A non-dispersive spiral antenna for UWB applications

Broadband antennas are very useful in many applications as they operate over a wide range of frequencies. The objective of this paper is to study the transient response of the spiral antenna over broad frequency ranges. As such, the phase response of the antenna as a function of frequency is of great interest. In the ensuing analysis, the antenna is excited by a monocycle pulse. The antenna has a dispersed output response. This paper deals with ways of converting the resonating spiral antenna to a non-dispersed antenna by using resistive loading. Appropriate loading increases the bandwidth of operation of the antenna. But the drawback is the additional loss in the load applied to the antenna structure, leading to loss of efficiency to around fifty percent.