UWB performance of single and multi layer dielectric Vivaldi antenna using cubic spline and exponential taper profile

Four Vivaldi antenna tapers were designed using a cubic spline and exponential fit to a stepped Chebychev transformer, and implemented in single layer and multilayer dielectric slot-line configurations on two different substrate materials. The three-antenna method was exploited to measure antennas transfer functions and by that impulse responses were computed. The results show that the single layer dielectric exponential and cubic-top point designs have the best impulse response in amplitude, rise time, and height of initial pulse, with minimal ringing, relative to the cubic-bottom design and while for the multilayer dielectric design a higher substrate loss reduces the magnitude of the transfer function, there is little degradation of the pulse performance in terms of rise time and ringing. It is suggested that the ringing is due primarily to limitations in the feeding circuit.