Three-bar novel RF MEMS switches

In this paper we report two novel RF MEMS series switches. The novel cantilever beam structures are supported by three low spring constant cantilever beam springs at the fixed end of the bridge. Design-2 has an additional extended cantilever beam structure at the front which further reduces the spring constant of the beam design. The spring constants of the cantilever beams are 3.37N/m and 3.31N/m respectively. The fabricated switches are electrostatically actuated and have achieved an actuation voltage of 19V and 23V respectively. The variation in the actuation voltage has been studied in relation to the presence of residual stress in the beams during the fabrication. The switches have shown good RF performance exhibiting isolation better than 24dB and 29dB respectively. The reported cantilever beam designs can easily be integrated into large multiport structures.