Essential Guide to Wireless Communications Applications, The

Radio 101

Radio signals are a type of electromagnetic radiation, a category that also includes light, infrared, and many other types of ray. They are usually thought of as transverse waves, which means they have a wavelength and a frequency. The wavelength is the distance between the peaks of sequential waves, shown in Figure 2.1, and the frequency is the number of wave cycles occurring each second.Cycles per second are usually called hertz (Hz), after Heinrich Hertz, the physicist who discovered radio.

The speed of a transverse wave can be calculated by multiplying the frequency and the wavelength, but all radio waves automatically travel at a constant speed—the speed of light, which in empty space is exactly 299,792,458 meters per second. ...