Compact fully anechoic chambers may gradually replace open area test sites as the preferred type of testing facility for the measurement of radiated emissions. This dissertation theoretically and experimentally investigates the suitability of a compact fully anechoic chamber with ferrite tiles being partially lined on the floor ground as a free-space environment at frequency range below 300MHz. The results show that, for vertical polarization, the practical chamber will behave like a free-space test site. However, for the horizontal polarization, it seems have relatively significant effect on the NSTL performance and will not behave well like a free-space test site. Based on FDTD modeling approach, a numerical tool with the measuring tunable dipole antennas being considered is established to simulate the NSTL performance of the compact EMC chamber with different layout design of ferrite tiles. Furthermore, several designs of reduced coverage of the ferrite tiles in the compact chamber are proposed and discussed. In addition, this dissertation also investigates the correlation test of a 3m fully anechoic chamber ¡]FAC¡^ and a 10m semi-anechoic chamber ¡]SAC¡^ at frequency range from 80MHz to 1000MHz. Based on correction factor between two test sites, the EMI behaviors of the EUT in a 10m SAC could be predicted rapidly at frequency from 200MHz to 900MHz. Thus, a 3m FAC has been expected to provide a low cost as a pre-compliance test site, if the predicted EMI behaviors of the EUT are close to the practical measured results in a 10m SAC.