Cyril Guines

Sub-hundred nanosecond electrostatic actuated RF MEMS switched capacitors

This paper presents a new mechanical architecture for RF MEMS components that are able to achieve reconfiguration faster than conventional MEMS switches. For most MEMS switches, the electrical switching speed is generally limited to a few microseconds, inherently restricted by the delay required to mechanically move their mobile membrane up and down. By using a proper mechanical design and the structural material fabrication process, this paper will show miniature bridges that are able to exhibit mechanical resonance frequencies over 10 MHz range to be compared to the few tens of kHz for conventional RF MEMS switches. As a result, the switching speed of these miniature components is greatly improved and reaches 50 to 100 ns. Such performance has been achieved using composite micro-beams based on the multilayer material assembly of alumina/aluminum/alumina. To our knowledge, this is the fastest switching speed reported for RF MEMS components so far.

Out-of-plane and inline RF switches based on Ge 2 Sb 2 Te 5 phase-change material

We present the fabrication and characterization of novel RF switches based on Ge2Sb2Te5 (GST) phase change material. Such ohmic devices show non-volatile switching with resistivity changes up to 105 as the material is transforming between the amorphous and the crystalline state by either applying a voltage pulse or direct heating. We investigated the RF properties and power handling of such devices in two configurations: out-of-plane (GST material between two electrodes) and inline switches. For a directly heated 10-μm length inline switch we measured an on-state resistance of 7 Ω, and an off-state capacitance and resistance of 13.7 fF and 6.47 MΩ, respectively, resulting in a cut-off frequency of ~1.6 THz.

Nanogap MEMS micro-relay with 70 ns switching speed

This paper presents Micro-electro-mechanical relays for very fast switching applications. Prototype relays have been fabricated tested and demonstrated reconfiguration capabilities as fast as 70 ns with a 300 ns additional settling time once electrical contact is fully stabilized. Such switching speed has been previously demonstrated on capacitive RF-MEMS switches, but this is the first time that such a fast mechanical switching is reported on relays, i.e. ohmic contact switches. The ability to open or close a contact at such speed can lead to many applications such as ultra low power electromechanical computing, or harsh environment electronics.

A quasi bistable RF-MEMS switched capacitor

This paper presents a novel concept for the realization of RF-MEMS switched capacitors. The proposed device uses a tilting metal beam combined with a non-linear electrostatic force generated by a DC voltage to maintain the device in two stable mechanical positions. Fabricated devices with relatively simple processing exhibit very low loss and a capacitive contrast of 8.5. Actuation requires only voltage pulses, toggling the device from one position to the other. Actuation voltages, both static and pulsed are in good agreement with simple mechanical modeling.