Accurate measurement and FDTD simulation of the efficiency-bandwidth product for dielectric loaded antennas

There are several criteria for antenna evaluation. The authors have studied on the efficiency-bandwidth product (EB) for small dielectric loaded antennas (DLAs). The EBs of DLAs were accurately measured and compared with calculated ones. The calculation simulated the procedure of the Wheeler (1947) cap method. Enhancement of the EB was observed even with the loading of lower permittivity. There seemed to be an optimum value for permittivity of the loading. It was also confirmed that some DLAs with a smaller electrical volume gave the better EB than the larger ones.