KEYWORDS: Switches, Single point diamond turning, Microelectromechanical systems, Ku band, X band, Signal attenuation, Inductance, Microwave radiation, Semiconductors, Waveguides
This paper describes the design and simulation of RF MEMS SPST shunt and SPDT shunt-shunt switches with modified
coplanar waveguide (CPW) configuration for X-band and Ku-band applications exhibiting high isolation and low
insertion loss. By modifying the basic CPW structure for a six-strip membrane having length 720 μm, the resonant
frequency can be reduced from 33.5 GHz to 13.5 GHz with isolation as high as -30 dB(-63 dB at resonant frequency) in
Ku-band. Similar results are also found in case SPST and SPDT switches with other membrane types.
The mechanical properties of the structural layer play an important role in the design and optimization of microelectromechanical system structures. The pull-in measurement is a popular technique used to measure the mechanical properties of a material, but its success depends on the accurate measurement of the gap (g) between the beam and the ground plane and its uniformity. We propose a novel technique that does not require accurate knowledge of the value of g. In our proposed method, a large number of beams with different lengths (L) are to be fabricated simultaneously and the off-capacitance (Coff) in addition to pull-in voltage (Vpi) measured in the same setup. To get accurate results, the range of length of beams must be properly chosen. We show, with the help of simulations, that by using our method the material properties can be extracted very accurately even when the gap (g) is nonuniform.
A low-temperature wet-release process for low stiffness structures fabricated using material of low Young's modulus has been developed and presented. The release process is described in the light of different forces that cause stiction during release. This technique is successfully demonstrated for different low stiffness structures with gold as the membrane material and positive photoresist or SiO2 as the sacrificial layer.
The mechanical properties of the structural layer play important role in the design and optimization of MEMS structures.
The pull-in measurement is a popular technique used to measure the mechanical properties of a material, but its success
depends on the accurate measurement of the gap (g) between the beam and the ground plane and its uniformity. In this
paper we propose a novel technique which does not require accurate knowledge of the value of 'g'. In our proposed
method, a large number of beams with different lengths (L) are to be fabricated simultaneously and the off-Capacitance
(Coff) in addition to pull-in voltage (Vpi) measured in the same set-up. This is followed by a plot of (C3off V3piL4/A3)vs (1/A) for beams under bending dominating condition and (C3off V2piL2/A3) 1/A for beams under stress dominating condition, where A is the area of a beam. The plots are extrapolated to intersect the y-axis. The value of the intercept can
be used to extract the values of Young's modulus and residual stress, without any definite knowledge of the value of 'g'.
In this paper, we have shown with the help of simulations that using our method the material properties can be extracted
very accurately even when the gap (g) is very nonuniform.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.