RF MEMS DPDT Switch

The paper explores the modelling and simulation of a Radio Frequency Micro Electro-Mechanical Systems (RF MEMS) switch with the use of a novel seesaw design providing Double-Pole Double-Throw (DPDT) functionality. This optimises the capabilities of the seesaw design structure for use in mobile communications systems and devices. After researching other available seesaw designs, it was realised that an improvement could be achieved by applying additional contacts. During its development, the DPDT switch achieved a low electrostatic actuation voltage of 14 V, providing the switch with improved compatibility for common voltage levels used in mobile devices. The switch is a progression of existing Single-Pole Single-Throw (SPST) seesaw switches, with an additional set of upper and lower contacts at each side of the seesaw, offering DPDT switching capabilities. The length of the switch is 41 μm, which is a suitable size for fabrication and conforms to the Microscale, from 1 μm to 100 μm. Copper Bulk General (Cu) was chosen for the pivot material on its merits of possessing good electrical conductivity and optimised flexibility and stiffness for elastic recovery. The simulation attained a working switch design with an ‘Air-Gap’ of 1μm between the contacts, thus providing isolation while the switch is open-circuited.