For user convenience, Keysight's Fundamentals of RF and Microwave Power Measurements, application note 64-1, has been updated and segmented into four technical subject groupings. The following abstracts explain how the total field of power measurement fundamentals is now presented.

Fundamentals of RF and Microwave Power Measurements (Part 1)
Introduction to Power, History, Definitions, International Standards, and Traceability
AN 1449-1, literature number 5988-9213EN

Part 1 introduces the historical basis for power measurements, and provides definitions for average, peak, and complex modulations. This application note overviews various sensor technologies needed for the diversity of test signals. It describes the hierarchy of international power traceability, yielding comparison to national standards at worldwide national measurement institutes (NMIs) like the U.S. National Institute of Standards and Technology. Finally, the theory and practice of power sensor comparison procedures are examined with regard to transferring calibration factors and uncertainties. A glossary is included which serves all four parts.

Fundamentals of RF and Microwave Power Measurements (Part 2)
Power Sensors and Instrumentation
AN 1449-2, literature number 5988-9214EN

Part 2 presents all the viable sensor technologies required to exploit the wide range of unknown modulations and signals under test. It starts with explanations of the sensor technologies, and how they came to be to meet certain measurement needs. Sensor choices range from the venerable thermistor to the innovative thermocouple to more recent improvements in diode sensors. In particular, clever variations of diode combinations are presented, which achieve ultra-wide dynamic range and square-law detection for complex modulations. New instrumentation technologies, which are underpinned with powerful computational processors, achieve new data performance.

Fundamentals of RF and Microwave Power Measurements (Part 3)
Power Measurement Uncertainty per International Guides
AN 1449-3, literature number 5988-9215EN

Part 3 discusses the all-important theory and practice of expressing measurement uncertainty, mismatch considerations, signal flowgraphs, ISO 17025, and examples of typical calculations. Considerable detail is shown on the ISO 17025 Guide or the Expression of Measurement Uncertainties, has become the international standard for determining operating specifications. Keysight has transitioned from ANSI/NCSL Z540-1-1994 to ISO 17025.

Fundamentals of RF and Microwave Power Measurements (Part 4)
An Overview of Keysight Instrumentation for RF/Microwave Power Measurements
AN 1449-4, literature number 5988-9216EN

Part 4 overviews various instrumentation for measuring RF and microwave power, including spectrum analyzers, microwave receivers, network/spectrum analyzers, and the most accurate method, power sensors/meters. It begins with the unknown signal, of arbitrary modulation format, and draws application-oriented comparisons for selection of the best instrumentation technology and products. Most of the note is devoted to the most accurate method, power meters and sensors. It includes comprehensive selection guides, frequency coverages, contrasting accuracy and dynamic performance to pulsed and complex digital modulations. These are especially crucial now with the advances in wireless communications formats and their statistical measurement needs.