TABLE OF CONTENTS There are several possible ways to connect a DUT to the measuring instrument. We always have to weigh and analyze the possible connection methods, cabling, calibration procedures and instrumentation before we decide which one to use. As a generic rule, simpler, less expensive, and easier-to-apply connections, cables, and calibrations tend to be more limited in bandwidth, accuracy, and dynamic range.
As shown in Figure 6.1, we can break down the connection between the DUT and measuring instrument into several blocks: interconnect on the fixture, connector, or probe interfacing the fixture and cable, and cable(s) connecting to the instrument. The location of the calibration or fixture compensation determines which quantity is being measured. Also, various implementations may differ in that some blocks may be combined or left out.
If the DUT is a single, small-size component, such as a bypass capacitor, we can attach the DUT to a fixture to measure its impedance together with the part. In this case, the calibrated reference plane may be at the end of the cable; so, we may or may not want or need to separate the measured data further by de-embedding or by compensating for the fixture. At the other end of the spectrum is a large system measurement. In a large system, there is probably no fixture; so we connect the instrument to the DUT through cables, with or without probes.
These options will be detailed and illustrated...
