Silicon bulk micromachined RF MEMS switches with 3.5 volts operation by using piezoelectric actuator

In this paper, fully integrated RF MEMS switches with piezoelectric actuation have been designed, fabricated, and characterized by using silicon bulk micromachining technology. Two different types of RF MEMS switches are proposed. One is a resistive type having a pure gold metal contact and the other is a capacitive type, which is comprised of Au/AlN/Au dielectric capacitor. Reliable and reproducible operations of these resistive and capacitive switches can be carried out at 3.5 volts. The measured isolation and insertion loss of the resistive are -62 dB and -0.8 dB switch at a frequency of 5 GHz, respectively. The capacitive switch exhibits an isolation of -18 dB and an insertion loss of -0.7 dB at a frequency of 5 GHz. The isolation curve of the capacitive switch is very flat over a very wide frequency ranged from 0.5 GHz to 30 GHz. The switching times of these switches are 4 μsec at the rising and 20 μsec at the falling actuation, respectively.