Electromagnetically actuated MEMS switches for optical and RF communication systems

Abstract

New electromagnetically actuated MEMS switches for optical and RF communication systems have been proposed to obtain mechanically robust structures and increase performances using large actuation forces. First, a new three-axis actuated micromirror for optical switch has been proposed and fabricated. This fabricated micromirror operates electromagnetically using an external magnetic field. The maximum actuation angle of three-axis actuated micromirror has been measured as ±4.2˚ for x-axis actuation, ±9.2˚ for y-axis actuation and ±42㎛ for z-axis actuation, respectively with an actuation voltage below 3V. The measured ROC of the fabricated micromirror is 7.72cm and the surface roughness of the surface of micromirror is 1.29 nm. The third z-axis actuation of the fabricated micromirror reduces the difficulty of assembly and increases the coupling efficiency of the micromirror based optical systems with large degree of freedom. Next, low voltage and low power series type and shunt type RF MEMS switches actuated by ingenious combination of electromagnetic and electrostatic forces are proposed and fabricated. From large electromagnetic force, the proposed RF MEMS switch can allow a large initial gap between the actuator and signal lines, resulting in good isolation at off state of the series type switch and least coupling of signal to the ground line of the shunt type switch. In addition to that, large actuation force can provide a mechanically robust structure to guarantee reliable operation. The fabricated switches have been performed mechanical and RF measurements. The actuation voltage is below 3V and holding voltage is below 4V. The required energy for actuation is 40.3μJ for series type switch and 87.9μJ for shunt type switch per switching, respectively. Also, the fabricated switches can be operated within several hundreds microsecond. In series type switch, the isolation is -34dB and insertion loss is -0.37dB at 20GHz. In shunt type switch, the isolation is...