Time-Domain Planar Near-Field Measurement Simulation for Wideband RCS and Antenna

This paper describes an UWB RCS/antenna planar near field (PNF) measurement system under construction to get the wideband RCS or the impulse response and transient characteristic of UWB antenna. A metal plate´s bistatic RCS measurement under TD-PNF was simulated and also was compared with the FD-PNF measurement result. The results show good agreement. Unlike the conventional antenna or RCS time domain test system, the UWB radar signal instead of the no-carrier short time pulse was used to excite the antenna that can avoid the decrease of the dynamic range. FDTD is used to calculate the transient E-field of MtimesN points in a fictitious plane just like the actual PNF sampling signals in the time domain (TD). The calculated results can be considered the actual oscilloscope´s sampling output signals. Through time domain near to far field transform, we get the almost same radiation pattern comparing to the FD measurement and the software simulation results.