Variable spring constant, high contact force RF MEMS switch

This paper presents the design, fabrication and measurements on a novel metal-contact RF MEMS switch with variable spring constant and high contact and release forces. The spring constant of the switch dramatically increases when the applied voltage is larger than the threshold voltage (V
t
), defined when the tip touches a dielectric block. This design shows a total contact force and restoring force of 0.6 – 1.1 mN and a 0.5 mN, respectively, for an actuation voltage of 75–90 V. The measured switching time is < 10 µs. The switch is an excellent candidate for high performance microwave applications requiring high power handling and a large contact force.