HFSS Simulation and VNA Measurement of Transmission Coefficient and Group Delay of UWB Vivaldi Antenna

#Antenna #UWB #Vivaldi

Speaker: Md. Nazmul Hasan

Vivaldi antennas are planar traveling wave antennas which have wide bandwidth. Ultra-wide band (UWB) antennas are a category of wide band antennas that operate with narrow pulses. For the UWB antenna, the investigation of dispersion characteristics is essential, unlike narrowband antennas. Dispersion means the stretching of various frequency components of the signal. This stretching of various frequency components of the signal distorts it which is undesirable effect. One way to quantify dispersion is by observing the group delay. For UWB antennas, the group delay must remain constant with respect to frequency. A flat group delay indicates the phase of the transmission coefficient (S21) is linear with respect to frequency. This ensures the signal from antenna is free from dispersion. In this talk, the simulation of Vivaldi antenna will be presented in HFSS. After that, the measurements of the group delay and S21 by using a VNA will be demonstrated.