RF-MEMS switching concepts for high power applications

Mechanical modelling of capacitive RF MEMS shunt switches

“…c F is the contact contribution, which can be divided in the Van Der Waals and surface forces, the first acting as attracting and the second one as repulsive, with a possible equilibrium position at a given distance from the bottom electrode of the switch [5]. Currently, many papers about the dynamics of the switch are available in literature (see, for instance, [10] and related references, or [3]), including also possible collateral effects due to the Casimir force [11], [12] or self-actuation mechanisms due to the RF power [13]. The capacitance of a shunt capacitive MEMS switch can be described in terms of two series capacitors, each of them having its own dielectric constant.…”

Dynamics of RF Micro-Mechanical Capacitive Shunt Switches in Coplanar Waveguide Configuration

“…In many physical situations, the condition 21    holds. This will depend on the geometry of the bridge and on the intrinsic damping of the medium.…”

“…In fact, this is the real case for devices implemented in RF configurations using the switch as a building block because, for application purposes, the RF and the DC paths have to be distinguished between them. Currently, many papers about the linear and non-linear dynamics of the switch are available in literature [3], [16]- [18] , including also possible collateral effects due to the Casimir force [19] [20] or self-actuation mechanisms due to the level of the RF power [21]- [23]. Actually, power is a quantity to be carefully considered for potential applications in bolometers, and for this reason self-actuation was also proposed in nano-and microsystems to get the power value from the actuation onset [24].…”

Electrothermally Actuated RF MEMS Switches Suspended on a Low-Resistivity Substrate

“…So far, several topologies and solutions have been proposed in literature to improve the RF power handling [12], [13], [35].…”