A MEMS-Based Wide-Band Multi-State Power Attenuator for Radio Frequency and Microwave Applications

In this work we present a novel implementation of a multi-state RF (Radio Frequency) power attenuator, entirely realized in MEMS (MicroElectroMechanical-Systems) technology. The network, based on a CPW (Coplanar Waveguide) structure and fabricated in FBK technology, features several resistors realized with an highly-doped poly-silicon layer. Each resistor can load the RF line or can be shorted, depending on the state (actuated/not actuated) of electrostatically controlled suspended membrane-based MEMS switches. The network realizes 128 attenuation levels with flat characteristics over broad frequency ranges. The network features two sections, namely a series and a parallel one, that are experimentally characterized in a few of the possible configurations up to 30 GHz and simulated within CSTTM Microwave Studio. After validating the simulated results for the two sections, simulated results of the whole RF-MEMS-based power attenuator are presented and discussed.