Thin film bulk wave acoustic resonators (FBAR) for wireless applications

155

119

We demonstrate piezoelectrically actuated, electrically tunable nanomechanical resonators based on multilayers containing a 100-nm-thin aluminum nitride ͑AlN͒ layer. Efficient piezoelectric actuation of very high frequency fundamental flexural modes up to ϳ80 MHz is demonstrated at room temperature. Thermomechanical fluctuations of AlN cantilevers measured by optical interferometry enable calibration of the transduction responsivity and displacement sensitivities of the resonators. Measurements and analyses show that the 100 nm AlN layer employed has an excellent piezoelectric coefficient, d 31 = 2.4 pm/ V. Doubly clamped AlN beams exhibit significant frequency tuning behavior with applied dc voltage.

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confidence: 99%

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confidence: 99%

Piezoelectric nanoelectromechanical resonators based on aluminum nitride thin films

Karabalin

Matheny

Feng

et al. 2009

155

119

“…There has also been active research on the improvement of various aspects of MEMS resonators for frequency filtering applications, such as producing high-Q, high-frequency, and highly selective filters, [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29] Both electrically and mechanically coupled resonators have been demonstrated for filter applications. [10][11][12][13][14][15][16][17] Highly tunable filters were studied, where the centre frequency and the bandwidth can be tuned independently.…”

Section: The Manuscriptmentioning

confidence: 99%

“…[18][19][20][21][22][23] Furthermore, various designs of resonators have been explored, such as ring shaped and rectangular plate resonators, to achieve high-Q high-frequency filter operation. [24][25][26] Parametric resonances, 27 32,33 In this work, we present a technique that combines the hardening and softening responses of The proposed filter consists of two nearly identical laterally actuated clamped-clamped microbeams. Each microbeam is anchored from its two ends with two fixed electrodes.…”

Section: The Manuscriptmentioning

confidence: 99%

Exploiting nonlinearities of micro-machined resonators for filtering applications

Ilyas

Chappanda

Younis

2017

We demonstrate the exploitation of the nonlinear behavior of two electrically coupled microbeam resonators to realize a band-pass filter. More specifically, we combine their nonlinear hardening and softening responses to realize a near flat pass band filter with sharp roll-off characteristics. The device is composed of two near identical doubly clamped and electrostatically actuated microbeams made of silicon. One of the resonators is buckled via thermal loading to produce a softening frequency response. It is then further tuned to create the desired overlap with the second resonator response of hardening behavior. This overlapping improves the pass band flatness. Also, the sudden jumps due to the softening and hardening behaviors create sharp roll-off characteristics. This approach can be promising for the future generation of filters with superior characteristics.

“…10 This work pursues an implementation on an all-silicon platform because of its maturity in electronics and photonics integration. Without the piezoelectric effect in silicon, excitation of the bulk acoustic modes is implemented through the capacitive force between a pair of patterned metal wires, one of which locates on an edge of the free-moving mechanical resonator and the other is fixed.…”

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confidence: 99%

A superhigh-frequency optoelectromechanical system based on a slotted photonic crystal cavity

Sun

Zhang

Xiong

et al. 2012

Abstract:We develop an all-integrated optoelectromechanical system that operates in the superhigh frequency band. This system is based on an ultrahigh-Q slotted photonic crystal (PhC) nanocavity formed by two PhC membranes, one of which is patterned with electrode and capacitively driven. The strong simultaneous electromechanical and optomechanical interactions yield efficient electrical excitation and sensitive optical transduction of the bulk acoustic modes of the PhC membrane. These modes are identified up to a frequency of 4.20 GHz, with their mechanical Q factors ranging from 240 to 1,730. Directly linking signals in microwave and optical domains, such optoelectromechanical systems will find applications in microwave photonics in addition to those that utilize the electromechanical and optomechanical interactions separately. a) Electronic mail: hong.tang@yale.edu.1 Nanoelectromechanical systems and nanooptomechanical systems that work at high frequencies have recently attracted great interest because of their use in studying mesoscopic quantum mechanics 1 as well as many practical applications such as high-speed sensing and coherent signal processing. [2][3][4][5][6][7][8][9] By combining these two types of systems into a single device where the mechanical degree of freedom is simultaneously coupled to both electrical and optical degrees of freedom, one achieves electro-optic interaction with capabilities that take advantage of the amplification from mechanical resonances. To this end, it is important to design a system possessing both strong electromechanical and optomechanical coupling such that the mechanical modes can be electrically excited efficiently and optically read out sensitively.Thin-film bulk acoustic resonators (TFBAR) are one type of electromechanical systems that have been widely used in wireless applications, where the microwave-frequency bulk acoustic modes are usually excited by a piezoelectric element which converts electrical energy directly into mechanical energy. 10 This work pursues an implementation on an all-silicon platform because of its maturity in electronics and photonics integration. Without the piezoelectric effect in silicon, excitation of the bulk acoustic modes is implemented through the capacitive force between a pair of patterned metal wires, one of which locates on an edge of the free-moving mechanical resonator and the other is fixed. The electromechanical coupling is thus provided via the strong dependence of the capacitance on the nanosized gap between the metalwire electrodes. 8 For optomechanical coupling, we employ slotted photonic crystal (PhC) nanocavities because of their simultaneous high optical quality (Q) factor and large optomechanical coupling. [11][12][13][14][15][16] The cavity is formed by a mode-gap confinement mechanism based on a variation from the corresponding slotted PhC waveguide. Among all the design schemes two are mostly implemented: one is tapering the lattice constant in the longitudinal 2 direction 11-13 and the other is shifting the ...