The RF MEMS switches developed today, even if quite
small, still follow the basic mechanical laws developed
200-400 years ago. However, the scale and relative importance
of the forces acting on the switches are significantly
different from the macro-world we experience
daily. Surface forces and viscous air damping dominate
over inertial and gravitational forces. The switches are
either fabricated using a fixed-fixed membrane or a
floating cantilever (diving-board design) and are modeled
as mechanical springs with an equivalent spring
constant, k [N/m] (Figures 2 and 3). The spring constant
depends on the geometrical dimensions of the
membrane or cantilever and on the Young’s modulus of
the material used (Au, Al, nitride, etc.) [1], [2] and is
5-40 N/m for most RF MEMS switch designs. The
switches have very low mass, around 10-10-10-11 kg and,
therefore, are not sensitive to acceleration forces