Radio

Abstract

Radio transmission and reception were perhaps one of the earliest applications of electronics, and make up — so far — the application that has had the greatest impact on society. Oddly, we can use radio, predict its properties and design circuits that work efficiently, but we know little about its real nature. Ask an electronics engineer what radio is, and the answer will be a confident ‘electromagnetic waves’. Ask a physicist what electromagnetic waves are, and he will begin to hedge, or he will tell you that, really, we don’t know. We do know that electromagnetic radiation is a form of energy, and that it behaves as if it is propagated as waves. The model becomes more of a model and less like reality when we discover that radio travels through a vacuum. How can there be waves in a vacuum? Perhaps in the future, theoretical physics will give us an understandable answer. In the meantime, we use radio, describe it mathematically, and design and use electronic circuits that function happily despite our underlying ignorance.