Numerical models of a hip prosthesis model sited within two different realistic human tissue models have demonstrated that the E-Pulse technique is capable of detecting target depth changes inside a frequency dependent lossy halfspace. The performance is highly related to the dielectric properties of the half space and the excitation frequency. The dispersive attenuation factor of the halfspace and the frequency response of the same target below two different halfspaces were also studied and it is concluded that the attenuation factor, the resonance frequency of the target and the Q factor of the resonant peaks are all closely related and directly affect the E-Pulse detection performance.