we measure derived properties of periodic signals as numbers. Scopes can also extract numbers from the diagrams. The result of a scope or analyzer measurement is a screen image, the result of a VNA measurement is a screen image and an S-parameter model file. The prototype board is referred to as the device under test (DUT). Most of this chapter is about high-frequency measurements.
