We created this guide to explain the basics of RF signals, help you understand the time and frequency domains, and introduce common RF measurement instrumentation and measurement techniques. We hope you find this information helpful.

Time vs. Frequency Domain
Events are often measured with respect to time. The average speed of a car, for example, can be calculated by dividing the distance traveled by the time it takes to travel that distance. Time domain measurements-those events measured with respect to time-are very useful to our understanding of the physical world and can be critical to building something that operates as intended.

In electronics, time domain measurements are extremely common. The point in time at which a certain event occurs can be key to the success or failure of a design. Unfortunately, humans don't have the ability to observe some elements of our world. Obviously, electrons are extremely useful, but they're notoriously small and hard to catch. However, we have been able to build tools that can help us observe electrons as they do their work. The oscilloscope is one of these tools. In fact, oscilloscopes are among the most common tools used to perform time domain measurements. In essence, an oscilloscope plots a graph of the voltage at its input with respect to time.