Time domain response of a UWB dipole array for impulse based chipless RFID reader

The time domain response of an ultra-wideband (UWB) 2 × 2 element dipole array is presented. The antenna is an elliptically shaped dipole array with a circular back reflector. It is operating over 3.9-9.5 GHz frequency band with >;9 dBi gain and 40° average 3 dB beamwidth. The forward transmission coefficient (S
₂₁
) vs frequency of two identical antennas were measured at a fixed distance. The measured data is transformed to time domain to calculate the transient response of the antenna. Measured transient response of the antenna shows good time domain response with a sharp peak and a low ringing time. Experimental verification of the time domain performance shows good agreement with the measured results. The antenna is suitable for using as reader antennas in reading multi-resonator based chipless RFID tags with pulse based interrogation techniques.