Novel High Isolation and High Capacitance Ratio RF MEMS Switch: Design, Analysis and Performance Verification

Abstract

In this paper, a novel high isolation and high-capacitance-ratio radio-frequency micro-electromechanical systems (RF MEMS) switch working at Ka-band is designed, fabricated, measured and analyzed. The proposed RF MEMS switch mainly consists of a MEMS metallic beam, coplanar waveguide (CPW) transmission line, dielectric layer and metal–insulator–metal (MIM) fixed capacitors. The measured results indicate that the insertion loss is better than 0.5 dB at 32 GHz, and the isolation is more than 35 dB at the resonant frequency. From the fitted results, the capacitance ratio is 246.3. Compared with traditional MEMS capacitive switches, this proposed MEMS switch exhibits a high capacitance ratio and provides a wonderful solution for cutting-edge performance in 5G and other high-performance applications.

Implementation of Highly Reliable Contacts for RF MEMS Switches

“…Due to the advantages of having a simple driving structure and fast response speed, electrostatic driving has become the preferred driving method for RF MEMS switches [ 1 ]. The reported electrostatic drive switches include all four types: series contact, series capacitor, shunt contact, and shunt capacitive [ 9 , 10 , 11 , 12 , 13 ]. Among them, electrostatic-driven direct contact switches have exhibited several advantages over other types of switches, such as better isolation in the commonly used low-frequency band and higher reliability [ 14 ].…”

Design and Demonstration of Radio Frequency Micro Electro-Mechanical System Switches with Meandered Beams for Reduced Actuation Voltage

“…As an example, the sole membrane employed in [17] has a footprint of 1600 × 240 µm 2 . Regarding the design of the beams, some examples can be traced in the recent literature, such as the fabricated samples described in [18,19], which are characterized by clamped-clamped structures with folded or convoluted beams and by the actuation voltages of 16 V and 5.8 V, respectively. Simulated clamped-clamped membranes with meandered and serpentine-shaped beams are reported in [20,21], featuring estimated pull-in voltages of 3.3 V and 2.5 V, respectively, while the simulated cantilever structures detailed in [22,23] displayed actuations at 9.1 V and 7.3 V.…”

Ultrabroadband (DC–80 GHz) RF MEMS DC/capacitive load shunt switch

“…Thus far, a single switch has not achieved high isolation from DC to the millimeter frequency range. [8][9][10] Shunt capacitive contact switches operate based on the capacitance that is determined by the combined overlapping area of both the top and bottom electrodes. The area of the bottom electrode and the dielectric present on top of this bottom electrode are fixed.…”

“…However, below 16 GHz, these switches are found to be nonfunctional. Thus far, a single switch has not achieved high isolation from DC to the millimeter frequency range 8–10 . Shunt capacitive contact switches operate based on the capacitance that is determined by the combined overlapping area of both the top and bottom electrodes.…”