Go to ieeexplore and add this paper once it's available:

G. Fedder and T. Mukherjee, Tunable RF and Analog Circuits Using On-Chip MEMS Passive Components, 
in Proceedings of the IEEE International Solid-State Circuits Conference (ISSCC '05), 
pp. 390-391, February 6-10, 2005, San Francisco, CA.