Utilization of fractal geometry for phase shifter implementation

Abstract

This paper reports a study on the modified implementation of MEMS-based phase shifter devices. The field of Microelectromechanical Systems or MEMS had gained prominence in academic research during 1990s and has proved capability in the design and development of several RF devices, phase shifters being a crucial member in the group. Fractal curve, an iterative structure, mapping several points in two-dimensional space is employed to modify the structural layout of MEMS-based phase shifters. Higher order phase shifters like 90° and 180° require several MEMS bridges cascaded linearly on a Coplanar Waveguide (CPW) based transmission line (t-line), thus occupying large lateral length (~few mm) and involving immense substrate wastage. MEMS phase shifters designs based on the iterative structure of Fractal Curve occupies lesser space and reports much lower loss performance when compared with linear cascaded structures in RF simulators.