US Patent 7126447 RF-mems switch

An RF-MEMS switch includes a plurality of movable electrodes disposed with a space provided therebetween in the direction of RF signal conduction of an RF signal-conducting unit which is provided above the RF signal-conducting unit. A movable electrode displacing unit for displacing all the movable electrodes at the same time in the same direction towards or away from the RF signal-conducting unit is provided. The electrical length of the RF signal-conducting unit sandwiched between the movable electrodes is set such that the amplitude of a combined signal including signals reflected in positions of the RF signal-conducting unit facing the movable electrodes is less than the amplitude of each of reflected signals reflected in positions of the RE signal-conducting unit facing the movable electrodes when the movable electrodes are displaced away from the RF signal-conducting unit and signal conduction of the RF signal-conducting unit is switched on.