RF MEMS switches are an emerging solution for wireless technology, but these devices typically require large switching voltages and have problems with long term reliability.

A new piezoelectric RF MEMS switch design from the University of Pennsylvania could overcome many of the challenges of electrostatic switches. This design provides a solution with high isolation, low insertion loss, and low power consumption.

In this dual-beam switch, an electric field is used to control the actuation of a thin aluminum nitride piezoelectric membrane. The two beams of the switch are pushed toward each other in the closed state and pushed apart in the open state via the piezoelectric action. Both beams are actuated simultaneously, which avoids the problems other MEMS switches face from residual stress and inconsistent air gap. The resulting design has a low switching voltage (<20V) and fast switching times (<2 μs). The design of this switch is compatible with CMOS fabrication, allowing for easier on-chip integration.

• Direct CMOS compatible fabrication
• Low switching voltage <20V
• Fast switching time <2 μs
• Increased reliability, avoids issues with process-induced inconsistent airgaps