Improvement in efficiency-bandwidth product in small dielectric loaded antennas

The efficiency-bandwidth product (EB) is used in the evaluation of small dielectric loaded monopole antennas (DLMAs). The EBs of the DLMAs have been precisely measured on the basis of the Wheeler cap method. As a result, an improvement in the EB of electrically small cylindrical DLMAs has been confirmed experimentally in comparison with that in a bare monopole antenna. In addition, within the category of electrically small antennas considered here, it seems that there exists an optimum value of permittivity for the dielectric loading for which the best EB value is obtained.