Question

4. A perpendicularly polarized wave has an angle of incidence of 30 degrees. thle drereltle boundary between air and a medium with relative dielectric permittivity of 4 is at z-0. a. b. Find the angle of the refracted wave Find the reflection coefficient 5. If the wave in problem 4 had parallel polarization, what would be the Brewster angle? 6. Write the phasor expressions for the incident waves described in problems 4 and 5 if the wave has a frequency of 100 MHz

Answer 1

For a perpendicularly polarised wave, electric field is perpendicular to plane of incidence and magnetic field is parallel to it Here theta_i, theta_r and theta_t are incident, reflected and refracted angular respectively theta^-_1 = 30 degree doublerightarrow = 30 degree We know that, relative permittivity k = n^2 here n_1 = 1 (air) n_2 = un known k = 4 (given) therefore n_2 = squareroot k = 2 = n_t a) By Snell's law, n_i sin theta_1 = n_t sin theta_t doublerightarrow theta_t = sin^- 1 (n_i/nt sin theta_i) = sin^- 1 (1/2 sin 30 degree) = 14.47 degree b) Reflection coefficient gamma_l (E) = n)t cos (theta_i) - n_i cos (theta_t)/n_t cos (theta_i) + n_i cos (theta_t) = 0.2828