Novel microstrip bandpass filter with substrates of fractal Cantor distribution

Abstract

In this paper, microstrip line with fractal Cantor distributing substrates is investigated. Transmission matrix method is used to calculating the transmittance and reflectance. Comparing with periodic distributing substrates, microstrip line with fractal Cantor distribution shows sharp resonances inside gap. The resonances in somewhere split and form more peaks with increasing of the number of generation. According to these properties, a novel bandpass filter is proposed, the bandpass filter centered at 10.69 GHz has 8.8% 3 dB fractional bandwidth and two transmission zeros.