Careers Related to the EM Spectrum

The Hidden World of the Electromagnetic (EM) Spectrum

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Center for Research in Wireless Communications, 301 Fluor Daniel Engineering Innovation Building
Holcombe Department of Electrical and Computer Engineering, Box 340915, Clemson, SC 29634-0915 -- 864.656.3946 (voice & fax)
Wilson.Pearson@ces.clemson.edu

Maintained by Tom Rogers. Last Updated: July 13, 2007

Area Code: 864, Information: 656-3311

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How can I prepare for a future in engineering or computing?

Getting a college degree in engineering or computer science is challenging but well worth the effort. These degrees tap into some of the best job markets in America.

As a high school student the best way to prepare is to take the challenging courses especially advanced placement (AP) courses in subjects like:

Calculus
Physics
Computer Science (courses with programming)
Statistics

In addition, get into hobbies and courses that hone your ability to communicate, such as public speaking, writing, photography and art. In today's world, engineering and computing professionals have to know how to effectively communicate ideas. They almost always work in teams.

Careers Related to the EM Spectrum

While there isn't a single career that's totally dedicated to using the EM spectrum, there are many where a working knowledge of it is important. If you're the kind of individual who likes math, science, and computers you're very likely to end up in one of the careers listed below.

Engineering

Electrical engineering top the list of professions using EM knowledge. They use sophisticated mathematical models to design all kinds of wireless equipment including radios, antennas, cell phones, wireless computer networks, etc. But they also work on a wide range of other problems such as electrical power generation and the design of all kinds of electrical devices and components.

Computer engineering, would of course be concerned with wireless computer networking, but guess what? Cell phones in addition to being radio transceivers are very powerful computers.

People who work in all branches of engineering learn details about the EM spectrum. While they might not design EM equipment, they often make use of it. For example, the civil engineers (the branch of engineering associated with designing buildings, bridges, and transportation systems) involved in hurricane research use wireless networks during hurricanes to collect data from sensors attached to building. The data enables them to design buildings with greater storm resistance . Other branches of engineering include: mechanical, chemical, and biomedical engineering. For more information click here.

Computing

Computer science and software engineering are two of the hottest job markets in America. Careers opportunities in these areas go far beyond those associated with the EM spectrum. Still, there are important areas involving the use of the EM spectrum for wireless communication. For more information about computing careers click here.

Not only is a cell phone a computer, but it needs a vast computer system to make it work. This system has to know where your cell phone is relative to the nearest tower in order to route calls to you. Your location is recorded in a data base that's constantly updated. If you happen to be using your cell phone while you're driving, the computer system has to continually monitor the strength of your signal and switch you from tower to tower, all without disrupting your conversation.

Human Wireless Communication

Much of the EM spectrum with wavelengths longer than visible light is used for human communications. For example, infrared is used for TV remote controls, microwaves for cell phones, radio waves for (you guessed it) radio, etc.

Waves in this section of the spectrum are not considered ionizing and at low levels of intensity they're not considered harmful. However, at high levels such as those found in microwave ovens, they can cause burns. The extremely high levels of infrared given off by nuclear bomb blasts can actually vaporize objects including people.

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Ionizing Radiation

EM waves are often referred to as EM radiation because waves radiate outward from their source. While we typically think of all radiation as harmful, most is not. The key dividing line is roughly at visible light. At shorter wavelengths (ultraviolet to gamma rays), EM radiation is called ionizing radiation because even the lowest levels of it can ionize by removing electrons from otherwise neutrally charged atoms. This removal creates sites for harmful chemical reactions resulting in conditions such as sunburn or defects in DNA molecules

The body can defend against ionizing radiation, if the level is not too high and the exposure not too long. For example, sun tanning helps defend against skin damage from ultraviolet (UV) light. However, even with a suntan, long term exposure to UV will eventually damage the skin and give it a leathery appearance.

EM Particles--Photons

While EM radiation is often modeled as a wave, it can also be modeled as particles called photons. Often the 2 models are combined. For example, the energy each photon has is directly related to the EM radiation's wave length. The photon's energy increases as wavelength decreases.

A single photon of ionizing EM radiation has enough energy to remove a single electron from its atom. The brighter or more intense the EM radiation is, the more photons it contains and the more electrons it can remove.

Relative Size: bacteria
Frequency: 300,000 GHz
Energy per Photon: 2.0 x 10	-19	J

Relative Size: virus
Frequency: 3,000,000 MHz
Energy per Photon: 2.0 x 10	-18	J

Relative Size: football field
Frequency: 0.003 GHz
Energy per Photon: 2.0 x 10	-27	J

Relative Size: blueberry
Frequency: 30 GHz
Energy per Photon: 2.0 x 10	-23	J

Relative Size: wheel dia of an 18-wheeler
Frequency: 0.3 GHz
Energy per Photon: 2.0 x 10	-25	J

Relative Size: water molecule
Frequency: 3,000,000,000 GHz
Energy per Photon: 2.0 x 10	-15	J

Relative Size: proteins
Frequency: 30,000,000 GHz
Energy per Photon: 2.0 x 10	-17	J

Relative Size: human hair
Frequency: 3,000 GHz
Energy per Photon: 2.0 x 10	-10	J

<-- Wave Length = 7x10^-7meters

Why does a red object look red?
White light is a mixture of all the wave lengths in the visible part of the EM spectrum. Shine white light on a red object, say an apple, and the apple will reflect most of the red waves while absorbing most of the others. Some of the reflected red light travels to your eyes so that the image of the apple looks red. Shine a blue light on a red apple and it will look black.

<-- Wave Length = 4x10^-7meters