External Links

External Links Here are webpages I recommend or that have a tie to Maxwell's Equations. Antenna Theory One of the widest uses of Maxwell's Equations is in the study of Antenna Theory. The goal of an antenna is to transmit and receive electromagnetic waves, and these waves are governed by Maxwell's Equations. Radiation patterns, electromagnetic boundary conditions, and VSWR are all related to Maxwell's Equations and you can't understand antennas without them. One of the most applicable examples is that Maxwell's Equations shows that an increase in permittivity or permeability produces a decrease in the wavelength of an electromagnetic wave at a given frequency. Antennas often need to be a certain fraction of a wavelength to radiate well (a half for many types of antennas), and so by surrounding the medium the antenna is in with a dielectric the required antenna size can be reduced. The Fourier Transform The Fourier Transform relates a signal in time to a sum of simple sinusoidal functions. This is true for any real world signal including electromagnetic waves. Hence, we can analyze Maxwell's Equations by assuming a sinusoidal wave of a given frequency for our Electric and Magnetic field. This simplifies the math greatly, as time derivatives become simply multiplied by i*2*pi*f. Frequency-domain analysis is critical to making Maxwell's Equations more managable. And we owe all of that to the Fourier Transform. The above link gives an intuitive discussion on that topic, with a good Table of Fourier Transforms. When does the Time Change? If you're like me, you can't remember when to set your clocks backward or forward, or even why. This problem occurs in most of the Western world. This might not relate directly to Maxwell's Equations, but it is a time based phenomenon. Electromagnetic Properties of Materials Maxwell's Equations shows that the world, as far as Electric and Magnetic fields are concerned, really only see things in terms of permittivity, permeability and conductivity. The above link gives some more background on materials in addition to what I've already presented on this site. Maxwell's Equations