Effects of Klopfenstein Tapered Feedlines on the Frequency- and Time-Domain Performance of Planar Monopole UWB Antennas

TitleEffects of Klopfenstein Tapered Feedlines on the Frequency- and Time-Domain Performance of Planar Monopole UWB Antennas
Publication TypeConference Paper
Year of Publication2008
AuthorsRuvio, G, Ammann, MJ
Conference NameIEEE AP-S International Symposium on Antennas and Propagation
PaginationSession 505, Paper 9
Conference Start Date05/07/2008
PublisherInstitute of Electronic & Electrical Engineers
Conference LocationSan Diego, CA, USA
Abstract

A Klopfenstein tapered feedline has been introduced in order to modify the mode distribution into a planar monopole UWB antenna under test. By tapering the feedline of the antenna according to a Klopfenstein distribution, multiple resonances occurring within the operating bandwidth can be controlled. A Klopfenstein tapered feedline can gradually match two different resistive terminations in order to reduce reflected waves and maximize the power transferred to a generic load. The impedance condition at the interface between feedline and antenna is a complex function of frequency. However, in this paper a Klopfenstein tapered feedline is demonstrated to be a valid tool to control the depth of resonances of the antenna in order to mitigate phase distortion. On the other hand, as the depth of resonances is decreased to attenuate phase distortion, the overall impedance bandwidth may be reduced, so that a compromise between impedance bandwidth and time-domain response has to be pursued.Different Klopfenstein tapered feedlines have been compared in terms of the resulting phase linearity and group delay of the antenna under test when the load impedance condition and the taper length are tuned. Numerical analysis for the different structures investigated was carried on using the finite integration time domain method, CST Microwave Studio.

URLhttp://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=4619876&isnumber=4618896
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