TY - JOUR

T1 - Fresnel region fields produced by circular loops and annular slots antennas

AU - Gonzalez, Guillermo

AU - Huerta, Manuel A.

N1 - Copyright:
Copyright 2010 Elsevier B.V., All rights reserved.

PY - 1973

Y1 - 1973

N2 - Exact closed-form expressions for the Fresnel region electric and magnetic fields of circular loop and annular slot antennas are given in terms of the functions en(σ,γ)=(1/2π)02π cos(nΦ) sin[σ(1-2γ cosΦ)1/2] dΦ and fn(σ ,γ)=(1/2π)02π cos(nΦ) cos[σ(1-2γ cosΦ) 1/2] dΦ, where - ∞ < σ < ∞ and 0 ≤ γ ≤ 1/2. For a circular loope antenna with a constant current distribution the Fresnel region fields are obtained in terms of the functions qn (σ,γ)=fn (σ,γ)+ie n(σ,γ), with n =0,1, and 2, and for a cosine current distribution the Fresnel region fields are obtained in terms of the functions qn(σ,γ), with n =0,1,2,3, and 4. The magnetic field of an annular slot antenna excited by a constant voltage is expressed exactly in terms of an infinite series involving the functions qn (σ,γ). The Fresnel region magnetic field of the annular slot antenna is simply given in terms of q1(σ,γ). The functions qn(σ,γ) permitted a simple evaluation of the electric and magnetic field strength in the Fresnel region. The functions q n(σ,γ) for n =0,1,2,3, and 4 are tabulated for values of σ=0.5, 1, 2, 5, 10, 25, and 50 and values of γ from 0.01 to 0.5.

AB - Exact closed-form expressions for the Fresnel region electric and magnetic fields of circular loop and annular slot antennas are given in terms of the functions en(σ,γ)=(1/2π)02π cos(nΦ) sin[σ(1-2γ cosΦ)1/2] dΦ and fn(σ ,γ)=(1/2π)02π cos(nΦ) cos[σ(1-2γ cosΦ) 1/2] dΦ, where - ∞ < σ < ∞ and 0 ≤ γ ≤ 1/2. For a circular loope antenna with a constant current distribution the Fresnel region fields are obtained in terms of the functions qn (σ,γ)=fn (σ,γ)+ie n(σ,γ), with n =0,1, and 2, and for a cosine current distribution the Fresnel region fields are obtained in terms of the functions qn(σ,γ), with n =0,1,2,3, and 4. The magnetic field of an annular slot antenna excited by a constant voltage is expressed exactly in terms of an infinite series involving the functions qn (σ,γ). The Fresnel region magnetic field of the annular slot antenna is simply given in terms of q1(σ,γ). The functions qn(σ,γ) permitted a simple evaluation of the electric and magnetic field strength in the Fresnel region. The functions q n(σ,γ) for n =0,1,2,3, and 4 are tabulated for values of σ=0.5, 1, 2, 5, 10, 25, and 50 and values of γ from 0.01 to 0.5.

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U2 - 10.1063/1.1662793

DO - 10.1063/1.1662793

M3 - Article

AN - SCOPUS:0015657090

VL - 44

SP - 3500

EP - 3504

JO - Journal of Applied Physics

JF - Journal of Applied Physics

SN - 0021-8979

IS - 8

ER -