Fundamentals of Engineering Electromagnetics 1st Edition by David Cheng

Exercise 38

The attenuation of propagating modes in a waveguide due to a lossy dielectric can be studied in terms of a complex permittivity d and an equivalent conductivity d shown in Eq. (9-97). (a) Substitute Eq. (9-97) in Eq. (9-24) to obtain a formula for the attenuation constant d due to lossy dielectric in terms of the ratio f c / f. (b) Calculate d in a 2.50 (cm) × 1.25 (cm) rectangular waveguide operating at 4.0 (GHz). The dielectric medium has a dielectric constant 4 and an equivalent conductivity 3 × 10 5 (S/m).