Résumé de section

  • hapter 5 covers the propagation of electromagnetic fields, focusing on plane waves in free space and lossless media derived from Maxwell's equations.

    Time-harmonic fields satisfy the Helmholtz equation ∇²E + k²E = 0, where k = ω√(με) is the wavenumber. Uniform plane waves propagate as E = E₀ e^{-j k · r}, with speed c = 1/√(με).

    Intrinsic impedance η = √(μ/ε) relates E and H fields; Poynting vector S = (1/2) Re(E × H*) gives time-average power flow. In dielectrics, waves attenuate negligibly if lossless, building to interface interactions in later chapters.