Gain compression is both a common and an important measurement of many active devices, particularly amplifiers and mixers. Similar to third order intercept, gain compression is a method of quantifying the linearity of these devices, and the one dB compression point (P1dB) is often used to define a device’s linear and non-linear regions. This presentation explains the fundamental concepts behind gain compression and P1dB, with special emphasis on how these are measured using different test and measurement instruments, such as power sensors, signal generators, spectrum analyzers, and VNAs.
