A THEORETICAL STUDY OF DIELECTRIC-COATED CYLINDRICAL ANTENNAS
HARVARD UNIV CAMBRIDGE MA CAMBRIDGE United States
Pagination or Media Count:
A cylindrical antenna, either infinite or finite, which is imbedded in a concentric dielectric rod has been investigated by employing a rigorous formulation. The infinite case is solved easily by a Fourier transform method the finite case is solved first by a numerical method, then by a two-term approximation. The mathematical analysis is intricate, nevertheless, the results obtained for the finite antenna are as simple as for the free-space dipole. It is shown in both cases that the input conductances are larger than for the corresponding free-space antennas, and the field patterns tend to be more broadside. The method is applicable regardless of the thicknesses of the antennas and the dielectric rod. This study is limited to thin antennas in rather thick dielectric cylinders. However, the dielectric rod is still not thick enough to support a T. M. mode.