One of the benefits of avery low frequency is that it can travel much farther than a high frequencybefore it loses power (that is, attenuates).
At the very low end of the spectrum are signals that would betraveling at 30Hz (that is, at 30 cycles per second). The electromagnetic spectrum is depicted as alogarithmic progression: The scale increases by multiples of 10, so the higherregions encompass a greater span of frequencies than do the lower regions.Īlthough the electromagnetic spectrum represents an enormous range offrequencies, not all the frequencies are suitable to purposes of humancommunications. The electromagnetic spectrum ranges from extremely low-frequency radio wavesof 30Hz, with wavelengths of nearly the earth's diameter, to high-frequencycosmic rays of more than 10 million trillion Hz, with wavelengths smaller thanthe nucleus of an atom. All modern communication depends on manipulating and controlling signalswithin the electromagnetic spectrum. This phenomenon was first predicted to exist by JamesMaxwell, in 1865, and it was first produced and observed by Heinrich Hertz in1887.
SPECTRUM BANDWIDTH FREE
When electrons move, they create electromagnetic waves that can propagatethrough free space. This section talks about bandwidth and about where the various transmissionmedia lie within the electromagnetic spectrum. Learn More Buy The Electromagnetic Spectrum and Bandwidth Telecommunications Essentials: The Complete Global Source for Communications Fundamentals, Data Networking and the Internet, and Next-Generation Networks
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