Mechanically Coupled Contour Mode Piezoelectric Aluminum Nitride MEMS Filters

Stephanou, P.J.; Piazza, Gianluca; White, Carolyn D.; Wijesundara, Muthu B. J.; Pisano, Albert P.

doi:10.1109/memsys.2006.1627947

Cited by 20 publications

(13 citation statements)

References 7 publications

(8 reference statements)

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“…To improve insertion loss, multiple resonators have been strongly coupled to increase transduction area in two-pole filters [22]. Alternatively, sets of 1D filters coupled electrically in parallel have been proposed and demonstrated [23]. However, pure electrical coupling does not ensure a coherent summation of the filter passband due to small variations between each electrically parallel 1D filter.…”

Section: Theorymentioning

confidence: 99%

The Resonant Body Transistor

2010

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Cornell University 2009With quality factors (Q) often exceeding 10,000, vibrating micromechanical resonators have emerged as leading candidates for on-chip versions of high-Q resonators used in wireless communications systems, sensor networks, and clocking sources in microprocessors. However, extending the frequency of MEMS resonators generally entails scaling of resonator dimensions leading to increased motional impedance. In this dissertation, I introduce a new transduction mechanism using dielectric materials to improve performance and increase frequency of silicon-based RF acoustic resonators.Traditionally, electrostatically transduced mechanical resonators have used air-gap capacitors for driving and sensing vibrations in the structure. To increase transduction efficiency, facilitate fabrication, and enable GHz frequencies of operation, it is desirable to replace air-gap transducers with dielectric films.In my doctoral work, I designed, fabricated, and demonstrated dielectrically transduced silicon bulk-mode resonators up to 6.2 GHz, marking the highest acoustic frequency measured in silicon to date. The concept of internal dielectric transduction is introduced, in which dielectric transducers are incorporated directly into the resonator body. With dielectric films positioned at points of maximum strain in the resonator, this transduction improves in efficiency with increasing frequency, enabling resonator scaling to previously unattainable frequencies. Using internal dielectric transduction, longitudinal-mode resonators exhibited the highest frequency-quality factor ( f Q) product in silicon to date

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Section: Theorymentioning

confidence: 99%

The Resonant Body Transistor

2010

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“…Piezoelectric actuation in aluminum nitride contour-mode resonators has been proven as a superior technology [6,[11][12][13][14], capable of intrinsically providing low motional resistance (25 to 1000 Ω) while maintaining high quality factors (1,000-2,500) and reasonable reactance values that ease their interface with state-of-the-art circuitry. This between a top and bottom electrode, the MEMS structure tends to expand laterally and can be excited in resonant vibrations whose frequency is set by the in-plane dimensions of the device [6].…”

Section: Introductionmentioning

confidence: 99%

One and two port piezoelectric higher order contour-mode MEMS resonators for mechanical signal processing

Piazza¹,

Stephanou²,

Pisano³

2007

Solid-State Electronics

121

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This paper reports on the design, fabrication and testing of novel one and two port piezoelectric higher order contour-mode MEMS resonators that can be employed in RF wireless communications as frequency reference elements or arranged in arrays to form banks of multi-frequency filters. The paper offers a comparison of one and two port resonant devices exhibiting frequencies approximately ranging from 200 to 800 MHz, quality factor of few thousands (1000-2500) and motional resistances ranging from 25 to 1000 Ω. Fundamental advantages and limitations of each solution are discussed. The reported experimental results focus on the response of a higher order one port resonator under different environmental conditions and a new class of two port contour resonators for narrow band filtering applications. Furthermore, an overview of novel frequency synthesis schemes that can be enabled by these contour-mode resonators is briefly presented. Keywords AbstractThis paper reports on the design, fabrication and testing of novel one and two port piezoelectric higher order contour-mode MEMS resonators that can be employed in RF wireless communications as frequency reference elements or arranged in arrays to form banks of multi-frequency filters. The paper offers a comparison of one and two port resonant devices exhibiting frequencies approximately ranging from 200 to 800 MHz, quality factor of few thousands (1,000-2,500) and motional resistances ranging from 25 to 1000 Ω. Fundamental advantages and limitations of each solution are discussed. The reported experimental results focus on the response of a higher order one port resonator under different environmental conditions and a new class of two port contour resonators for narrow band filtering applications. Furthermore, an overview of novel frequency synthesis schemes that can be enabled by these contour-mode resonators is briefly presented.

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“…In addition, electrical cascading of resonators offer rapid implementation of complex designs with zeros (also known as attenuation poles) in the filter transfer function. Advantages of mechanically coupled resonators include the ability to set the bandwidth of the filter independently of material properties [23] and the ability to improve out-of-band rejection. Theoretically the use of mechanically coupled resonators eliminates the limit on the maximum achievable bandwidth imposed by the material properties, and increases the out-of-band rejection by eliminating the parallel capacitance of the device.…”

Section: Resonator Arraysmentioning

confidence: 99%

Single-Chip Multiple-Frequency ALN MEMS Filters Based on Contour-Mode Piezoelectric Resonators

Piazza

Stephanou

Pisano

2007

J. Microelectromech. Syst.

207

115

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This paper reports experimental results on a new class of single-chip multiple-frequency (up to 236 MHz) filters that are based on low motional resistance contour-mode aluminum nitride piezoelectric micromechanical resonators. Rectangular plates and rings are made out of an aluminum nitride layer sandwiched between a bottom platinum electrode and a top aluminum electrode. For the first time, these devices have been electrically cascaded to yield high performance, low insertion loss (as low as 4 dB at 93MHz), and large rejection (27 dB at 236 MHz) micromechanical bandpass filters. This novel technology could revolutionize wireless communication systems by allowing cofabrication of multiple frequency filters on the same chip, potentially reducing form factors and manufacturing costs. In addition, these filters require terminations (1 kOmega termination is used at 236 MHz) that can be realized with on-chip inductors and capacitors, enabling their direct interface with standard 50-Omega systems. This material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE endorsement of any of the University of Pennsylvania's products or services. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to pubs-permissions@ieee.org. By choosing to view this document, you agree to all provisions of the copyright laws protecting it.

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Mechanically Coupled Contour Mode Piezoelectric Aluminum Nitride MEMS Filters

Cited by 20 publications

References 7 publications

The Resonant Body Transistor

The Resonant Body Transistor

One and two port piezoelectric higher order contour-mode MEMS resonators for mechanical signal processing

Single-Chip Multiple-Frequency ALN MEMS Filters Based on Contour-Mode Piezoelectric Resonators

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