Design and Analysis of a L-Band Metasurface Based Bandpass Filter for GPS Application

This paper presents the design and analysis of an L-band metasurface-based single layer, single band, low loss bandpass filter for GPS applications. The proposed device further offers very good out of band rejection along with very low transmission coefficient of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{- 0. 2 3} \mathbf{d B}$</tex>. The filter has been designed using FR-4 substrate <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(\varepsilon_{r}=4.4$</tex> and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\tan \delta=0.025)$</tex> for operating at 1.564 GHz which is intended for use in navigation systems such as GPS and GLONASS. Single layer substrate is used and step by step evaluation of design is performed. The results show that the metasurface filter offers improved selectivity, reduced size, increased design flexibility and narrow bandwidth. Navigation systems such as GPS and GLONASS rely on accurate and reliable signal processing to provide location and timing information. The filter exhibits uniform response for phase variation due to four-fold symmetry of the proposed structure along with angular stability up to 40°.