Abstract
This article will explore the characteristics of various broadband instruments that are available to measure microwave (MW) and radio-frequency (RF) electromagnetic fields. Instrument selection depends on both the design of the instrument and the characteristics of the field to be measured, including its frequency, modulation, and pulse width. Of the instrumentation currently available, accurate near-field and far-field measurements can be made if the inherent design strengths and limitations of the various types of instruments are known in advance. All broadband instrumentation consists of three basic components—an antenna, a detector, and a transmission line—although their responses to a particular RF or MW field may be dramatically different. The important characteristics of these instruments include their out-of-band response, isotropy, zero stability, linearity, RF potential sensitivity, and nonsinusoidal response. Calibration of instruments, the various methods of calibration available, and applicability to a particular frequency range will be considered.