Characteristics of a horizontal circular loop antenna over a multilayered, dissipative half-space

The problem of a horizontal loop antenna located above a stratified dissipative half-space is investigated. Current distribution is formally obtained by cosinusoidal expansion around the loop. The effect of the lower half-space on each modal current is discussed in the case of a small loop (k₀b = 0.3) and a resonant loop (k₀b = 1). Change in input admittance as a function of height and as a function of the electric parameters of a homogeneous dissipative haft-space are presented. Such change is found to be very pronounced when the loop is close to the interface and when the loop is near resonance. The effect of a second layer in the lower half-space is then discussed.