Band-Pass filters using OSRR cells

Abstract

This paper presents the design process (including optimization and characterization) of a band-pass filter through the use of OSRR-structured meta-material cells over micro-strip substrates. The proposed design, which stems from the OSRR cell model, includes a partial ground plane etched at the bottom plane instead of, and square windows etched at the bottom plane and achieve optimization through a parametric analysis carried out over the transmission-line segments that connect the cells to the main transmission line as well as over inter-cell lines. The results yielded a resonance central frequency and a corresponding bandwidth of 2.7 GHz and 700MHz, respectively. By controlling the length of the connecting lines from the cells to the main transmission line, it is possible to tune the central frequency to a lower frequency than that of an OSRR cell. With respect to the ground plane windows version, the partial ground plane version has the capacity to add transmission zero (4.6GHz) above a/the transmission pole, which improves the rejection depth (8dB) without increasing the filter size.