The Theory of Top Loaded Antennas Integral Equations for the Currents英文电子书.pdf

, - - ~. 186 IEEE TRANSACTIOWS ON ANTENNAS ~LNDPROPAGATION, VOL. M-19, NO. 2, MARCH 1971 The Theoryof Top-Loaded Antennas: Integral Equationsfor the Currents Abslract-The generalproblem involving the distribution of THEORETICALMODEL current and the driving-point impedance of a top-loaded antenna is formulated.Consideration is given to an idealized structure The general form of the a,ntenna under study is indi- having one or more cylindricaltop-loading elements.For the cated in Fig. 1. It consists of a central element of length practically importantcase involving conductors of smallradius, the axial currents are obtained as the solution to a pair of coupled h with N top-loadingelementsdisplaceduniformly in integralequations. Approximate solutionsobtainedbynumerical azimuth, each top-loading element being of length 1 and methods for theinverted L-, T-,andfour-element top-loaded placed at an angle OA with the central axis.The axis of antennas are compared with measured driving-point impedances. the central element coincides with the z axis of a Carte- Satisfactoryagreementindicates the possibility of utilizing the theory in the analysis of practicalconfigurationsinvolving many sian (x,y,z) coordinatesystem, a.nd thestructureis ex- top-loading elements. cited by a localized source of EMF of strength v” at