Detectors
Ronald E. Ham · Encyclopedia of RF and Microwave Engineering · 2024
Abstract Microwave energy cannot be effectively detected with equipment used for lower frequency applications. Changes in microwave frequency voltage are too rapid to be captured on any but the fastest sampling oscilloscopes, and response time and parasitics of common test meters render them useless. Microwave detectors measure power in controlled impedance environments afforded by transmission lines and waveguides. Since the system impedance is known, voltage and current magnitudes can be derived. With the judicious application of other microwave components such as power splitters and quadrature couplers, phase information can be extracted from multiple power measurements; therefore, complete characterization of a system or component is possible with only microwave detectors to convert microwave signal characteristics into readily observable and measurable quantities of low‐frequency voltages and currents.