Field of an antenna submerged in a dissipative dielectric medium

Abstract

The field components due to a horizontal dipole antenna submerged in a lake are represented in integral forms. The integrals are then evaluated using three techniques: 1) numerical integration along branch cuts where the integrands are smoothly varying as a function of the integration variable, 2) integration along the real axis with the fast Fourier transform technique, and 3) analytical integration with the modified saddle point method. Both the transmitter and the receiver are placed very near the interface. While the analytical result is good only at the larger distances from the transmitter, the numerical integration methods provide savings in computer time for small distances from the transmitter. Thus the analytical and numerical methods are good complements of each other. All three approaches yield essentially identical results over the distance ranges of interest. The theoretical results are compared with recent experimental measurements.