%0 Journal Article
%A Ruiz Martínez, Juan de Dios
%A Martínez Viviente, Félix Lorenzo
%A Hinojosa Jiménez, Juan
%T Optimization of chirped and tapered microstrip koch fractal electromagnetic band gap (KFEBG) structures for improved low-pass filter design
%D 2015
%@ 1751-8725
%U http://hdl.handle.net/10317/5402
%X This study presents electromagnetic bandgap (EBG) structures in microstrip technology based on onedimensional
Koch fractal patterns (Koch fractal EBG (KFEBG)). This fractal geometry allows to adjust the radius r and
distance a between patterns so that a low-pass filter response is obtained when the ratio r/a is higher than 0.5.
However, in such case undesired strong ripples appear in the low bandpass region. We demonstrate that the
performance in the passband of this filter can be improved by applying a tapering function to the Koch fractal
dimensions and to the width of the microstrip line, while simultaneously chirping (modulating) the Koch fractal
periodic pattern distance (a) so as to maintain a constant r/a ratio. Several tapering functions scaled by a factor K are
presented, and the results of their application to the KFEBG microstrip structure are compared by means of relevant
characteristic parameters. Optimal performance has been obtained for the Kaiser and Cauchy distributions applied to
the Koch fractal pattern, combined with a rectangular and Cauchy distribution applied to the microstrip width, respectively.
%K Electromagnetic bandgap (EBG)
%K Koch fractal EBG (KFEBG)
%K 2202 Electromagnetismo
%~ GOEDOC, SUB GOETTINGEN