About equation of wave

1. Wave Equation

2. Time Varying Potentials
Ref.: Elements of Electromagnetics by Matthew N O Sadiku, pp. 447
 For static EM fields, the electric scalar potential is
 For static EM fields, the magnetic vector potential is
 We would like to examine what happens to these potentials when the fields
are time varying.

3. Time Varying Potentials
Ref.: Elements of Electromagnetics by Matthew N O Sadiku, pp. 447
 A vector field is uniquely defined when its curl and divergence are specified.
The curl of A has been specified by equation for reasons that
will be obvious shortly, we may choose the divergence of A as
 This choice relates A and V.
 It is called the Lorenz condition for potentials

4. Wave Equation
Ref.: Elements of Electromagnetics by Matthew N O Sadiku, pp. 447
 By imposing the Lorenz condition the electric scalar potential and the
magnetic vector potentials for time varying situations can be given as
 These are known as wave equations

5. Electromagnetic (EM) Waves
Ref.: Elements of Electromagnetics by Matthew N O Sadiku, pp. 447
 In general, waves are means of transporting energy or information.
 A wave is a function of both space and time.
 Typical examples of EM waves include radio waves, TV signals, radar
beams, and light rays.
 All forms of EM energy share three fundamental characteristics:
 they all travel at high velocity;
 in traveling, they assume the properties of waves; and t
 hey radiate outward from a source, without benefit of any discernible
physical vehicles.

6. Electromagnetic (EM) Waves

7. Wave Equation
Ref.: Elements of Electromagnetics by Matthew N O Sadiku, pp. 447
 Solve Maxwell's equations and describe EM wave motion in the following
media
 where 𝜔 is the angular frequency of the wave.

8. Wave Propagation in Lossy Dielectric
Ref.: Elements of Electromagnetics by Matthew N O Sadiku, pp. 447
 A lossy dielectric is a medium in which an EM wave, as it propagates, loses
power owing to imperfect dielectric.