RF Match Basics and Active Source VSWR Measurement

Mismatch error is one of the major contributions to measurement uncertainty in RF & Microwave calibration, often not well understood or appropriately considered by users. When a signal source is used in calibration applications, knowledge of the output impedance (or source VSWR) is necessary to enable users to estimate the mismatch uncertainty contribution when performing their measurement uncertainty calculations. However, measuring the output match of an active levelled source can be difficult. The measurement techniques generally used for passive components cannot be used for active levelled sources. If those methods are used, they are likely to give erroneous misleading results. This web seminar presents the basics of RF match theory and practice, and describes the method used in manufacturing test and calibration systems for output VSWR measurement and accredited certification of the Fluke 9640A RF Reference Source instrument.