Design Of Miniaturized Rf Mems Phase Shifter Using Mems Switches

Abstract

Radio frequency micro electro mechanical systems (RF MEMS) phase shifter is used in beam steering application of antenna arrays to electronically steer the beam. Nowa- days, MEMS devices are widely used for various applications ranging from switches to sensors. This thesis presents the design, simulation modeling, and analysis of low voltage RF MEMS switches and miniaturized MEMS phase shifters. The primary aim of this thesis is focused on developing high performance MEMS switches and design a 5-bit miniaturized phase shifter. One of the unique features of the proposed switch is a triangular shaped with improved characteristics such as low actuation voltage, high isolation, low insertion loss, low-stress factor, and good return loss. The MEMS switch is designed in a series configuration with coplanar waveguide (CPW) implementation. The design of novel triangular switch consists of the step by step characteristics of the rectangular, triangular and proposed triangular low voltage switch for RF, mechan- ical, and the phase shifts are studied and compared. A detailed parametric analysis and RF performance simulations of the proposed switch is performed using finite ele- ment method (FEM) based Ansoft HFSS* , and mechanical analysis is performed on Intellisuite* MEMS software. The performance of the triangular switch showed an insertion loss of about 0.2 dB and return loss of 20 dB, at the ON state, whereas at the OFF state, isolation is around 26 dB at DC - 20 GHz. Further, pull-in voltage of the proposed design is optimized to 5.6 V with the maximum induced stress of about 5 MPa. The proposed low voltage triangular switch is used to build the miniature phase shifter