An exact expression for the fields produced by an electrically small loop antenna is obtained in terms of a series involving a new set of functions, namely en(σ,γ)=(1/2π)∫02π cos(nΦ)sin[σ(1-2γ cosΦ)1/2]dΦ and f n(σ,γ)=(1/2π)×∫02π cos(nΦ) cos[σ(1-2γ cosΦ)1/2]dΦ, where - ∞ < σ < ∞ and 0≤γ≤1/2. Series expansion, approximate expressions for γ2σ≪1 and recursion relations for the functions are derived. These functions permit the exact evaluation of the fields in the Fresnel and near-field regions of the loop antenna. In the case that the distance to the point of observation is of the order of a wavelength or greater, but greater than the loop radius, the field expression is given in terms of the function q1(σ,γ) = f1(σ,γ) + ie1(σ,γ). Numerical results describing the behavior of the functions f1(σ,γ) and e1(σ,γ) are given. Field expressions for the electrically large loop antenna are also derived.
ASJC Scopus subject areas
- Physics and Astronomy(all)