This paper appears in: Solid-State Circuits, IEEE Journal of
Publication Date: Apr 2000
Volume: 35,
Issue: 4
On page(s): 512-526
ISSN: 0018-9200
References Cited: 36
CODEN: IJSCBC
INSPEC Accession Number: 6601061
Digital Object Identifier: 10.1109/4.839911
Current Version Published: 2002-08-06
Abstract
IC-compatible microelectromechanical intermediate frequency
filters using integrated resonators with Q's in the thousands to achieve
filter Q's in the hundreds have been demonstrated using a polysilicon
surface micromachining technology. These filters are composed of two
clamped-clamped beam micromechanical resonators coupled by a soft
flexural-mode mechanical spring. The center frequency of a given filter
is determined by the resonance frequency of the constituent resonators,
while the bandwidth is determined by the coupling spring dimensions and
its location between the resonators. Quarter-wavelength coupling is
required on this microscale to alleviate mass loading effects caused by
similar resonator and coupler dimensions. Despite constraints arising
from quarter-wavelength design, a range of percent bandwidths is still
attainable by taking advantage of low-velocity spring attachment
locations. A complete design procedure is presented in which
electromechanical analogies are used to model the mechanical device via
equivalent electrical circuits. Filter center frequencies around 8 MHz
with Q's from 40 to 450 (i.e., percent bandwidths from 0.23 to 2.5%),
associated insertion losses less than 2 dB, and spurious-free dynamic
ranges around 78 dB are demonstrated using low-velocity designs with
input and output termination resistances of the order of 12 kΩ
Index
Terms
Available to subscribers and IEEE members.
References
Available to subscribers and IEEE members.
Citing Documents
Available to subscribers and IEEE members.