Showing papers on "Thin-film bulk acoustic resonator published in 2003"
05 Oct 2003
TL;DR: In this paper, the longitudinal coupling of thin film bulk acoustic resonator (FBAR) is investigated in order to design coupled resonator filter (CRF), which is dedicated to high-frequency filter applications.
Abstract: The longitudinal coupling of thin film bulk acoustic resonator (FBAR) is investigated in order to design coupled resonator filter (CRF). Such devices are dedicated to high-frequency filter applications. A scattering matrix algorithm that was already used to simulate simple FBARs devices is used to study the behavior of these structures. The principle of the algorithm is recalled and is explained how it can be adapted to the simulation of multiport devices. Then an example of filter design is given.
61 citations
08 Jun 2003
TL;DR: The aluminum nitride (AlN) thin film bulk acoustic resonator (FBAR) as mentioned in this paper achieved a Q factor of 780 and an effective electro-mechanical coupling constant (k/sub eff/sup 2 ) of 5.36 % at a resonant frequency of 2 GHz.
Abstract: This paper describes the development of the aluminum nitride (AlN) thin film bulk acoustic resonator (FBAR) using noble MEMS techniques for CMOS integration. This resonator has an air gap between a substrate for acoustic isolation. Germanium (Ge) was used as a sacrificial layer to make the air gap. This technique gives simple process and high CMOS compatibility. The resonator achieved a Q factor of 780 and an effective electro-mechanical coupling constant (k/sub eff//sup 2/) of 5.36 % at a resonant frequency of 2 GHz.
12 citations
05 Oct 2003
TL;DR: In this article, a full-field view laser ultrasonic imaging method has been developed that measures acoustic motion at a surface without scanning, and images are recorded at normal video frame rates and heterodyne principles are used to allow operation at any frequency from Hz to GHz.
Abstract: A full-field view laser ultrasonic imaging method has been developed that measures acoustic motion at a surface without scanning. Images are recorded at normal video frame rates and heterodyne principles are used to allow operation at any frequency from Hz to GHz. Both acoustic amplitude and phase are recorded allowing Fourier transformation of the displacement images to provide a mapping of excited mode wavenumbers at each frequency. Measurements as a function of frequency provide a means for mode identification and a direct measure of the lateral mode dispersion. Results are presented at frequencies near the first longitudinal plate thickness mode (/spl sim/876 MHz) demonstrating simultaneous excitation of lateral modes with nonzero wavenumbers in an electrically driven AlN thin film bulk acoustic resonator. Discussion and analysis are presented illustrating identification of specific lateral modes and illustration of the effects of physical dimensions and material elastic properties on the measured dispersion relations.
11 citations
Patent•
10 Mar 2003TL;DR: In this article, a local oscillator having an electroacoustic resonator and zero intermediate frequency signal processing circuitry coupled to the oscillator is described, and in certain embodiments, the electro-acoustic oscillator may be a thin film bulk acoustic resonator.
Abstract: An apparatus in accordance with one embodiment of the present invention may include a local oscillator having an electroacoustic resonator; and zero intermediate frequency signal processing circuitry coupled to the local oscillator. In certain embodiments, the electroacoustic oscillator may be a thin film bulk acoustic resonator.
10 citations
08 Jun 2003
TL;DR: The aluminum nitride (AlN) thin film bulk acoustic resonator (FBAR) as discussed by the authors achieved a resonant frequency of 2 GHz, a Q factor of 780 and an effective electro-mechanical coupling constant (k/sub eff//sup 2/) of 5.36%.
Abstract: We report the development of aluminum nitride (AlN) thin film bulk acoustic resonator (FBAR). This resonator has an air gap beneath the resonator to obtain high Q factor and low spurious response. Germanium (Ge) was used as a sacrificial layer for the air gap. This technique gives very simple process and high CMOS compatibility. The FBAR was evaluated about the effect of the air gap and the electrode size. The FBAR achieved a resonant frequency of 2 GHz, a Q factor of 780 and an effective electro-mechanical coupling constant (k/sub eff//sup 2/) of 5.36%.
4 citations
TL;DR: In this article, a thin-film bulk acoustic resonator (FBAR) filter design technique based on the GA was proposed, which is used to optimise the structure of each FBAR with its exact analytical impedance expressions.
Abstract: A thin-film bulk acoustic resonator (FBAR) filter design technique based on the genetic algorithm (GA) is proposed. Instead of using the approximate Butterworth-Van Dyke (BVD) model, the GA is used to optimise the structure of each FBAR with its exact analytical impedance expressions. US-PCS Rx/Tx bandpass filters, obtained by the proposed method, exhibit better response than those obtained by the BVD model.
4 citations
TL;DR: In this article, a thin film bulk acoustic resonator consisting of a single chip for minimizing phase noise by controlling resonance frequency and a voltage controlled oscillator using the same is presented, where a fixed body has a first electrode, a driving body having a second electrode installed to be adjacent to the fixed body and moved toward the ground due to voltage applied to the first and second electrodes.
Abstract: Provided are a thin film bulk acoustic resonator consisting of a single chip for minimizing phase noise by controlling resonance frequency and a voltage controlled oscillator using the same. The thin film bulk acoustic resonator comprises: a fixed body having a first electrode; a driving body having a second electrode installed to be adjacent to the fixed body and moved toward the fixed body due to voltage applied to the first and second electrodes; and a thin film bulk acoustic resonator for controlling the resonance frequency according to change of stress generated due to the movement of the driving body.
3 citations
Patent•
07 Apr 2003
TL;DR: In this paper, a thin film bulk acoustic resonator and a band pass filter using the same and a fabrication method thereof are provided, which varies a resonant frequency of a TFBAR selectively, after fabricating the TFBARS.
Abstract: PURPOSE: A thin film bulk acoustic resonator and a band pass filter using the same and a fabrication method thereof are provided, which varies a resonant frequency of a TFBAR selectively, after fabricating the TFBAR. CONSTITUTION: According to the method, a supporting layer(2) is deposited on a top surface and a bottom surface of a substrate(1), and a plurality of bottom electrodes(3) are formed by patterning a metal deposited on the supporting layer. A piezoelectric material is deposited on the top of the above structure, and a piezoelectric layer(4) is formed on the bottom electrode by patterning the piezoelectric material. A top electrode(5) is formed on the piezoelectric material by patterning a metal deposited on the above structure. A resonance frequency control layer(10) is formed on the top electrode by patterning a metal deposited on the above structure. And a bottom of the supporting layer is revealed by etching a part of the supporting layer and the substrate.
3 citations
Patent•
23 Jan 2003
TL;DR: In this article, a method for fabricating a band pass filter using a TFBAR (Thin Film Bulk Acoustic Resonator) is provided to form TFBARS having different resonant frequencies on the same substrate by using the difference of mass between resonant regions due to the difference in thickness of support layers.
Abstract: PURPOSE: A method for fabricating a band pass filter using a TFBAR(Thin Film Bulk Acoustic Resonator) is provided to form TFBAR having different resonant frequencies on the same substrate by using the difference of mass between resonant regions due to the difference of thickness of support layers. CONSTITUTION: A support layer(2) is formed by depositing a nitride layer or an ONO layer on an upper face and a lower face of a silicon substrate(1). A photoresist pattern is formed on a part of the support layer(2). The exposed support layer(2) is partially removed. A metal is deposited on an entire face of the resultant. A lower electrode(5) having an IF band is formed on an upper portion of the support layer(2). A lower electrode(5) having an RF band is formed on the upper portion of the support layer(2). A piezoelectric layer(4) is formed by depositing ZnO2 or AlN on an upper surface of the resultant. The piezoelectric layer(4) is patterned. An upper electrode is formed on the piezoelectric layer(4).
2 citations
Patent•
27 Aug 2003
TL;DR: In this article, a voltage control oscillator using a bulk acoustic wave resonator and a fabricating method thereof are provided to improve a characteristic of a phase noise by using a heating portion for changing a resonant frequency according to a controlled voltage.
Abstract: PURPOSE: A voltage control oscillator using a bulk acoustic wave resonator and a fabricating method thereof are provided to improve a characteristic of a phase noise by using a heating portion for changing a resonant frequency according to a controlled voltage. CONSTITUTION: A voltage control oscillator using a bulk acoustic wave resonator includes a bulk acoustic wave resonator and an amplifier. The bulk acoustic wave resonator is used for controlling a resonant frequency according to a controlled voltage. The amplifier is used for generating an output signal of a particular frequency by amplifying a resonant frequency of the bulk acoustic wave resonator. The bulk acoustic wave resonator includes a heating coil(7) in order to change the resonant frequency according to a heating degree.
2 citations
Patent•
25 Jul 2003
TL;DR: In this article, a method for adjusting the resonant frequency of an acoustic resonator is provided with a step for identifying electrode-piezoelectric stacks (72 and 86) equipped with conductive electrode layers (74 and 78) on both sides respectively while having resonant frequencies out of a target.
Abstract: PROBLEM TO BE SOLVED: To provide a production method having a resonant frequency within the allowable margin of the error of a target resonant frequency and a thin film bulk acoustic resonator (FBAR) to be reproduced as a result, and further to provide a production method for stabilizing the resonant frequency of the FBAR for avoiding an undesired frequency shift. SOLUTION: The method for adjusting the resonant frequency of an acoustic resonator is provided with a step for identifying electrode-piezoelectric stacks (72 and 86) equipped with conductive electrode layers (74 and 78) on both sides respectively while having resonant frequencies out of a target, and a step for oxidizing at least one of the conductive electrode layers (74 and 78) to achieve and target resonant frequency different from the resonant frequencies out of the target while including the intentional induction of oxidization by exposing at least one of the conductive electrode layers (74 and 78) of the electrode- piezoelectric stacks (72 and 86) under an oxide environment. COPYRIGHT: (C)2003,JPO
Patent•
26 Apr 2003
TL;DR: In this paper, a TFBAR (Thin Film Bulk Acoustic Resonator) and structures of a band pass filter and a duplexer using the same structures are provided to form a band-pass filter and duplexers on one substrate by setting up and tuning easily a resonant frequency of the TFBARS.
Abstract: PURPOSE: A TFBAR(Thin Film Bulk Acoustic Resonator) and structures of a band pass filter and a duplexer using the same are provided to form a band pass filter and a duplexer on one substrate by setting up and tuning easily a resonant frequency of the TFBAR. CONSTITUTION: A resonant frequency of TFBAR is changed by fixing the thickness of a piezoelectric layer(4) and changing the thickness of a bottom electrode(3) or an upper electrode(5). Or the resonant frequency of TFBAR is changed by fixing the thickness of the piezoelectric layer(4) and changing a physical property of the bottom electrode(3) or the upper electrode(5). Or the resonant frequency of TFBAR is changed by fixing the thickness and the physical properties of the piezoelectric layer(4), the bottom electrode(3), and the upper electrode(5) and changing the thickness of a support layer(2). Or the resonant frequency of TFBAR is changed by fixing a stacked structure of the support layer(2), the bottom electrode(3), the piezoelectric layer(4), and the upper electrode(5) and forming an electrode(6) under the support layer(2).
Patent•
29 Mar 2003
TL;DR: In this paper, a duplexer fabricating method is provided to make band pass filters for receiver and transmitter having a different center frequency on the same substrate by using a TFBAR CONSTITUTION.
Abstract: PURPOSE: A duplexer fabricating method is provided to be capable of making band pass filters for receiver and transmitter having a different center frequency on the same substrate by using a TFBAR CONSTITUTION: A method comprises a step of forming a support layer(2) on upper and lower parts of a substrate(1), a step of forming a plurality of lower electrodes(3) on the support layer, a step of depositing a piezoelectric layer(4) on an entire surface to form a piezoelectric layer pattern by patterning the piezoelectric layer(4), a step of forming an upper electrode(5) for receiver on the piezoelectric layer formed at a band pass filter for receiver, a step of forming an upper electrode for transmitter on the piezoelectric layer formed at a band pass filter for transmitter, a step of attaching an etch mask(6) at a lower side of a resultant structure, and partially etching the support layer(2) of an exposed band pass filter for receiver