A new electrostatically actuated rotary three-state DC-contact RF MEMS switch for antenna switch applications

In this paper, we present a novel laterally actuated DC-contact three-state RF MEMS switch. Rotary electrostatic comb-drive actuators which can be rotated both clockwise and anti-clockwise are chosen as the drive mechanism of the switch and are integrated inside of the switch, hence the switch has a very compact structure. The proposed switch is designed in such a way that it can be used in antenna switch applications where having high isolation and low insertion loss are of most important operating characteristics. The switch has three operating states of ON, OFF and deep-OFF. Different FEM simulations are carried out in order to optimize RF and mechanical behavior of the switch. The switch has acceptable RF performance in a frequency range from DC up to 40 GHz with near to zero power consumption. The actuation voltage of the switch is 50 V. The switching time from OFF to ON state or deep-OFF state is 79 mu s and return time to OFF state is 130 mu s. The switch has an insertion loss less than -0.87 dB up to 40 GHz, and return loss below -21 dB at the same frequency range. The OFF state and deep-OFF state isolations are -35 and -60 dB up to 40 GHz, respectively.