Advanced Measurement Techniques

There are many advanced situations where the basic coaxial calibration techniques are inadequate. This chapter discusses a compendium of advanced calibration techniques. The two main types of calibration methods, short‐open‐load‐thru and thru‐reflect‐line, each require different calibration standards. The chapter discusses fixturing and de‐embedding techniques, and shows how to determine the exact S‐parameters for fixtures by modeling the fixture in a linear simulator or 3‐D EM structure simulator. It also describes the use of automatic port extensions and explains automatic fixture removal using time domain. Port matching and embedding involves measuring a device‐under‐test (DUT), directly at the vector network analyzer ports, but adding the effects of other virtual elements to the measured response of the DUT. Fixturing and de‐embedding techniques can enable implementation of the impedance transformation by creating an S‐parameter model of an ideal, lossless transformer and then embedding that into a measurement.