Efficient characterization of UWB antennas using the FDTD method

In this paper, we present a method for the efficient characterization of UWB antennas based on a combination of FDTD simulation and the Lorentz reciprocity principle. In order to obtain a complete spatio-temporal characterization it is sufficient to determine the transmit transfer function by using first a single numerical simulation of the antenna in transmit mode, in only a small nearfield region, followed by a nearfield to farfield transformation. The application of the Lorentz reciprocity theorem then yields the receive transfer function from the transmit transfer function. The transfer functions of the antenna allows the calculation of all quality measures of interest either in the frequency domain or the time domain. The proposed method is validated by a comparison of its results with an EMPIRE™ FDTD simulation of an entire two antenna system.