CMOS Compatible Fast Switching RF MEMS Varactors

This paper presents fast switching RF-MEMS CMOS compatible varactors. By introducing bended sides on a conventional air bridge, it is shown experimentally that the resonance frequency of aluminum bridges is increased by a factor 2.5. Based on miniature bridges design (around ten times smaller than standard MEMS varactors), presented devices allow to reach higher mechanical resonance frequencies, resulting in faster switching times. Several designs are presented with recorded resonance frequencies between 1 and 3 MHz and measured switching time under 600 ns.