11-04-2012, 02:44 PM
RF MEMS in Wireless Architectures
26-4.ppt (Size: 7.75 MB / Downloads: 179)
Introduction:
Miniaturization of Transceivers
need for high-Q
merged transistor/MEMS process
MEMS Components for RF Front Ends
micromechanical RF switches
tunable micromechanical C’s & L’s
vibrating micromechanical resonators
LSI Micromechanical Circuits
Conclusions
MEMS Replaceable Components
Micromachined versions of off-chip components, including vibrating resonators, switches, capacitors, and inductors, could maintain or shrink the size of future wireless phones
Micromechanical Switch
Performance: I.L.~0.1dB, IIP3 ~ 66dBm (extremely linear)
Issues: switching voltage ~ 50V, switching time: 1-5ms
Larger Capacitive Tuning Range
Use comb-transducers to actuate multiple plate capacitors
Left: lateral comb-capacitor in deep RIE’ed silicon
Nearly 250% tuning range with ~100V of actuation input
Out-of-Plane Micromachined Inductor
Molybdenum-chromium metal solenoids perpendicular to the plane of the substrate
reduced substrate loss high Q
Assembled out-of-plane via curling stresses, then locked into place
Record Q’s: ~70 on glass, ~40 on 20W-cm silicon (85 w/ Cu underside)